Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017
Abstract Background Yellow fever, Dengue, West Nile and Zika viruses are re-emerging mosquito-borne Flaviviruses of public health concern. However, the extent of human exposure to these viruses and associated disease burden in Kenya and Africa at large remains unknown. We assessed the seroprevalence...
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| Format: | Article |
| Language: | English |
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BMC
2019-05-01
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| Series: | Virology Journal |
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| Online Access: | http://link.springer.com/article/10.1186/s12985-019-1176-y |
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| author | E. Chepkorir D. P. Tchouassi S. L. Konongoi J. Lutomiah C. Tigoi Z. Irura F. Eyase M. Venter R. Sang |
| author_facet | E. Chepkorir D. P. Tchouassi S. L. Konongoi J. Lutomiah C. Tigoi Z. Irura F. Eyase M. Venter R. Sang |
| author_sort | E. Chepkorir |
| collection | DOAJ |
| description | Abstract Background Yellow fever, Dengue, West Nile and Zika viruses are re-emerging mosquito-borne Flaviviruses of public health concern. However, the extent of human exposure to these viruses and associated disease burden in Kenya and Africa at large remains unknown. We assessed the seroprevalence of Yellow fever and other Flaviviruses in human populations in West Pokot and Turkana Counties of Kenya. These areas border Uganda, South Sudan and Ethiopia where recent outbreaks of Yellow fever and Dengue have been reported, with possibility of spillover to Kenya. Methodology Human serum samples collected through a cross-sectional survey in West Pokot and Turkana Counties were screened for neutralizing antibodies to Yellow fever, Dengue-2, West Nile and Zika virus using the Plaque Reduction Neutralization Test (PRNT). Seroprevalence was compared by county, site and important human demographic characteristics. Adjusted odds ratios (aOR) were estimated using Firth logistic regression model. Results Of 877 samples tested, 127 neutralized with at least one of the four flaviviruses (14.5, 95% CI 12.3–17.0%), with a higher proportion in Turkana (21.1%, n = 87/413) than in West Pokot (8.6%, n = 40/464). Zika virus seroprevalence was significantly higher in West Pokot (7.11%) than in Turkana County (0.24%; χ2 P < 0.0001). A significantly higher Yellow fever virus seroprevalence was also observed in Turkana (10.7%) compared to West Pokot (1.29%; χ2 P < 0.0001). A high prevalence of West Nile virus was detected in Turkana County only (10.2%) while Dengue was only detected in one sample, from West Pokot. The odds of infection with West Nile virus was significantly higher in males than in females (aOR = 2.55, 95% CI 1.22–5.34). Similarly, the risk of Zika virus infection in West Pokot was twice higher in males than females (aOR = 2.01, 95% CI 0.91–4.41). Conclusion Evidence of neutralizing antibodies to West Nile and Zika viruses indicates that they have been circulating undetected in human populations in these areas. While the observed Yellow Fever prevalence in Turkana and West Pokot Counties may imply virus activity, we speculate that this could also be as a result of vaccination following the Yellow Fever outbreak in the Omo river valley, South Sudan and Uganda across the border. |
| first_indexed | 2024-12-14T04:21:46Z |
| format | Article |
| id | doaj.art-b315f57edc3b4c559af19a8eb8efc746 |
| institution | Directory Open Access Journal |
| issn | 1743-422X |
| language | English |
| last_indexed | 2024-12-14T04:21:46Z |
| publishDate | 2019-05-01 |
| publisher | BMC |
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| series | Virology Journal |
| spelling | doaj.art-b315f57edc3b4c559af19a8eb8efc7462022-12-21T23:17:20ZengBMCVirology Journal1743-422X2019-05-0116111010.1186/s12985-019-1176-ySerological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017E. Chepkorir0D. P. Tchouassi1S. L. Konongoi2J. Lutomiah3C. Tigoi4Z. Irura5F. Eyase6M. Venter7R. Sang8International Centre of Insect Physiology and EcologyInternational Centre of Insect Physiology and EcologyCenter for Virus Research, Kenya Medical Research InstituteCenter for Virus Research, Kenya Medical Research InstituteInternational Centre of Insect Physiology and EcologyDivision of Disease Surveillance and Response, Ministry of HealthJomo Kenyatta University of Agriculture and TechnologyCenter for Viral Zoonoses, Department of Medical Virology, University of PretoriaInternational Centre of Insect Physiology and EcologyAbstract Background Yellow fever, Dengue, West Nile and Zika viruses are re-emerging mosquito-borne Flaviviruses of public health concern. However, the extent of human exposure to these viruses and associated disease burden in Kenya and Africa at large remains unknown. We assessed the seroprevalence of Yellow fever and other Flaviviruses in human populations in West Pokot and Turkana Counties of Kenya. These areas border Uganda, South Sudan and Ethiopia where recent outbreaks of Yellow fever and Dengue have been reported, with possibility of spillover to Kenya. Methodology Human serum samples collected through a cross-sectional survey in West Pokot and Turkana Counties were screened for neutralizing antibodies to Yellow fever, Dengue-2, West Nile and Zika virus using the Plaque Reduction Neutralization Test (PRNT). Seroprevalence was compared by county, site and important human demographic characteristics. Adjusted odds ratios (aOR) were estimated using Firth logistic regression model. Results Of 877 samples tested, 127 neutralized with at least one of the four flaviviruses (14.5, 95% CI 12.3–17.0%), with a higher proportion in Turkana (21.1%, n = 87/413) than in West Pokot (8.6%, n = 40/464). Zika virus seroprevalence was significantly higher in West Pokot (7.11%) than in Turkana County (0.24%; χ2 P < 0.0001). A significantly higher Yellow fever virus seroprevalence was also observed in Turkana (10.7%) compared to West Pokot (1.29%; χ2 P < 0.0001). A high prevalence of West Nile virus was detected in Turkana County only (10.2%) while Dengue was only detected in one sample, from West Pokot. The odds of infection with West Nile virus was significantly higher in males than in females (aOR = 2.55, 95% CI 1.22–5.34). Similarly, the risk of Zika virus infection in West Pokot was twice higher in males than females (aOR = 2.01, 95% CI 0.91–4.41). Conclusion Evidence of neutralizing antibodies to West Nile and Zika viruses indicates that they have been circulating undetected in human populations in these areas. While the observed Yellow Fever prevalence in Turkana and West Pokot Counties may imply virus activity, we speculate that this could also be as a result of vaccination following the Yellow Fever outbreak in the Omo river valley, South Sudan and Uganda across the border.http://link.springer.com/article/10.1186/s12985-019-1176-yDengue virusYellow fever virusWest Nile virusZika virusSeroprevalencePlaque reduction neutralization test |
| spellingShingle | E. Chepkorir D. P. Tchouassi S. L. Konongoi J. Lutomiah C. Tigoi Z. Irura F. Eyase M. Venter R. Sang Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 Virology Journal Dengue virus Yellow fever virus West Nile virus Zika virus Seroprevalence Plaque reduction neutralization test |
| title | Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 |
| title_full | Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 |
| title_fullStr | Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 |
| title_full_unstemmed | Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 |
| title_short | Serological evidence of Flavivirus circulation in human populations in Northern Kenya: an assessment of disease risk 2016–2017 |
| title_sort | serological evidence of flavivirus circulation in human populations in northern kenya an assessment of disease risk 2016 2017 |
| topic | Dengue virus Yellow fever virus West Nile virus Zika virus Seroprevalence Plaque reduction neutralization test |
| url | http://link.springer.com/article/10.1186/s12985-019-1176-y |
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