Clinical and ecoepidemiological situation of human arboviruses in Brazilian Amazonia

RESUMO

The main aspects of clinic manifestations and epidemiological data about human arboviruses in the Brazilian Amazonian region is reviewed. Thirty four types of arboviruses from 183 types isolated in the Amazonia have been associated with human diseases. Four of them are important in public health and are involved with epidemics; they are namely, Dengue (DEN), Mayaro (MAY), Oropouche (ORO) and Yellow Fever (YF) viruses. ORO and DEN are associated with human epidemic diseases in urban areas while MAY and YF in rural areas. Basically, ORO causes a febrile disease, sometimes accompanied with aseptic meningitis. MAY and DEN are associated with rash febrile disease, while YF determines hemorrhagic fever. Thirty other arboviruses are involved with febrile illnesses in a few and sporadic cases. All arboviruses (apart from DEN) are maintained within a sylvatic cycle in the forest, where several species of hemathophagous insects act as vectors and wild vertebrates are involved as hosts. DEN has a cycle where the Aedes aegypti mosquito is the vector and man is the host. With the exception of the four viruses associated with epidemics which determine great economical and social impacts, including death (as in the case of YF), the real involvement of these viruses as systematic agents of human disease is unknown. Further studies are needed to clarify unclear aspects of the epidemiological cycles of these viruses.