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Assouguem A, Joutei AB, Lahlali R, Kara M, Bari A, Ali EA, Fidan H, Laabidine HZ, El Ouati Y, Farah A, Lazraq A. Evaluation of the impact of two citrus plants on the variation of Panonychus citri (Acari: Tetranychidae) and beneficial phytoseiid mites. Open Life Sci 2024; 19:20220837. [PMID: 38585628 PMCID: PMC10997146 DOI: 10.1515/biol-2022-0837] [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: 11/19/2023] [Revised: 12/30/2023] [Accepted: 02/05/2024] [Indexed: 04/09/2024] Open
Abstract
The abundance of Panonychus citri McGregor 1916 (Acari: Tetranychidae) and its associated enemies (Euseius stipulatus Athias-Henriot, 1960; Typhlodromus sp.; Phytoseiulus persimilis Athias-Henriot, 1957) was studied on two 12-year-old citrus cultivars, specifically Clementine "Nules" (Citrus Clementina) and Valencia (Citrus sinensis), in the Gharb region of Morocco. Throughout the entire monitoring period in the Valencia late cultivar, the density of the spider mite P. citri on leaves was notably higher at 38.0% (n = 1,212 mobile forms). Predator P. persimilis exhibited a leaf occupancy of 25.0% (n = 812), followed by Typhlodromus sp. at 20.0% (n = 643). Conversely, the abundance of E. stipulatus was lower at 17.0% (n = 538). In the Nules variety, P. citri abundance recorded a higher percentage at 48.0% (n = 1,922). E. stipulatus emerged as the most abundant predator at 23.0% (n = 898), followed by P. persimilis with 16.0% (n = 639). Meanwhile, the population of Typlodromus sp. remained notably low at 13.0% (n = 498). Regarding the fluctuation of the different mites studied on the two cultivars across monitoring dates, the period from May 4 to June 1 was characterized by low temperatures and a diminished presence of mite populations (P. citri, E. stipulatus, Typhlodromus sp., and P. persimilis). However, from June 7 to June 19, characterized by high temperatures, a notable increase in the presence of mite populations was observed. As regards the effect of the variety on the different mites studied, the varietal impact was significant.
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Affiliation(s)
- Amine Assouguem
- Laboratory of Functional Ecology and Environment, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, Imouzzer Street, P.O. Box 2202, Fez, Morocco
- Department of Protection of Plants and Environment, National School of Agriculture, Meknes, Morocco
| | | | - Rachid Lahlali
- Department of Protection of Plants and Environment, National School of Agriculture, Meknes, Morocco
| | - Mohammed Kara
- Laboratory of Biotechnology, Conservation and Valorisation of Natural Resources (LBCVNR), Faculty of Sciences Dhar El Mehraz, Sidi Mohamed Ben Abdallah University, BP 1796 Atlas, Fez30000, Morocco
| | - Ahmed Bari
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Essam A. Ali
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Hafize Fidan
- Department of Tourism and Culinary Management, Faculty of Economics, University of Food Technologies, Plovdiv, Bulgaria
| | - Hajar Zine Laabidine
- Laboratory of Biotechnology, the Law, Philosophy and Society Laboratory (ESSOR), The Faculty of Law, Economic and Social Sciences, Sidi Mohamed Ben Abdallah University, BP 1796 Atlas, Fez30000, Morocco
| | - Younouss El Ouati
- Laboratory of Biotechnology, the Law, Philosophy and Society Laboratory (ESSOR), The Faculty of Law, Economic and Social Sciences, Sidi Mohamed Ben Abdallah University, BP 1796 Atlas, Fez30000, Morocco
| | - Abdellah Farah
- Laboratory of Applied Organic Chemistry, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, Imouzzer Street, FezP.O. Box 2202, Morocco
| | - Abderrahim Lazraq
- Laboratory of Functional Ecology and Environment, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, Imouzzer Street, P.O. Box 2202, Fez, Morocco
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Omondi S, Kosgei J, Musula G, Muchoki M, Abong'o B, Agumba S, Ogwang C, McDermott DP, Donnelly MJ, Staedke SG, Schultz J, Gutman JR, Gimnig JE, Ochomo E. Late morning biting behaviour of Anopheles funestus is a risk factor for transmission in schools in Siaya, western Kenya. Malar J 2023; 22:366. [PMID: 38037026 PMCID: PMC10691009 DOI: 10.1186/s12936-023-04806-w] [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: 10/06/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Children in Kenya spend a substantial amount of time at school, including at dawn and dusk when mosquitoes are active. With changing vector behaviour towards early morning biting, it is important to determine whether there is an additional risk of transmission in schools. This study sought to understand whether late morning biting by Anopheles funestus, previously documented in households in western Kenya, was replicated in schools. METHODS From the 4th to the 6th of August 2023, human landing collections were conducted hourly in four schools in Alego Usonga sub-County, Siaya County. The collections were conducted in and outside five classrooms in each school and ran for 17 h, starting at 18:00 until 11:00 h the next morning. RESULTS Anopheles funestus was the predominant species collected, forming 93.2% (N = 727) of the entire collection, with peak landing between 06:00 and 07:00 h and continuing until 11:00 h. More than half of the collected An. funestus were either fed or gravid, potentially indicative of multiple bloodmeals within each gonotrophic cycle, and had a sporozoite rate of 2.05%. CONCLUSION School children spend up to 10 h of their daytime in schools, reporting between 06:00 and 07:00 h and staying in school until as late as 17:00 h, meaning that they receive potentially infectious mosquito bites during the morning hours in these settings. There is a need to consider vector control approaches targeting schools and other peridomestic spaces in the morning hours when An. funestus is active.
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Affiliation(s)
- Seline Omondi
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Jackline Kosgei
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - George Musula
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Margaret Muchoki
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Bernard Abong'o
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Silas Agumba
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Caroline Ogwang
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya
| | - Daniel P McDermott
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Sarah G Staedke
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Jonathan Schultz
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Julie R Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - John E Gimnig
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, 30333, USA
| | - Eric Ochomo
- Entomology Section, Centre for Global Health Research, Kenya Medical Research Institute, P.O. Box 1578-40100, Kisumu, Kenya.
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3
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Mutinda J, Mwamburi SM, Oduor KO, Vincent Omolo M, Ntabo RM, Gathiru JM, Mwangangi J, Nonoh JOM. Profiles of bacterial communities and environmental factors associated with proliferation of malaria vector mosquitoes within the Kenyan Coast. Access Microbiol 2023; 5:acmi000606.v4. [PMID: 37691847 PMCID: PMC10484320 DOI: 10.1099/acmi.0.000606.v4] [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: 04/11/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
Background Since Anopheles mosquitoes which transmit and maintain the malaria parasite breed in the outdoor environment, there is an urgent need to manage these mosquito breeding sites. In order to elaborate more on the ecological landscape of mosquito breeding sites, the bacterial community structure and their interactions with physicochemical factors in mosquito larval habitats was characterised in Kwale County (Kenya), where malaria is endemic. Methods The physical characteristics and water physicochemical parameters of the habitats were determined and recorded. Water samples were also collected from the identified sites for total metagenomic DNA extraction in order to characterise the bacterial communities within the breeding sites. Results and Discussion Sites where mosquito larvae were found were described as positive and those without mosquito larvae as negative. Electrical conductivity, total dissolved solids, salinity and ammonia were lower in the rainy season than in the dry season, which also coincided with a high proportion of positive sites. Pseudomonadota was the most common phyla recovered in all samples followed by Bacteroidota and then Actinomycetota. The presence or absence of mosquito larvae in a potential proliferation site was not related to the bacterial community structure in the sampled sites, but was positively correlated with bacterial richness and evenness. Conclusion Generally, the presence of Anopheles mosquito larvae was found to be positively correlated with rainy season, bacterial richness and evenness, and negatively correlated with electrical conductivity, total dissolved solids, salinity and ammonia. The findings of this study have implications for predicting the potential of environmental water samples to become mosquito proliferation sites.
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Affiliation(s)
| | - Samuel Mwakisha Mwamburi
- Kenya Marine and Fisheries Research Institute, P.O Box 81651- 80100, English Point, Mkomani, Mombasa, Kenya
| | - Kennedy Omondi Oduor
- Kenya Marine and Fisheries Research Institute, P.O Box 81651- 80100, English Point, Mkomani, Mombasa, Kenya
| | - Maurice Vincent Omolo
- Masinde Muliro University of Science and Technology, Centre for African Medicinal and Nutritional Flora and Fauna (CAMNFF), P.O Box 190-50100, Kakamega, Kenya
| | | | | | - Joseph Mwangangi
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine Research - Coast, Kilifi P.O. Box 428, Kilifi – 80108, Kenya
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4
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Khan A, Bisanzio D, Mutuku F, Ndenga B, Grossi-Soyster EN, Jembe Z, Maina PW, Chebii PK, Ronga CO, Okuta V, LaBeaud AD. Spatiotemporal overlapping of dengue, chikungunya, and malaria infections in children in Kenya. BMC Infect Dis 2023; 23:183. [PMID: 36991340 PMCID: PMC10053720 DOI: 10.1186/s12879-023-08157-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
Malaria, chikungunya virus (CHIKV), and dengue virus (DENV) are endemic causes of fever among children in Kenya. The risks of infection are multifactorial and may be influenced by built and social environments. The high resolution overlapping of these diseases and factors affecting their spatial heterogeneity has not been investigated in Kenya. From 2014-2018, we prospectively followed a cohort of children from four communities in both coastal and western Kenya. Overall, 9.8% were CHIKV seropositive, 5.5% were DENV seropositive, and 39.1% were malaria positive (3521 children tested). The spatial analysis identified hot-spots for all three diseases in each site and in multiple years. The results of the model showed that the risk of exposure was linked to demographics with common factors for the three diseases including the presence of litter, crowded households, and higher wealth in these communities. These insights are of high importance to improve surveillance and targeted control of mosquito-borne diseases in Kenya.
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Affiliation(s)
- Aslam Khan
- Stanford University School of Medicine, Stanford, CA, USA.
- Center for Academic Medicine, 453 Quarry Road, Palo Alto, CA, 94304, USA.
| | | | | | | | | | - Zainab Jembe
- Msambweni County Referral hospital, Msambweni, Kenya
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Nyangau PN, Nzuma JM, Irungu P, Junglen S, Kassie M. Health education impact on knowledge and management of arboviral diseases in Kenya: Evidence from randomised control trials. Glob Public Health 2023; 18:2274436. [PMID: 37902054 DOI: 10.1080/17441692.2023.2274436] [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: 04/24/2023] [Accepted: 10/18/2023] [Indexed: 10/31/2023]
Abstract
Communities' knowledge and management strategies are crucial for mitigating and controlling the threat of existing and emerging diseases. In this study, we conducted randomised control trials (RCT) to examine the impact of health education on households' knowledge and management of three Arboviral Diseases (ADs); Rift Valley fever, Chikungunya fever, and Dengue fever in Kenya. The study was based on a sample of 629 households drawn from the three of Kenya's AD hotspot counties; Baringo, Kwale, and Kilifi. Employing a difference-in-difference method, our findings indicate that health education intervention significantly improved households' understanding of ADs transmission modes, causes, and prevention strategies. However, this intervention did not sufficiently influence households' disease management behaviour. We recommend the implementation of community engagement and outreach initiatives which have the potential to drive behavioural changes at the household level, thus enhancing the management and control of ADs in Kenya.
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Affiliation(s)
- Paul Nyamweya Nyangau
- Department of Agricultural Economics, Faculty of Agriculture, University of Nairobi, Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Jonathan Makau Nzuma
- Department of Agricultural Economics, Faculty of Agriculture, University of Nairobi, Nairobi, Kenya
| | - Patrick Irungu
- Department of Agricultural Economics, Faculty of Agriculture, University of Nairobi, Nairobi, Kenya
| | - Sandra Junglen
- Berlin Institute of Health, Institute of Virology, Charité - Universitätsmedizin Berlin, Corporate Member of Free University Berlin, Humboldt-University Berlin, Berlin, Germany
- German Centre for Infection Research (DZIF), Associated Partner Site Charité, Berlin, Germany
| | - Menale Kassie
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Masika MM, Korhonen EM, Smura T, Uusitalo R, Ogola J, Mwaengo D, Jääskeläinen AJ, Alburkat H, Gwon YD, Evander M, Anzala O, Vapalahti O, Huhtamo E. Serological Evidence of Exposure to Onyong-Nyong and Chikungunya Viruses in Febrile Patients of Rural Taita-Taveta County and Urban Kibera Informal Settlement in Nairobi, Kenya. Viruses 2022; 14:v14061286. [PMID: 35746757 PMCID: PMC9230508 DOI: 10.3390/v14061286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/28/2022] [Accepted: 06/08/2022] [Indexed: 02/01/2023] Open
Abstract
Several alphaviruses, such as chikungunya (CHIKV) and Onyong-nyong (ONNV), are endemic in Kenya and often cause outbreaks in different parts of the country. We assessed the seroprevalence of alphaviruses in patients with acute febrile illness in two geographically distant areas in Kenya with no previous record of alphavirus outbreaks. Blood samples were collected from febrile patients in health facilities located in the rural Taita-Taveta County in 2016 and urban Kibera informal settlement in Nairobi in 2017 and tested for CHIKV IgG and IgM antibodies using an in-house immunofluorescence assay (IFA) and a commercial ELISA test, respectively. A subset of CHIKV IgG or IgM antibody-positive samples were further analyzed using plaque reduction neutralization tests (PRNT) for CHIKV, ONNV, and Sindbis virus. Out of 537 patients, 4 (0.7%) and 28 (5.2%) had alphavirus IgM and IgG antibodies, respectively, confirmed on PRNT. We show evidence of previous and current exposure to alphaviruses based on serological testing in areas with no recorded history of outbreaks.
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Affiliation(s)
- Moses Muia Masika
- KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya; (J.O.); (O.A.)
- Department of Medical Microbiology, University of Nairobi, POB 19676, Nairobi 00202, Kenya;
- Correspondence: ; Tel.: +254-721770306
| | - Essi M. Korhonen
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland
| | - Teemu Smura
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- HUS Diagnostic Center, HUSLAB, Virology and Immunology, Helsinki University Hospital, 00029 Helsinki, Finland
| | - Ruut Uusitalo
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland
- Department of Geosciences and Geography, University of Helsinki, 00014 Helsinki, Finland
| | - Joseph Ogola
- KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya; (J.O.); (O.A.)
- Department of Medical Microbiology, University of Nairobi, POB 19676, Nairobi 00202, Kenya;
| | - Dufton Mwaengo
- Department of Medical Microbiology, University of Nairobi, POB 19676, Nairobi 00202, Kenya;
| | - Anne J. Jääskeläinen
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- HUS Diagnostic Center, HUSLAB, Virology and Immunology, Helsinki University Hospital, 00029 Helsinki, Finland
| | - Hussein Alburkat
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
| | - Yong-Dae Gwon
- Department of Clinical Microbiology, Umeå University, 90185 SE Umeå, Sweden; (Y.-D.G.); (M.E.)
| | - Magnus Evander
- Department of Clinical Microbiology, Umeå University, 90185 SE Umeå, Sweden; (Y.-D.G.); (M.E.)
| | - Omu Anzala
- KAVI Institute of Clinical Research, University of Nairobi, POB 19676, Nairobi 00202, Kenya; (J.O.); (O.A.)
- Department of Medical Microbiology, University of Nairobi, POB 19676, Nairobi 00202, Kenya;
| | - Olli Vapalahti
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland
- HUS Diagnostic Center, HUSLAB, Virology and Immunology, Helsinki University Hospital, 00029 Helsinki, Finland
| | - Eili Huhtamo
- Department of Virology, University of Helsinki, 00014 Helsinki, Finland; (E.M.K.); (T.S.); (R.U.); (A.J.J.); (H.A.); (O.V.); (E.H.)
- Department of Veterinary Biosciences, University of Helsinki, 00014 Helsinki, Finland
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Jared Owiti Y. Efficacy of a simply resting box baited with crude fruit and leaf ethanol extracts of Phytolaccadodecandra (L' Herit) in capturing and killing of indoor mosquitoes (Diptera: Culicidae) at Korando, Western Kenya. Saudi J Biol Sci 2021; 28:5221-5228. [PMID: 34466100 PMCID: PMC8380997 DOI: 10.1016/j.sjbs.2021.05.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 11/23/2022] Open
Abstract
Effective capture and elimination of indoor resting mosquito population is important in the fight against mosquito borne diseases. This study aimed at evaluating the efficacy of a simply resting box baited with crude fruit and leaf ethanol extracts of Phytolacca dodecandra in attracting and killing indoor mosquitoes at Korando, Western Kenya. The study was conducted in three phases: pre-intervention, intervention and post intervention. Simple resting boxes made from galvanized wire frame measuring 30 cm × 30 cm × 30 cm, covered in blue and black tunic in and out and lined with carton boards were used. The boxes were baited with socks with strong human odour and 80 ml/100mls (e/w) solution of either crude ethanol fruit or leaf extracts of P. dodecandra, ethanol leaf extracts of Azadiracta indica or Deltamethrin. Deltamethrin and Azadiracta indica were used as positive and water as negative control. The treatments were applied at the intervention phase only. The boxes were left overnight in the houses and mosquitoes collected by 6.30 h. It was observed that more Culicines than Anopheline were captured irrespective of phase or treatment used. Mosquito densities reduced with phase of activity. P. dodecandra leaf extracts killed more mosquitoes than fruit or A. indica leaf extracts though the number were less than that of Deltamethrin or WHO threshold of >80% mortality. In conclusion, the simple resting boxes were effective in collecting and killing indoor mosquitoes though lethality did not matched the WHO threshold. With improved structural set up and use of pure extracts of P. dodecandra, the resting boxes can serve as effective tools for capture, elimination and management of mosquito borne diseases.
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Affiliation(s)
- Yugi Jared Owiti
- School of Science and Technology, University of Kabianga, P. O. Box 20230-20300, Kericho, Kenya
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Ogega OM, Alobo M. Impact of 1.5 oC and 2 oC global warming scenarios on malaria transmission in East Africa. AAS Open Res 2021; 3:22. [PMID: 33842833 PMCID: PMC8008358 DOI: 10.12688/aasopenres.13074.3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 11/20/2022] Open
Abstract
Background: Malaria remains a global challenge with approximately 228 million cases and 405,000 malaria-related deaths reported in 2018 alone; 93% of which were in sub-Saharan Africa. Aware of the critical role than environmental factors play in malaria transmission, this study aimed at assessing the relationship between precipitation, temperature, and clinical malaria cases in East Africa and how the relationship may change under 1.5
oC and 2.0
oC global warming levels (hereinafter GWL1.5 and GWL2.0, respectively). Methods: A correlation analysis was done to establish the current relationship between annual precipitation, mean temperature, and clinical malaria cases. Differences between annual precipitation and mean temperature value projections for periods 2008-2037 and 2023-2052 (corresponding to GWL1.5 and GWL2.0, respectively), relative to the control period (1977-2005), were computed to determine how malaria transmission may change under the two global warming scenarios. Results: A predominantly positive/negative correlation between clinical malaria cases and temperature/precipitation was observed. Relative to the control period, no major significant changes in precipitation were shown in both warming scenarios. However, an increase in temperature of between 0.5
oC and 1.5
oC and 1.0
oC to 2.0
oC under GWL1.5 and GWL2.0, respectively, was recorded. Hence, more areas in East Africa are likely to be exposed to temperature thresholds favourable for increased malaria vector abundance and, hence, potentially intensify malaria transmission in the region. Conclusions: GWL1.5 and GWL2.0 scenarios are likely to intensify malaria transmission in East Africa. Ongoing interventions should, therefore, be intensified to sustain the gains made towards malaria elimination in East Africa in a warming climate.
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Affiliation(s)
- Obed Matundura Ogega
- Programmes, The African Academy of Sciences, Nairobi, Kenya.,School of Environmental Studies, Kenyatta University, Nairobi, Kenya
| | - Moses Alobo
- Programmes, The African Academy of Sciences, Nairobi, Kenya
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Ogega OM, Alobo M. Impact of 1.5 oC and 2 oC global warming scenarios on malaria transmission in East Africa. AAS Open Res 2021; 3:22. [PMID: 33842833 PMCID: PMC8008358 DOI: 10.12688/aasopenres.13074.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 12/23/2023] Open
Abstract
Background: Malaria remains a global challenge with approximately 228 million cases and 405,000 malaria-related deaths reported in 2018 alone; 93% of which were in sub-Saharan Africa. Aware of the critical role than environmental factors play in malaria transmission, this study aimed at assessing the relationship between precipitation, temperature, and clinical malaria cases in East Africa and how the relationship may change under 1.5 oC and 2.0 oC global warming levels (hereinafter GWL1.5 and GWL2.0, respectively). Methods: A correlation analysis was done to establish the current relationship between annual precipitation, mean temperature, and clinical malaria cases. Differences between annual precipitation and mean temperature value projections for periods 2008-2037 and 2023-2052 (corresponding to GWL1.5 and GWL2.0, respectively), relative to the control period (1977-2005), were computed to determine how malaria transmission may change under the two global warming scenarios. Results: A predominantly positive/negative correlation between clinical malaria cases and temperature/precipitation was observed. Relative to the control period, no major significant changes in precipitation were shown in both warming scenarios. However, an increase in temperature of between 0.5 oC and 1.5 oC and 1.0 oC to 2.0 oC under GWL1.5 and GWL2.0, respectively, was recorded. Hence, more areas in East Africa are likely to be exposed to temperature thresholds favourable for increased malaria vector abundance and, hence, potentially intensify malaria transmission in the region. Conclusions: GWL1.5 and GWL2.0 scenarios are likely to intensify malaria transmission in East Africa. Ongoing interventions should, therefore, be intensified to sustain the gains made towards malaria elimination in East Africa in a warming climate.
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Affiliation(s)
- Obed Matundura Ogega
- Programmes, The African Academy of Sciences, Nairobi, Kenya
- School of Environmental Studies, Kenyatta University, Nairobi, Kenya
| | - Moses Alobo
- Programmes, The African Academy of Sciences, Nairobi, Kenya
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10
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Karisa J, Muriu S, Omuoyo D, Karia B, Ngari M, Nyamwaya D, Rono M, Warimwe G, Mwangangi J, Mbogo CM. Urban Ecology of Arboviral Mosquito Vectors Along the Kenyan Coast. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:428-438. [PMID: 32623459 PMCID: PMC7613328 DOI: 10.1093/jme/tjaa136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Indexed: 05/04/2023]
Abstract
The purpose of this study was to determine the ecology of the common arboviral mosquito vectors in Mombasa, Kilifi and Malindi urban areas of coastal Kenya. Mosquito larvae were collected using standard dippers and pipettes. Egg survivorship in dry soil was evaluated by collecting soil samples from dry potential larval developmental sites, re-hydrating them for hatching and rearing of the eventual larvae to adults. Adult mosquitoes were collected with CDC light traps and BG-Sentinel traps. All blood-fed females were tested for bloodmeal origin. Mosquitoes were screened for arboviruses using RT-qPCR. Overall, the predominant species were Culex quinquefasciatus (Say) 72.4% (n = 2,364) and Aedes aegypti (L.), 25.7%, (n = 838). A total of 415 larval developmental sites were identified indoors (n = 317) and outdoors (n = 98). The most productive larval developmental sites, both indoors and outdoors, were assorted small containers, water tanks, drainages, drums, and jerricans. Overall, 62% (n = 18) of the soil samples collected were positive for larvae which were used as a proxy to measure the presence of eggs. The mosquitoes fed on humans (29.8%) and chickens (3.7%). Of 259 mosquitoes tested for viral infection, 11.6% were positive for Flavivirus only. The most productive larval developmental sites for arboviral vectors indoors were small containers, water tanks, jerricans, and drums whereas small containers, water tanks, drainage channels, buckets, tires, and water troughs were the productive larval developmental sites outdoors.
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Affiliation(s)
- Jonathan Karisa
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
- Bioscience Research Centre (PUBReC), Pwani University, Kilifi, Kenya
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Simon Muriu
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
- Bioscience Research Centre (PUBReC), Pwani University, Kilifi, Kenya
| | - Donwilliams Omuoyo
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Boniface Karia
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Moses Ngari
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Doris Nyamwaya
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Martin Rono
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
- Bioscience Research Centre (PUBReC), Pwani University, Kilifi, Kenya
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - George Warimwe
- Bioscience Research Centre (PUBReC), Pwani University, Kilifi, Kenya
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Joseph Mwangangi
- Department of Biological Sciences, Pwani University, Kilifi, Kenya
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
- Public Health Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
| | - Charles M Mbogo
- Center for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
- Public Health Department, KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
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Rodrigue Simonet PN, Alexandre Michel NN, Abel W, Albert E, Martin Hermann G, Franziska S. Diversity and Abundance of Potential Vectors of Rift Valley Fever Virus in the North Region of Cameroon. INSECTS 2020; 11:insects11110814. [PMID: 33227891 PMCID: PMC7699143 DOI: 10.3390/insects11110814] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 11/16/2022]
Abstract
Simple Summary Rift Valley fever (RVF) is a mosquito-borne disease caused by the Rift Valley fever virus (RVFV) transmitted by various genera of mosquitoes usually classified into primary vectors and secondary vectors. The former, belonging to the genus Aedes, are known for their ability to lay drought resistant eggs that can maintain the virus on dry soil for many years in geomorphic structures in the form of shallow depressions. After heavy rains, mosquitoes hatch from these eggs, some of which are infected and transmit the virus to neighboring animals. The secondary vectors, mainly mosquitoes of the genera Culex, Anopheles, and Mansonia, can colonize these sites, reproduce in abundance, and subsequently spread RVFV. Although the northern regions of Cameroon host more than half of the country’s cattle, sheep, and goat populations, there is a dearth of information on the occurrence and transmission of RVFV and its vectors. The very common transhumance of animals during periods of drought leads to contact between domestic and wild animals and creates opportunities for cross-transmission of the virus. It also increases the possibilities of exposure of herds to vectors, in particular at water points. In addition, rare heavy rainfall, flooding, and irrigation-based agricultural practices in these regions provide conditions for vector proliferation and increase the risk of the spread of vector-borne diseases, including RVF. Therefore, this study aimed to determine species diversity and spatial distribution of potential RVFV vectors in the North Region of Cameroon. The study revealed the presence of potential primary and secondary vectors of RVFV with an abundance and a diversity varying according to the ecological sites studied. This presence of potential vectors with their variable number per trap, per night, or per site may create areas of variable risk for disease transmission to susceptible hosts. Molecular analysis (PCR) tests for RVFV RNA research and viral isolation methods on these vectors to determine their role in the epidemiology and control of RVF cannot be overemphasized. Abstract Rift Valley fever (RVF) is a major viral zoonosis transmitted by mosquitoes. The virus is endemic in most parts of sub-Saharan Africa and can affect humans, livestock, and wild ungulates. Knowledge of the biology of vectors of Rift Valley fever virus (RVFV) is essential for the establishment of effective control measures of the disease. The objective of this study was to determine the species diversity and relative abundance of potential RVFV vectors in the North Region of Cameroon. Adult mosquitoes were trapped during the wet and dry seasons from December 2017 to January 2019 with “EVS Light” traps with CO2 baits placed at selected sites. The captured mosquitoes were identified using dichotomous keys according to standard procedures. The abundance was calculated with regard to site, zone, and collection season. A total of 27,851 mosquitoes belonging to four genera (Aedes, Anopheles, Mansonia, and Culex) and comprising 31 species were caught (including 22 secondary vectors (98.05%) and nine primary vectors (1.94%). The total number of mosquitoes varied significantly depending on the locality (p-value < 0.001). The average number of mosquitoes collected per trap night was significantly higher in irrigated areas (p-value < 0.001), compared to urban and non-irrigated areas. The study revealed the presence of potential primary and secondary vectors of RVFV with varying abundance and diversity according to locality and ecological site in the North Region of Cameroon. The results showed that the genus Mansonia with the species Ma. uniformis and Ma. africana formed the dominant taxon (52.33%), followed by the genera Culex (45.04%) and Anopheles (2.61%). The need for molecular analysis (PCR) tests for RVFV RNA research and viral isolation methods on these vectors to determine their role in the epidemiology and control of RVF cannot be overemphasized.
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Affiliation(s)
- Poueme Namegni Rodrigue Simonet
- National Veterinary Laboratory Cameroon (LANAVET), Garoua BP 503, Cameroon;
- Department of Biological Sciences, The University of Ngaoundere, Ngaoundere BP 454, Cameroon;
- Correspondence:
| | | | - Wade Abel
- National Veterinary Laboratory Cameroon (LANAVET), Garoua BP 503, Cameroon;
| | - Eisenbarth Albert
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (E.A.); (G.M.H.); (S.F.)
| | - Groschup Martin Hermann
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (E.A.); (G.M.H.); (S.F.)
| | - Stoek Franziska
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, 17493 Greifswald, Insel Riems, Germany; (E.A.); (G.M.H.); (S.F.)
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Parvin N, Mandal TK, Nagajyothi PC, Reddy PM, Reddy NR, Joo SW. Highly Fluorescent Doped Fe3O4@C Nanoparticles Cross the Blood–Brain Barrier: Help in Brain Imaging and Blocking the Life Cycle of Mosquitoes. J CLUST SCI 2020. [DOI: 10.1007/s10876-020-01938-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Munyao V, Karisa J, Munyao CM, Ngari M, Menza N, Peshu N, Rono M, Mbogo C, Mwangangi J. Surveillance of Culicine Mosquitoes in Six Villages of Taita-Taveta County, Kenya, With Host Determinations From Blood-Fed Females. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1972-1982. [PMID: 32533693 PMCID: PMC7613318 DOI: 10.1093/jme/tjaa109] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Indexed: 06/11/2023]
Abstract
Culicine mosquitoes are vectors of human disease-causing pathogens like filarial worms and several arthropod-borne viruses (arboviruses). Currently, there has been an increase in emerging and re-emerging vector-borne diseases along coastal Kenya, which has been of major concern in public health. This study aimed at determining culicine mosquito species abundance, diversity and their host feeding preferences in Taita-Taveta County, Coastal Kenya. Entomological sampling was done during the long-wet season (March and May) and long dry season (June to October) 2016-2018. Mosquito sampling was done using CDC light traps and Backpack aspiration for indoor and outdoor environments. All culicine mosquitoes collected were identified morphologically and categorized according to their physiological status. Blood fed culicine mosquitoes were tested for bloodmeal sources using ELISA. In total, 3,278 culicine mosquitoes were collected, of which 738 (22.5 %) were found indoors and 2,540, (77.5 %) outdoors. The mosquitoes consisted of 18 species belonging to four genera: Aedes (7), Culex (8), Mansonia (2), and Coquillettidia (1). Overall, there was high mosquito species diversity (H) in outdoors (H = 2.4339) than in indoors (H = 2.2523), whereas even distribution (EH) was higher in indoors (EH = 0.9064) than outdoors (EH = 0.8266). Majorly the bloodmeals identified were from multiple host sources with (51.6%), single hosts (41.3%), and unidentified (7.2%). This study has demonstrated a high diversity of culicine mosquitoes with relaxed feeding tendencies. These mosquitoes are contributing to mosquito biting nuisance and the likelihood of exposure of populations to diseases of public health.
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Affiliation(s)
- Vanessa Munyao
- Department of Medical Laboratory Sciences, Kenyatta University, Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
| | - Jonathan Karisa
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
- Pwani University Bioscience Research Centre (PUBreC), Kilifi, Kenya
| | | | - Moses Ngari
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
| | - Nelson Menza
- Department of Medical Laboratory Sciences, Kenyatta University, Nairobi, Kenya
| | - Norbert Peshu
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
| | - Martin Rono
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
- Pwani University Bioscience Research Centre (PUBreC), Kilifi, Kenya
| | - Charles Mbogo
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
| | - Joseph Mwangangi
- Kenya Medical Research Institute (KEMRI), Center for Geographic Medicine Coast, Kilifi, Kenya
- Pwani University Bioscience Research Centre (PUBreC), Kilifi, Kenya
- KEMRI, Center for Vector Disease Control, Kwale, Kenya
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Ogega OM, Alobo M. Impact of 1.5 oC and 2 oC global warming scenarios on malaria transmission in East Africa. AAS Open Res 2020; 3:22. [DOI: 10.12688/aasopenres.13074.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2020] [Indexed: 11/20/2022] Open
Abstract
Background: Malaria remains a global challenge with approximately 228 million cases and 405,000 malaria-related deaths reported in 2018 alone; 93% of which were in sub-Saharan Africa. Aware of the critical role than environmental factors play in malaria transmission, this study aimed at assessing the relationship between precipitation, temperature, and clinical malaria cases in E. Africa and how the relationship may change under 1.5 oC and 2.0 oC global warming levels (hereinafter GWL1.5 and GWL2.0, respectively). Methods: A correlation analysis was done to establish the current relationship between annual precipitation, mean temperature, and clinical malaria cases. Differences between annual precipitation and mean temperature value projections for periods 2008-2037 and 2023-2052 (corresponding to GWL1.5 and GWL2.0, respectively), relative to the control period (1977-2005), were computed to determine how malaria transmission may change under the two global warming scenarios. Results: A predominantly positive/negative correlation between clinical malaria cases and temperature/precipitation was observed. Relative to the control period, no major significant changes in precipitation were shown in both warming scenarios. However, an increase in temperature of between 0.5 oC and 1.5 oC and 1.0 oC to 2.0 oC under GWL1.5 and GWL2.0, respectively, was recorded. Hence, more areas in E. Africa are likely to be exposed to temperature thresholds favourable for increased malaria vector abundance and, hence, potentially intensify malaria transmission in the region. Conclusions: GWL1.5 and GWL2.0 scenarios are likely to intensify malaria transmission in E. Africa. Ongoing interventions should, therefore, be intensified to sustain the gains made towards malaria elimination in E. Africa in a warming climate.
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