Dataset Information

High rates of o'nyong nyong and Chikungunya virus transmission in coastal Kenya.

ABSTRACT:

Background

Chikungunya virus (CHIKV) and o'nyong nyong virus (ONNV) are mosquito-borne alphaviruses endemic in East Africa that cause acute febrile illness and arthritis. The objectives of this study were to measure the seroprevalence of CHIKV and ONNV in coastal Kenya and link it to demographics and other risk factors.

Methodology

Demographic and exposure questionnaires were administered to 1,848 participants recruited from two village clusters (Milalani-Nganja and Vuga) in 2009. Sera were tested for alphavirus exposure using standardized CHIKV IgG ELISA protocols and confirmed with plaque reduction neutralization tests (PRNT). Logistic regression models were used to determine the variables associated with seropositivity. Weighted K test for global clustering of houses with alphavirus positive participants was performed for distance ranges of 50-1,000 meters, and G* statistic and kernel density mapping were used to identify locations of higher seroprevalence.

Principal findings

486 (26%) participants were seropositive by IgG ELISA. Of 443 PRNT confirmed positives, 25 samples (6%) were CHIKV+, 250 samples (56%) were ONNV+, and 168 samples (38%) had high titers for both. Age was significantly associated with seropositivity (OR 1.01 per year, 95% C.I. 1.00-1.01); however, younger adults were more likely to be seropositive than older adults. Males were less likely to be seropositive (p<0.05; OR 0.79, 95% C.I. 0.64-0.97). Adults who owned a bicycle (p<0.05; OR 1.37, 95% C.I. 1.00-1.85) or motor vehicle (p<0.05; OR 4.64, 95% C.I. 1.19-18.05) were more likely to be seropositive. Spatial analysis demonstrated hotspots of transmission within each village and clustering among local households in Milalani-Nganja, peaking at the 200-500m range.

Conclusions/significance

Alphavirus exposure, particularly ONNV exposure, is common in coastal Kenya with ongoing interepidemic transmission of both ONNV and CHIKV. Women and adults were more likely to be seropositive. Household location may be a defining factor for the ecology of alphaviral transmission in this region.

SUBMITTER: LaBeaud AD

PROVIDER: S-EPMC4319898 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature

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Publications

High rates of o'nyong nyong and Chikungunya virus transmission in coastal Kenya.

LaBeaud A Desiree AD Banda Tamara T Brichard Julie J Muchiri Eric M EM Mungai Peter L PL Mutuku Francis M FM Borland Erin E Gildengorin Ginny G Pfeil Sarah S Teng Crystal Y CY Long Kristin K Heise Mark M Powers Ann M AM Kitron Uriel U King Charles H CH

PLoS neglected tropical diseases 20150206 2

<h4>Background</h4>Chikungunya virus (CHIKV) and o'nyong nyong virus (ONNV) are mosquito-borne alphaviruses endemic in East Africa that cause acute febrile illness and arthritis. The objectives of this study were to measure the seroprevalence of CHIKV and ONNV in coastal Kenya and link it to demographics and other risk factors.<h4>Methodology</h4>Demographic and exposure questionnaires were administered to 1,848 participants recruited from two village clusters (Milalani-Nganja and Vuga) in 2009. ...[more]

PMID: 25658762

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Dataset Information

High rates of o'nyong nyong and Chikungunya virus transmission in coastal Kenya.

Background

Methodology

Principal findings

Conclusions/significance

Publications

High rates of o'nyong nyong and Chikungunya virus transmission in coastal Kenya.

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