Hantavirus Pulmonary Syndrome in Argentina, 1995–2008

Abstract

We report a large case series of hantavirus pulmonary syndrome (HPS) in Argentina that was confi rmed by laboratory results from 1995 through 2008.The geographic and temporal distribution of cases by age, sex, fatality rate, and risk factors for HPS was analyzed.A total of 710 cases were unequally distributed among 4 of the 5 Argentine regions.Different case-fatality rates were observed for each affected region, with a maximum rate of 40.5%.The male-to-female ratio for HPS case-patients was 3.7:1.0;the case-fatality rate was signifi cantly higher for women.Agriculture-associated activities were most commonly reported as potential risk factors, especially among men of working age.Although HPS cases occurred predominantly in isolation, we identifi ed 15 clusters in which strong relationships were observed between members, which suggests ongoing but limited person-to-person transmission.H antavirus pulmonary syndrome (HPS) was fi rst recog- nized in 1993 during an outbreak of acute respiratory distress syndrome in the southwestern United States (1,2).Previously, only Old World hantaviruses had been associated with illness in humans as the causative agents of hemorrhagic fever with renal syndrome.After recognition of HPS, cases in other countries of Central and South America were quickly identifi ed, along with the associated virus and rodent reservoirs (3-10).Although serologic studies provided the initial evidence of hantavirus circulation in Argentina (11,12), the etiologic agent of HPS in Argentina was fi rst described in 1995 after an outbreak occurred in the Andean sector of Patagonia where Andes virus (ANDV) was characterized (4).Several reports have been published since then, describing HPS cases in 4 regions of the country: Northwest, Northeast, Central, and Patagonia.Six lineages of ANDV were associated with HPS in the 4 regions of Argentina: AND-Oran, AND-Bermejo, AND-BsAs, AND-Lechiguanas, AND-Plata, and AND-South (10,13-16).Juquitiba virus (JUQV) and Laguna Negra (LN)-like virus were also found in the Northeast and Northwest regions, respectively (14,17).We describe the epidemiologic features of a large proportion of confi rmed HPS cases in Argentina.Detailed data were compiled for analysis of age, sex, onset of symptoms, clinical signs, case-fatality rates, geographic origin, and the most probable risk activities. Materials and Methods Study SiteArgentina is located at the southern extreme of South America.It has a large longitudinal extension, 3,779 km, and the highest altitudinal range of the continent.With a continental extension of 2,791,810 km 2 , Argentina is the second largest country in South America and the eighth largest in the world.The size of the country supports multiple natural ecosystems.Argentina has been divided into 5 epidemiologic regions: Northwest, Northeast, Cuyo, Central, and Patagonia (Figure 1).It has been also classifi ed into 18 ecoregions on the basis of geographic, climatic, and biologic factors (18).