Hantavirus pulmonary syndrome (HPS) is the most frequently reported fatal rodent-borne disease in Brazil, with the majority of cases occurring in Santa Catarina. We analysed the clinical, laboratory and epidemiological data of the 251 confirmed cases of HPS in Santa Catarina in 1999–2011. The number of cases ranged from 10 to 47 per year, with the highest incidences in 2004–2006. Gastrointestinal tract manifestations were found in >60% of the cases, potentially confounding diagnosis and leading to inappropriate therapy. Dyspnoea, acute respiratory failure, renal failure, increased serum creatinine and urea levels, increased haematocrits and the presence of pulmonary interstitial infiltrate were significantly more common in HPS patients who died. In addition, we demonstrated that the six cases from the midwest region of the state were associated with Juquitiba virus genotype. The case-fatality rate in this region, 19·2%, was lower than that recorded for other mesoregions. In the multivariate analysis increase of serum creatinine and urea was associated with death by HPS. Our findings help elucidate the epidemiology of HPS in Brazil, where mast seeding of bamboo can trigger rodent population eruptions and subsequent human HPS outbreaks. We also emphasize the need for molecular confirmation of the hantavirus genotype of human cases for a better understanding of the mortality-related factors associated with HPS cases in Brazil.

This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT–PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50–83·7%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

Hantavirus pulmonary syndrome (HPS) is a zoonosis and a public health concern in the Americas due to its high fatality rate. Since the first cases were identified in USA in 1993, HPS has been observed over a wide area of the American continents. Over 1600 HPS cases have been confirmed in Brazil since 1993, and different genotypes of hantavirus have been identified in several biomes in this country of continental dimensions. We performed a retrospective study of data from 2001 to 2011 that encompassed all notified cases of HPS in the National Disease Notification System (SINAN) of Brazil to determine the regional differences and temporal trends of the disease. During the study period, 1486 cases were reported, and analyses of the temporal trends of the disease revealed that the number of cases in Brazil increased over this period (P <  0·01). The frequency distributions of the cases stratified by region revealed different patterns of seasonality; however, these patterns were not statistically significant with the exception of the South region (P < 0·05). We found regional differences in the occurrence of the disease throughout the year and a trend towards an increasing number of cases. These findings reinforce the necessity of adjusting surveillance tools and control policies to respond effectively to this public health problem.