Zika virus epidemiology in Bolivia: A seroprevalence study in volunteer blood donors

Zika virus (ZIKV) is a virus of African origin, transmitted by Aedes mosquitoes, and related to dengue and yellow fever virus. It was originally believed to be responsible for a mild febrile illness in Africa and South-east Asia. However, in recent years, ZIKV has been responsible for outbreaks in the Pacific Islands before massively spreading in Latin America and the Caribbean. On this occasion, ZIKV has unexpectedly been associated with non-vector transmission (i.e., sexual and mother-to-foetus transmission) and with severe complications such as foetal abnormalities (e.g. microcephaly) and Guillain-Barré syndromes. Little is known about the actual proportion of the populations infected by ZIKV in Latin America. Here, we report a seroprevalence data in this region, after studying 814 asymptomatic Bolivian volunteer blood donors residing in various eco-environments corresponding to contrasting entomological activities. We conclude that ZIKV has been circulating in Bolivian tropical areas but not in highlands, and that the epidemic has not been limited by previous immunity against dengue. Specific attention should be paid to the region of Santa Cruz, where the seroprevalence is still limited, but the density of Aedes aegypti populations makes plausible further spreading of the disease.
http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0006239