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Han S, Miot EF, Liao Y, Somboon P, Harbach RE, Sze-To KM, Tang LTW, Guénard B, Lam TTY. Updated checklist with new records and molecular data for the mosquitoes (Diptera: Culicidae) of Hong Kong. JOURNAL OF MEDICAL ENTOMOLOGY 2024:tjae125. [PMID: 39349390 DOI: 10.1093/jme/tjae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 08/20/2024] [Accepted: 09/09/2024] [Indexed: 10/02/2024]
Abstract
An extensive mosquito survey was carried out in Hong Kong from September to October 2022, employing a variety of collection methods. Specimens were identified using a combination of morphology and mitochondrial cytochrome C oxidase subunit 1 (COI) barcode sequences. Twenty-nine species, including three new records, i.e., Culex bicornutus (Theobald), Culex cinctellus Edwards, and Lutzia chiangmaiensis Somboon & Harbach, were collected. Phylogenetic analysis of COI sequences of Culex annulus Theobald and Culex vishnui Theobald collected in Hong Kong and elsewhere revealed that the sequences of the two nominal species are genetically very similar and are included in the same clade. Consequently, the synonymy of Cx. annulus with Cx. vishnui is reinstated. Lutzia halifaxii (Theobald) is removed from the list of species in Hong Kong and is replaced with Lutzia vorax Edwards, the identification of which is confirmed in the present study. The record of Culex spiculothorax Bram recorded in Hong Kong is replaced with the senior synonym Culex sasai Kano, Nitahara & Awaya. The occurrence of Anopheles fluviatilis James and Aedes aegypti (Linnaeus) is discussed. Finally, an updated checklist of the mosquitoes of Hong Kong, which now includes 76 species representing 14 genera, is provided, with notation of those species that vector pathogens of human diseases.
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Affiliation(s)
- Shaolin Han
- Centre for Immunology & Infection, Hong Kong SAR, China
- State Key Laboratory of Emerging Infectious Diseases, School of Public Health, The University of Hong Kong, Hong Kong SAR, China
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Elliott F Miot
- Centre for Immunology & Infection, Hong Kong SAR, China
- State Key Laboratory of Emerging Infectious Diseases, School of Public Health, The University of Hong Kong, Hong Kong SAR, China
- MIVEGEC, Université de Montpellier, IRD, CNRS, 34394 Montpellier, France
| | - Yunshi Liao
- Centre for Immunology & Infection, Hong Kong SAR, China
- State Key Laboratory of Emerging Infectious Diseases, School of Public Health, The University of Hong Kong, Hong Kong SAR, China
| | - Pradya Somboon
- Department of Parasitology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Ralph E Harbach
- Department of Science, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Ka Mei Sze-To
- Centre for Immunology & Infection, Hong Kong SAR, China
| | | | - Benoit Guénard
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Tommy Tsan-Yuk Lam
- Centre for Immunology & Infection, Hong Kong SAR, China
- State Key Laboratory of Emerging Infectious Diseases, School of Public Health, The University of Hong Kong, Hong Kong SAR, China
- Laboratory of Data Discovery for Health, Hong Kong SAR, China
- HKU-Pasteur Research Pole, Hong Kong SAR, China
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Massebo F, Ashine T, Negash N, Eligo N, Hailemeskel E, Minda TT, Lindtjørn B, Gadisa E. The expansion of an invasive malaria vector: Anopheles stephensi emergence in Arba Minch town in the southern Rift Valley of Ethiopia. Parasitol Res 2024; 123:333. [PMID: 39331165 PMCID: PMC11436467 DOI: 10.1007/s00436-024-08356-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 09/20/2024] [Indexed: 09/28/2024]
Abstract
Urban areas in malaria-endemic countries in East Africa are experiencing a significant increase in malaria cases, with the establishment of an "exotic" urban malaria vector, Anopheles stephensi, increasing the risk of urban malaria. To this end, the present study aimed to investigate the emergence of this species in Arba Minch, Ethiopia. Following the detection of An. stephensi in other parts of Ethiopia, 76 artificial containers (55 discarded tyres, 18 concrete water storage, and three plastic containers) were sampled in 21 locations in Arba Minch town, for immature Anopheles mosquito stages, using the standard dipping technique. Larvae were reared into adults which were morphologically identified at the species level 2-3 days after emergence. Morphological identification results were confirmed by species-specific polymerase chain reaction. Of the examined containers, 67 (88%) had at least one Anopheles larva. Thirty-two of the adults emerged were morphologically identified as An. stephensi, with 26 (81%) confirmed by molecular analysis. This is the first study to report An. stephensi from Arba Minch, one of South Ethiopia's largest towns, highlighting the need for increased vigilance. The planned and ongoing study in and around Arba Minch will contribute to understanding the bionomics and role of An. stephensi in malaria parasite transmission, helping develop a strategy to address the impending risk of urban malaria in Ethiopia.
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Affiliation(s)
- Fekadu Massebo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia.
| | - Temesgen Ashine
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Nigatu Negash
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Nigatu Eligo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | | | - Thomas T Minda
- Faculty of Meteorology and Hydrology, Arba Minch University, Arba Minch, Ethiopia
| | - Bernt Lindtjørn
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
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Athni TS, Childs ML, Glidden CK, Mordecai EA. Temperature dependence of mosquitoes: Comparing mechanistic and machine learning approaches. PLoS Negl Trop Dis 2024; 18:e0012488. [PMID: 39283940 DOI: 10.1371/journal.pntd.0012488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 08/27/2024] [Indexed: 09/21/2024] Open
Abstract
Mosquito vectors of pathogens (e.g., Aedes, Anopheles, and Culex spp. which transmit dengue, Zika, chikungunya, West Nile, malaria, and others) are of increasing concern for global public health. These vectors are geographically shifting under climate and other anthropogenic changes. As small-bodied ectotherms, mosquitoes are strongly affected by temperature, which causes unimodal responses in mosquito life history traits (e.g., biting rate, adult mortality rate, mosquito development rate, and probability of egg-to-adult survival) that exhibit upper and lower thermal limits and intermediate thermal optima in laboratory studies. However, it remains unknown how mosquito thermal responses measured in laboratory experiments relate to the realized thermal responses of mosquitoes in the field. To address this gap, we leverage thousands of global mosquito occurrences and geospatial satellite data at high spatial resolution to construct machine-learning based species distribution models, from which vector thermal responses are estimated. We apply methods to restrict models to the relevant mosquito activity season and to conduct ecologically plausible spatial background sampling centered around ecoregions for comparison to mosquito occurrence records. We found that thermal minima estimated from laboratory studies were highly correlated with those from the species distributions (r = 0.87). The thermal optima were less strongly correlated (r = 0.69). For most species, we did not detect thermal maxima from their observed distributions so were unable to compare to laboratory-based estimates. The results suggest that laboratory studies have the potential to be highly transportable to predicting lower thermal limits and thermal optima of mosquitoes in the field. At the same time, lab-based models likely capture physiological limits on mosquito persistence at high temperatures that are not apparent from field-based observational studies but may critically determine mosquito responses to climate warming. Our results indicate that lab-based and field-based studies are highly complementary; performing the analyses in concert can help to more comprehensively understand vector response to climate change.
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Affiliation(s)
- Tejas S Athni
- Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Marissa L Childs
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, California, United States of America
- Center for the Environment, Harvard University, Cambridge, Massachusetts, United States of America
| | - Caroline K Glidden
- Department of Biology, Stanford University, Stanford, California, United States of America
- Stanford Institute for Human-centered Artificial Intelligence, Stanford University, Stanford, California, United States of America
| | - Erin A Mordecai
- Department of Biology, Stanford University, Stanford, California, United States of America
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4
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Chaumeau V, Wasisakun P, Watson JA, Oo T, Aryalamloed S, Sue MP, Htoo GN, Tha NM, Archusuksan L, Sawasdichai S, Gornsawun G, Mehra S, White NJ, Nosten FH. Transmission-blocking activities of artesunate, chloroquine, and methylene blue on Plasmodium vivax gametocytes. Antimicrob Agents Chemother 2024; 68:e0085324. [PMID: 39058023 PMCID: PMC11382624 DOI: 10.1128/aac.00853-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Accepted: 06/30/2024] [Indexed: 07/28/2024] Open
Abstract
Plasmodium vivax is now the main cause of malaria outside Africa. The gametocytocidal effects of antimalarial drugs are important to reduce malaria transmissibility, particularly in low-transmission settings, but they are not well characterized for P. vivax. The transmission-blocking effects of chloroquine, artesunate, and methylene blue on P. vivax gametocytes were assessed. Blood specimens were collected from patients presenting with vivax malaria, incubated with or without the tested drugs, and then fed to mosquitos from a laboratory-adapted colony of Anopheles dirus (a major malaria vector in Southeast Asia). The effects on oocyst and sporozoite development were analyzed under a multi-level Bayesian model accounting for assay variability and the heterogeneity of mosquito Plasmodium infection. Artesunate and methylene blue, but not chloroquine, exhibited potent transmission-blocking effects. Gametocyte exposures to artesunate and methylene blue reduced the mean oocyst count 469-fold (95% CI: 345 to 650) and 1,438-fold (95% CI: 970 to 2,064), respectively. The corresponding estimates for the sporozoite stage were a 148-fold reduction (95% CI: 61 to 470) and a 536-fold reduction (95% CI: 246 to 1,311) in the mean counts, respectively. In contrast, high chloroquine exposures reduced the mean oocyst count only 1.40-fold (95% CI: 1.20 to 1.64) and the mean sporozoite count 1.34-fold (95% CI: 1.12 to 1.66). This suggests that patients with vivax malaria often remain infectious to anopheline mosquitos after treatment with chloroquine. Use of artemisinin combination therapies or immediate initiation of primaquine radical cure should reduce the transmissibility of P. vivax infections.
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Affiliation(s)
- Victor Chaumeau
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, England, United Kingdom
| | - Praphan Wasisakun
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - James A Watson
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, England, United Kingdom
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Thidar Oo
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Sarang Aryalamloed
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Mu Phang Sue
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Gay Nay Htoo
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Naw Moo Tha
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Laypaw Archusuksan
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Sunisa Sawasdichai
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Gornpan Gornsawun
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
| | - Somya Mehra
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas J White
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, England, United Kingdom
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - François H Nosten
- Shoklo Malaria Research Unit, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, Thailand
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, England, United Kingdom
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5
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Iyaloo DP, Zohdy S, Carney RM, Mosawa VR, Elahee KB, Munglee N, Latchooman N, Puryag S, Bheecarry A, Bhoobun H, Rasamoelina-Andriamanivo H, Bedja SA, Spear J, Baldet T, Carter TE. A regional One Health approach to the risk of invasion by Anopheles stephensi in Mauritius. PLoS Negl Trop Dis 2024; 18:e0011827. [PMID: 39259766 PMCID: PMC11444417 DOI: 10.1371/journal.pntd.0011827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 10/01/2024] [Accepted: 07/29/2024] [Indexed: 09/13/2024] Open
Abstract
BACKGROUND Anopheles stephensi is an invasive malaria vector in Africa that threatens to put an additional 126 million people at risk of malaria if it continues to spread. The island nation of Mauritius is highly connected to Asia and Africa and is at risk of introduction due to this connectivity. For early detection of An. stephensi, the Vector Biology and Control Division under the Ministry of Health in Mauritius, leveraged a well-established Aedes program, as An. stephensi is known to share Aedes habitats. These efforts triggered multisectoral coordination and cascading benefits of integrated vector and One Health approaches. METHODS Beginning June 2021, entomological surveys were conducted at points of entry (seaport, airport) and on ships transporting livestock in collaboration with the Civil Aviation Department, the Mauritian Port Authority and National Veterinary Services. A total of 18, 39, 723 mosquito larval surveys were respectively conducted in the airport, seaport, and other localities in Mauritius while two, 20, and 26 adult mosquito surveys were respectively conducted in the airport, seaport, and twenty-six animal assembly points. Alongside adult mosquito surveys, surveillance of vectors of veterinary importance (e.g.- Culicoides spp.) was also carried out in collaboration with National Parks and Conservation Service and land owners. RESULTS A total of 8,428 adult mosquitoes were collected and 1,844 larval habitats were positive for mosquitoes. All collected mosquitoes were morphologically identified and 151 Anopheles and 339 Aedes mosquitoes were also molecularly characterized. Mosquito species detected were Aedes albopictus, Anopheles arabiensis, An. coustani, An. merus, Culex quinquefasciatus, Cx. thalassius and Lutzia tigripes. Anopheles stephensi was not detected. The One Health approach was shared with the French Agricultural Research Centre for International Development (CIRAD), strengthening collaboration between Mauritius and Réunion Island on vector surveillance at entry points and insecticide resistance monitoring. The Indian Ocean Commission (IOC) was also alerted to the risk of An. stephensi, leading to regional efforts supporting trainings and development of a response strategy to An. stephensi bringing together stakeholders from Comoros, Madagascar, Mauritius, Réunion Island and Seychelles. CONCLUSIONS Mauritius is a model system showing how existing public health entomology capabilities can be used to enhance vector surveillance and control and create multisectoral networks to respond to any emerging public and veterinary health vector-borne disease threat.
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Affiliation(s)
- Diana P Iyaloo
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Sarah Zohdy
- US President's Malaria Initiative, US Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - Ryan M Carney
- Department of Integrative Biology, College of Arts & Sciences, University of South Florida, Tampa, Florida, United States of America
| | - Varina Ramdonee Mosawa
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Khouaildi B Elahee
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Nabiihah Munglee
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Nilesh Latchooman
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Surendra Puryag
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Ambicadutt Bheecarry
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Hemant Bhoobun
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Livestock and Veterinary Division, Ministry of Agro Industry and Food Security, Reduit, Mauritius
| | - Harena Rasamoelina-Andriamanivo
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Indian Ocean Commission, Ebene, Mauritius
| | - Saïd Ahmed Bedja
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Indian Ocean Commission, Ebene, Mauritius
| | - Joseph Spear
- Department of Biology, College of Arts & Sciences, Baylor University, Waco, Texas, United States of America
| | - Thierry Baldet
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- UMR ASTRE, Cirad, INRAe, Univ. Montpellier, Sainte-Clotilde, La Réunion, France
| | - Tamar E Carter
- Department of Biology, College of Arts & Sciences, Baylor University, Waco, Texas, United States of America
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6
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Maneerattanasak S, Ngamprasertchai T, Tun YM, Ruenroengbun N, Auewarakul P, Boonnak K. Prevalence of dengue, Zika, and chikungunya virus infections among mosquitoes in Asia: A systematic review and meta-analysis. Int J Infect Dis 2024; 148:107226. [PMID: 39216785 DOI: 10.1016/j.ijid.2024.107226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 08/06/2024] [Accepted: 08/24/2024] [Indexed: 09/04/2024] Open
Abstract
BACKGROUND Dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) continue to pose significant public health risks. This study aims to assess the prevalence of these arbovirus infections in field-caught mosquitoes across Asia. METHODS Studies published after the year 2000 on DENV, ZIKV, and/or CHIKV infections in Asian mosquitoes were identified from Embase, Scopus, PubMed, and Ovid. A random-effects model estimated the pooled prevalence, defined as the overall prevalence from included studies, adjusted for variability among the studies. Meta-regression models were used to evaluate the association between predictors and their prevalence. RESULTS A total of 2529 articles were retrieved; 57 met the inclusion criteria. Pooled prevalence of DENV, ZIKV, and CHIKV infections in Asian mosquitoes were 5.85%, 2.15%, and 1.26%, respectively. Subgroup analysis revealed varying DENV prevalence across regions: East Asia (3.32%), South Asia (5.26%), and Southeast Asia (6.92%). Univariate regression analysis demonstrated significant associations between mosquito capture site and DENV prevalence (P < 0.001), and between study region and ZIKV prevalence (P = 0.005). However, no significant predictors were identified for CHIKV prevalence. CONCLUSION Our findings provide reference pooled summary estimates of arbovirus infections in mosquitoes, offering crucial insight into the regional disease burden and - guidance in the development and implementation of arbovirus surveillance in mosquitoes.
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Affiliation(s)
- Sarunya Maneerattanasak
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Thundon Ngamprasertchai
- Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Yin May Tun
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; Health Intervention and Technology Assessment Program (HITAP), Ministry of Public Health, Nonthaburi, Thailand
| | - Narisa Ruenroengbun
- Department of Pharmaceutical Care, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand
| | - Prasert Auewarakul
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kobporn Boonnak
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
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7
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de Souza WM, Weaver SC. Effects of climate change and human activities on vector-borne diseases. Nat Rev Microbiol 2024; 22:476-491. [PMID: 38486116 DOI: 10.1038/s41579-024-01026-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2024] [Indexed: 03/18/2024]
Abstract
Vector-borne diseases are transmitted by haematophagous arthropods (for example, mosquitoes, ticks and sandflies) to humans and wild and domestic animals, with the largest burden on global public health disproportionately affecting people in tropical and subtropical areas. Because vectors are ectothermic, climate and weather alterations (for example, temperature, rainfall and humidity) can affect their reproduction, survival, geographic distribution and, consequently, ability to transmit pathogens. However, the effects of climate change on vector-borne diseases can be multifaceted and complex, sometimes with ambiguous consequences. In this Review, we discuss the potential effects of climate change, weather and other anthropogenic factors, including land use, human mobility and behaviour, as possible contributors to the redistribution of vectors and spread of vector-borne diseases worldwide.
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Affiliation(s)
- William M de Souza
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, College of Medicine, Lexington, KY, USA
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston, TX, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
- Global Virus Network, Baltimore, MD, USA
| | - Scott C Weaver
- World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch, Galveston, TX, USA.
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA.
- Global Virus Network, Baltimore, MD, USA.
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8
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Taylor R, Messenger LA, Abeku TA, Clarke SE, Yadav RS, Lines J. Invasive Anopheles stephensi in Africa: insights from Asia. Trends Parasitol 2024; 40:731-743. [PMID: 39054167 DOI: 10.1016/j.pt.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/03/2024] [Accepted: 06/19/2024] [Indexed: 07/27/2024]
Abstract
Anopheles stephensi is a highly competent urban malaria vector species, endemic in South Asia and the Persian Gulf, which has colonised eight countries in sub-Saharan Africa (SSA) since 2013 and is now spreading uncontrollably. In urban areas of Africa, where malaria transmission has previously been low or non-existent, the invasion of An. stephensi represents a significant problem, particularly to immunologically naïve populations. Despite this rapidly advancing threat, there is a paucity of information regarding the bionomics of An. stephensi in SSA. Here, we offer a critical synthesis of literature from An. stephensi's native range, focusing on the future of An. stephensi in a rapidly urbanising Africa, and highlighting key questions that warrant prioritisation by the global malaria vector control community.
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Affiliation(s)
- Roz Taylor
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | - Louisa A Messenger
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA; Parasitology and Vector Biology (PARAVEC) Laboratory, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA
| | - Tarekegn A Abeku
- Malaria Consortium, Green House, 244-254 Cambridge Heath Road, London E2 9DA, UK
| | - Sian E Clarke
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Rajpal S Yadav
- Academy of Public Health Entomology, Udaipur 313002, Rajasthan, India
| | - Jo Lines
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
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9
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Vajda ÉA, Ross A, Doum D, Fairbanks EL, Chitnis N, Hii J, Moore SJ, Richardson JH, Macdonald M, Sovannaroth S, Kimheng P, McIver DJ, Tatarsky A, Lobo NF. Field evaluation of a volatile pyrethroid spatial repellent and etofenprox treated clothing for outdoor protection against forest malaria vectors in Cambodia. Sci Rep 2024; 14:17348. [PMID: 39069597 PMCID: PMC11284218 DOI: 10.1038/s41598-024-67470-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 07/11/2024] [Indexed: 07/30/2024] Open
Abstract
Cambodia's goal to eliminate malaria by 2025 is challenged by persistent transmission in forest and forest fringe areas, where people are exposed to Anopheles mosquito bites during the day and night. Volatile pyrethroid spatial repellents (VPSRs) and insecticide-treated clothing (ITC) could address these gaps. This study evaluated the outdoor application of one passive transfluthrin-based VPSR, four etofenprox-ITCs paired with a picaridin topical repellent, and a combination of VPSR and ITC against wild Anopheles landing in Cambodia. A 7 × 7 Latin-square study was conducted over 49 collection nights in temporary open structures in Mondulkiri Province. All interventions substantially reduced Anopheles landing, with protective efficacy ranging from 61 to 95%. Mathematical modeling showed significant reductions in vectoral capacity, especially with the combined ITC and VPSR and VPSR alone, albeit with decreased effectiveness over time. These interventions have the potential to reduce outdoor and daytime Anopheles biting, offering valuable contributions to malaria elimination efforts in Cambodia and the Greater Mekong Subregion, contingent upon achieving effective coverage and adherence.
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Affiliation(s)
- Élodie A Vajda
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA.
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland.
| | - Amanda Ross
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Dyna Doum
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
- Health Forefront Organization, Phnom Penh, Cambodia
| | - Emma L Fairbanks
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Nakul Chitnis
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
| | - Jeffrey Hii
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Sarah J Moore
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
- University of Basel, Petersplatz 1, 2003, Basel, Switzerland
- Vector Control Product Testing Unit, Environmental Health and Ecological Science Department, Ifakara Health Institute, P. O. Box 74, Bagamoyo, Tanzania
| | - Jason H Richardson
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, L3 5QA, UK
| | - Michael Macdonald
- Innovative Vector Control Consortium, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Merseyside, L3 5QA, UK
| | - Siv Sovannaroth
- National Center for Parasitology, Entomology and Malaria Control, 477, Phnom Penh, Cambodia
| | - Pen Kimheng
- Department of Health of Mondulkiri, C5XX+CP4, 76, Krong Saen Monourom, Cambodia
| | - David J McIver
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Allison Tatarsky
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
| | - Neil F Lobo
- University of California, San Francisco, 550 16th Street, San Francisco, CA, 94158, USA
- University of Notre Dame, Notre Dame, IN, 46556, USA
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10
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Chaumeau V, Piarroux M, Kulabkeeree T, Sawasdichai S, Inta A, Watthanaworawit W, Nosten F, Piarroux R, Nabet C. Identification of Southeast Asian Anopheles mosquito species using MALDI-TOF mass spectrometry. PLoS One 2024; 19:e0305167. [PMID: 38968228 PMCID: PMC11226003 DOI: 10.1371/journal.pone.0305167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 05/24/2024] [Indexed: 07/07/2024] Open
Abstract
Malaria elimination in Southeast Asia remains a challenge, underscoring the importance of accurately identifying malaria mosquitoes to understand transmission dynamics and improve vector control. Traditional methods such as morphological identification require extensive training and cannot distinguish between sibling species, while molecular approaches are costly for extensive screening. Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a rapid and cost-effective tool for Anopheles species identification, yet its current use is limited to few specialized laboratories. This study aimed to develop and validate an online reference database for MALDI-TOF MS identification of Southeast Asian Anopheles species. The database, constructed using the in-house data analysis pipeline MSI2 (Sorbonne University), comprised 2046 head mass spectra from 209 specimens collected at the Thailand-Myanmar border. Molecular identification via COI and ITS2 DNA barcodes enabled the identification of 20 sensu stricto species and 5 sibling species complexes. The high quality of the mass spectra was demonstrated by a MSI2 median score (min-max) of 61.62 (15.94-77.55) for correct answers, using the best result of four technical replicates of a test panel. Applying an identification threshold of 45, 93.9% (201/214) of the specimens were identified, with 98.5% (198/201) consistency with the molecular taxonomic assignment. In conclusion, MALDI-TOF MS holds promise for malaria mosquito identification and can be scaled up for entomological surveillance in Southeast Asia. The free online sharing of our database on the MSI2 platform (https://msi.happy-dev.fr/) represents an important step towards the broader use of MALDI-TOF MS in malaria vector surveillance.
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Affiliation(s)
- Victor Chaumeau
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Martine Piarroux
- Institut Pierre-Louis d’Epidémiologie et de Santé Publique, Inserm, IPLESP, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Parasitologie-Mycologie, Sorbonne Université, Paris, France
| | - Thithiworada Kulabkeeree
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
| | - Sunisa Sawasdichai
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
| | - Aritsara Inta
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
| | - Wanitda Watthanaworawit
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
| | - François Nosten
- Faculty of Tropical Medicine, Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Mahidol University, Mae Ramat, Thailand
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Renaud Piarroux
- Institut Pierre-Louis d’Epidémiologie et de Santé Publique, Inserm, IPLESP, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Parasitologie-Mycologie, Sorbonne Université, Paris, France
| | - Cécile Nabet
- Institut Pierre-Louis d’Epidémiologie et de Santé Publique, Inserm, IPLESP, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Parasitologie-Mycologie, Sorbonne Université, Paris, France
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11
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Assada M, Al-Hadi M, Esmail MA, Al-Jurban J, Alkawri A, Shamsan A, Terreri P, Samake JN, Aljasari A, Awash AA, Al Eryani SM, Carter TE. Molecular Confirmation of Anopheles stephensi Mosquitoes in the Al Hudaydah Governorate, Yemen, 2021 and 2022. Emerg Infect Dis 2024; 30:1467-1471. [PMID: 38916721 PMCID: PMC11210655 DOI: 10.3201/eid3007.240331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024] Open
Abstract
We detected malaria vector Anopheles stephensi mosquitoes in the Al Hudaydah governorate in Yemen by using DNA sequencing. We report 2 cytochrome c oxidase subunit I haplotypes, 1 previously found in Ethiopia, Somalia, Djibouti, and Yemen. These findings provide insight into invasive An. stephensi mosquitoes in Yemen and their connection to East Africa.
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12
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Jobe NB, Franz NM, Johnston MA, Malone AB, Ruberto I, Townsend J, Will JB, Yule KM, Paaijmans KP. The Mosquito Fauna of Arizona: Species Composition and Public Health Implications. INSECTS 2024; 15:432. [PMID: 38921147 PMCID: PMC11203593 DOI: 10.3390/insects15060432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 05/26/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024]
Abstract
Arizona is home to many mosquito species, some of which are known vectors of infectious diseases that harm both humans and animals. Here, we provide an overview of the 56 mosquito species that have been identified in the State to date, but also discuss their known feeding preference and the diseases they can (potentially) transmit to humans and animals. This list is unlikely to be complete for several reasons: (i) Arizona's mosquitoes are not systematically surveyed in many areas, (ii) surveillance efforts often target specific species of interest, and (iii) doubts have been raised by one or more scientists about the accuracy of some collection records, which has been noted in this article. There needs to be an integrated and multifaceted surveillance approach that involves entomologists and epidemiologists, but also social scientists, wildlife ecologists, ornithologists, representatives from the agricultural department, and irrigation and drainage districts. This will allow public health officials to (i) monitor changes in current mosquito species diversity and abundance, (ii) monitor the introduction of new or invasive species, (iii) identify locations or specific populations that are more at risk for mosquito-borne diseases, and (iv) effectively guide vector control.
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Affiliation(s)
- Ndey Bassin Jobe
- The Center for Evolution & Medicine, Arizona State University, Tempe, AZ 85281, USA; (N.B.J.); (A.B.M.)
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA;
| | - Nico M. Franz
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA;
| | - Murray A. Johnston
- Department of Entomology, Purdue University, West Lafayette, IN 47907, USA;
| | - Adele B. Malone
- The Center for Evolution & Medicine, Arizona State University, Tempe, AZ 85281, USA; (N.B.J.); (A.B.M.)
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA;
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ 85009, USA; (J.T.); (J.B.W.)
| | - Irene Ruberto
- Arizona Department of Health Services, Phoenix, AZ 85007, USA;
| | - John Townsend
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ 85009, USA; (J.T.); (J.B.W.)
| | - James B. Will
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ 85009, USA; (J.T.); (J.B.W.)
| | - Kelsey M. Yule
- Biodiversity Knowledge Integration Center, Arizona State University, Tempe, AZ 85281, USA;
| | - Krijn P. Paaijmans
- The Center for Evolution & Medicine, Arizona State University, Tempe, AZ 85281, USA; (N.B.J.); (A.B.M.)
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA;
- Simon A. Levin Mathematical, Computational and Modeling Sciences Center, Arizona State University, Tempe, AZ 85281, USA
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13
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Msellemu D, Tanner M, Yadav R, Moore SJ. Occupational exposure to malaria, leishmaniasis and arbovirus vectors in endemic regions: A systematic review. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2024; 6:100185. [PMID: 39027087 PMCID: PMC11252614 DOI: 10.1016/j.crpvbd.2024.100185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/26/2024] [Accepted: 06/01/2024] [Indexed: 07/20/2024]
Abstract
Vector-borne diseases, including dengue, leishmaniasis and malaria, may be more common among individuals whose occupations or behaviours bring them into frequent contact with these disease vectors outside of their homes. A systematic review was conducted to ascertain at-risk occupations and situations that put individuals at increased risk of exposure to these disease vectors in endemic regions and identify the most suitable interventions for each exposure. The review was conducted in accordance with PRISMA guidelines on articles published between 1945 and October 2021, searched in 16 online databases. The primary outcome was incidence or prevalence of dengue, leishmaniasis or malaria. The review excluded ecological and qualitative studies, abstracts only, letters, commentaries, reviews, and studies of laboratory-acquired infections. Studies were appraised, data extracted, and a descriptive analysis conducted. Bite interventions for each risk group were assessed. A total of 1170 articles were screened and 99 included. Malaria, leishmaniasis and dengue were presented in 47, 41 and 24 articles, respectively; some articles presented multiple conditions. The most represented populations were soldiers, 38% (43 of 112 studies); refugees and travellers, 15% (17) each; migrant workers, 12.5% (14); miners, 9% (10); farmers, 5% (6); rubber tappers and missionaries, 1.8% (2) each; and forest workers, 0.9% (1). Risk of exposure was categorised into round-the-clock or specific times of day/night dependent on occupation. Exposure to these vectors presents a critical and understudied concern for outdoor workers and mobile populations. When devising interventions to provide round-the-clock vector bite protection, two populations are considered. First, mobile populations, characterized by their high mobility, may find potential benefits in insecticide-treated clothing, though more research and optimization are essential. Treated clothing offers personal vector protection and holds promise for economically disadvantaged individuals, especially when enabling them to self-treat their clothing to repel vectors. Secondly, semi-permanent and permanent settlement populations can receive a combination of interventions that offer both personal and community protection, including spatial repellents, suitable for extended stays. Existing research is heavily biased towards tourism and the military, diverting attention and resources from vulnerable populations where these interventions are most required like refugee populations as well as those residing in sub-Saharan Africa.
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Affiliation(s)
- Daniel Msellemu
- Vector Control Product Testing Unit, Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Marcel Tanner
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Rajpal Yadav
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
- Academy of Public Health Entomology, Udaipur, 313 002, India
| | - Sarah J. Moore
- Vector Control Product Testing Unit, Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Tanzania
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, 4123, Allschwil, Switzerland
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
- The Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box 447, Tengeru, Arusha, Tanzania
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14
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Cramer EY, Nguyen XQ, Hertz JC, Nguyen DV, Quang HH, Mendenhall IH, Lover AA. Measuring effects of ivermectin-treated cattle on potential malaria vectors in Vietnam: A cluster-randomized trial. PLoS Negl Trop Dis 2024; 18:e0012014. [PMID: 38683855 PMCID: PMC11098492 DOI: 10.1371/journal.pntd.0012014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/16/2024] [Accepted: 02/19/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Malaria elimination using current tools has stalled in many areas. Ivermectin (IVM) is a broad-antiparasitic drug and mosquitocide and has been proposed as a tool for accelerating progress towards malaria elimination. Under laboratory conditions, IVM has been shown to reduce the survival of adult Anopheles populations that have fed on IVM-treated mammals. Treating cattle with IVM has been proposed as an important contribution to malaria vector management, however, the impacts of IVM in this One Health use case have been untested in field trials in Southeast Asia. METHODS Through a randomized village-based trial, this study quantified the effect of IVM-treated cattle on anopheline populations in treated vs. untreated villages in Central Vietnam. Local zebu cattle in six rural villages were included in this study. In three villages, cattle were treated with IVM at established veterinary dosages, and in three additional villages cattle were left as untreated controls. For the main study outcome, the mosquito populations in all villages were sampled using cattle-baited traps for six nights before, and six nights after a 2-day IVM-administration (intervention) period. Anopheline species were characterized using taxonomic keys. The impact of the intervention was analyzed using a difference-in-differences (DID) approach with generalized estimating equations (with negative binomial distribution and robust errors). This intervention was powered to detect a 50% reduction in total nightly Anopheles spp. vector catches from cattle-baited traps. Given the unusual diversity in anopheline populations, exploratory analyses examined taxon-level differences in the ecological population diversity. RESULTS Across the treated villages, 1,112 of 1,523 censused cows (73% overall; range 67% to 83%) were treated with IVM. In both control and treated villages, there was a 30% to 40% decrease in total anophelines captured in the post-intervention period as compared to the pre-intervention period. In the control villages, there were 1,873 captured pre-intervention and 1,079 captured during the post-intervention period. In the treated villages, there were 1,594 captured pre-intervention, and 1,101 captured during the post-intervention period. The difference in differences model analysis comparing total captures between arms was not statistically significant (p = 0.61). Secondary outcomes of vector population diversity found that in three villages (one control and two treatment) Brillouin's index increased, and in three villages (two control and one treatment) Brillouin's index decreased. When examining biodiversity by trapping-night, there were no clear trends in treated or untreated vector populations. Additionally, there were no clear trends when examining the components of biodiversity: richness and evenness. CONCLUSIONS The ability of this study to quantify the impacts of IVM treatment was limited due to unexpectedly large spatiotemporal variability in trapping rates; an area-wide decrease in trapping counts across all six villages post-intervention; and potential spillover effects. However, this study provides important data to directly inform future studies in the GMS and beyond for IVM-based vector control.
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Affiliation(s)
- Estee Y. Cramer
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Massachusetts, United States of America
| | - Xuan Quang Nguyen
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | | | - Do Van Nguyen
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | - Huynh Hong Quang
- Institute of Malariology-Parasitology & Entomology Quy Nhon, Ministry of Health, Vietnam
| | - Ian H. Mendenhall
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore
| | - Andrew A. Lover
- Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts-Amherst, Massachusetts, United States of America
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15
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Ashine T, Eyasu A, Asmamaw Y, Simma E, Zemene E, Epstein A, Brown R, Negash N, Kochora A, Reynolds AM, Bulto MG, Tafesse T, Dagne A, Lukus B, Esayas E, Behaksra SW, Woldekidan K, Kassa FA, Deressa JD, Assefa M, Dillu D, Assefa G, Solomon H, Zeynudin A, Massebo F, Sedda L, Donnelly MJ, Wilson AL, Weetman D, Gadisa E, Yewhalaw D. Spatiotemporal distribution and bionomics of Anopheles stephensi in different eco-epidemiological settings in Ethiopia. Parasit Vectors 2024; 17:166. [PMID: 38556881 PMCID: PMC10983662 DOI: 10.1186/s13071-024-06243-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/11/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Malaria is a major public health concern in Ethiopia, and its incidence could worsen with the spread of the invasive mosquito species Anopheles stephensi in the country. This study aimed to provide updates on the distribution of An. stephensi and likely household exposure in Ethiopia. METHODS Entomological surveillance was performed in 26 urban settings in Ethiopia from 2021 to 2023. A kilometer-by-kilometer quadrant was established per town, and approximately 20 structures per quadrant were surveyed every 3 months. Additional extensive sampling was conducted in 50 randomly selected structures in four urban centers in 2022 and 2023 to assess households' exposure to An. stephensi. Prokopack aspirators and CDC light traps were used to collect adult mosquitoes, and standard dippers were used to collect immature stages. The collected mosquitoes were identified to species level by morphological keys and molecular methods. PCR assays were used to assess Plasmodium infection and mosquito blood meal source. RESULTS Catches of adult An. stephensi were generally low (mean: 0.15 per trap), with eight positive sites among the 26 surveyed. This mosquito species was reported for the first time in Assosa, western Ethiopia. Anopheles stephensi was the predominant species in four of the eight positive sites, accounting for 75-100% relative abundance of the adult Anopheles catches. Household-level exposure, defined as the percentage of households with a peridomestic presence of An. stephensi, ranged from 18% in Metehara to 30% in Danan. Anopheles arabiensis was the predominant species in 20 of the 26 sites, accounting for 42.9-100% of the Anopheles catches. Bovine blood index, ovine blood index and human blood index values were 69.2%, 32.3% and 24.6%, respectively, for An. stephensi, and 65.4%, 46.7% and 35.8%, respectively, for An. arabiensis. None of the 197 An. stephensi mosquitoes assayed tested positive for Plasmodium sporozoite, while of the 1434 An. arabiensis mosquitoes assayed, 62 were positive for Plasmodium (10 for P. falciparum and 52 for P. vivax). CONCLUSIONS This study shows that the geographical range of An. stephensi has expanded to western Ethiopia. Strongly zoophagic behavior coupled with low adult catches might explain the absence of Plasmodium infection. The level of household exposure to An. stephensi in this study varied across positive sites. Further research is needed to better understand the bionomics and contribution of An. stephensi to malaria transmission.
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Affiliation(s)
- Temesgen Ashine
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University, Arba Minch, Ethiopia.
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
| | - Adane Eyasu
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Yehenew Asmamaw
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Eba Simma
- Department of Biology, College of Natural Sciences, Jimma University, Jimma, Ethiopia
| | - Endalew Zemene
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Adrienne Epstein
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Rebecca Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Nigatu Negash
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Abena Kochora
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Alison M Reynolds
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | | | - Temesgen Tafesse
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Alemayehu Dagne
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Biniyam Lukus
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Endashaw Esayas
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Kidist Woldekidan
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Jimma Dinsa Deressa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Muluken Assefa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Dereje Dillu
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Gudissa Assefa
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Ahmed Zeynudin
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Fekadu Massebo
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University, Arba Minch, Ethiopia
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Martin James Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Anne L Wilson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Endalamaw Gadisa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
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16
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Wang Y, Chitnis N, Fairbanks EL. Optimizing malaria vector control in the Greater Mekong Subregion: a systematic review and mathematical modelling study to identify desirable intervention characteristics. Parasit Vectors 2024; 17:162. [PMID: 38553759 PMCID: PMC10981350 DOI: 10.1186/s13071-024-06234-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/04/2024] [Indexed: 04/01/2024] Open
Abstract
BACKGROUND In the Greater Mekong Subregion (GMS), new vector-control tools are needed to target mosquitoes that bite outside during the daytime and night-time to advance malaria elimination. METHODS We conducted systematic literature searches to generate a bionomic dataset of the main malaria vectors in the GMS, including human blood index (HBI), parity proportion, sac proportion (proportion with uncontracted ovary sacs, indicating the amount of time until they returned to host seeking after oviposition) and the resting period duration. We then performed global sensitivity analyses to assess the influence of bionomics and intervention characteristics on vectorial capacity. RESULTS Our review showed that Anopheles minimus, An. sinensis, An. maculatus and An. sundaicus display opportunistic blood-feeding behaviour, while An. dirus is more anthropophilic. Multivariate regression analysis indicated that environmental, climatic and sampling factors influence the proportion of parous mosquitoes, and resting duration varies seasonally. Sensitivity analysis highlighted HBI and parity proportion as the most influential bionomic parameters, followed by resting duration. Killing before feeding is always a desirable characteristic across all settings in the GMS. Disarming is also a desirable characteristic in settings with a low HBI. Repelling is only an effective strategy in settings with a low HBI and low parity proportion. Killing after feeding is only a desirable characteristic if the HBI and parity proportions in the setting are high. CONCLUSIONS Although in general adopting tools that kill before feeding would have the largest community-level effect on reducing outdoor transmission, other modes of action can be effective. Current tools in development which target outdoor biting mosquitoes should be implemented in different settings dependent on their characteristics.
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Affiliation(s)
- Yuqian Wang
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Nakul Chitnis
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland
| | - Emma L Fairbanks
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Kreuzstrasse 2, Allschwill, 4123, Basel, Switzerland.
- University of Basel, Petersplatz 1, 4001, Basel, Switzerland.
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17
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Laojun S, Changbunjong T, Chaiphongpachara T. Insights into the mitochondrial cytochrome oxidase I (mt-COI) gene and wing morphometrics of Anopheles baimaii (Diptera: Culicidae) in malaria-endemic islands of Thailand. Parasitol Res 2024; 123:171. [PMID: 38530429 DOI: 10.1007/s00436-024-08195-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/21/2024] [Indexed: 03/28/2024]
Abstract
Anopheles baimaii (Diptera: Culicidae) significantly contributes to the transmission of parasites causing malaria in Southeast Asia and South Asia. This study examined the morphological (wing shape) and molecular (mitochondrial gene) variations of An. baimaii in four of Thailand's border islands, and also investigated the presence of Plasmodium parasites in these mosquitoes. No Plasmodium infections were detected in the samples. Significant differences in wing shape were observed in most island populations (p < 0.05). A single-linkage tree, constructed using Mahalanobis distances, clustered the populations into two groups based on geographical locations. Genetic variation in An. baimaii was also analyzed through cytochrome c oxidase subunit I (COI) gene sequences. This analysis identified 22 segregating sites and a low nucleotide diversity of 0.004. Furthermore, 18 distinct haplotypes were identified, indicating a high haplotype diversity of 0.825. Neutrality tests for the overall population revealed a significantly negative Fu's Fs value (-5.029), indicating a population expansion. In contrast, Tajima's D yielded a negative value (-1.028) that did not reach statistical significance. The mismatch distribution analysis exhibited a bimodal pattern, and the raggedness index was 0.068, showing no significant discrepancy (p = 0.485) between observed and expected distributions. Pairwise genetic differentiation assessments demonstrated significant differences between all populations (p < 0.05). These findings provide valuable insights into the COI gene and wing morphometric variations in An. baimaii across Thailand's islands, offering critical information for understanding the adaptations of this malaria vector and guiding future comprehensive research.
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Affiliation(s)
- Sedthapong Laojun
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Samut Songkhram, 75000, Thailand
| | - Tanasak Changbunjong
- Department of Pre-Clinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
- The Monitoring and Surveillance Center for Zoonotic Diseases in Wildlife and Exotic Animals (MoZWE), Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Tanawat Chaiphongpachara
- Department of Public Health and Health Promotion, College of Allied Health Sciences, Suan Sunandha Rajabhat University, Samut Songkhram, 75000, Thailand.
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Liu Q, Wang M, Du YT, Xie JW, Yin ZG, Cai JH, Zhao TY, Zhang HD. Possible potential spread of Anopheles stephensi, the Asian malaria vector. BMC Infect Dis 2024; 24:333. [PMID: 38509457 PMCID: PMC10953274 DOI: 10.1186/s12879-024-09213-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Anopheles stephensi is native to Southeast Asia and the Arabian Peninsula and has emerged as an effective and invasive malaria vector. Since invasion was reported in Djibouti in 2012, the global invasion range of An. stephensi has been expanding, and its high adaptability to the environment and the ongoing development of drug resistance have created new challenges for malaria control. Climate change is an important factor affecting the distribution and transfer of species, and understanding the distribution of An. stephensi is an important part of malaria control measures, including vector control. METHODS In this study, we collected existing distribution data for An. stephensi, and based on the SSP1-2.6 future climate data, we used the Biomod2 package in R Studio through the use of multiple different model methods such as maximum entropy models (MAXENT) and random forest (RF) in this study to map the predicted global An. stephensi climatically suitable areas. RESULTS According to the predictions of this study, some areas where there are no current records of An. stephensi, showed significant areas of climatically suitable for An. stephensi. In addition, the global climatically suitability areas for An. stephensi are expanding with global climate change, with some areas changing from unsuitable to suitable, suggesting a greater risk of invasion of An. stephensi in these areas, with the attendant possibility of a resurgence of malaria, as has been the case in Djibouti. CONCLUSIONS This study provides evidence for the possible invasion and expansion of An. stephensi and serves as a reference for the optimization of targeted monitoring and control strategies for this malaria vector in potential invasion risk areas.
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Affiliation(s)
- Qing Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ming Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Yu-Tong Du
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Jing-Wen Xie
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Zi-Ge Yin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Jing-Hong Cai
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Tong-Yan Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
| | - Heng-Duan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
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19
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Pepey A, Souris M, Kim S, Obadia T, Chy S, Ea M, Ouk S, Remoue F, Sovannaroth S, Mueller I, Witkowski B, Vantaux A. Comparing malaria risk exposure in rural Cambodia population using GPS tracking and questionnaires. Malar J 2024; 23:75. [PMID: 38475843 DOI: 10.1186/s12936-024-04890-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND The Great Mekong Subregion has attained a major decline in malaria cases and fatalities over the last years, but residual transmission hotspots remain, supposedly fueled by forest workers and migrant populations. This study aimed to: (i) characterize the fine-scale mobility of forest-goers and understand links between their daily movement patterns and malaria transmission, using parasites detection via real time polymerase chain reaction (RT PCR) and the individual exposure to Anopheles bites by quantification of anti-Anopheles saliva antibodies via enzyme-linked immunosorbent assay; (ii) assess the concordance of questionnaires and Global Positioning System (GPS) data loggers for measuring mobility. METHODS Two 28 day follow-ups during dry and rainy seasons, including a GPS tracking, questionnaires and health examinations, were performed on male forest goers representing the population at highest risk of infection. Their time spent in different land use categories and demographic data were analyzed in order to understand the risk factors driving malaria in the study area. RESULTS Malaria risk varied with village forest cover and at a resolution of only a few kilometers: participants from villages outside the forest had the highest malaria prevalence compared to participants from forest fringe's villages. The time spent in a specific environment did not modulate the risk of malaria, in particular the time spent in forest was not associated with a higher probability to detect malaria among forest-goers. The levels of antibody response to Anopheles salivary peptide among participants were significantly higher during the rainy season, in accordance with Anopheles mosquito density variation, but was not affected by sociodemographic and mobility factors. The agreement between GPS and self-reported data was only 61.9% in reporting each kind of visited environment. CONCLUSIONS In a context of residual malaria transmission which was mainly depicted by P. vivax asymptomatic infections, the implementation of questionnaires, GPS data-loggers and quantification of anti-saliva Anopheles antibodies on the high-risk group were not powerful enough to detect malaria risk factors associated with different mobility behaviours or time spent in various environments. The joint implementation of GPS trackers and questionnaires allowed to highlight the limitations of both methodologies and the benefits of using them together. New detection and follow-up strategies are still called for.
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Affiliation(s)
- Anaïs Pepey
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia.
| | - Marc Souris
- UMR Unité des Virus Emergents, UVE: Aix-Marseille Univ-IRD 190-Inserm 1207-IHU 5 Méditerranée Infection, 13005, Marseille, France
| | - Saorin Kim
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
| | - Thomas Obadia
- Institut Pasteur, G5 Infectious Disease Epidemiology and Analytics, Université Paris Cité, 75015, Paris, France
- Institut Pasteur, Bioinformatics and Biostatistics Hub, Université Paris Cité, 75015, Paris, France
| | - Sophy Chy
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
| | - Malen Ea
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
| | - Sivkeng Ouk
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
| | - Franck Remoue
- UMR MIVEGEC, IRD, CNRS, University of Montpellier, Montpellier, France
| | - Siv Sovannaroth
- National Centre for Parasitology Entomology and Malaria Control (CNM), Phnom Penh 120 801, Phnom Penh, Cambodia
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
- Genetic and Biology of Plasmodium Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Amélie Vantaux
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, 5 Blvd Monivong, Phnom Penh 120 210, Phnom Penh, BP983, Cambodia
- Genetic and Biology of Plasmodium Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
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20
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Afrane YA, Abdulai A, Mohammed AR, Akuamoah-Boateng Y, Owusu-Asenso CM, Sraku IK, Yanney SA, Malm K, Lobo NF. Detection of Invasive Anopheles stephensi Mosquitoes through Molecular Surveillance, Ghana. Emerg Infect Dis 2024; 30:605-608. [PMID: 38316032 PMCID: PMC10902527 DOI: 10.3201/eid3003.231638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
The invasive Anopheles stephensi mosquito has rapidly expanded in range in Africa over the past decade. Consistent with World Health Organization guidelines, routine entomologic surveillance of malaria vectors in Accra, Ghana, now includes morphologic and molecular surveillance of An. stephensi mosquitoes. We report detection of An. stephensi mosquitoes in Ghana.
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21
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Zhou G, Zhong D, Yewhalaw D, Yan G. Anopheles stephensi ecology and control in Africa. Trends Parasitol 2024; 40:102-105. [PMID: 38142196 DOI: 10.1016/j.pt.2023.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/25/2023]
Abstract
The encroachment and rapid spread of Anopheles stephensi across Africa presents a significant challenge to malaria control and elimination efforts. Understanding the ecology and behavior of An. stephensi will critically inform control measures and provide prerequisite knowledge for exploring new larval and adult control tools to contain its spread.
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Affiliation(s)
- Guofa Zhou
- Program in Public Health, University of California, Irvine, CA 92697, USA.
| | - Daibin Zhong
- Program in Public Health, University of California, Irvine, CA 92697, USA
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Centre, Jimma University, Jimma, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA 92697, USA
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22
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Akirso A, Tamiru G, Eligo N, Lindtjørn B, Massebo F. High human blood meal index of mosquitoes in Arba Minch town, southwest Ethiopia: an implication for urban mosquito-borne disease transmission. Parasitol Res 2024; 123:102. [PMID: 38233721 PMCID: PMC10794327 DOI: 10.1007/s00436-024-08121-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 01/03/2024] [Indexed: 01/19/2024]
Abstract
Unplanned human population shifts in urban areas are expected to increase the prevalence of vector-borne diseases. This study aimed to investigate mosquito species composition, blood meal sources, and malaria vectors in an urban area. Indoor-resting adult mosquitoes were collected using Prokopack and host-seeking mosquitoes using Centers for Disease Control and Prevention light traps in Arba Minch town. Larval collection from artificial containers was done in those houses selected for adult mosquito collection. Anopheles adults collected and emerged from larvae were identified morphologically using a taxonomic key. ELISA was used to identify blood meal sources in freshly fed Anopheles and Culex mosquitoes, and CSP of Anopheles mosquitoes. A total of 16,756 female mosquitoes were collected. Of these, 93% (15,571) were Culex, 6% (1016) were Anopheles, and 1% (169) were Aedes mosquitoes. Out of the 130 adult mosquitoes that were raised from larvae collected from the containers, 20% were An. rhodesiensis, while the remaining 80% were Aedes mosquitoes. Out of 823 mosquitoes tested for blood meal origins, 86.3% (710/823) tested positive for human blood, 2.2% (18/823) tested positive for bovine blood, and 11.5% (95/823) were negative for human and bovine antibodies. Anopheles gambiae complex had a human blood meal index (HBI) of 50% (90/180; CI 42.3-57.5%) and a bovine blood meal index (BBI) of only 0.5% (95% CI 0.01-3.1%). Culex HBI was 96.7% (620/641), and its BBI index was 2.4% (15/641). While it was low (0.8%) in Culex, the proportion of An. gambiae complex with unidentified blood meal sources was 49.5% (95 CI% 41.9-56.9%). Among the 1016 Anopheles mosquitoes tested, a single An. gambiae complex (0.1%; 1/1016) was positive for P. vivax CSP. The high HBI indicates frequent contact between humans and vectors. To reduce human exposure, personal protection tools should be implemented.
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Affiliation(s)
- Adisu Akirso
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Girum Tamiru
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Nigatu Eligo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
| | - Bernt Lindtjørn
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia
- Centre for International Health, University of Bergen, Bergen, Norway
| | - Fekadu Massebo
- Department of Biology, Arba Minch University, Arba Minch, Ethiopia.
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23
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Hadebe MT, Malgwi SA, Okpeku M. Revolutionizing Malaria Vector Control: The Importance of Accurate Species Identification through Enhanced Molecular Capacity. Microorganisms 2023; 12:82. [PMID: 38257909 PMCID: PMC10818655 DOI: 10.3390/microorganisms12010082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/08/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Many factors, such as the resistance to pesticides and a lack of knowledge of the morphology and molecular structure of malaria vectors, have made it more challenging to eradicate malaria in numerous malaria-endemic areas of the globe. The primary goal of this review is to discuss malaria vector control methods and the significance of identifying species in vector control initiatives. This was accomplished by reviewing methods of molecular identification of malaria vectors and genetic marker classification in relation to their use for species identification. Due to its specificity and consistency, molecular identification is preferred over morphological identification of malaria vectors. Enhanced molecular capacity for species identification will improve mosquito characterization, leading to accurate control strategies/treatment targeting specific mosquito species, and thus will contribute to malaria eradication. It is crucial for disease epidemiology and surveillance to accurately identify the Plasmodium spp. that are causing malaria in patients. The capacity for disease surveillance will be significantly increased by the development of more accurate, precise, automated, and high-throughput diagnostic techniques. In conclusion, although morphological identification is quick and achievable at a reduced cost, molecular identification is preferred for specificity and sensitivity. To achieve the targeted malaria elimination goal, proper identification of vectors using accurate techniques for effective control measures should be prioritized.
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Affiliation(s)
| | | | - Moses Okpeku
- Discipline of Genetics, School of Life Sciences, University of KwaZulu-Natal, Westville, Durban 4000, South Africa
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24
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Athni TS, Childs ML, Glidden CK, Mordecai EA. Temperature dependence of mosquitoes: comparing mechanistic and machine learning approaches. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.569955. [PMID: 38105988 PMCID: PMC10723351 DOI: 10.1101/2023.12.04.569955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Mosquito vectors of pathogens (e.g., Aedes , Anopheles , and Culex spp. which transmit dengue, Zika, chikungunya, West Nile, malaria, and others) are of increasing concern for global public health. These vectors are geographically shifting under climate and other anthropogenic changes. As small-bodied ectotherms, mosquitoes are strongly affected by temperature, which causes unimodal responses in mosquito life history traits (e.g., biting rate, adult mortality rate, mosquito development rate, and probability of egg-to-adult survival) that exhibit upper and lower thermal limits and intermediate thermal optima in laboratory studies. However, it remains unknown how mosquito thermal responses measured in laboratory experiments relate to the realized thermal responses of mosquitoes in the field. To address this gap, we leverage thousands of global mosquito occurrences and geospatial satellite data at high spatial resolution to construct machine-learning based species distribution models, from which vector thermal responses are estimated. We apply methods to restrict models to the relevant mosquito activity season and to conduct ecologically-plausible spatial background sampling centered around ecoregions for comparison to mosquito occurrence records. We found that thermal minima estimated from laboratory studies were highly correlated with those from the species distributions (r = 0.90). The thermal optima were less strongly correlated (r = 0.69). For most species, we did not detect thermal maxima from their observed distributions so were unable to compare to laboratory-based estimates. The results suggest that laboratory studies have the potential to be highly transportable to predicting lower thermal limits and thermal optima of mosquitoes in the field. At the same time, lab-based models likely capture physiological limits on mosquito persistence at high temperatures that are not apparent from field-based observational studies but may critically determine mosquito responses to climate warming.
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25
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St Laurent B. Genomic complexity of parasites and vectors challenges malaria control in Southeast Asia. CURRENT OPINION IN INSECT SCIENCE 2023; 60:101113. [PMID: 37690774 DOI: 10.1016/j.cois.2023.101113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/02/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023]
Abstract
Southeast Asia is a uniquely complex region of malaria transmission that maintains an astounding level of species diversity among potential malaria vectors and also generates drug-resistant and quickly diverging populations of malaria parasites. All five human malaria species circulate in Southeast Asia with over 50 Anopheles species that vary in their ability to transmit these pathogens. The intricate relationships of these parasites and vectors are not well-understood. Human activity in Southeast Asian countries has created an increasingly fragmented landscape, bringing humans and mosquitoes into more frequent contact, sustaining malaria transmission in a region where few control tools are effective. Genomic shifts at the species, population, and individual level in parasites and vectors introduce variation that has produced drug- and insecticide resistance. The goal of this review is to highlight genomic studies of Southeast Asian malaria parasites and vectors that demonstrate how diversity in these organisms presents unique challenges and opportunities for global malaria control and eradication efforts.
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26
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Afrane YA, Abdulai A, Mohammed AR, Akuamoah-Boateng Y, Owusu-Asenso CM, Sraku IK, Yanney SA, Malm K, Lobo NF. First detection of Anopheles stephensi in Ghana using molecular surveillance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569589. [PMID: 38076990 PMCID: PMC10705536 DOI: 10.1101/2023.12.01.569589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
The invasive Anopheles stephensi mosquito has been rapidly expanding in range in Africa over the last decade, spreading from the Indian sub-continent to several East African countries (Djibouti, Ethiopia, Sudan, Somalia and Kenya) and now in West Africa, Nigeria. The rapid expansion of this invasive vector poses a major threat to current malaria control and elimination efforts. In line with the WHO's strategy to stop the spread of this invasive species by enhancing surveillance and control measures in Africa, we incorporated morphological and molecular surveillance of An. stephensi into routine entomological surveillance of malaria vectors in the city of Accra, Ghana. Here, we report on the first detection of An. stephensi in Ghana. An. stephensi mosquitoes were confirmed using PCR and sequencing of the ITS2 regions. These findings highlight the urgent need for increased surveillance and response strategies to mitigate the spread of An. stephensi in Ghana.
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Emiru T, Getachew D, Murphy M, Sedda L, Ejigu LA, Bulto MG, Byrne I, Demisse M, Abdo M, Chali W, Elliott A, Vickers EN, Aranda-Díaz A, Alemayehu L, Behaksera SW, Jebessa G, Dinka H, Tsegaye T, Teka H, Chibsa S, Mumba P, Girma S, Hwang J, Yoshimizu M, Sutcliffe A, Taffese HS, Bayissa GA, Zohdy S, Tongren JE, Drakeley C, Greenhouse B, Bousema T, Tadesse FG. Evidence for a role of Anopheles stephensi in the spread of drug- and diagnosis-resistant malaria in Africa. Nat Med 2023; 29:3203-3211. [PMID: 37884028 PMCID: PMC10719088 DOI: 10.1038/s41591-023-02641-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Anopheles stephensi, an Asian malaria vector, continues to expand across Africa. The vector is now firmly established in urban settings in the Horn of Africa. Its presence in areas where malaria resurged suggested a possible role in causing malaria outbreaks. Here, using a prospective case-control design, we investigated the role of An. stephensi in transmission following a malaria outbreak in Dire Dawa, Ethiopia in April-July 2022. Screening contacts of patients with malaria and febrile controls revealed spatial clustering of Plasmodium falciparum infections around patients with malaria in strong association with the presence of An. stephensi in the household vicinity. Plasmodium sporozoites were detected in these mosquitoes. This outbreak involved clonal propagation of parasites with molecular signatures of artemisinin and diagnostic resistance. To our knowledge, this study provides the strongest evidence so far for a role of An. stephensi in driving an urban malaria outbreak in Africa, highlighting the major public health threat posed by this fast-spreading mosquito.
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Affiliation(s)
- Tadele Emiru
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Maxwell Murphy
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | | | | | - Isabel Byrne
- London School of Hygiene and Tropical Medicine, London, UK
| | | | - Melat Abdo
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Wakweya Chali
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
- Radboudumc, Nijmegen, the Netherlands
| | - Aaron Elliott
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Eric Neubauer Vickers
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Andrés Aranda-Díaz
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Lina Alemayehu
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Gutema Jebessa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hunduma Dinka
- Adama Science and Technology University, Adama, Ethiopia
| | - Tizita Tsegaye
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Hiwot Teka
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Sheleme Chibsa
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Peter Mumba
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Samuel Girma
- U.S. President's Malaria Initiative, USAID, Addis Ababa, Ethiopia
| | - Jimee Hwang
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Alice Sutcliffe
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Sarah Zohdy
- U.S. President's Malaria Initiative, Entomology Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jon Eric Tongren
- U.S. President's Malaria Initiative, Malaria Branch, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, UK
| | - Bryan Greenhouse
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, San Francisco, CA, USA
| | | | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
- London School of Hygiene and Tropical Medicine, London, UK.
- Radboudumc, Nijmegen, the Netherlands.
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28
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Unger HW, Acharya S, Arnold L, Wu C, van Eijk AM, Gore-Langton GR, Ter Kuile FO, Lufele E, Chico RM, Price RN, Moore BR, Thriemer K, Rogerson SJ. The effect and control of malaria in pregnancy and lactating women in the Asia-Pacific region. Lancet Glob Health 2023; 11:e1805-e1818. [PMID: 37858590 DOI: 10.1016/s2214-109x(23)00415-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/10/2023] [Accepted: 08/23/2023] [Indexed: 10/21/2023]
Abstract
Half of all pregnancies at risk of malaria worldwide occur in the Asia-Pacific region, where Plasmodium falciparum and Plasmodium vivax co-exist. Despite substantial reductions in transmission, malaria remains an important cause of adverse health outcomes for mothers and offspring, including pre-eclampsia. Malaria transmission is heterogeneous, and infections are commonly subpatent and asymptomatic. High-grade antimalarial resistance poses a formidable challenge to malaria control in pregnancy in the region. Intermittent preventive treatment in pregnancy reduces infection risk in meso-endemic New Guinea, whereas screen-and-treat strategies will require more sensitive point-of-care tests to control malaria in pregnancy. In the first trimester, artemether-lumefantrine is approved, and safety data are accumulating for other artemisinin-based combinations. Safety of novel antimalarials to treat artemisinin-resistant P falciparum during pregnancy, and of 8-aminoquinolines during lactation, needs to be established. A more systematic approach to the prevention of malaria in pregnancy in the Asia-Pacific is required.
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Affiliation(s)
- Holger W Unger
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Department of Obstetrics and Gynaecology, Royal Darwin Hospital, Tiwi, NT, Australia; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Sanjaya Acharya
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Lachlan Arnold
- Royal Melbourne Hospital Clinical School, The University of Melbourne, Parkville, VIC, Australia
| | - Connie Wu
- Royal Melbourne Hospital Clinical School, The University of Melbourne, Parkville, VIC, Australia
| | - Anna Maria van Eijk
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Georgia R Gore-Langton
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Elvin Lufele
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Vector-Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia; Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Brioni R Moore
- Curtin Medical School, Curtin University, Bentley, WA, Australia; Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia; Telethon Kids Institute, Perth Children's Hospital, Nedlands, WA, Australia
| | - Kamala Thriemer
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Stephen J Rogerson
- Department of Infectious Diseases, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia; Department of Medicine, University of Melbourne, The Doherty Institute, Melbourne, VIC, Australia
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Phasomkusolsil S, Tawong J, Monkanna N, Kornkan T, Jitbantrengphan T, Chaiyasab M, Pongda N, Kamram T, Lindroth EJ. The effects of human and rhesus macaque blood meal sources on mosquito reproduction and adult survival under laboratory conditions. Exp Parasitol 2023; 253:108591. [PMID: 37558194 DOI: 10.1016/j.exppara.2023.108591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/29/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
Mass rearing of mosquitoes as required to fulfil research studies is a technically challenging endeavor. Blood meal source has been recognized as a key consideration in mass rearing of mosquitoes that affects colony health and fecundity. Four species of laboratory-colonized mosquitoes from the Department of Entomology, US Army Medical Directorate - Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS); Anopheles cracens, An. dirus, An. minimus and An. sawadwongporni were fed blood meals from human and rhesus macaque sources using an artificial membrane feeder. The effects of different blood meal sources were evaluated concerning blood-feeding, survival and reproduction (fecundity and hatching rates). Adult survival was monitored at days 7, 14 and 21 post blood-feeding. Although the mosquitoes fed on human blood exhibited higher rates of engorgement, there were no significant differences in blood-feeding rates in An. cracens (P = 0.08) and An. dirus (P = 0.91) between rhesus macaque and human blood sources. Twenty-one days post-feeding, no significant differences were observed in the survival rates of mosquitoes fed on human versus rhesus macaque blood. Except for An. dirus, which had better survival rates with human blood (97.5%) than after feeding on rhesus macaque blood (95.4%). All mosquito species fed on human blood produced significantly more eggs when compared to those fed on rhesus macaque blood. However, there was no statistical difference in hatching rates between blood sources, except for An. dirus, which had better hatching rates with human blood. These results indicate that human and rhesus macaque blood may be a viable alternative for maintaining Anopheles mosquitoes in colony.
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Affiliation(s)
- Siriporn Phasomkusolsil
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand.
| | - Jaruwan Tawong
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Nantaporn Monkanna
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Tanaporn Kornkan
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Thanin Jitbantrengphan
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Marisa Chaiyasab
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Natchanida Pongda
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Thinadda Kamram
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
| | - Erica J Lindroth
- Department of Entomology, US Army Medical Directorate, Armed Forces Research Institute of Medical Sciences, Bangkok, 10400, Thailand
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Haldar K, Alam MS, Koepfli C, Lobo NF, Phru CS, Islam MN, Faiz A, Khan WA, Haque R. Bangladesh in the era of malaria elimination. Trends Parasitol 2023; 39:760-773. [PMID: 37500334 DOI: 10.1016/j.pt.2023.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 06/06/2023] [Accepted: 06/20/2023] [Indexed: 07/29/2023]
Abstract
Bangladesh has dramatically reduced malaria by 93% from 2008 to 2020. The strategy has been district-wise, phased elimination; however, the last districts targeted for elimination include remote, forested regions which present several challenges for prevention, detection, and treatment of malaria. These districts border Myanmar which harbors Plasmodium falciparum malaria parasites resistant to artemisinins, key drugs used in artemisinin-based combination therapies (ACTs) that have been vital for control programs. Challenges in monitoring emergence of artemisinin resistance (AR), tracking parasite reservoirs, changes in vector behavior and responses to insecticides, as well as other environmental and host factors (including the migration of Forcibly Displaced Myanmar Nationals; FDMNs) may pose added hazards in the final phase of eliminating malaria in Bangladesh.
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Affiliation(s)
- Kasturi Haldar
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, IN, USA; Boler-Parseghian Center for Rare and Neglected Diseases, University of Notre Dame, Notre Dame, Indiana, IN, USA; Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, IN, USA.
| | - Mohammed Shafiul Alam
- Infectious Disease Division, International Center of Diarrheal Diseases, Bangladesh, (icddr, b), Dhaka, Bangladesh
| | - Cristian Koepfli
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, IN, USA; Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, IN, USA
| | - Neil F Lobo
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, IN, USA; Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, IN, USA
| | - Ching Shwe Phru
- Infectious Disease Division, International Center of Diarrheal Diseases, Bangladesh, (icddr, b), Dhaka, Bangladesh
| | | | - Abul Faiz
- Dev Care Foundation, Dhaka, Bangladesh
| | - Wasif Ali Khan
- Infectious Disease Division, International Center of Diarrheal Diseases, Bangladesh, (icddr, b), Dhaka, Bangladesh
| | - Rashidul Haque
- Infectious Disease Division, International Center of Diarrheal Diseases, Bangladesh, (icddr, b), Dhaka, Bangladesh
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Lippi CA, Mundis SJ, Sippy R, Flenniken JM, Chaudhary A, Hecht G, Carlson CJ, Ryan SJ. Trends in mosquito species distribution modeling: insights for vector surveillance and disease control. Parasit Vectors 2023; 16:302. [PMID: 37641089 PMCID: PMC10463544 DOI: 10.1186/s13071-023-05912-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 08/04/2023] [Indexed: 08/31/2023] Open
Abstract
Species distribution modeling (SDM) has become an increasingly common approach to explore questions about ecology, geography, outbreak risk, and global change as they relate to infectious disease vectors. Here, we conducted a systematic review of the scientific literature, screening 563 abstracts and identifying 204 studies that used SDMs to produce distribution estimates for mosquito species. While the number of studies employing SDM methods has increased markedly over the past decade, the overwhelming majority used a single method (maximum entropy modeling; MaxEnt) and focused on human infectious disease vectors or their close relatives. The majority of regional models were developed for areas in Africa and Asia, while more localized modeling efforts were most common for North America and Europe. Findings from this study highlight gaps in taxonomic, geographic, and methodological foci of current SDM literature for mosquitoes that can guide future efforts to study the geography of mosquito-borne disease risk.
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Affiliation(s)
- Catherine A Lippi
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA.
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32601, USA.
| | - Stephanie J Mundis
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA
| | - Rachel Sippy
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA
- School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS, UK
| | - J Matthew Flenniken
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA
| | - Anusha Chaudhary
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA
| | - Gavriella Hecht
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32601, USA
| | - Colin J Carlson
- Center for Global Health Science and Security, Georgetown University Medical Center, Georgetown University, Washington, DC, USA
| | - Sadie J Ryan
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, 32601, USA.
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32601, USA.
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Sawasdichai S, Chaumeau V, Kearney E, Wasisakun P, Simpson JA, Price DJ, Chotirat S, Rénia L, Bergmann-Leitner E, Fowkes F, Nosten F. Characterizing antibody responses to mosquito salivary antigens of the Southeast Asian vectors of malaria and dengue with a human challenge model of controlled exposure: a protocol. Wellcome Open Res 2023; 8:135. [PMID: 37456919 PMCID: PMC10338987 DOI: 10.12688/wellcomeopenres.19049.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2023] [Indexed: 07/18/2023] Open
Abstract
Background: Measurement of antibody titers directed against mosquito salivary antigens in blood samples has been proposed as an outcome measure to assess human exposure to vector bites. However, only a handful of antigens have been identified and the specificity and longitudinal dynamics of antibody responses are not well known. We report the protocol of a clinical trial of controlled exposure to mosquito bites that aims to identify and validate biomarkers of exposure to bites of mosquito vector species that transmit malaria and dengue in Southeast Asia and some other parts of the world. Methods: This study is an exploratory factorial randomized control trial of controlled exposure to mosquito bites with 10 arms corresponding to different species ( Aedes aegypti, Ae. albopictus, Anopheles dirus, An. maculatus and An. minimus) and numbers of bites (35 or 305 bites in total over 6 weeks). Blood samples will be collected from study participants before, during and after mosquito biting challenges. Candidate peptides will be identified from published literature with antigen prediction algorithms using mosquito DNA sequence data and with immunoblotting assays carried out using protein extracts of dissected mosquito salivary glands and participants samples. Antibody titers against candidate peptides will be determined in participants samples with high-throughput cutting-edge immuno-assays. Quantification of the antibody response profile over time (including an estimate of the decay rate) and the effect of the number of bites on the antibody response will be determined using linear and logistic mixed-effects models for the continuous and the binary response, respectively. Conclusion: This research is expected to generate important knowledge for vector sero-surveillance and evaluation of vector-control interventions against malaria and dengue in the Greater Mekong Subregion. Registration: This study is registered with clinicaltrials.gov (NCT04478370) on July 20 th, 2020.
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Affiliation(s)
- Sunisa Sawasdichai
- Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, 63140, Thailand
| | - Victor Chaumeau
- Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, 63140, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, England, OX3 7BN, UK
| | - Ellen Kearney
- Burnet Institute, Melbourne, VIC 3004, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, VIC 3010, Australia
| | - Praphan Wasisakun
- Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, 63140, Thailand
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, VIC 3010, Australia
| | - David J. Price
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, VIC 3010, Australia
- Department of Infectious Diseases, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, VIC 3000, Australia
| | - Sadudee Chotirat
- Malaria Vivax Research Unit, Faculty of Tropical medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Laurent Rénia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
- A*STAR Infectious Diseases Labs, Agency for Science, Technology, and Research, Singapore, 138648, Singapore
| | | | - Freya Fowkes
- Burnet Institute, Melbourne, VIC 3004, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, VIC 3010, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, VIC 3052, Australia
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Ramat, Tak, 63140, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, England, OX3 7BN, UK
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Al-Eryani SM, Irish SR, Carter TE, Lenhart A, Aljasari A, Montoya LF, Awash AA, Mohammed E, Ali S, Esmail MA, Hussain A, Amran JG, Kayad S, Nouredayem M, Adam MA, Azkoul L, Assada M, Baheshm YA, Eltahir W, Hutin YJ. Public health impact of the spread of Anopheles stephensi in the WHO Eastern Mediterranean Region countries in Horn of Africa and Yemen: need for integrated vector surveillance and control. Malar J 2023; 22:187. [PMID: 37337209 PMCID: PMC10278259 DOI: 10.1186/s12936-023-04545-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/30/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND Anopheles stephensi is an efficient vector of both Plasmodium falciparum and Plasmodium vivax in South Asia and the Middle East. The spread of An. stephensi to countries within the Horn of Africa threatens progress in malaria control in this region as well as the rest of sub-Saharan Africa. METHODS The available malaria data and the timeline for the detection of An. stephensi was reviewed to analyse the role of An. stephensi in malaria transmission in Horn of Africa of the Eastern Mediterranean Region (EMR) in Djibouti, Somalia, Sudan and Yemen. RESULTS Malaria incidence in Horn of Africa of EMR and Yemen, increased from 41.6 in 2015 to 61.5 cases per 1000 in 2020. The four countries from this region, Djibouti, Somalia, Sudan and Yemen had reported the detection of An. stephensi as of 2021. In Djibouti City, following its detection in 2012, the estimated incidence increased from 2.5 cases per 1000 in 2013 to 97.6 cases per 1000 in 2020. However, its contribution to malaria transmission in other major cities and in other countries, is unclear because of other factors, quality of the urban malaria data, human mobility, uncertainty about the actual arrival time of An. stephensi and poor entomological surveillance. CONCLUSIONS While An. stephensi may explain a resurgence of malaria in Djibouti, further investigations are needed to understand its interpretation trends in urban malaria across the greater region. More investment for multisectoral approach and integrated surveillance and control should target all vectors particularly malaria and dengue vectors to guide interventions in urban areas.
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Affiliation(s)
- Samira M Al-Eryani
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt.
| | - Seth R Irish
- World Health Organization, Headquarters, 1211, Geneva, Switzerland
| | | | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Adel Aljasari
- World Health Organization, Country Office, Sana'a, Yemen
| | | | - Abdullah A Awash
- World Health Organization, Country Office, Sub-Office, Aden, Yemen
| | | | - Said Ali
- National Malaria Control Programme, Ministry of Health Development, Hargeisa, Somaliland
| | - Mohammed A Esmail
- National Malaria Control Programme, Ministry of Public Health & Population, Sana'a, Yemen
| | | | - Jamal G Amran
- World Health Organization, Country Office, Mogadishu, Somalia
| | - Samatar Kayad
- National Malaria Control Programme, Ministry of Health, Djibouti, Djibouti
| | | | - Mariam A Adam
- World Health Organization, Country Office, Khartoum, Sudan
| | - Lina Azkoul
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt
| | - Methaq Assada
- National Malaria Control Programme, Ministry of Public Health & Population, Sana'a, Yemen
| | - Yasser A Baheshm
- National Malaria Control Programme, Ministry of Public Health & Population, Aden, Yemen
| | - Walid Eltahir
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum, Sudan
| | - Yvan J Hutin
- Department of Universal Health Coverage/Communicable Diseases Prevention and Control, Eastern Mediterranean Regional Office, World Health Organization, Cairo, Egypt
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Al-Amin HM, Rodriguez I, Phru CS, Khan WA, Haque R, Nahlen BL, Burton TA, Alam MS, Lobo NF. Composition of Anopheles species and bionomic characteristics over the peak malaria transmission season in Bandarban, Bangladesh. Malar J 2023; 22:176. [PMID: 37280591 DOI: 10.1186/s12936-023-04614-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/01/2023] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND Joint efforts by government and non-government organizations have helped to reduce malaria in Bangladesh and set the country on a clear path to eventual malaria elimination. However, achieving that goal would be challenging without a comprehensive understanding of vector bionomics. METHODS Targeted capturing of Anopheles mosquitoes over a rainy season, utilizing specific sampling methods, including human landing catches (HLCs), CDC-light traps (CDC-LTs), and pyrethrum spray catches (PSCs) were aimed to characterize entomological drivers of transmission in four sites of Bandarban, Bangladesh. RESULTS Molecular characterization of a subset of 4637 mosquitoes has demonstrated the presence of at least 17 species whose capture rates were representative of the rainy season. Species compositions and bionomic traits did not vary between sites with Anopheles maculatus having the highest landing rate by HLCs and Anopheles vagus having the highest capture rate with CDC-LTs. Interestingly, Anopheles species compositions and capture rates varied significantly (p < 0.05) for An. vagus, between HLCs and its often-used proxy-CDC-LTs- suggesting impacts on downstream analysis. CDC-LTs capture rates demonstrated differing compositions with indoor and outdoor biting rates. For example, Anopheles nigerrimus and Anopheles nivipes were more endophagic by HLCs and more exophagic by CDC-LTs. The use of a cow-baited CDC-LT also demonstrated significantly different results when compared to a human-baited CDC-LT considering the high degree of anthropophily in these species. The exception to both zoophily and indoor resting was An. vagus, which demonstrated both anthropophily and high resting rates indoors-pointing to this species being a possible primary vector at this site. CONCLUSION A diverse Anopheles fauna in Bandarban has been confirmed through molecular methods, highlighting the potential impact of sampling techniques. Given the complexity of the local ecosystem, a better understanding of mosquito behaviour and ecology is required to achieve the goal of malaria elimination in Bangladesh.
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Affiliation(s)
- Hasan Mohammad Al-Amin
- International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh.
- Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
- School of Biological Sciences, University of Queensland, Brisbane, QLD, Australia.
| | - Isabella Rodriguez
- Eck Institute for Global Health (EIGH), University of Notre Dame, Notre Dame, IN, USA
| | - Ching Swe Phru
- International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Wasif A Khan
- International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Rashidul Haque
- International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Bernard L Nahlen
- Eck Institute for Global Health (EIGH), University of Notre Dame, Notre Dame, IN, USA
| | - Timothy A Burton
- Eck Institute for Global Health (EIGH), University of Notre Dame, Notre Dame, IN, USA
| | - Mohammad Shafiul Alam
- International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Neil F Lobo
- Eck Institute for Global Health (EIGH), University of Notre Dame, Notre Dame, IN, USA
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Mutsaers M, Engdahl CS, Wilkman L, Ahlm C, Evander M, Lwande OW. Vector competence of Anopheles stephensi for O'nyong-nyong virus: a risk for global virus spread. Parasit Vectors 2023; 16:133. [PMID: 37069603 PMCID: PMC10111657 DOI: 10.1186/s13071-023-05725-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/02/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND O'nyong-nyong virus (ONNV) is a mosquito-borne alphavirus causing sporadic outbreaks of febrile illness with rash and polyarthralgia. Up to now, ONNV has been restricted to Africa and only two competent vectors have been found, Anopheles gambiae and An. funestus, which are also known malaria vectors. With globalization and invasive mosquito species migrating to ONNV endemic areas, there is a possible risk of introduction of the virus to other countries and continents. Anopheles stephensi, is closely related to An. gambiae and one of the invasive mosquito species of Asian origin that is now present in the Horn of Africa and spreading further east. We hypothesize that An. stephensi, a known primary urban malaria vector, may also serve as a new possible vector for ONNV. METHODS One-week-old female adult An. stephensi were exposed to ONNV-infected blood, and the vector competence for ONNV, i.e. infection rates (IRs), dissemination rates (DRs), transmission rates (TRs), dissemination efficiency (DEs) and transmission efficiency (TEs), were evaluated. Infection (IRs), dissemination efficiency (DEs) and transmission efficiency (TEs) were determined. Detection of ONNV RNA was analysed by RT-qPCR in the thorax and abdomen, head, wings, legs and saliva of the infected mosquitoes at four different time points, day 7, 14, 21 and 28 after blood meal. Infectious virus in saliva was assessed by infection of Vero B4 cells. RESULTS The mean mortality across all sampling times was 27.3% (95 confidence interval [CI] 14.7-44.2%). The mean rate of infection across all sampling periods was 89.5% (95% CI 70.6-95.9). The mean dissemination rate across sampling intervals was 43.4% (95% CI 24.3-64.2%). The mean TR and TE across all mosquito sampling time intervals were 65.3 (95% CI 28.6-93.5) and 74.6 (95% CI 52.1-89.4). The IR was 100%, 79.3%, 78.6% and 100% respectively at 7, 14, 21 and 28 dpi. The DR was the highest at 7 dpi with 76.0%, followed by 28 dpi at 57.1%, 21 dpi at 27.3% and 14 dpi at the lowest DR of 13.04%. DE was 76%, 13.8%, 25%, 57.1% and TR was 79%, 50%, 57.1% and 75% at 7, 14, 21 and 28 dpi respectively. The TE was the highest at 28 dpi, with a proportion of 85.7%. For 7, 14 and 21 dpi the transmission efficiency was 72.0%, 65.5% and 75.0% respectively. CONCLUSION Anopheles stephensi is a competent vector for ONNV and being an invasive species spreading to different parts of the world will likely spread the virus to other regions.
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Affiliation(s)
- Maud Mutsaers
- Department of Clinical Microbiology, Umeå University, 901 85, Umeå, Sweden
| | | | - Lukas Wilkman
- Department of Clinical Microbiology, Umeå University, 901 85, Umeå, Sweden
| | - Clas Ahlm
- Department of Clinical Microbiology, Umeå University, 901 85, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, 90187, Umeå, Sweden
| | - Magnus Evander
- Department of Clinical Microbiology, Umeå University, 901 85, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, 90187, Umeå, Sweden
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Sawasdichai S, Chaumeau V, Kearney E, Wasisakun P, Simpson JA, Price DJ, Chotirat S, Rénia L, Bergmann-Leitner E, Fowkes F, Nosten F. Characterizing antibody responses to mosquito salivary antigens of the Southeast Asian vectors of malaria and dengue with a human challenge model of controlled exposure: a protocol. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.19049.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Background: Measurement of antibody titers directed against mosquito salivary antigens in blood samples has been proposed as an outcome measure to assess human exposure to vector bites. However, only a handful of antigens have been identified and the specificity and longitudinal dynamics of antibody responses are not well known. We report the protocol of a clinical trial of controlled exposure to mosquito bites that aims to identify and validate biomarkers of exposure to bites of mosquito vector species that transmit malaria and dengue in Southeast Asia and some other parts of the world. Methods: This study is an exploratory factorial randomized control trial of controlled exposure to mosquito bites with 10 arms corresponding to different species (Aedes aegypt, Ae. albopictus, Anopheles dirus, An. maculatus and An. minimus) and numbers of bites (35 or 305 bites in total over 6 weeks). Blood samples will be collected from study participants before, during and after mosquito biting challenges. Candidate peptides will be identified from published literature with antigen prediction algorithms using mosquito DNA sequence data and with immunoblotting assays carried out using protein extracts of dissected mosquito salivary glands and participants samples. Antibody titers against candidate peptides will be determined in participants samples with high-throughput cutting-edge immuno-assays. Quantification of the antibody response profile over time (including an estimate of the decay rate) and the effect of the number of bites on the antibody response will be determined using linear and logistic mixed-effects models for the continuous and the binary response, respectively. Conclusion: This research is expected to generate important knowledge for vector sero-surveillance and evaluation of vector-control interventions against malaria and dengue in the Greater Mekong Subregion. Registration: This study is registered with clinicaltrials.gov (NCT04478370) on July 20th, 2020.
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Wong ML, Zulzahrin Z, Vythilingam I, Lau YL, Sam IC, Fong MY, Lee WC. Perspectives of vector management in the control and elimination of vector-borne zoonoses. Front Microbiol 2023; 14:1135977. [PMID: 37025644 PMCID: PMC10070879 DOI: 10.3389/fmicb.2023.1135977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 02/28/2023] [Indexed: 04/08/2023] Open
Abstract
The complex transmission profiles of vector-borne zoonoses (VZB) and vector-borne infections with animal reservoirs (VBIAR) complicate efforts to break the transmission circuit of these infections. To control and eliminate VZB and VBIAR, insecticide application may not be conducted easily in all circumstances, particularly for infections with sylvatic transmission cycle. As a result, alternative approaches have been considered in the vector management against these infections. In this review, we highlighted differences among the environmental, chemical, and biological control approaches in vector management, from the perspectives of VZB and VBIAR. Concerns and knowledge gaps pertaining to the available control approaches were discussed to better understand the prospects of integrating these vector control approaches to synergistically break the transmission of VZB and VBIAR in humans, in line with the integrated vector management (IVM) developed by the World Health Organization (WHO) since 2004.
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Affiliation(s)
- Meng Li Wong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Zulhisham Zulzahrin
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - I-Ching Sam
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Medical Microbiology, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
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Survey of malaria vectors on the Cambodia, Thailand and China-Laos Borders. Malar J 2022; 21:399. [PMID: 36585690 PMCID: PMC9801360 DOI: 10.1186/s12936-022-04418-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 12/15/2022] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Anopheles maculatus, Anopheles minimus and Anopheles dirus are the major vectors of malaria transmission in the Greater Mekong Subregion (GMS). The malaria burden in this region has decreased significantly in recent years as all GMS countries progress towards malaria elimination. It is necessary to investigate the Anopheles diversity and abundance status and assess the Plasmodium infection rates to understand the malaria transmission potential of these vector species in GMS countries to guide the development of up-to-date vector control strategies and interventions. METHODS A survey of mosquitoes was conducted in Stung Treng, Sainyabuli and Phongsaly Provinces on the Cambodia-Laos, Thailand-Laos and China-Laos borders, respectively. Mosquito collection was done by overnight trapping at sentinel sites in each province. After morphological identification, the 18S rRNA-based nested-PCR was performed to detect malaria parasites in the captured Anopheles mosquitoes. RESULTS A total of 18 965 mosquitoes comprising of 35 species of 2 subgenera (Subgenus Anopheles and Subgenus Cellia) and 4 tribes (Tribes Culicini, Aedini, Armigerini and Mansoniini) were captured. Tribe Culicini accounted for 85.66% of captures, followed by Subgenus Anopheles (8.15%). Anopheles sinensis dominated the Subgenus Anopheles by 99.81%. Plasmodium-infection was found in 25 out of the 1 683 individual or pooled samples of Anopheles. Among the 25 positive samples, 19, 5 and 1 were collected from Loum, Pangkhom and Siem Pang village, respectively. Eight Anopheles species were found infected with Plasmodium, i.e., An. sinensis, Anopheles kochi, Anopheles vagus, An. minimus, Anopheles annularis, Anopheles philippinensis, Anopheles tessellatus and An. dirus. The infection rates of Plasmodium falciparum, Plasmodium vivax and mixture of Plasmodium parasite species were 0.12% (2/1 683), 1.31% (22/1 683) and 0.06% (1/1 683), respectively. CONCLUSIONS Overall, this survey re-confirmed that multiple Anopheles species carry malaria parasites in the international border areas of the GMS countries. Anopheles sinensis dominated the Anopheles collections and as carriers of malaria parasites, therefore may play a significant role in malaria transmission. More extensive investigations of malaria vectors are required to reveal the detailed vector biology, ecology, behaviour, and genetics in GMS regions in order to assist with the planning and implementation of improved malaria control strategies.
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Bhattarai S, Blackburn JK, Ryan SJ. Malaria transmission in Nepal under climate change: anticipated shifts in extent and season, and comparison with risk definitions for intervention. Malar J 2022; 21:390. [PMID: 36544194 PMCID: PMC9773623 DOI: 10.1186/s12936-022-04417-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Climate and climate change affect the spatial pattern and seasonality of malaria risk. Season lengths and spatial extents of mapped current and future malaria transmission suitability predictions for Nepal were assessed for a combination of malaria vector and parasites: Anopheles stephensi and Plasmodium falciparum (ASPF) and An. stephensi and Plasmodium vivax (ASPV) and compared with observed estimates of malaria risk in Nepal. METHODS Thermal bounds of malaria transmission suitability for baseline (1960-1990) and future climate projections (RCP 4.5 and RCP 8.5 in 2030 and 2050) were extracted from global climate models and mapped for Nepal. Season length and spatial extent of suitability between baseline and future climate scenarios for ASPF and ASPV were compared using the Warren's I metric. Official 2010 DoHS risk districts (DRDs) and 2021 DoHS risk wards (DRWs), and spatiotemporal incidence trend clusters (ITCs) were overlaid on suitability season length and extent maps to assess agreement, and potential mismatches. RESULTS Shifts in season length and extent of malaria transmission suitability in Nepal are anticipated under both RCP 4.5 and RCP 8.5 scenarios in 2030 and 2050, compared to baseline climate. The changes are broadly consistent across both future climate scenarios for ASPF and ASPV. There will be emergence of suitability and increasing length of season for both ASPF and ASPV and decreasing length of season for ASPV by 2050. The emergence of suitability will occur in low and no-risk DRDs and outside of high and moderate-risk DRWs, season length increase will occur across all DRD categories, and outside of high and moderate-risk DRWs. The high and moderate risk DRWs of 2021 fall into ITCs with decreasing trend. CONCLUSIONS The study identified areas of Nepal where malaria transmission suitability will emerge, disappear, increase, and decrease in the future. However, most of these areas are anticipated outside of the government's current and previously designated high and moderate-risk areas, and thus outside the focus of vector control interventions. Public health officials could use these anticipated changing areas of malaria risk to inform vector control interventions for eliminating malaria from the country, and to prevent malaria resurgence.
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Affiliation(s)
- Shreejana Bhattarai
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, USA.
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
| | - Jason K Blackburn
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- Spatial Epidemiology and Ecology Research (SEER) Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA
| | - Sadie J Ryan
- Quantitative Disease Ecology and Conservation (QDEC) Lab, Department of Geography, University of Florida, Gainesville, FL, USA.
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
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Ahmed A, Irish SR, Zohdy S, Yoshimizu M, Tadesse FG. Strategies for conducting Anopheles stephensi surveys in non-endemic areas. Acta Trop 2022; 236:106671. [PMID: 36058292 PMCID: PMC11004664 DOI: 10.1016/j.actatropica.2022.106671] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 11/29/2022]
Abstract
Anopheles stephensi, a malaria vector species previously only known from Asia, was first detected in Africa in Djibouti in 2012, has been subsequently collected in Ethiopia, Sudan, and Somalia, and may be spreading further. Countries may wish to implement mosquito surveys to determine if An. stephensi is present, or to determine the extent of its distribution, if present. Furthermore, mosquito surveys can provide data on the bionomics of An. stephensi and its adaptation to the local environment that can help plan and implement control activities. The present strategies provide suggestions on surveillance approaches for monitoring An. stephensi. The first step is to determine the aim of the study, as this will determine the specific activities conducted in each location. Challenges related to identification and detection of resistance and sporozoites are also discussed. Results should be communicated to relevant stakeholders in a timely manner, both in country and internationally, to help understand the introduction, distribution, and bionomics of An. stephensi in a given country and work towards cross-border and coordinated international response.
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Affiliation(s)
- Ayman Ahmed
- Swiss Tropical and Public Health Institute (Swiss TPH), Kreuzstrasse 2, 4123 Allschwil, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland; Institute of Endemic Diseases, University of Khartoum, P.O. Box 102, 11111 Khartoum, Sudan; Molecular Biology Unit, Sirius Training and Research Centre, 47 Al Steen Street, 11111 Khartoum, Sudan; Directorate of Environmental Health, Federal Ministry of Health, P.O. Box 303, 11111 Khartoum, Sudan
| | - Seth R Irish
- Swiss Tropical and Public Health Institute (Swiss TPH), Kreuzstrasse 2, 4123 Allschwil, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland; U.S. President's Malaria Initiative, Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, United States.
| | - Sarah Zohdy
- U.S. President's Malaria Initiative, Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA 30329, United States
| | - Melissa Yoshimizu
- U.S. President's Malaria Initiative, U.S. Agency for International Development, 500 D Street SW, Washington, DC 20547, United States
| | - Fitsum G Tadesse
- Malaria and NTD directorate, Armauer Hansen Research Institute, P.O. Box 1005, ALERT Hospital Compound, Addis Ababa, Ethiopia
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Kweka EJ. Anopheles stephensi: a guest to watch in urban Africa. Trop Dis Travel Med Vaccines 2022; 8:7. [PMID: 35361266 PMCID: PMC8973991 DOI: 10.1186/s40794-022-00165-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/04/2022] [Indexed: 11/10/2022] Open
Abstract
Malaria vector control programs in Sub-Saharan Africa have invested many efforts and resources in the control of eight-sibling species of Anopheles gambiae complex and An. funestus group. The behaviour of sibling species of these vectors is well known and used for implementing the current intervention tools. The reports of An. stephensi in urban Africa with different habitats breeding behaviour is an alert on the success of malaria vector control efforts achieved so far. This communication intends to give an insight on what should be considered as a challenge for the management of An. stephensi in urban Africa to retain the achievement attained in malaria control.
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Population genomics reveal distinct and diverging populations of An. minimus in Cambodia. Commun Biol 2022; 5:1308. [PMID: 36443434 PMCID: PMC9705317 DOI: 10.1038/s42003-022-04259-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 11/15/2022] [Indexed: 11/29/2022] Open
Abstract
Anopheles minimus is an important malaria vector throughout its wide geographic range across Southeast Asia. Genome sequencing could provide important insights into the unique malaria transmission dynamics in this region, where many vector species feed and rest outdoors. We describe results from a study using Illumina deep whole-genome sequencing of 302 wild-caught An. minimus collected from three Cambodian provinces over several years (2010, 2014, 2016) and seasons to examine the level of population structure and genetic diversity within this species. These specimens cluster into four distinct populations of An. minimus s.s., with two populations overlapping geographically. We describe the underlying genetic diversity and divergence of these populations and investigated the genetic variation in genes known to be involved in insecticide resistance. We found strong signals of selection within these An. minimus populations, most of which were present in the two Northeastern Cambodian populations and differ from those previously described in African malaria vectors. Cambodia is the focus of the emergence and spread of drug-resistant malaria parasites, so understanding the underlying genetic diversity and resilience of the vectors of these parasites is key to implementing effective malaria control and elimination strategies. These data are publicly available as part of the MalariaGEN Vector Observatory, an open access resource of genome sequence data.
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Plasmodium cynomolgi in humans: current knowledge and future directions of an emerging zoonotic malaria parasite. Infection 2022; 51:623-640. [PMID: 36401673 PMCID: PMC9676733 DOI: 10.1007/s15010-022-01952-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/01/2022] [Indexed: 11/21/2022]
Abstract
Plasmodium cynomolgi (Pcy), a simian malaria parasite, is a recent perfect example of emerging zoonotic transfer in human. This review summarizes the current knowledge on the epidemiology of natural Pcy infections in humans, mosquitoes and monkeys, along with its biological, clinical and drug sensitivity patterns. Knowledge gaps and further studies on Pcy in humans are also discussed. This parasite currently seems to be geographically limited in South-East Asia (SEA) with a global prevalence in human ranging from 0 to 1.4%. The Pcy infections were reported in local SEA populations and European travelers, and range from asymptomatic carriage to mild/moderate attacks with no evidence of pathognomonic clinical and laboratory patterns but with Pcy strain-shaped clinical differences. Geographical distribution and competence of suitable mosquito vectors and non-primate hosts, globalization, climate change, and increased intrusion of humans into the habitat of monkeys are key determinants to emergence of Pcy parasites in humans, along with its expansion outside SEA. Sensitization/information campaigns coupled with training and assessment sessions of microscopists and clinicians on Pcy are greatly needed to improve data on the epidemiology and management of human Pcy infection. There is a need for development of sensitive and specific molecular tools for individual diagnosis and epidemiological studies. The development of safe and efficient anti-hypnozoite drugs is the main therapeutic challenge for controlling human relapsing malaria parasites. Experience gained from P. knowlesi malaria, development of integrated measures and strategies—ideally with components related to human, monkeys, mosquito vectors, and environment—could be very helpful to prevent emergence of Pcy malaria in humans through disruption of transmission chain from monkeys to humans and ultimately contain its expansion in SEA and potential outbreaks in a context of malaria elimination.
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Zhao DZ, Wang XK, Zhao T, Li H, Xing D, Gao HT, Song F, Chen GH, Li CX. A Swin Transformer-based model for mosquito species identification. Sci Rep 2022; 12:18664. [PMID: 36333318 PMCID: PMC9636261 DOI: 10.1038/s41598-022-21017-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/21/2022] [Indexed: 11/06/2022] Open
Abstract
Mosquito transmit numbers of parasites and pathogens resulting in fatal diseases. Species identification is a prerequisite for effective mosquito control. Existing morphological and molecular classification methods have evitable disadvantages. Here we introduced Deep learning techniques for mosquito species identification. A balanced, high-definition mosquito dataset with 9900 original images covering 17 species was constructed. After three rounds of screening and adjustment-testing (first round among 3 convolutional neural networks and 3 Transformer models, second round among 3 Swin Transformer variants, and third round between 2 images sizes), we proposed the first Swin Transformer-based mosquito species identification model (Swin MSI) with 99.04% accuracy and 99.16% F1-score. By visualizing the identification process, the morphological keys used in Swin MSI were similar but not the same as those used by humans. Swin MSI realized 100% subspecies-level identification in Culex pipiens Complex and 96.26% accuracy for novel species categorization. It presents a promising approach for mosquito identification and mosquito borne diseases control.
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Affiliation(s)
- De-Zhong Zhao
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Xin-Kai Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Teng Zhao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Hu Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Dan Xing
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - He-Ting Gao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Fan Song
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
| | - Guo-Hua Chen
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Chun-Xiao Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
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Cleary E, Hetzel MW, Clements ACA. A review of malaria epidemiology and control in Papua New Guinea 1900 to 2021: Progress made and future directions. FRONTIERS IN EPIDEMIOLOGY 2022; 2:980795. [PMID: 38455277 PMCID: PMC10910954 DOI: 10.3389/fepid.2022.980795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/29/2022] [Indexed: 03/09/2024]
Abstract
The research and control of malaria has a long history in Papua New Guinea, sometimes resulting in substantial changes to the distribution of infection and transmission dynamics in the country. There have been four major periods of malaria control in PNG, with the current control programme having commenced in 2004. Each previous control programme was successful in reducing malaria burden in the country, but multiple factors led to programme failures and eventual breakdown. A comprehensive review of the literature dating from 1900 to 2021 was undertaken to summarize control strategies, epidemiology, vector ecology and environmental drivers of malaria transmission in PNG. Evaluations of historical control programs reveal poor planning and communication, and difficulty in sustaining financial investment once malaria burden had decreased as common themes in the breakdown of previous programs. Success of current and future malaria control programs in PNG is contingent on adequate planning and management of control programs, effective communication and engagement with at-risk populations, and cohesive targeted approaches to sub-national and national control and elimination.
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Affiliation(s)
- Eimear Cleary
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
- WorldPop, School of Geography and Environmental Science, University of Southampton, Southampton, United Kingdom
| | - Manuel W. Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Archie C. A. Clements
- Curtin University, Perth, WA, Australia
- Telethon Kids Institute, Perth, WA, Australia
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Genetic Diversity of Circumsporozoite Surface Protein of Plasmodium vivax from the Central Highlands, Vietnam. Pathogens 2022; 11:pathogens11101158. [PMID: 36297215 PMCID: PMC9611680 DOI: 10.3390/pathogens11101158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/01/2022] [Accepted: 10/05/2022] [Indexed: 11/05/2022] Open
Abstract
The circumsporozoite surface protein of Plasmodium vivax (PvCSP) plays a critical role in parasite biology. It has been extensively studied as a leading vivax-malaria-vaccine candidate. In this study, the genetic polymorphism and natural selection of pvcsp in P. vivax isolates collected from the Central Highlands, Vietnam were analyzed to understand the genetic structure of the parasite circulating in the endemic area and to provide baseline information for effective vaccine development based on the protein. Only two major alleles, VK210 and VK247, were detected in Vietnamese pvcsp, with VK247 being the predominant one. The N-terminal and C-terminal regions of Vietnamese VK210 and VK247 variants showed a low genetic diversity. Amino acid substitutions, insertions of a single amino acid or octapeptide (ANKKAEDA in VK210 and ANKKAGDA in VK247), and tetrapeptide repeat motifs (GGNA) were the main factors generating genetic diversity in the two regions of the Vietnamese VK210 and VK247 variants. Interestingly, these two regions of Vietnamese pvcsp displayed a unique natural selection pressure distinct from global pvcsp, particularly with the neighboring Southeast Asian pvcsp population. Meanwhile, the central repeat region (CRR) in both the VK210 and VK247 variants showed a high degree of polymorphic characters, caused by varying numbers, types, and combinations of peptide repeat motifs (PRMs) in Vietnamese pvcsp. Highly complicated polymorphic patterns of the CRR were also detected in global pvcsp. These results expand our understanding of the genetic structure of Vietnamese pvcsp and the population dynamics of P. vivax in the Central Highlands, Vietnam.
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Geometric morphometric and molecular techniques for discriminating among three cryptic species of the Anopheles barbirostris complex (Diptera: Culicidae) in Thailand. Heliyon 2022; 8:e11261. [PMID: 36339998 PMCID: PMC9634016 DOI: 10.1016/j.heliyon.2022.e11261] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 07/09/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Anopheles members of the Barbirostris complex are important vectors of malaria in Thailand. However, they are morphologically indistinguishable because they are closely related species. In this study, wing geometric morphometrics (GM) and DNA barcoding based on the cytochrome c oxidase subunit 1 (COI) gene were applied to differentiate cryptic species of the Barbirostris complex in Thailand. Three cryptic species of the Barbirostris complex, Anopheles dissidens (19.44%), Anopheles saeungae (24.54%), and Anopheles wejchoochotei (56.02%) were initially identified using the multiplex polymerase chain reaction assay. DNA barcoding analyses showed low intraspecific distances (range, 0.27%–0.63%) and high interspecific distances (range, 1.92%–3.68%), consistent with the phylogenetic analyses that showed clear species groups. While wing size and shape analyses based on landmark-based GM indicated differences between three species (p < 0.05). The cross-validated reclassification revealed that the overall efficacy of wing size analysis for species identification of the Barbirostris complex was less than the wing shape analysis (56.43% vs. 74.29% total performance). Therefore, this study's results are guidelines for applying modern techniques to identify members within the Barbirostris complex, which are still difficult to distinguish by morphology-based identification and contribute to further appropriate malaria control. DNA barcoding based on the cytochrome c oxidase subunit 1 (COI) gene is the most reliable identification tool for the Anopheles barbirostris complex. Analysis of wing size and shape of Anopheles dissidens, An. saeungae and An. wejchoochotei based on geometric morphometrics revealed differences between species (p < 0.05). The efficacy of wing shape analysis for species identification of the Barbirostris complex was moderate levels of performance (74.29% accuracy score).
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Lee SY, Kim HC, Klein TA, Ryu J, Won MH, Choi JW, Kim MS, Chong ST, Lee SH, Kim YH, Kim JH, Choi KS. Species Diversity of Anopheles Mosquitoes and Plasmodium vivax Infection Rates, Gyeonggi Province, Republic of Korea During 2020. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:1778-1786. [PMID: 35819996 DOI: 10.1093/jme/tjac086] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Indexed: 06/15/2023]
Abstract
There are currently >300 malaria cases reported annually in the Republic of Korea (ROK), with most cases attributed to exposure in northern Gangwon and Gyeonggi provinces near the demilitarized zone (DMZ). The species diversity and malaria infection rate were determined for a sample of Anopheles mosquitoes collected from May to early November 2020 for six sites in a malaria high-risk area in/near the DMZ and two malaria low-risk areas in southern Gyeonggi province using Mosquito Magnet traps in the ROK. A total of 1864 Anopheles spp. were identified to species by PCR. Overall, An. kleini (31.4%, 510/1622) was the most frequently species assayed, followed by An. pullus (25.5%, 413/1622), An. sineroides (23.9%, 387/1622), and An. sinensis (10.2%, 165/1622), while the other four species only accunted for 9.1% (147/1622) collected in/near the DMZ. Only three species, An. pullus, An. sinensis, and An. sineroides were collected at Humphreys US Army Garrison (USAG) (235 individuals), while only An. sinensis was collected at Yongsan USAG (7 individuals). A total of 36 Anopheles specimens belonging to five species collected in/near the DMZ were positive for Plasmodium vivax by PCR. Anopheles kleini (9) was the most frequent species positive for P. vivax, followed by An. belenrae (8), An. pullus (8), An. sinensis (5), An. sineroides (5), and a member of the Anopheles Lindesayi Complex in the ROK (1). This is the first report of P. vivax in a member of the An. Lindesayi Complex in the ROK. These findings can assist in guiding future malaria vector management in the ROK.
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Affiliation(s)
- So Youn Lee
- School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, 41566, Korea
- Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, Korea
| | - Heung Chul Kim
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271-5281, USA
- U Inc. 34-gil, Daesakwan-ro, Yongsan-gu, Seoul, 04409, Repulic of Korea
| | - Terry A Klein
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271-5281, USA
| | - Jihun Ryu
- School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, 41566, Korea
- Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, Korea
| | - Min Hyeok Won
- School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, 41566, Korea
- Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, Korea
| | - Jae Won Choi
- School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, 41566, Korea
- Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, Korea
| | - Myung Soon Kim
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271-5281, USA
| | - Sung Tae Chong
- Force Health Protection and Preventive Medicine, Medical Department Activity-Korea/65th Medical Brigade, Unit 15281, APO AP 96271-5281, USA
| | - Si Hyeock Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Young Ho Kim
- Department of Entomology, Kyungpook National University, Sangju, Crea
| | - Ju Hyeon Kim
- Department of Tropical Medicine and Parasitology, College of Medicine, Seoul National University, Seoul, Korea
| | - Kwang Shik Choi
- School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu, 41566, Korea
- Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu, Korea
- Institute for Phylogenomics and Evolution, Kyungpook National University, Daegu, Korea
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49
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Waage J, Grace D, Fèvre EM, McDermott J, Lines J, Wieland B, Naylor NR, Hassell JM, Chan K. Changing food systems and infectious disease risks in low-income and middle-income countries. Lancet Planet Health 2022; 6:e760-e768. [PMID: 36087606 PMCID: PMC9451496 DOI: 10.1016/s2542-5196(22)00116-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 06/15/2023]
Abstract
The emergence of COVID-19 has drawn the attention of health researchers sharply back to the role that food systems can play in generating human disease burden. But emerging pandemic threats are just one dimension of the complex relationship between agriculture and infectious disease, which is evolving rapidly, particularly in low-income and middle-income countries (LMICs) that are undergoing rapid food system transformation. We examine this changing relationship through four current disease issues. The first is that greater investment in irrigation to improve national food security raises risks of vector-borne disease, which we illustrate with the case of malaria and rice in Africa. The second is that the intensification of livestock production in LMICs brings risks of zoonotic diseases like cysticercosis, which need to be managed as consumer demand grows. The third is that the nutritional benefits of increasing supply of fresh vegetables, fruit, and animal-sourced foods in markets in LMICs pose new food-borne disease risks, which might undermine supply. The fourth issue is that the potential human health risks of antimicrobial resistance from agriculture are intensified by changing livestock production. For each disease issue, we explore how food system transition is creating unintentional infectious disease risks, and what solutions might exist for these problems. We show that successfully addressing all of these challenges requires a coordinated approach between public health and agricultural sectors, recognising the costs and benefits of disease-reducing interventions to both, and seeking win-win solutions that are most likely to attract broad policy support and uptake by food systems.
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Affiliation(s)
- Jeff Waage
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
| | - Delia Grace
- International Livestock Research Institute, Nairobi, Kenya; Natural Resources Institute, University of Greenwich, London, UK
| | - Eric M Fèvre
- International Livestock Research Institute, Nairobi, Kenya; Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - John McDermott
- International Food Policy Research Institute, Washington, DC, USA
| | - Jo Lines
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - Barbara Wieland
- International Livestock Research Institute, Nairobi, Kenya; Institute of Virology and Immunology, Mittelhäusern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Nichola R Naylor
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
| | - James M Hassell
- International Livestock Research Institute, Nairobi, Kenya; Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Kallista Chan
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK
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50
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Molina-Guzmán LP, Gutiérrez-Builes LA, Ríos-Osorio LA. Models of spatial analysis for vector-borne diseases studies: A systematic review. Vet World 2022; 15:1975-1989. [PMID: 36313837 PMCID: PMC9615510 DOI: 10.14202/vetworld.2022.1975-1989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/24/2022] [Indexed: 11/16/2022] Open
Abstract
Background and Aim: Vector-borne diseases (VBDs) constitute a global problem for humans and animals. Knowledge related to the spatial distribution of various species of vectors and their relationship with the environment where they develop is essential to understand the current risk of VBDs and for planning surveillance and control strategies in the face of future threats. This study aimed to identify models, variables, and factors that may influence the emergence and resurgence of VBDs and how these factors can affect spatial local and global distribution patterns.
Materials and Methods: A systematic review was designed based on identification, screening, selection, and inclusion described in the research protocols according to the preferred reporting items for systematic reviews and meta-analyses guide. A literature search was performed in PubMed, ScienceDirect, Scopus, and SciELO using the following search strategy: Article type: Original research, Language: English, Publishing period: 2010–2020, Search terms: Spatial analysis, spatial models, VBDs, climate, ecologic, life cycle, climate variability, vector-borne, vector, zoonoses, species distribution model, and niche model used in different combinations with "AND" and "OR."
Results: The complexity of the interactions between climate, biotic/abiotic variables, and non-climate factors vary considerably depending on the type of disease and the particular location. VBDs are among the most studied types of illnesses related to climate and environmental aspects due to their high disease burden, extended presence in tropical and subtropical areas, and high susceptibility to climate and environment variations.
Conclusion: It is difficult to generalize our knowledge of VBDs from a geospatial point of view, mainly because every case is inherently independent in variable selection, geographic coverage, and temporal extension. It can be inferred from predictions that as global temperatures increase, so will the potential trend toward extreme events. Consequently, it will become a public health priority to determine the role of climate and environmental variations in the incidence of infectious diseases. Our analysis of the information, as conducted in this work, extends the review beyond individual cases to generate a series of relevant observations applicable to different models.
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Affiliation(s)
- Licet Paola Molina-Guzmán
- Grupo Biología de Sistemas, Escuela de Ciencias de la Salud, Facultad de Medicina, Universidad Pontificia Bolivariana, Medellín, Colombia; Grupo de Investigación Salud y Sostenibilidad, Escuela de Microbiología, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin - Colombia
| | - Lina A. Gutiérrez-Builes
- Grupo Biología de Sistemas, Escuela de Ciencias de la Salud, Facultad de Medicina, Universidad Pontificia Bolivariana, Medellín, Colombia
| | - Leonardo A. Ríos-Osorio
- Grupo de Investigación Salud y Sostenibilidad, Escuela de Microbiología, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellin - Colombia
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