Alphaviruses in Northeastern Peru

Kanya Long (Biology)

Spatial risk of exposure to alphaviruses in northeastern Peru

Serological surveys of people living in urban and rural areas of northeastern Peru were conducted in 2008 for an assessment of human exposure to alphaviruses, and all sera were tested for the presence of neutralizing antibody to both Mayaro (MAYV) and Venezuelan equine encephalitis (VEEV) viruses. While prior MAYV exposure was associated strongly with rural residence, participants showed only a slight increase in risk for infection with VEEV along an urban to rural gradient.  Further, there is evidence that circulation of these viruses may be competitively excluded from one another in these rural study sites. Because both viruses are mosquito-borne, this pattern is likely mediated by ecological habitat that favors the distinct mosquito vectors (Culex melanaconion species have been implicated as the vector for VEEV; MAYV vectors in the region are undetermined).  The hypothesis of the proposed research is that circulation of MAYV and VEEV is highly focal and associated with remotely definable ecological habitats. In Aim 1, I will analyze risk of infection at the household, sector and village levels, and in Aim 2, I will explore the association of landscape ecology variables with infection risk. Despite their medical importance and expected wide distribution across the Amazon Basin, limiting habitat for these viruses has not been examined rigorously. Results of these analyses will identify rural clinics most likely to be impacted by these infections, refine targets for entomologic survey, and provide a baseline risk map for use in a region of rapid ecologic change.