Hantavirus Pulmonary Syndrome, Central Plateau, Southeastern, and Southern Brazil

Hantavirus pulmonary syndrome (HPS) is an increasing health problem in Brazil because of encroachment of sprawling urban, agricultural, and cattle-raising areas into habitats of subfamily Sigmodontinae rodents, which serve as hantavirus reservoirs. From 1993 through June 2007, a total of 884 cases of HIPS were reported in Brazil (case-fatality rate 39%). To better understand this emerging disease, we collected 89 human serum samples and 68 rodent lung samples containing antibodies to hantavirus from a 2,500-km-wide area in Brazil. RNA was isolated from human samples and rodent lung tissues and subjected to reverse transcription-PCR. Partial sequences of nucleocapsid protein and glycoprotein genes from 22 human and 16 rodent sources indicated only Araraquara virus and Juquitiba virus lineages. The case-fatality rate of HPS was higher in the area with Araraquara virus. This virus, which may be the most virulent hantavirus in Brazil, was associated with areas that have had greater anthropogenic changes.

Role of mixed Th1 and Th2 serum cytokines on pathogenesis and prognosis of hantavirus pulmonary syndrome

The hantavirus pulmonary syndrome (HPS) is an emerging syndrome in the Americas. The disease results from intense immune activation and changes in vascular permeability. The aim of this study was to determine the profile of serum cytokines in HPS patients looking for correlation with the clinical parameters, severity and outcome of illness. Studying 21 HPS patients, we found that IL-6 may have an important role in the pathogenesis of HPS, being associated with fatal outcome. Our results also support a mixed Th1/Th2 immune response during the course of HPS and that the magnitude of Th1 response effector cytokines is correlated to HPS severity. The decreased levels of TGF-beta observed in HPS patients suggest that immunoregulatory activity could be damaged in these patients. (c) 2008 Elsevier Masson SAS. All rights reserved.

HANTAVIRUS PULMONARY SYNDROME IN THE PROVINCE OF RIO NEGRO, ARGENTINA, 1993-1996

Early in 1995 the first case of Hantavirus Pulmonary Syndrome was serologically confirmed in El Bolsón (Province of Río Negro, Argentina), corresponding to the third outbreak reported in Argentina. A total of 26 cases of HPS related to the Andean region of Rio Negro Province, were reported from 1993 to 1996, 17 in El Bolsón, 4 in San Carlos de Bariloche, and 5 in Buenos Aires. The incidence rate was 5.03 x 100000 with a mortality rate of 51.85 x 100. The occurrence of cases was mainly seasonal, with a significantly greater number in the spring, and the persons affected mainly lived in urban or periurban areas. In four cases, the affected individuals were members of a couple, spouses or live-in contacts. Seven cases were Health workers (physicians, nurses or administrative staff). Twelve cases were related among them, due to an outbreak of 80 days. Two of them did not visit the Andean region. A total of 139 rodents were captured and seven of them, Olygoryzomys longicaudatus, were found to be serologically positive. The possibility of infection by contact with rodents or fecal matter is being analyzed and also hypothesis related with interhuman transmission

Hantavirus Pulmonary Syndrome: Report of the first three cases in São Paulo, Brazil

The hantavirus pulmonary syndrome was first recognized in cases that occurred in the U.S. in 1993, which served as an alert not only for American physicians but also for physicians in other countries for the identification of the disease. In the city of São Paulo, Brazil, 3 cases of the syndrome were recorded in 1993. The patients were young brothers residing in the Mata Atlântica (Atlantic Forest) region submitted to recent deforestation. Two of the patients died of acute respiratory insufficiency and the third recovered without sequelae. In the surviving patient the diagnosis was established by a laboratory criterion based on the detection of specific IgM and IgG class antibodies by indirect immunofluorescence. In the two patients who died, the diagnosis was confirmed by laboratory tests using immunoperoxidase technique for hantavirus in tissue, in histological lung and heart sections in one case, and by clinical and epidemiological data in the other

HANTAVIRUS PULMONARY SYNDROME (HPS) IN GUARIBA, SP, BRAZIL: REPORT OF 2 CASES

Human infections caused by a hantavirus were reported in different regions of the State of São Paulo (SP), Brazil during the first six months of 1998. Two cases of fatal pulmonary syndrome occurred in May of 1998 in the City of Guariba, located in the Northeastern Region of SP. Both patients worked in a corn storage barn infested by rodents. These patients, after 2 or 3 days of non-specific febrile illness, developed a severe interstitial pneumonia spreading widely in both lungs, causing respiratory failure and death. At autopsy both patients showed lung interstitial edema with immunoblast-like mononuclear cell infiltrates, consistent with a viral etiology. Hantavirus infection was diagnosed by ELISA in both cases and by RT-PCR in one of the patients. Aspects of the clinical presentation, physiopathology and differential diagnosis of Hantavirus Pulmonary Syndrome are discussed.

Hantavirus pulmonary syndrome in Brazil: clinical aspects of three new cases

Hantavirus pulmonary syndrome (HPS) has been recognized recently in Brazil, where 28 cases have been reported as of September 1999. We report here the clinical and laboratory findings of three cases whose diagnoses were confirmed serologically. All the patients were adults who presented a febrile illness with respiratory symptoms that progressed to respiratory failure that required artificial ventilation in two of them. Laboratory findings were most of the time consistent with those reported in the United States in patients infected with the Sin Nombre virus, and included elevated hematocrit and thrombocytopenia; presence of atypical lymphocytes was observed in one patient. The chest radiological findings observed in all the patients were bilateral, diffuse, reticulonodular infiltrates. Two patients died. Histopathological examination of the lungs of these patients revealed interstitial and alveolar edema, alveolar hemorrhage, and mild interstitial pneumonia characterized by infiltrate of immunoblasts and mononuclear cells. In the epidemiologic investigation of one of the cases, serologic (ELISA) tests were positive in 3 (25%) out of 12 individuals who shared the same environmental exposure. HPS should be included in the differential diagnosis of interstitial pneumonia progressing to acute respiratory failure.

Hantavirus pulmonary syndrome in Anajatuba, Maranhão, Brazil

The authors report a confirmed case of hantavirus pulmonary syndrome in the rural area of the municipality of Anajatuba, state of Maranhão. Two other suspected cases from the same region are also described. The confirmed case involved a previously healthy young woman who died with signs and symptoms of acute respiratory insufficiency 5 days after presenting fever, myalgia and a dry cough. The patient was a student who was helping her parents with work in the fields; it was a habit of the family to store rice inside the house. The suspected cases involved two first-degree relatives working as field hands who died of acute respiratory insufficiency 24 and 48 hours, respectively, after presenting fever, myalgia and a dry cough. Both stored rice and corn inside their home. People living in the region reported massive infestations with rats in the woods and fields.

Clinical and laboratory findings related to a favorable evolution of hantavirus pulmonary syndrome

The medical records of 27 patients with hantavirus pulmonary syndrome were analyzed according to the need for invasive mechanical ventilation in relation to the following data up on hospital admission: age, gender, fever, cough, dyspnea, systolic arterial blood pressure, heart rate, levels of hemoglobin, hematocrit, leukocytes, lymphocytes, platelets, creatinine and arterial blood gases. The volume infused during the first 24 hours after admission, the use of inotropic agents, the use of corticosteroids and the patient outcomes were also evaluated. A favorable outcome was related to systolic blood pressure³ 100mmHg, heart rate lower than 100 beats per minute, creatinine below 1.6mg/dl, arterial blood pH³ 7.35, bicarbonate higher than 15mEq/dl, oxygen saturation higher than 84.1%, lower rehydration volume in the first 24 hours of hospitalization and no use of inotropic agents. Absence of clinical and laboratory signs of circulatory shock up on admission was associated with a favorable outcome of the patients.

Hantavirus pulmonary syndrome in Uberaba, Minas Gerais, Brazil

This report describes the epidemiological and clinical-evolutive characteristics of eight patients with hantavirus pulmonary syndrome (HPS) in Uberaba, Minas Gerais, Brazil. A positive history of contact with rodents was present in 100% of the cases. The time between the onset of symptoms and hospital care was, on average, 3.6 days. All patients showed clinical and laboratory findings suggestive of HPS. Elevated urea and creatinine levels were observed in 6 (75%) cases, PO2 was < 60 mmHg in 100% of the cases, and a chest X-ray demonstrated a bilateral interstitial-alveolar infiltrate. The diagnosis was confirmed by the detection of IgM antibodies against Sin Nombre virus by ELISA. Three patients died as a direct consequence of HPS.

Hantavirus pulmonary syndrome: prognostic factors for death in reported cases in Brazil

Hantavirus pulmonary syndrome (HPS) was described for the first time in Brazil in 1993 and has occurred endemically throughout the country. This study analysed clinical and laboratory aspects as well as death-related factors for HPS cases in Brazil from 1993 to 2006. The investigation comprised a descriptive and exploratory study of the history of cases as well as an analytical retrospective cohort survey to identify prognostic factors for death due to HPS. A total of 855 Brazilian HPS cases were assessed. The majority of cases occurred during spring (33.5%) and winter (27.6%), mainly among young male adults working in rural areas. The global case fatality rate was 39.3%. The mean interval between the onset of symptoms and hospitalisation was 4 days and that between hospitalisation and death was 1 day. In the multiple regression analysis, adult respiratory distress syndrome and mechanical respiratory support were associated with risk of death; when these two variables were excluded from the model, dyspnoea and haemoconcentration were associated with a higher risk of death. (C) 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Association of-308G/A polymorphism in the tumor necrosis factor-alpha gene promoter with susceptibility to development of hantavirus cardiopulmonary syndrome in the Ribeiro Preto region, Brazil

Activation of the immune response in hantavirus cardiopulmonary syndrome (HCPS) leads to a high TNF production, probably contributing to the disease. The polymorphic TNF2 allele (TNF -308G/A) has been associated with increased cytokine production. We investigated the association of the TNF2 allele with the outcome of hantavirus infection in Brazilian patients. A total of 122 hantavirus-exposed individuals (26 presenting HCPS and 96 only hantavirus seroconversion) were studied. The TNF2 allele was more frequently found in HCPS patients than in individuals with positive serology for hantavirus but without a history of HCPS illness, suggesting that the TNF2 allele could represent a risk factor for developing HCPS.

Hantavirus infection associated to a staphylococcal sepsis. Report of one case

We report a previously healthy 36-year-old male who developed a pulmonary syndrome caused by Hantavirus infection He was admitted to an intensive care unit in shock awl respiratory failure and died four hours after admission. Blood cultures were positive for Staphylococcus aureus This patient could be an index case that shows, for the first time, an association of Hantavirus Pulmonary Syndrome with Staphylococcus nitwits infection similar to what happens with other viruses (Rev Med Chile 2010, 138: 338-340).

A serosurvey for hantavirus infection in wild rodents from the states of Rio de Janeiro and Pernambuco, Brazil

Sera from 269 rodents obtained during the routine surveillance operations in plague areas of Rio de Janeiro and Pernambuco states, Brazil were tested by ELISA for specific IgG antibodies against a recombinant nucleocapsid (N) protein of Araraquara hantavirus. ELISA-positive sera were submitted to reverse transcriptase-polymerase chain reaction (RT-PCR) for amplification of the virus genome and later sequencing for identification of the viral variant. The samples from the state of Pernambuco were antibody negative, and although four from Rio de Janeiro were ELISA-positive, they failed to yield viral cDNA by RT-PCR. This is the first report of the presence of antibodies to a hantavirus among rodents from Rio de Janeiro and suggests the possibility of human cases of hantavirus pulmonary syndrome (HPS) in that state, although no case has yet been reported. (C) 2008 Elsevier B.V. All rights reserved.

Serologic survey for hantavirus infections among wild animals in rural areas of São Paulo State, Brazil

A serosurvey was conducted in wild animals captured close to two areas where hantavirus cardiopulmonary syndrome (HCPS) occurred in São Paulo State, Brazil. Serum samples from a total of 43 mammals were tested for antibodies reactive with Sin Nombre (SN) hantavirus using a strip immunoblot assay. RNAs from the blood clots of the positive samples were submitted to reverse transcriptase-polymerase chain reaction (RT-PCR). Two rodents of the genus Oligoryzomys were positive for hantavirus antibodies. These animals were captured in the Iguape region and represented 16.7% (2/12) of the sera from rodents and 100.0% (2/2) of the Oligoryzomys captured in that area. RT-PCR failed to amplify any viral cDNA. These results are in agreement with other data that suggest that members of this genus are important reservoirs of hantaviruses in Brazil.