A Seroepidemiological Survey of Hantavirus in Ilheus County

Hantaviral diseases are infections caused by a group of viruses that belong to the genus hantavirus and the family Bunyaviridae. In Brazil, several cases of hantavirus have been detected with the use of serological methods including immunofluorescence and Enzyme-Linked Immunosorbent Assay (ELISA). To date, 1.573 cases have been reported in several states across the country with a fatality rate of 41%. No seroepidemiologic study has ever been conducted in the city of, or region surrounding, Ilheus, where large remnants of the Atlantic Forest provide shelter for a variety of rodents. The authors used the N recombinant protein of Araraquara virus as antigen to test for the presence of hantavirus-specific IgG antibodies by ELISA in samples provided by blood donors in the city of Ilheus, State of Bahia. The authors collected blood samples from 500 donors. Among these, 93.6% of the donors came from an urban area and 6.4% were from a rural area. A total of 0.6% of the donors was seropositive for anti-hantavirus IgG antibodies. This positivity was detected only in males at a rate of 1.1%. However, there was no observed association for hantavirus seropositivity between the genders (p = 0.252). There was a higher frequency of seropositive individuals aged between 31 and 40 years (1.6%), although the difference observed was not statistically significant (p = 0.41). There was also a higher rate of seropositive individuals among donors from rural areas (6.6%); the association for seropositivity between participants in rural and urban areas was statistically significant (p = 0.011) by Fisher’s exact test (p<0.05). The present study describes Araraquara virus circulation in this region for the first time. The results of this study provide the basis for future investigation of the hantaviruses that are associated with cardiopulmonary syndrome and the other antigenic ally related hantaviruses in this region.