Pathogenic hantaviruses cocirculating in Misiones Province of northeastern Argentina and eastern Paraguay

PAULA PADULA.; VALERIA P. MARTINEZ; CARLA BELLOMO; SILVINA MAIDANA; JORGE SAN JUAN; PAULINA TAGLIAFERRI; SEVERINO BARGARDI; CINTIA VAZQUEZ; NORMA COLUCCI; JULIO ESTÉVEZ; MARÍA ALMIRÓN

Ciudad de Buenos Aires. Argentina.

Conferencia; VII International Conference on HFRS, SPH and Hantaviruses; 2007

Fundación Mundo Sano

               Hantavirus Pulmonary Syndrome (HPS) is an emerging disease in South America and investigations strength the believe that the disease is underestimated. Despite being surrounded by countries endemic for HPS, Misiones Province from Argentina, had not had HPS reported cases until 2003. Furthermore, HPS cases have not been documented in eastern Paraguay. We describe here hantavirus associated with 3 cases occurred in northeastern Argentina, Misiones Province, limiting with two other hantavirus endemic countries, Brazil and Paraguay and the first case occurred in eastern Paraguay. We also analyzed rodents captured in Misiones and characterized a novel genetic hantavirus lineage from the Biological Reserve of Limoy in eastern Paraguay region. We studied 3 HPS cases that were confirmed in Misiones, in 2003 and a case of a rural area of Itapua occurred in 2005. Clinical manifestations of the 4 patients studied were similar to those reported for AND hantavirus infections: fever, myalgia, headache and vomiting, soon followed by pulmonary edema. Renal involvement was minimal, neither oliguria nor renal failure was observed in any case, but all patients showed petechiae. The 4 HPS cases had AND IgM and IgG antibodies and all of them survived. Two pathogenic hantaviruses were probed to be circulating in Misiones: AND Cent Lec and Juquitiba virus.  The occurred cases led us to begin investigating reservoirs for hantaviruses in Misiones. A total of 59 rodents were trapped where O. nigripes was the most frequently captured rodent (42 specimens), from which 5 resulted seropositive followed by Akodon montensis (11 specimens). The capture revealed 5 O. nigripes positive rodents (11.9%) of 42 tested from this species. We confirmed O. nigripes as the reservoir species associated with 2 JUQV cases in Misiones. In eastern Paraguay, AND Nort Bermejo lineage produced HPS. Another different strain was obtained from the A. cursor rodent captured in Limoy Reserve, being the most distinctly strain. The highest degree of identity exhibited was around 77%. There have been no reports of Akodon-borne hantavirus associated with cases in America. Precisely identification of source populations in the reservoir and quantitative data collection on their relative contribution to hantavirus transmission will be essential for disease control in the triple frontier.