Prediction model to discriminate leptospirosis from hantavirus

SUMMARY OBJECTIVE: The aim of this study was to build a prediction model to discriminate precociously hantavirus infection from leptospirosis, identifying the conditions and risk factors associated with these diseases. METHODS: A logistic regression model in which the response variable was the presence of hantavirus or leptospirosis was adjusted. RESULTS: As a result, the method selected the following variables that influenced the prediction formula: sociodemographic variables, clinical manifestations, and exposure to environmental risks. All variables considered in the model presented statistical significance with a p<0.05 value. The accuracy of the model to differentiate hantavirus from leptospirosis was 88.7%. CONCLUSIONS: Concluding that the development of statistical tools with high potential to predict the disease, and thus differentiate them precociously, can reduce hospital costs, speed up the patient's care, reduce morbidity and mortality, and assist health professionals and public managers in decision-making.

The Serological Cross-Detection of Bat-Borne Hantaviruses: A Valid Strategy or Taking Chances?

Bats are hosts of a range of viruses, and their great diversity and unique characteristics that distinguish them from all other mammals have been related to the maintenance, evolution, and dissemination of these pathogens. Recently, very divergent hantaviruses have been discovered in distinct species of bats worldwide, but their association with human disease remains unclear. Considering the low success rates of detecting hantavirus RNA in bat tissues and that to date no hantaviruses have been isolated from bat samples, immunodiagnostic tools could be very helpful to understand pathogenesis, epidemiology, and geographic range of bat-borne hantaviruses. In this sense, we aimed to identify in silico immunogenic B-cell epitopes present on bat-borne hantaviruses nucleoprotein (NP) and verify if they are conserved among them and other selected members of Mammantavirinae, using a combination of (the three most used) different prediction algorithms, ELLIPRO, Discotope 2.0, and PEPITO server. To support our data, we in silico modeled 3D structures of NPs from representative members of bat-borne hantaviruses, using comparative and ab initio methods due to the absence of crystallographic structures of studied proteins or similar models in the Protein Data Bank. Our analysis demonstrated the antigenic complexity of the bat-borne hantaviruses group, showing a low sequence conservation of epitopes among members of its own group and a minor conservation degree in comparison to Orthohantavirus, with a recognized importance to public health. Our data suggest that the use of recombinant rodent-borne hantavirus NPs to cross-detect antibodies against bat- or shrew-borne viruses could underestimate the real impact of this virus in nature.

Seroprevalence of arenavirus and hantavirus in indigenous populations from the Caribbean, Colombia

Abstract INTRODUCTION: In Colombia, there is insufficient epidemiological surveillance of zoonotic hemorrhagic viruses. METHODS: We performed a sero-epidemiological study in indigenous populations of Wayuü, Kankuamos, and Tuchin communities using Maciel hantavirus and Junin arenavirus antigens for IgG detection by ELISA. RESULTS IgG antibodies to hantavirus and arenavirus were found in 5/506 (1%) and 2/506 (0.4%) serum samples, respectively. CONCLUSIONS: Arenavirus and hantavirus circulate in indigenous populations from the Colombian Caribbean region, and the results indicate that the indigenous populations are exposed to these zoonotic agents, with unknown consequences on their health, despite low seroprevalence.

Undifferentiated tropical febrile illness in Cordoba, Colombia: Not everything is dengue.

In Colombia, undifferentiated tropical febrile illness (UTFI) are frequent and of considerable concern. They also share many clinical features. Between 2012 and 2013 in an endemic tropical area of Cordoba, Colombia, we conducted a prospective study to establish an etiological diagnosis of UTFI. Using diagnostic tests for dengue, leptospirosis, hantavirus, malaria, rickettsia, brucellosis, hepatitis A and B on 100 patients recruited for the study. We identified 69 patients with presumed UTFI: leptospirosis (n=27), dengue (n=26), hantavirus infection (n=4), malaria (n=4), rickettsial infection (n=2), hepatitis A (n=1), and brucellosis (n=1); no hepatitis B cases were detected. Co-infections with malaria and leptospirosis (n=1), hepatitis A and dengue (n=1), hantavirus and dengue (n=1), hantavirus, dengue, and leptospirosis (n=1) were also identified. No etiologic agent was identified for 31 patients. We conclude that other etiologic agents besides dengue virus deserve greater attention by physicians and public health authorities in tropical area of Colombia.

Circulation of hantaviruses in the influence area of the Cuiabá-Santarém Highway

We describe evidence of circulation of hantaviruses in the influence area of the Santarém-Cuiabá Highway (BR-163) in the Brazilian Amazon through the prevalence of specific antibodies against hantaviruses in inhabitants living in four municipalities of this area: Novo Progresso (2.16 percent) and Trairão (4.37 percent), in state of Pará (PA), and Gua-rantã do Norte (4.74 percent) and Marcelândia (9.43 percent), in state of Mato Grosso. We also demonstrate the ongoing association between Castelo dos Sonhos virus (CASV) and hantavirus pulmonary syndrome (HPS) cases in the Castelo dos Sonhos district (municipality of Altamira, PA) and the first report of CASV in the municipalities of Novo Progresso and Guarantã do Norte. The results of this work highlight the risk for a possible increase in the number of HPS cases and the emergence of new hantavirus lineages associated with deforestation in this Amazonian area after the conclusion of paving works on BR-163 Highway.

Hantaviruses as emergent zoonoses

Hantaviruses belong to the Bunyaviridae family, which consists of vector-borne viruses. These viruses can provoke two infection types: hemorrhagic fever with renal syndrome (HFRS) - which occurs in the Old World - and hantavirus cardiopulmonary syndrome (HCPS) - an emergent zoonosis that can be found in many countries of the western hemisphere. Rodents are hantavirus reservoirs and each species seems to host a different virus type. Humans acquire the infection by inhaling contaminated aerosol particles eliminated by infected animals. The factors involved in the emergence of hantavirus infections in the human population include ecological modifications and changes in human activities. The most important risk factor is contact between man and rodents, as a result of agricultural, forestry or military activities. Rodent control remains the primary strategy for preventing hantavirus diseases, including via health education and hygienic habits.(AU)

Hantaviruses as emergent zoonoses

Hantaviruses belong to the Bunyaviridae family, which consists of vector-borne viruses. These viruses can provoke two infection types: hemorrhagic fever with renal syndrome (HFRS) - which occurs in the Old World - and hantavirus cardiopulmonary syndrome (HCPS) - an emergent zoonosis that can be found in many countries of the western hemisphere. Rodents are hantavirus reservoirs and each species seems to host a different virus type. Humans acquire the infection by inhaling contaminated aerosol particles eliminated by infected animals. The factors involved in the emergence of hantavirus infections in the human population include ecological modifications and changes in human activities. The most important risk factor is contact between man and rodents, as a result of agricultural, forestry or military activities. Rodent control remains the primary strategy for preventing hantavirus diseases, including via health education and hygienic habits.

A questão ambiental na promoção da saúde: uma oportunidade de ação multiprofissional sobre doenças emergentes / Environmental issues on health promotion: a multi-professional action on emerging diseases

A discussão sobre a emergência de agravos à saúde coloca todos os profissionais de saúde em alerta. Através de uma revisão sobre os conceitos de doença emergente, relacionando-a com uma situação concreta, a emergência da hantavirose em Santa Catarina, Brasil, constatou-se a necessidade de um enfoque sobre as condições ambientais em tais situações. O melhor conhecimento sobre os fatores ambientais envolvidos e contextualizados torna possível um melhor posicionamento para a elaboração das políticas de controle e prevenção a serem adotadas. Tal posicionamento possibilita a ação multiprofissional, sob a forma de orientação às comunidades, como necessidade de um modelo assistencial diferenciado.

The discussion on the emergence of health injuries preoccupies all health workers. In a review on the concepts of emerging disease, related to a concrete situation, the emergence of the Hantaviruses in the State of Santa Catarina, Brazil, the author highlights the need for focusing on environmental conditions in such situations. The best knowledge on environmental factors makes it possible to elaborate controlling and preventive policies. This enables the multi-professional action in providing community information, as the need for a differentiated assistance model.

Síndrome pulmonar e cardiovascular por Hantavirus: aspectos epidemiológicos, clínicos, do diagnóstico laboratorial e do tratamento / Hantavirus pulmonary and cardiovascular syndrome: epidemiology, clinical presentation, laboratory diagnosis and treatment

The Hantavirus pulmonary and cardiovascular syndrome (HPCVS) is an emerging disease in Brazil. In this study, eight confirmed cases of HPCVS were studied. All the patients presented fever and dyspnea as well as thrombocytopenia and hypoxemia. Tachycardia, malaise, hypotension and lung rales occurred in 75 to 87.5% of the cases. Hemoconcentration, blood cell count increased and immature neutrophils, and high levels of creatinine were observed in 75 to 87.5%. Intravenous liquid infusion, the use of drugs for increasing systemic vascular resistance and inotropism, and mechanic ventilation were used for the patients. Mechanical ventilation and volume administration should be started precociously, preferable in intensive care units employing recommended universal and respiratory precautions. Careful volume administration should be limited if signs of pulmonary edema develop. Mortality (50%) is high and probably related to the severity of the disease as well as to a delayed attending of the patients for intensive management. It is important to report hantaviruses and HPCVS to the Brazilian medical community considering that many cases could be undiagnosed.

A síndrome pulmonar e cardiovascular por Hantavirus (SPCVH), é doença emergente com descrição crescente de casos no Brasil. Neste trabalho, estudou-se 8 casos confirmados da doença. Todos apresentaram febre e dispnéia. Taquicardia, astenia, hipotensão e estertoração pulmonar ocorreram em 75 a 87,5% dos casos. Plaquetopenia e hipoxemia ocorreram em 100% dos casos, hemoconcentração, leucocitose com desvio à esquerda e elevação de uréia e creatinina séricas em 75 a 87,5%. Assistência respiratória, hidratação endovenosa e utilização de aminas vasoativas foram as medidas utilizadas nos pacientes. Ressalta-se que o suporte ventilatório e cardiovascular deve ser precocemente instituído, preferencialmente em unidades de terapia intensiva, com precauções universais e respiratórias de isolamento. Deve-se ter cuidados com infusão excessiva de líquidos para não agravar o edema pulmonar. A mortalidade observada, de 50%, é elevada, deveu-se à gravidade da doença e ao comparecimento tardio para tratamento intensivo. Deve-se informar sobre a SPCVH aos profissionais de saúde, considerando que casos de SPCVH, provavelmente, vêm passando desapercebidos.

Contribuiçäo ao conhecimento sobre a Hantavirose no Brasil / A contribution to the knowledge of hantaviruses in Brazil

Foram revistos diferentes aspectos da síndrome pulmonar e cardiovascular por hantavírus, uma doença emergente transmitida pela inalação das excretas de roedores silvestres e que ocorre principalmente em indivíduos que têm contato com o meio rural e com estes animais. Trata-se de doença grave, com letalidade acima de 50%, que leva à insuficiência respiratória e ao choque. A terapia de suporte ventilatório e cardiovascular deve ser precocemente instituída, preferencialmente em unidades de terapia intensiva. A presença de edema pulmonar exige cuidados de ventilação precoces. Apesar dos pacientes apresentarem-se em choque, deve-se ter cuidados com a infusão de líquidos para que não se agrave o edema pulmonar. É necessário informar os profissionais de saúde sobre a doença, considerando que muitos casos devem passar despercebidos. O diagnóstico laboratorial de hantavirose acessível e rápido precisa ser implementado e para tanto, precisa-se de pesquisas desenvolvendo métodos diagnósticos sensíveis e confiáveis. O controle da doença exige envolvimento de múltiplos profissionais visando conhecer sua história natural, a biologia do reservatório e a do vírus.

Hantavirus pulmonary and cardiovascular syndrome, an emerging disease transmitted by the inhalation of wild rodent excreta and affecting mostly agriculture workers and other professionals in contact with these animals, is reviewed. Hantavirus pulmonary syndrome is a severe disease with case fatality ratio greater than 50%. The syndrome is characterized by respiratory distress and shock. Disease management includes early mechanical ventilation and volume administration, preferable in intensive care units. Caution is advised during liquid infusion for shock treatment since pulmonary edema develops frequently. Information about hantavirus pulmonary and cardiovascular syndrome should be widely disseminated among the Brazilian medical community considering that, many cases can be undiagnosed. Rapid and accessible laboratory diagnosis of hantaviruses must be implemented in Brazil and research focused on the development of sensible and reliable diagnostic methods and reagents is encouraged. The control of hantaviruses depends on a multi-professional approach aiming to know the natural history, the biology of the reservoir and of the virus.