Serosurvey of hantavirus infection in humans in the border region between Brazil and Argentina

Abstract

Introduction: According to reports by the Ministry of Health, in the far western region of the State of Santa Catarina, there have been no reports of hantavirus pulmonary syndrome, a zoonotic disease transmitted by feces of infected rodents. A seroepidemiological study of residents of this region, was conducted, with the aim of determining the presence of hantavirus infections. A total of 340 volunteers of both genus, from the towns of Belmonte and Paraíso, were studied. Methods: The serum of these patients was collected and used to detect IgG antibodies against recombinant N protein of Araraquara hantavirus, by ELISA assay. The positive samples were then titrated and confirmed by immunofluorescence assay. Results: This study demonstrated the presence of IgG antibodies against hantavirus N protein in 3.5% of the population. The most frequent occupation was farm worker, 81% had direct and indirect contact with rodents, 91.7% of positive cases were farm workers, indicating that the probable cause of infection occurred during barn cleaning. These antibodies are noteworthy, given that the levels of antibodies were verified in individuals whose contact with hantavirus may have occurred many years ago. Conclusions: This study shows the circulation of hantavirus in the region, a fact that until now, had not reported. All the serum reagents had contact with the pathogen, but did not develop pulmonary and cardiovascular syndrome. It is important to remain alert, because hantavirus is a serious and emerging disease of some relevance. Keywords: Hantavirus. Seroprevalence in Santa Catarina. Morbidity. RESUMO Introdução:De acordo com relatórios do Ministério da Saúde, na região do extremo oeste do Estado de Santa Catarina, não há relatos de síndrome pulmonar por hantavírus, doença zoonótica transmitida por excretas de roedores contaminados. Com a finalidade de demosntrar a infecção por hantavírus, um estudo soroepidemiológico de moradores da região foi realizado. Assim, foi estudado um total de 340 voluntários de ambos os gêneros, dos municípios de Belmonte e Paraíso. Métodos: O soro destes pacientes foi coletado e usado para a detecção de anticorpos IgG contra a proteína N recombinante de hantavírus Araraquara, pelo teste de ELISA. As amostras positivas foram tituladas e confirmadas por imunofluorescência indireta. Resultados: Este estudo demonstrou a presença de anticorpos IgG contra a proteína N hantavírus em 3,5% da população. A ocupação de lavrador foi a mais frequente, e 81% tiveram contato direto e indireto com os roedores, 91,7% dos casos positivos foram os agricultores, a causa provável da infecção foi através da limpeza de celeiros. Estes anticorpos são notáveis, dado que os níveis de anticorpos são encontrados nos indivíduos cujo contato com o hantavírus pode ter ocorrido há muitos anos. Conclusões: Este estudo mostra a circulação de hantavírus na região, um fato que até então não havia relatado, todos os reagentes soro tiveram contato com o patógeno, mas não desenvolveram a síndrome pulmonar e cardiovascu...

Antibody levels to hantavirus in inhabitants of western Santa Catarina State, Brazil

“…These antibody levels are similar to those reported in other South American studies using IgG-ELISA where seropositivity ranged from 0.2% to 14.3% 2,6,12,18,24,25,27 . Therefore, hantavirus infections are probably occurring in the studied municipalities despite of no HCPS reported cases.…”

“…Currently, two known strains circulate in the state: Juquitiba associated to Oligoryzomys nigripes and Jabora related to Akodon montensis 21,28 . Although, HCPS cases were not reported in the west of the state of Santa Catarina, a previous study in this region showed individuals previously infected by hantavirus in two municipalities 27 . Thus, this work has been done in order to obtain better information on antibody levels to hantavirus in the west of the state Santa Catarina, at the border with northern Argentina.…”

“…Serum samples were diluted 1:100 in saline buffer and the Anti-Human IgG FITCs (Sigma, USA) was diluted 1:2000 in saline buffer. The IFA was performed as previously described 15,27 .…”

Seropositivity diagnosis for hantavirus in Jataí, Goiás State, Brazil

“…In another study conducted in cities near the border between Brazil and Argentina, still in the State of Santa Catarina, they found a 3.5% seroprevalence 11 . The highest reported level of infection with an index of 4.7% was found in the City of Cássia dos Coqueiros, located in the State of São Paulo, in the Southeast region 12 .…”

“…Residents of urban areas also have links to the field, through work or field-related activities which might increase the risk of exposure to rodent reservoirs 11,13 . Thus, when the questionnaire was administered, a majority of the population expressed having experienced situations considered to enhance the risk for hantavirus infection, including rural tourism (74%) and exposure to house cleaning in the countryside, sheds, and other similarities (71%).…”