Journal Article

Serological and spatial analysis of alphavirus and flavivirus prevalence and risk factors in a rural community in western Kenya

Krystosik, Amy R., Fèvre, Eric M., Lee, Justin, Wamae, C. Njeri, Cook, Elizabeth A. J., de Glanville, William A., LaBeaud, A. Desiree, Thomas, Lian F., Grossi-Soyster, Elysse N., Kariuki, Samuel

2017

Overview

Alphaviruses, such as chikungunya virus, and flaviviruses, such as dengue virus, are (re)-emerging arboviruses that are endemic in tropical environments. In Africa, arbovirus infections are often undiagnosed and unreported, with febrile illnesses often assumed to be malaria. This cross-sectional study aimed to characterize the seroprevalence of alphaviruses and flaviviruses among children (ages 5-14, n = 250) and adults (ages 15 ≥ 75, n = 250) in western Kenya. Risk factors for seropositivity were explored using Lasso regression. Overall, 67% of participants showed alphavirus seropositivity (CI95 63%-70%), and 1.6% of participants showed flavivirus seropositivity (CI95 0.7%-3%). Children aged 10-14 were more likely to be seropositive to an alphavirus than adults (p < 0.001), suggesting a recent transmission period. Alphavirus and flavivirus seropositivity was detected in the youngest participants (age 5-9), providing evidence of inter-epidemic transmission. Demographic variables that were significantly different amongst those with previous infection versus those without infection included age, education level, and occupation. Behavioral and environmental variables significantly different amongst those in with previous infection to those without infection included taking animals for grazing, fishing, and recent village flooding. Experience of recent fever was also found to be a significant indicator of infection (p = 0.027). These results confirm alphavirus and flavivirus exposure in western Kenya, while illustrating significantly higher alphavirus transmission compared to previous studies.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Adult / Adults / Aedes albopictus / Age / Aged / Aged, 80 and over / Alphavirus - classification / Alphavirus Infections - epidemiology / Alphavirus Infections - virology / Analysis / Antibodies, Viral - blood / Arboviruses / Biology and life sciences / Causes of / Chikungunya virus / Child / Child, Preschool / Children / Culicidae / Demographic variables / Demographics / Dengue / Dengue fever / Disease transmission / Distribution / Earth Sciences / Epidemics / Female / Fever / Fishing / Flavivirus - classification / Flavivirus Infections - epidemiology / Flavivirus Infections - virology / Flooding / Human diseases / Humans / Illnesses / Infections / Kenya - epidemiology / Laboratories / Malaria / Male / Medicine and Health Sciences / Middle Aged / Mosquitoes / People and Places / Prevalence studies (Epidemiology) / Regression analysis / Risk analysis / Risk Factors / Rural areas / Rural communities / Rural Population / Serologic Tests / Serology / Spatial analysis / Transmission / Tropical climate / Tropical diseases / Tropical environment / Tropical environments / Vector-borne diseases / Viral diseases / Viruses / Young Adult / Zoonoses