1
|
Ramalingam B, Venkatesan V, Abraham PR, Adinarayanan S, Swaminathan S, Raju KHK, Hoti SL, Kumar A. Detection of Wuchereria bancrofti DNA in wild caught vector and non-vector mosquitoes: implications for elimination of lymphatic filariasis. Mol Biol Rep 2024; 51:291. [PMID: 38329553 DOI: 10.1007/s11033-024-09256-4] [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: 11/30/2023] [Accepted: 01/15/2024] [Indexed: 02/09/2024]
Abstract
BACKGROUND Transmission Assessment Survey (TAS) is the WHO recommended method used for decision-making to stop or continue the MDA in lymphatic filariasis (LF) elimination programme. The WHO has also recommended Molecular Xenomonitoring (MX) of LF infection in vectors as an adjunct tool in settings under post-MDA or validation period. Screening of non-vectors by MX in post-MDA / validation settings could be useful to prevent a resurgence of LF infection, as there might be low abundance of vectors, especially in some seasons. In this study, we investigated the presence of LF infection in non-vectors in an area endemic for LF and has undergone many rounds of annual MDA with two drugs (Diethylcarbamazine and Albendazole, DA) and two rounds of triple drug regimens (Ivermectin + DA). METHODS AND RESULTS Mosquitoes were collected from selected villages of Yadgir district in Karnataka state, India, during 2019. A total of 680 female mosquitoes were collected, identified morphologically by species and separated as pools. The female mosquitoes belonging to 3 species viz., Anopheles subpictus, Culex gelidus and Culex quinquefaciatus were separated, pooled, and the DNA extracted using less expensive method and followed by LDR based real-time PCR assay for detecting Wuchereria bancrofti infection in vector as well as non-vector mosquitoes. One pool out of 6 pools of An. subpictus, 2 pools out of 6 pools of Cx. gelidus, and 4 pools out of 8 pools of Cx. quinquefaciatus were found to be positive for W. bancrofti infection by RT-PCR. The infection rate in vectors and non-vectors was found to be 1.8% (95% CI: 0.5-4.2%) and 0.9% (95% CI: 0.2-2.3%), respectively. CONCLUSIONS Our study showed that non-vectors also harbour W. bancrofti, thus opening an opportunity of using these mosquitoes as surrogate vectors for assessing risk of transmission to humans in LF endemic and post MDA areas.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Ashwani Kumar
- Centre for Global Health Research, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai 605102, India
| |
Collapse
|
2
|
Sumitha MK, Kalimuthu M, Kumar MS, Paramasivan R, Kumar NP, Sunish IP, Balaji T, Sarma DK, Kumar D, Suman DS, Srivastava H, Bhowmick IP, Vaishnav K, Singh OP, Patil PB, Tyagi S, Mohanty SS, Barik TK, Uragayala S, Kumar A, Gupta B. Genetic differentiation among Aedes aegypti populations from different eco-geographical zones of India. PLoS Negl Trop Dis 2023; 17:e0011486. [PMID: 37498944 PMCID: PMC10409278 DOI: 10.1371/journal.pntd.0011486] [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: 01/19/2023] [Revised: 08/08/2023] [Accepted: 06/27/2023] [Indexed: 07/29/2023] Open
Abstract
The present study explicitly evaluated the genetic structure of Aedes aegypti Linn, the vector of dengue, chikungunya, and Zika viruses, across different geo-climatic zones of India and also elucidated the impact of ecological and topographic factors. After data quality checks and removal of samples with excess null alleles, the final analysis was performed on 589 individual samples using 10 microsatellite markers. Overall findings of this study suggested that, Ae. aegypti populations are highly diverse with moderate genetic differentiation between them. Around half of the populations (13 out of 22) formed two genetic clusters roughly associated with geographical regions. The remaining nine populations shared genetic ancestries with either one or both of the clusters. A significant relationship between genetic and geographic distance was observed, indicating isolation by distance. However, spatial autocorrelation analysis predicted the signs of long-distance admixture. Post-hoc environmental association analysis showed that 52.7% of genetic variations were explained by a combination of climatic and topographic factors, with latitude and temperature being the best predictors. This study indicated that though overall genetic differentiation among Ae. aegypti populations across India is moderate (Fst = 0.099), the differences between the populations are developing due to the factors associated with geographic locations. This study improves the understanding of the Ae. aegypti population structure in India that may assist in predicting mosquito movements across the geo-climatic zones, enabling effective control strategies and assessing the risk of disease transmission.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Devendra Kumar
- Department of Zoology, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
| | - Devi Shankar Suman
- Estuarine Biology Regional Centre, Zoological Survey of India, Gopalpur-on-Sea, Ganjam, Odisha, India
| | - Hemlata Srivastava
- School of Biological Sciences, Institute of Management Studies (University Courses Campus), Ghaziabad, Delhi, India
| | | | | | - Om P. Singh
- ICMR-National Institute of Malaria Research, New Delhi, India
| | | | - Suchi Tyagi
- ICMR-National Institute of Malaria Research, New Delhi, India
| | - Suman S. Mohanty
- ICMR-National Institute for Implementation Research on Non-Communicable Diseases, Jodhpur, India
| | - Tapan Kumar Barik
- Medical Entomology Laboratory, Post Graduate Department of Zoology, Berhampur University, Ganjam, Odisha, India
| | - Sreehari Uragayala
- ICMR-National Institute of Malaria Research, Field Unit, Bengaluru, India
| | - Ashwani Kumar
- ICMR-Vector Control Research Centre, Puducherry, India
| | - Bhavna Gupta
- ICMR-Vector Control Research Centre, Field Station, Madurai, India
| |
Collapse
|
3
|
Diptyanusa A, Herini ES, Indarjulianto S, Satoto TBT. Estimation of Japanese encephalitis virus infection prevalence in mosquitoes and bats through nationwide sentinel surveillance in Indonesia. PLoS One 2022; 17:e0275647. [PMID: 36223381 PMCID: PMC9555671 DOI: 10.1371/journal.pone.0275647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 09/11/2022] [Indexed: 11/26/2022] Open
Abstract
Indonesia belongs to endemic areas of Japanese encephalitis (JE), yet data regarding the true risk of disease transmission are lacking. While many seroprevalence studies reported its classic enzootic transmission, data related to the role of bats in the transmission of JE virus are limited. This current study aimed to identify the potential role of bats in the local transmission of the JE virus to aid the ongoing active case surveillance in Indonesia, in order to estimate the transmission risk. Mosquitoes and bats were collected from 11 provinces in Indonesia. The detection of the JE virus used polymerase chain reaction (PCR). Maps were generated to analyze the JE virus distribution pattern. Logistic regression analysis was done to identify risk factors of JE virus transmission. JE virus was detected in 1.4% (7/483) of mosquito pools and in 2.0% (68/3,322) of bat samples. Mosquito species positive for JE virus were Culex tritaeniorhynchus and Cx. vishnui, whereas JE-positive bats belonged to the genera Cynopterus, Eonycteris, Hipposideros, Kerivoula, Macroglossus, Pipistrellus, Rousettus, Scotophilus and Thoopterus. JE-positive mosquitoes were collected at the same sites as the JE-positive bats. Collection site nearby human dwellings (AOR: 2.02; P = 0.009) and relative humidity of >80% (AOR: 2.40; P = 0.001) were identified as independent risk factors for JE virus transmission. The findings of the current study highlighted the likely ongoing risk of JE virus transmission in many provinces in Indonesia, and its potential implications on human health.
Collapse
Affiliation(s)
- Ajib Diptyanusa
- Doctoral Study Program of Health and Medical Sciences, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- World Health Organization Indonesia Country Office, Jakarta, Indonesia
| | - Elisabeth Siti Herini
- Department of Child Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Soedarmanto Indarjulianto
- Department of Internal Medicine, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Tri Baskoro Tunggul Satoto
- Department of Parasitology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
- * E-mail:
| |
Collapse
|
4
|
Suresh KP, Nayak A, Dhanze H, Bhavya AP, Shivamallu C, Achar RR, Silina E, Stupin V, Barman NN, Kumar SK, Syed A, Kollur SP, Shreevatsa B, Patil SS. Prevalence of Japanese encephalitis (JE) virus in mosquitoes and animals of the Asian continent: A systematic review and meta-analysis. J Infect Public Health 2022; 15:942-949. [PMID: 35914358 DOI: 10.1016/j.jiph.2022.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/08/2022] [Accepted: 07/21/2022] [Indexed: 10/16/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is a viral zoonotic disease that has been found in several countries of Asia and is responsible for high mortality and morbidity of men and animals in rural and sub-urban endemic areas due to the virus re-circulation among diverse hosts and vectors. The present study estimates the prevalence of the JE virus in the vector and animal population of the Asian continent using a systematic review and meta-analysis. METHODS The Cochran collaborators' Preferred Reporting Items for Systematic Reviews and Meta-Analysis [PRISMA] guidelines were used for systematic review and meta-analysis. The heterogeneity was observed in meta-regression analysis due to several factors including region, species, and different diagnostic assays used in various studies. Thus we did sensitivity and subgroup analysis. RESULTS The prevalence of the JE virus was calculated using a total sample size of 47,391. Subgroup analysis revealed the JE virus prevalence of 39% in the Southeast Asia region, followed by East Asia with 35% and South Asia with 15% prevalence. Hence, the overall pooled prevalence of the JE virus was 26% in the Asian continent. CONCLUSIONS The highest proportion of infection was found in pigs amongst all animals, reinforcing the fact that they can be used as sentinels to predict outbreaks in humans. The findings of this study will enable researchers and policymakers in better understanding the disease's spatial and temporal distribution, as well as in creating and implementing location-specific JE prevention and control measures.
Collapse
Affiliation(s)
| | - Akshata Nayak
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Himani Dhanze
- ICAR-Indian Veterinary Research Institute, Bareilly, UP, India
| | - Anenahalli Panduranga Bhavya
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Chandan Shivamallu
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Raghu Ram Achar
- Division of Biochemistry, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, India
| | - Ekaterina Silina
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Victor Stupin
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Nagendra Nath Barman
- Department of Microbiology, College of Veterinary Sciences (AAU), Guwahati, Assam, India
| | - Seethakempanahalli Kempanna Kumar
- Department of Ethnoveterinary Sciences and Practices, The University of Trans-Disciplinary Health Science and Technology, Jarakabandekaval, Yelahanka, Bengaluru, India
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Shiva Prasad Kollur
- Department of Sciences, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru, Karnataka, India
| | - Bhargav Shreevatsa
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India.
| |
Collapse
|
5
|
Walsh MG, Pattanaik A, Vyas N, Saxena D, Webb C, Sawleshwarkar S, Mukhopadhyay C. High-risk landscapes of Japanese encephalitis virus outbreaks in India converge on wetlands, rain-fed agriculture, wild Ardeidae, and domestic pigs and chickens. Int J Epidemiol 2022; 51:1408-1418. [PMID: 35355081 PMCID: PMC9557850 DOI: 10.1093/ije/dyac050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 03/10/2022] [Indexed: 11/19/2022] Open
Abstract
Background Japanese encephalitis virus (JEV) is a zoonotic mosquito-borne virus that causes a significant burden of disease across Asia, particularly in India, with high mortality in children. JEV circulates in wild ardeid birds and domestic pig reservoirs, both of which generate sufficiently high viraemias to infect vector mosquitoes, which can then subsequently infect humans. The landscapes of these hosts, particularly in the context of anthropogenic ecotones and resulting wildlife–livestock interfaces, are poorly understood and thus significant knowledge gaps in the epidemiology of JEV persist. This study sought to investigate the landscape epidemiology of JEV outbreaks in India over the period 2010–2020 to determine the influence of shared wetland and rain-fed agricultural landscapes and animal hosts on outbreak risk. Methods Using surveillance data from India’s National Centre for Disease Control Integrated Disease Surveillance Programme, JEV outbreaks were modelled as an inhomogeneous Poisson point process and externally validated against independently sourced data. Results Outbreak risk was strongly associated with the habitat suitability of ardeid birds, both pig and chicken density, and the shared landscapes between fragmented rain-fed agriculture and both river and freshwater marsh wetlands. Conclusion The results from this work provide the most complete understanding of the landscape epidemiology of JEV in India to date and suggest important One Health priorities for control and prevention across fragmented terrain comprising a wildlife–livestock interface that favours spillover to humans.
Collapse
Affiliation(s)
- Michael G Walsh
- Faculty of Medicine and Health, School of Public Health, The University of Sydney, Camperdown, New South Wales, Australia.,Faculty of Medicine and Health, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead, New South Wales, Australia.,One Health Centre, The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.,The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Amrita Pattanaik
- Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Navya Vyas
- One Health Centre, The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.,The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Deepak Saxena
- Department of Epidemiology, Indian Institute of Public Health Gandhinagar, Gandhinagar, Gujarat, India
| | - Cameron Webb
- Faculty of Medicine and Health, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead, New South Wales, Australia.,Department of Medical Entomology, NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Shailendra Sawleshwarkar
- Faculty of Medicine and Health, Sydney Institute for Infectious Diseases, The University of Sydney, Westmead, New South Wales, Australia.,One Health Centre, The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.,The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India.,The University of Sydney, Faculty of Medicine and Health, Westmead Clinical School, Westmead, New South Wales, Australia
| | - Chiranjay Mukhopadhyay
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India.,Centre for Emerging and Tropical Diseases, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| |
Collapse
|
6
|
Van den Eynde C, Sohier C, Matthijs S, De Regge N. Japanese Encephalitis Virus Interaction with Mosquitoes: A Review of Vector Competence, Vector Capacity and Mosquito Immunity. Pathogens 2022; 11:317. [PMID: 35335641 PMCID: PMC8953304 DOI: 10.3390/pathogens11030317] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 02/01/2023] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne zoonotic flavivirus and a major cause of human viral encephalitis in Asia. We provide an overview of the knowledge on vector competence, vector capacity, and immunity of mosquitoes in relation to JEV. JEV has so far been detected in more than 30 mosquito species. This does not necessarily mean that these species contribute to JEV transmission under field conditions. Therefore, vector capacity, which considers vector competence, as well as environmental, behavioral, cellular, and biochemical variables, needs to be taken into account. Currently, 17 species can be considered as confirmed vectors for JEV and 10 other species as potential vectors. Culex tritaeniorhynchus and Culex annulirostris are considered primary JEV vectors in endemic regions. Culex pipiens and Aedes japonicus could be considered as potentially important vectors in the case of JEV introduction in new regions. Vector competence is determined by various factors, including vector immunity. The available knowledge on physical and physiological barriers, molecular pathways, antimicrobial peptides, and microbiome is discussed in detail. This review highlights that much remains to be studied about vector immunity against JEV in order to identify novel strategies to reduce JEV transmission by mosquitoes.
Collapse
Affiliation(s)
- Claudia Van den Eynde
- Exotic Viruses and Particular Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium; (C.S.); (N.D.R.)
| | - Charlotte Sohier
- Exotic Viruses and Particular Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium; (C.S.); (N.D.R.)
| | - Severine Matthijs
- Enzootic, Vector-Borne and Bee Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium;
| | - Nick De Regge
- Exotic Viruses and Particular Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium; (C.S.); (N.D.R.)
| |
Collapse
|
7
|
Auerswald H, Maquart PO, Chevalier V, Boyer S. Mosquito Vector Competence for Japanese Encephalitis Virus. Viruses 2021; 13:v13061154. [PMID: 34208737 PMCID: PMC8234777 DOI: 10.3390/v13061154] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 12/30/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.
Collapse
Affiliation(s)
- Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia
- Correspondence:
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia;
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, 34000 Montpellier, France
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
- Institut Pasteur, 75015 Paris, France
| |
Collapse
|
8
|
Paulraj P, Thenmozhi V, Mishra S, Nagaraj J, Paramasivan R. Seasonal abundance and infection of Japanese encephalitis vectors from Gorakhpur district, Uttar Pradesh, India. J Vector Borne Dis 2021; 58:265-272. [DOI: 10.4103/0972-9062.321740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
|
9
|
Hoseini Z, Alipour H, Azizi K, Soltani A. Molecular-based Survey of Rickettsia spp. and Coxiella burnetii in Mosquitoes (Diptera: Culicidae) from Fars Province, Southern Iran, during 2017-18. Open Microbiol J 2020. [DOI: 10.2174/1874434602014010281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Objectives:
Since there have not been any studies on the roles of the Iranian mosquitoes in the transmission of Rickettsia spp. and Coxiella burneti, the present study investigates the roles of mosquitoes in the transmission of the pathogens using the PCR techniques for the first time in Iran.
Methods:
The present study was conducted in Fars province during the activity seasons of mosquitoes in 2017-18. The primer design was done to investigate the probability of mosquito’s contamination with Rickettsia spp. and Coxiella burnetii. The conventional PCR was used after the extraction of DNA from mosquitoes to study the contamination.
Results:
A total of 1103 adult mosquitoes were collected and identified. Among them, 3 genera and 11 species were identified, including Anopheles (25.74%), Culex (51.84%) and Culiseta (22.39%) genera. All tested mosquitoes were negative in terms of contamination to Rickettsia spp. and Coxiella burnetii.
Conclusion:
Based on the results, mosquitoes are not considered as vectors of Rickettsia spp. and Coxiella burnetii in this part of the country currently. Further studies on a larger scale are needed to examine the exact role of mosquitoes (as a possible vector with high abundance and mobility) in the transmission of these pathogens in tropical areas of Iran.
Collapse
|
10
|
Thankachy S, Dash S, Sahu SS. Entomological factors in relation to the occurrence of Japanese encephalitis in Malkangiri district, Odisha State, India. Pathog Glob Health 2019; 113:246-253. [PMID: 31544624 DOI: 10.1080/20477724.2019.1670926] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Japanese encephalitis is a mosquito-borne arbo-viral disease with seasonal occurrence. Since 2009, AES/JE cases have been reported from Malkangiri district of Odisha State, India at an interval of one year.In the current study, the entomological parameters of known JE vector mosquito species were assessed for one year in Malkangiri district. Mosquito collections were done fortnightly in the index villages from August 2015 to July 2016 to record the density, their breeding habitats, feeding behaviour, parity, dusk index (DI) and infection status with JE virus. A total of 2347 JE vector mosquitoes belonging to nine species were collected from dusk collections. Culex vishnui (38.3%) was the predominant species followed by Cx. whitmorei (17.3%), Cx. fuscocephalus (13.6%), Cx. tritaeniorhynchus (11.1%), Cx. bitaeniorhynchus (6.1%), Anopheles subpictus (4.8%), An. barbirostris (4.4%), Cx. quinquefasciatus (2.3%) and Cx. gelidus (2.2%). The average DI of Cx. vishnui was 0.37 which was highest among all JE vector species and varied between 0.02 (April) and 0.9 (November). The human blood indexof Cx. vishnui was 0.026. A total of 1835 JE vector mosquitoes were screened for the isolation of JE virus, but none was found positive. Presence of paddy fields and ponds, abundance of JE vectors and their human feeding habit indicate the risk of JE transmission in the study area. Detection of JE virus in Cx. vishnui during 2016 outbreak in Malkangiri district further confirms that there would be a threat of JE transmission during the favourable period.
Collapse
Affiliation(s)
- Sonia Thankachy
- Vector Biology and Control, Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
| | - Smrutidhara Dash
- Vector Biology and Control, Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
| | - Sudhansu Sekhar Sahu
- Vector Biology and Control, Indian Council of Medical Research-Vector Control Research Centre, Puducherry, India
| |
Collapse
|
11
|
Samy AM, Alkishe AA, Thomas SM, Wang L, Zhang W. Mapping the potential distributions of etiological agent, vectors, and reservoirs of Japanese Encephalitis in Asia and Australia. Acta Trop 2018; 188:108-117. [PMID: 30118701 DOI: 10.1016/j.actatropica.2018.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/11/2018] [Accepted: 08/12/2018] [Indexed: 12/15/2022]
Abstract
Japanese encephalitis virus (JEV) is a substantial cause of viral encephalitis, morbidity, and mortality in South-East Asia and the Western Pacific. World Health Organization recognized Japanese Encephalitis (JE) as a public health priority in demands to initiate active vaccination programs. Recently, the geographic distribution of JEV has apparently expanded into other areas in the Pacific islands and northern Australia; however, major gaps exist in knowledge in regard to its current distribution. Here, we mapped the potential distribution of mosquito vectors of JEV (Culex tritaeniorhynchus, Cx. pseudovishnui, Cx. vishnui, Cx. fuscocephala, Cx. gelidus), and reservoirs (Egretta garzetta, E. intermedia, Nycticorax nycticorax) based on ecological niche modeling approach. Ecological niche models predicted all species to occur across Central, South and South East Asia; however, Cx. tritaeniorhynchus, E. garzetta, E. intermedia, and N. nycticorax had broader potential distributions extending west to parts of the Arabian Peninsula. All predictions were robust and significantly better than random (P < 0.001). We also tested the JEV prediction based on 4335 additional independent human case records collected by the Chinese Information System for Disease Control and Prevention (CISDCP); 4075 cases were successfully predicted by the model (P < 0.001). Finally, we tested the ecological niche similarity among JEV, vector, and reservoir species and could not reject any of the null hypotheses of niche similarity in all combination pairs.
Collapse
|
12
|
Abstract
Mosquitoes are the most important vectors for arboviral human diseases across the world. Diseases such as Dengue Fever (DF), West Nile Virus (WNV), Yellow Fever (YF), Japanese Encephalitis (JE), Venezuelan Equine Encephalitis (VEE), and St. Louis Encephalitis (SLE), among others, have a deep impact in public health. Usually mosquitoes acquire the arboviral infection when they feed on viremic animals (birds or mammals), so their infection can be detected along the year or in short periods of time (seasons). All of this depends on the frequency and seasonality of the encounters between viremic animals and vectors.With the convergence of several phenomena like the increasing traveling of human populations, globalization of economy and more recently the global warming, the introduction of nonendemic arbovirus into new areas has become the current scenario. As examples of this new social and environmental frame we can mention the outbreak of West Nile Virus in North America in the late 1990s and more recently the outbreaks of chikungunya and Zika virus in the Americas. The present chapter deals with one of the first steps in the development of research studies and diagnosis programs, the surveillance of arboviruses in their vectors, the sampling design and mosquito trapping methods. The chapter also includes some important considerations and tips to be taken into account during the mosquito fieldwork.
Collapse
|
13
|
Karthikeyan A, Shanmuganathan S, Pavulraj S, Prabakar G, Pavithra S, Porteen K, Elaiyaraja G, Malik YS. JAPANESE ENCEPHALITIS, RECENT PERSPECTIVES ON VIRUS GENOME, TRANSMISSION, EPIDEMIOLOGY, DIAGNOSIS AND PROPHYLACTIC INTERVENTIONS. ACTA ACUST UNITED AC 2017. [DOI: 10.18006/2017.5(6).730.748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|