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Iguape: a newly recognized flavivirus from São Paulo State, Brazil
T L Coimbra1, E S Nassar, A H Nagamori
1Seção de Vírus Transmitidos por Artrópodos, Instituto Adolfo Lutz, São Paulo, Brasil.
Abstract:
A new virus, SP An 71686, was isolated from sentinel mice exposed in a forest area in Iguape county, São Paulo state, Brazil, in 1979. The results suggest [hemagglutination inhibition (HI), complement fixation, neutralization, and ELISA] that SP An 71686 virus is a new arbovirus and that it demonstrates some cross-reactivity with other members of the family Flaviviridae, but can be differentiated from them. Although there is an intensive circulation of several arboviruses in the area, the only diagnosed cases of human disease were caused by Rocio virus during and after the epidemic of encephalitis that occurred in 1975-1977, one case of febrile illness by Caraparu virus in 1983, and by subtype IF of Venezuelan equine encephalitis virus in soldiers during jungle survival training in 1990. Wild animals had a prevalence of SP An 71686 HI monotype antibodies: 46% of birds captured in 1990, 40% in 1991 and 19.5% in 1992. These results suggested that wild birds may play a role in the virus transmission cycle. Mammals (rodents and marsupials) must also be considered potential hosts. However, the virus reservoir-vector relationships need further studies which would help to clarify the ecology of this virus.
Insights
A novel arbovirus, SP An 71686, was identified in Brazil. Wild birds show high antibody prevalence, suggesting their role in the SP An 71686 virus transmission cycle.
Area of Science:
- Arbovirology
- Virology
- Epidemiology
Background:
- The SP An 71686 virus was first isolated in sentinel mice in Brazil in 1979.
- Arboviruses circulate widely in the region, but human cases are rare and linked to specific viruses like Rocio virus and Venezuelan equine encephalitis virus.
Purpose of the Study:
- To characterize the newly isolated SP An 71686 virus.
- To investigate the potential role of wild animals in the SP An 71686 virus transmission cycle.
Main Methods:
- Virus isolation from sentinel mice.
- Serological assays including hemagglutination inhibition (HI), complement fixation, neutralization, and ELISA.
- Prevalence studies of SP An 71686 antibodies in wild birds and mammals.
Main Results:
- SP An 71686 was confirmed as a new arbovirus within the Flaviviridae family, showing some cross-reactivity but distinct from other members.
- Significant prevalence of SP An 71686 HI antibodies was found in wild birds: 46% in 1990, 40% in 1991, and 19.5% in 1992.
- Mammals like rodents and marsupials are also considered potential hosts.
Conclusions:
- SP An 71686 represents a novel arbovirus in Brazil.
- Wild birds are likely involved in the SP An 71686 virus transmission cycle.
- Further research is needed to elucidate the reservoir-vector relationships and ecology of SP An 71686 virus.