Modelamiento del síndrome cardiopulmonar por hantavirus / Modeling of hantavirus cardiopulmonary syndrome

INTRODUCCIÓN: El síndrome cardiopulmonar por hantavirus es una enfermedad causada por un virus perteneciente al orden bunyanvirales, y transmitida hacia los humanos a través de roedores. Esta enfermedad en Chile es considerada endémica, la cual tiene una alta tasa de letalidad. En la actualidad existen estudios que evidencian el contagio entre personas del virus Andes, cuya localidad se concentra en los países de Argentina y Chile. OBJETIVOS: Analizar la posibilidad de transmisión de hantavirus entre humanos, mediante un modelo matemático tipo SEIR. MÉTODOS: Se plantea un modelo matemático tipo SEIR (susceptible, expuesto, infeccioso y recuperado) para expresar la dinámica de la enfermedad por hantavirus, incluyendo la posibilidad de transmisión entre humanos y la percepción del riesgo. Resultados: El máximo de contagio entre humanos disminuye cerca de 25% tras aumentar la percepción de riesgo de las personas, mediante la reducción de la tasa de resistencia al cambio y aumento la velocidad de reaccionar de las personas. CONCLUSIONES: Es urgente revisar las estrategias de comunicación de riesgo y medidas de prevención ante esta posibilidad de contagios masivos entre humanos, además de fortalecer la investigación y proyectar el desarrollo de una vacuna para proteger las poblaciones expuestas a esta enfermedad con alta tasa de letalidad.

INTRODUCTION: Hantavirus cardiopulmonary syndrome is an infection caused by rodents of the Bunyanvirales family towards humans. This disease in Chile is considered endemic, which has a high fatality rate. At present, some studies show the contagion between people of the Andes virus, whose locality is concentrated in Argentina and Chile. OBJECTIVES: Analyze the possibility of hantavirus transmission between humans using an SEIR-type mathematical model. METHODS: An SEIR (Susceptible, Exposed, Infectious and Recovered) mathematical model to express the dynamics of hantavirus disease is proposed, including the possibility of human-to-human transmission and the perception of risk. RESULTS: The peak of human-to-human contagion decreases by about 25% after increasing people's perception of risk by reducing the rate of resistance to changeand increasing the speed of people's reaction. CONCLUSIONS: It is urgent to review risk communication strategies and prevention measures in the face of this possibility of massive human-tohuman infections, in addition to strengthening research and planning the development of a vaccine to protect populations exposed to this disease with a high fatality rate.

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.

Rodent-borne viruses survey in rural settlers from Central Brazil

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

First serologic evidence of human hantavirus infection in Alagoas State in Northeastern Brazil

Abstract INTRODUCTION: Hantavirus cardiopulmonary syndrome (HCPS) is rare in Northeastern Brazil. METHODS: Prospective surveillance was conducted over a two-year period in Alagoas State, Northeastern Brazil. The prevalence of anti-hantavirus N-antigen IgM and IgG in human serum samples was determined by enzyme-linked immunosorbent assay testing. RESULTS: High avidity IgG was found in nine of 476 serum samples tested (from 102 patients with clinical manifestations compatible with HCPS, 124 patients with leptospirosis, and 250 healthy rural workers). CONCLUSIONS: Serologic evidence of past hantavirus infection in residents of Alagoas State indicates that hantaviruses are present in northeastern Brazil, even in areas silent for HCPS.

Seropositivity diagnosis for hantavirus in Jataí, Goiás State, Brazil

Abstract INTRODUCTION: Emerging diseases are of great interest, especially those associated with high mortality rates such as hantaviruses. We aimed to conduct a seroepidemiological survey to determine the levels of hantavirus infection. METHODS: In-house enzyme-linked immunosorbent assay (ELISA) was used to detect specific antibodies. RESULTS: Of the 429 samples collected, seropositivity of 3.9% to anti-hantavirus immunoglobulin G (IgG) was observed (CI 95%: 2.3-5.7). Moreover, in three cases, immunoglobulin M (IgM) was detected, of which two were diagnosed as hantavirus cardiopulmonary syndrome (HCPS). CONCLUSIONS: Our data indicate the considerable occurrence of previous hantavirus infections, highlighting occurrences from sub-clinical cases to HCPS.

Estudo transversal da letalidade da hantavirose no estado de Goiás, 2007-2013 / Estudio transversal de la letalidad de la infección por hantavirus en el estado de Goiás, Brasil, 2007-2013 / Cross-sectional study on case fatality rate due to hantavirus infection in Goiás State, Brazil, 2007-2013

OBJETIVO: descrever o perfil epidemiológico e clínico da hantavirose e analisar fatores associados à letalidade em Goiás, Brasil. MÉTODOS: foi conduzido um estudo transversal com dados do Sistema de Informação de Agravos de Notificação (Sinan), referentes ao período de 2007 a 2013, no estado de Goiás. Regressão logística foi empregada para estimar razões de chances (OR) com intervalos de confiança de 95% (IC95%). RESULTADOS: foram notificados 1.171 casos suspeitos de hantavirose e 73 (6,2%) confirmados. Entre os confirmados, observou-se maior frequência entre homens (n=50), febre como sintoma mais frequente (n=70) e elevada proporção de hospitalizações (n=68). A taxa de letalidade foi de 57,5%. Foram fatores associados ao óbito: insuficiência respiratória aguda (IRpA) (OR=3,6; IC95%1,2;10,6), hemoconcentração (OR=3,3; IC95%1,1;7,9) e não uso do respirador mecânico (OR=3,4; IC95%1,3;9,1). Após ajuste, a IRpA permaneceu associada ao óbito (OR=3,4; IC95%1,0;11,6). CONCLUSÃO: foi identificada alta taxa de letalidade, associada principalmente com insuficiência respiratória.

OBJETIVO: evaluar el perfil clínico y epidemiológico del hantavirus y los factores asociados con su letalidad en Goiás, Brasil. MÉTODOS: estudio transversal usando datos del Sistema de Información de Enfermedades de Declaración Obligatoria (Sinan), referentes al periodo 2007-2013, en el estado de Goias. Usamos regresión logística para calcular odds ratio (OR) con intervalos de confianza al 95%. RESULTADOS: fueron reportados 1.171 casos sospechosos de hantavirus 73 fueron confirmados (6,2%). Entre los confirmados la frecuencia fue mayor entre hombres (n=50), fiebre fue síntoma más común (n=70), 68 fueron hospitalizados, la tasa de letalidad fue 57,5%. Variables asociadas con letalidad: insuficiencia respiratoria aguda (IRpA) (OR=3,6 IC95% 1,2; 10,6), hemoconcentración (OR=3.3 IC95% 1,1; 7,9) y no usar respirador mecánico (OR=3,4 IC95% 1,3; 9,1). Sólo IRpA se mantuvo asociado en modelos multivariados (OR=3,4 IC95% 1,0; 11,6). CONCLUSIÓN: identificamos una alta tasa de letalidad asociada principalmente con insuficiencia respiratoria.

OBJECTIVE: to describe the epidemiological and clinical profile of hantavirus infection and to analyze factors associated with case-fatality in Goiás, Brazil. METHODS: this was a cross-sectional study on case fatality due to hantavirus infection from 2007 to 2013 using data from the Notifiable Diseases Information System (SINAN) for Goiás State. Logistic regression analysis was performed to estimate odds ratios (OR) with 95% confidence intervals (95%CI). RESULTS: 1,171 suspected cases were reported, of which 73 (6.2%) were confirmed. Among the confirmed cases, greater frequency was found among males (n=50), fever was the most common symptom (n=70), and there was a high proportion of hospitalization (n=68). The case-fatality rate was 57.5% . The following factors were associated with death: acute respiratory failure (ARF) (OR=3.6; 95%CI 1.2;10.6), hemoconcentration (OR=3.3; 95%CI 1.1;7.9) and not using a mechanical ventilator (OR=3.4; 95%CI 1.3;9.1). After adjustment, the ARF was still associated with death (OR=3.4; 95%CI 1.0;11.6). CONCLUSION: the case-fatality rate was high, primarily associated with respiratory failure.

Evidencia serológica retrospectiva de infecciones por Leptospira spp, dengue, hantavirus y arenavirus en indígenas Emberá-Katío, Colombia / Serological evidence of Leptospira spp, dengue, hantavirus and arenavirus infection in Embera-Katío indigenous population, Colombia

We have developed a study in the Embera-Katío indigenous community and we found that the seropositivity for IgG antibodies to Leptospira spp. was 18.1%; to dengue was 61.1%; to arenavirus was 3.1% and to hantavirus was 1.5%. We conclude that this indigenous community live in conditions that promote the reemerging and emerging, infections.

Ten years of a hantavirus disease emergency in the Federal District, Brazil

Abstract: INTRODUCTION: Hantavirus diseases are emerging human diseases caused by Hantavirus spp. of the Bunnyaviridae family. Hantavirus pulmonary syndrome (HPS) has been detected in the Federal District (DF) of Brazil since 2004. Among the 27 Brazilian Federal Units, DF has the highest fatality rate. More than 10 years have already passed since then, with confirmation of cases caused by the Araraquara and Paranoa species. The reservoir is Necromys lasiurus. METHODS: Local surveillance data of the confirmed cases were analyzed, including age, sex, month and year of occurrence, clinical symptoms, syndromes and outcomes, and probable transmission place (PTP). The cases were mainly confirmed by IgM detection with a capture enzyme immunoassay. The cases were classified as autochthonous if PTPs were in the DF area. RESULTS: From 2004 to 2013, in the DF, 126 cases of hantavirus were confirmed, and the cumulative incidence was 5.0 per 100,000 inhabitants. The occurrence of cases was predominantly from April to August. At least 75% of the cases were autochthonous. Acute respiratory failure was reported in 47.5% of cases, and the fatality rate was 40%. CONCLUSIONS: In the DF, the cumulative incidence of HPS was one of the highest worldwide. A seasonal pattern of hantavirus disease in the dry season is clear. There was a high frequency of severe clinical signals and symptoms as well as a high fatality rate. For the near future, visitors and inhabitants of DF rural areas, particularly male adults, should receive continuous education about hantavirus transmission and prevention.

Evidência sorológica de infecção por Bartonella spp., Coxiella burnetii e Hantavirus em profissionais de um abrigo de animais no município do Rio de Janeiro / Serological evidence of infection with Bartonella spp., Coxiella burnetii and Hantavirus in professional an animal shelter in the city of Rio de Janeiro

O risco de infecção por agentes zoonóticos é considerado maior em profissionais quemanuseiam animais. O crescente aumento de animais abandonados nos grandes centrosurbanos e o seu recolhimento em abrigos, cujas condições sanitárias e de infraestruturasão precárias aumentam o risco de transmissão de tais agentes não somente entre osanimais, mas também para os profissionais, determinando, assim, a ocorrência dezoonoses ocupacionais. Neste cenário, cinco funcionários de um abrigo de animais domunicípio do Rio de Janeiro morreram, após um surto de febre maculosa, e um inquéritosorológico realizado entre os profissionais desse abrigo e nos cães demonstrou queempregados e cães eram sororreativos com elevados títulos sorológicos. Diante doexposto e da necessidade de complementar a pesquisa sobre outros agentes zoonóticosque pudessem estar associados com doença ocupacional, foi realizado um estudo com oobjetivo de investigar a presença de anticorpos anti-Coxiella burnetii, anti-Bartonella,anti-Hantavirus em profissionais de um abrigo, como parte das medidas instituídas nocontexto da vigilância epidemiológica do Laboratório de Hantavirose e Rickettsioses doInstituto Oswaldo Cruz, onde o estudo foi realizado. O resultado da análise mostrou umasoroprevalência de 8,7 por cento (8/92) para febre Q, uma prevalência superior à comparada àsoutras taxas encontradas na população geral brasileira. A prevalência de anticorpos antiBartonellaspp. foi de 1,7 por cento (2/118), muito inferior se comparada às taxas observadas emoutros estudos, principalmente no Brasil onde as taxas são superiores a 30 por cento. Todas as118 amostras foram negativas para hantavirose. Apesar das limitações de um estudoretrospectivo utilizando dados secundários, o presente estudo alerta para a necessidade dese instituir medidas de precauções efetivas nos abrigos de animais para diminuir o riscoocupacional de infecções zoonóticas em profissionais que manuseiam animais...

The risk of zoonotic agents infection is considered higher in professionals who care foranimals. The increasing of abandoned animals in the big cities and your accommodationin shelters (with poor sanitary conditions and inadequate infrastructure) increase the riskof transmission of zoonotic agents not only in animals but also for professionals, thusdetermining the occurrence of occupational zoonoses. In this scenario, five employees ofan animal shelter in a city of Rio de Janeiro died after an outbreak of Rocky Mountainspotted fever, in which a serological survey in the animal shelter workers and dogsdemonstrated that employees and dogs were seroreactive with high titers. Given the aboveand the need for additional research on other zoonotic agents that might be associatedwith occupational disease, an study was conducted in order to investigate the presence ofanti-Coxiella burnetii, anti-Bartonella, anti-Hantavirus in professional na an animalshelter as part of the measures imposed in the contexto of epidemiological surveillanceof Hantavirus and Rickettsiosis Laboratory of the Oswaldo Cruz Institute, where the studywas conducted. The analisys showed a prevalence of 8.7 percent (8/92) for Q fever, a higherprevalence compared to the other rates found in the general Brasilian population. Theprevalence of antibodies anti-Bartonella spp. was 1.7 percent (2/118), much lower comparedto rates observed in other studies, particularly in Brazil where rates above 30 percent. All 118samples were negative for hantavirus. Despite the limitations of a retrospective studyusing secondary data, this study points to the need establish effective precautionmeansures in animal shelters to reduce occupational risk of zoonotic infections inprofessionals who care for animals...

Serologic surve on hantavirus in blood donors from the state of santa Catarina, Braiil / Inquérito sorológico para hantavírus em doadores de sangue no Estado de Santa Catarina, Brasil

Emergent diseases such as Hantavirus Cardio-pulmonary Syndrome (HCPS) are able to create a significant impact on human populations due to their seriousness and high fatality rate. Santa Catarina, located in the South of Brazil, is the leading state for HCPS with 267 reported cases from 1999 to 2011. We present here a serological survey on hantavirus in blood donors from different cities of the state of Santa Catarina, with an IgG-ELISA using a recombinant nucleocapsid protein from Araraquara hantavirus as an antigen. In total, 314 donors from blood banks participated in the study, geographically covering the whole state. Among these, 14 individuals (4.4%) had antibodies to hantavirus: four of 50 (8% positivity) from Blumenau, four of 52 (7.6%) from Joinville, three of 50 (6%) from Florianópolis, two of 50 (4%) from Chapecó and one of 35 (2.8%) from Joaçaba. It is possible that hantaviruses are circulating across almost the whole state, with important epidemiological implications. Considering that the seropositive blood donors are healthy individuals, it is possible that hantaviruses may be causing unrecognized infections, which are either asymptomatic or clinically nonspecific, in addition to HCPS. It is also possible that more than one hantavirus type could be circulating in this region, causing mostly benign infections.

Doenças emergentes como a Síndrome Cárdio-Pulmonar por Hantavírus (SCPH) são capazes de promover um grande impacto nas populações humanas devido a sua severidade e alta letalidade. Santa Catarina, localizada ao Sul do Brasil, é o estado com o maior número de relatos de SCPH, com 267 casos desde 1999 a 2011. Apresentamos aqui um inquérito sorológico para hantavírus em doadores de sangue de diferentes cidades do Estado de Santa Catarina, usando um teste IgG-ELISA com proteína recombinante de nucleocapsídeo do hantavírus Araraquara como antígeno. No total, 314 doadores de banco de sangue participaram do estudo, cobrindo geograficamente todo o Estado. Dentre estes, 14 indivíduos (4,4%) apresentaram anticorpos para hantavírus: quatro de 50 (8% de positividade) provenientes de Blumenau, quatro de 52 (7,6%) de Joinville, três de 50 (6%) de Florianópolis, dois de 50 (4%) de Chapecó e um de 35 (2,8%) de Joaçaba. É possível que hantavírus estejam circulando praticamente em todo o Estado, com implicações epidemiológicas importantes. Considerando que os doadores de sangue soropositivos são indivíduos saudáveis, é possível que hantavírus possam estar causando infecções não diagnosticadas, sejam elas assintomáticas ou clinicamente inespecíficas, além da SCPH. É possível ainda que mais de um tipo de hantavírus possa estar circulando na região, causando infecções mais benignas.

Análise do perfil epidemiológico da hantavirose no Brasil no período de 2007 a 2012 / Analysis of the epidemiological profile of hanavirus in Brazil for the period 2007 to 2012

As hantaviroses são zoonoses que causam doenças humanas graves como a síndrome cardiopulmonar por hantavírus (SCPH) registrada no continente americano. No Brasil a SCPH é doença de notificação obrigatória aos serviços de saúde por apresentar elevada letalidade e incipiente conhecimento da sua epidemiologia. O presente estudo descreve o perfil epidemiológico da SCPH no Brasil para o período de 2007 a 2012. Foi realizado um estudo descritivo dos registros do Sistema Nacional de Agravos de Notificação, foram analisadas as fichas de notificação e investigação e os dados foram avaliados quanto a completitude da informação, oportunidade e perfil dos casos registrados. Os resultados são apresentados em números brutos, medidas de proporção e tendência central e as analises foram desenvolvidas pelos softwares Excel 2010, Tabwin 32 e TerraView. No período estudado foram notificados 8.456 casos de SCPH, com confirmação de 9 porcento (756/8.456), preferencialmente pelo critério laboratorial 91,1 porcento (689/756). O coeficiente de letalidade médio para o período foi de 38,2 porcento, as maiores incidências da doença foram nos estados do Mato Grosso, Santa Catarina e Distrito Federal e as maiores letalidades no Amazonas, Mato Grosso e São Paulo. Quanto à sazonalidade foram observados casos em todos os meses do ano; os óbitos foram mais frequentes em homens 72,3 porcento (209/289) e maior letalidade 42,3 porcento (80/189) foi observada em mulheres. Os casos acometeram principalmente pessoas que exerciam atividades relacionadas à agricultura 18,8 porcento (90/478) que se expuseram ao ambiente com roedores 36,9 porcento (279/756)...

Hantaviruses are zoonoses that cause serious human diseases in the Americas such as hantavirus pulmonary syndrome (HPS). In Brazil HPS is a notifiable disease to health services due to its high lethality and incipient knowledge of its epidemiology. The present study describes the epidemiology of HPS in Brazil for the period 2007-2012. We conducted a descriptive study of the records of the National Notifiable Diseases System, analyzed the reporting forms and research, and the data were evaluated for completeness of information, opportunity and profile of registered cases. The results are presented as raw numbers, measures of central tendency and proportion and analyses developed using Excel 2010 software, and 32 Tabwin terraView. In the study period 8,456 cases of HPS were reported, with confirmation of 9 percent (756/8,456), ideally by laboratory testing 91.1 percent (689/756). The average coefficient of lethality for the period was 38.2 percent, whilst the highest incidences of the disease were in the states of Mato Grosso, Santa Catarina and the Federal District and the greatest lethalities were in Amazonas, Mato Grosso and São Paulo. Regarding seasonality, cases were observed in all months of the year. Deaths were more frequent in males 72.3 percent (209/289) and high mortality was observed in women 42.3 percent (80/189). The cases were mainly people who conducted activities related to agriculture 18.8 percent (90/478) who were exposed to the rodent environment, 36.9 percent (279/756)...

Avaliação da infecção por Hantavirus em amostras humanas e de roedores silvestres e sinantrópicos no Estado do Rio de Janeiro / Assessment for hantavirus infection in human specimens and wild and synanthropic rodents in Rio de Janeiro

A síndrome pulmonar por hantavírus (SPH) tem sido registrada no Brasil desde1993 e a transmissão para o homem ocorre através da inalação de partículas viraispresentes em aerossóis de excretas de roedores infectados. No Brasil, nove genótiposvirais caracterizados a partir de roedores e/ou humanos foram descritos, sendo seiscomprovadamente patogênicos. Desde os primeiros registros, mais de 1600 casoshumanos foram confirmados, com ampla distribuição entre a maioria dos estadosbrasileiros e alta taxa de letalidade. A SPH apresenta-se como doença febril agudacaracterizada pelo grave comprometimento cardiovascular e respiratório. Os pacientespodem exibir uma ampla variedade de manifestações clínicas, onde os sinais e sintomaspodem ser confundidos com os de outras doenças. Assim é necessário o diagnósticodiferencial separando casos de SPH de outros agravos com manifestações clínicassemelhantes, como é o caso da dengue. Embora não existam relatos de casos humanosno estado do Rio de Janeiro, foram encontradas evidências sorológicas em humanos econfirmação de circulação de hantavírus patogênico entre roedores silvestres, maisespecificamente, na espécie Oligoryzomys nigripes, no Parque Nacional da Serra dosÓrgãos, em Teresópolis. Neste cenário, este estudo teve como objetivos avaliar ainfecção por hantavírus em amostras humanas e em amostras de roedores silvestres esinantrópicos provenientes de diversos municípios fluminenses. Um total de 497amostras de soro de pacientes negativos para dengue pelos testes sorológicos, cedidaspelo LACEN/RJ, provenientes de 25 municípios, e de 235 amostras de roedoresprovenientes de sete municípios, foram analisadas através do ensaio imunoenzimáticopara detecção de anticorpos anti-hantavírus da classe IgM e IgG (ELISA IgM e IgG) ede testes moleculares...

Hantavirus pulmonary syndrome (HPS) has been registered in Brazil since 1993and transmission to humans occurs through inhalation of viral particles present inaerosols from excreta of infected rodents. In Brazil, nine viral genotypes characterizedfrom rodents and/or humans have been described, six of them pathogenic. Over 1.600human cases were confirmed, with wide distribution among most Brazilian states andhigh lethality. Hantavirus pulmonary syndrome presents as an acute febrile illnesscharacterized by severe cardiovascular and respiratory compromise. Patients mayexhibit a wide variety of clinical manifestations, where signs and symptoms can beconfused with other diseases. Thus the differential diagnosis of HPS is necessary fromother illnesses with similar clinical manifestations, such as dengue. There are no reportsof human cases in Rio de Janeiro state, until now, but serologic evidence in humans andconfirmation of circulating pathogenic hantavirus among wild rodents in ParqueNacional da Serra dos Órgãos in Teresopolis, related to the rodent Oligoryzomysnigripes were found. In this scenario, this study aimed to evaluate hantavirus infectionin human, wild and synanthropic rodents samples from different municipalities in Riode Janeiro state. Serum samples from 497 dengue fever seronegative patients, from 25municipalities provided by the LACEN/RJ, and 235 serum samples from rodents, fromseven municipalities, were analyzed by enzyme-linked immunosorbent assay fordetection of anti-hantavirus antibodies of IgM and IgG (IgM and IgG ELISA) andmolecular tests. Five human samples, from Valença, Vassouras and Nova Friburgomunicipalities, presented IgM antibodies against hantavirus...

Etiología y caracterización epidemiológica del síndrome febril no palúdico en tres municipios del Urabá antioqueño, Colombia / Etiology and epidemiological characterization of non-malarial febrile syndrome in three municipalities of Urabá (Antioquia), Colombia

Introducción. La región de Urabá es endémica para varias enfermedades febriles agudas de origen infeccioso. Sin embargo, solo los pacientes con malaria pueden acceder a un diagnóstico oportuno y rápido, motivo por el cual muchos síndromes febriles no palúdicos quedan sin diagnóstico etiológico claro. Objetivo. Establecer la etiología, describir las manifestaciones clínicas y explorar algunos posibles factores de riesgo relacionados con los síndromes febriles agudos no palúdicos en pacientes procedentes de los municipios de Necoclí, Turbo y Apartadó. Materiales y métodos. Se tomaron muestras de suero en fase aguda y de convalecencia de 220 pacientes febriles negativos para malaria, provenientes de zonas rurales y urbanas de Necoclí, Turbo y Apartadó en los años 2007 y 2008. Se practicaron pruebas para diagnóstico de dengue (detección de anticuerpos IgM por ELISA), leptospirosis (detección de anticuerpos IgM e IgG por IFI), rickettsiosis (detección de anticuerpos IgG por IFI), hantavirus y arenavirus (detección de anticuerpos IgG por ELISA). Resultados. Se encontraron frecuencias de dengue, leptospirosis, rickettsiosis y arenavirus de 37,3 %, 14,1 %, 2,7 % y 0,5 %, respectivamente. Se presentaron 12 casos de coinfección de leptospirosis-dengue y uno de leptospirosis-rickettsiosis-dengue. El sexo masculino y la humedad relativa media, fueron factores de riesgo para dengue. El inicio de signos clínicos en febrero de 2008, se asoció tanto con la infección por dengue como por leptospirosis. Conclusión. Se reafirma la importancia del virus del dengue, Rickettsia spp. y Leptospira spp., como agentes causantes del síndrome febril en la región del Urabá.

Introduction: Urabá, a region on the northern coast of Colombia, is endemic to several acute febrile illnesses of infectious origin; however, only patients with malaria may have access to quick and effective diagnosis. For this reason, many non-malarial febrile patients go without a clear etiologic diagnosis. Aim: To establish the etiology and clinical signs of acute febrile non-malaria syndromes and explore some of the likely risk factors in patients originating in the municipalities of Necocli, Turbo and Apartado who exhibit these symptoms. Materials and methods: We obtained acute and convalescent sera from 220 non-malarial febrile patients from the rural and urban zones of Necocli, Turbo and Apartado during 2007 and 2008. Serologic tests for dengue (IgM by ELISA), leptospirosis (IgM and IgG by IFA), rickettsiosis (IgG by IFI), hanta and arenavirus (IgG by ELISA) were performed. Results: We found that the frequency of infection for dengue, leptospirosis, rickettsiosis and arenavirus, was 37.3%; 14.1%; 2.7% and 0.5%, respectively. There were 12 co-infection cases of leptospirosis-dengue and one of leptospirosis-rickettsiosis-dengue. Male gender and relative humidity were considered risk factors for dengue, and the beginning of clinical signs in February of 2008 was associated with the infection of dengue and leptospirosis. Conclusion: This study confirms previous records that underline the importance of Rickettsia spp, dengue virus and Leptospira spp as causal agents of febrile syndrome in this region of Colombia.

Serological survey of hantavirus in rodents in Uberlândia, Minas Gerais, Brazil / Inquérito sorológico de hantavírus em roedores, Uberlândia, Minas Gerais, Brasil

We conducted a serological survey to determine the presence of hantavirus infection in rodents in Uberlândia, Minas Gerais as well as to identify and characterize associated factors. Rodents were captured using Sherman live-capture traps set in rural and peri-urban environments. A total of 611 rodents were captured. There was a higher trap success in peri-urban areas (26.3%) and a higher prevalence of antibodies among rodents captured in rural areas (2.9%). Necromys lasiurus was the most common species (42.2%) and the more frequently infected (4.6%). One Calomys tener (1/141; 0.7%) and one Calomys sp. (1/14; 7.1%) were also positive for the hantavirus infection. In N. lasiurus, antibody prevalence correlated with population density (p < 0.01), age class (p = 0.003) and presence of scars (p = 0.02). The data confirm that horizontal transmission is the main mechanism that maintains the virus in nature. The higher seropositivity in N. lasiurus is consistent with genetic studies that associate this species with an Araraquara virus reservoir; the seropositivity of C. tener and Calomys sp. may indicate the occurrence of spillover infection or the presence of other circulating hantaviruses.

Realizamos um estudo transversal para identificar a presença de infecção por hantavírus em roedores em Uberlândia, Minas Gerais, e também para identificar e caracterizar fatores associados. Roedores foram capturados usando armadilhas do tipo Sherman em ambientes rural e periurbano. Um total de 611 roedores foi capturado. Houve maior sucesso de captura na área periurbana (26,3%) e maior prevalência de anticorpos entre os roedores capturados na área rural (2,9%). Necromys lasiurus foi a espécie mais encontrada (42,2%) e a mais frequentemente infectada (4,6%). Um Calomys tener (1/141; 0.7%) e um Calomys sp. (1/14; 7.1%) foram também positivos. Os dados obtidos mostram que em N. lasiurus, a prevalência de anticorpos está relacionada à densidade populacional (p < 0.01), a classe de idade (p = 0.003) e a presença de cicatrizes (p = 0.02), confirmando que a transmissão horizontal é o principal mecanismo que mantém o vírus na natureza. A maior positividade em N. lasiurus é consistente com estudos genéticos que permitem associar esta espécie como reservatório do vírus Araraquara; a soropositividade de C. tener e Calomys sp. pode indicar a ocorrência de "spillover infection" ou a presença de outros hantavírus circulantes.

Prevalence of antibody to hantaviruses in humans and rodents in the Caribbean region of Colombia determined using Araraquara and Maciel virus antigens

We tested sera from 286 agricultural workers and 322 rodents in the department of Córdoba, northeastern Colombia, for antibodies against two hantaviruses. The sera were analysed by indirect ELISA using the lysate of Vero E6 cells infected with Maciel virus (MACV) or the N protein of Araraquara virus (ARAV) as antigens for the detection of antibodies against hantaviruses. Twenty-four human sera were IgG positive using one or both antigens. We detected anti-MACV IgG antibodies in 10 sera (3.5%) and anti-ARAV antibodies in 21 sera (7.34%). Of the 10 samples that were positive for MACV, seven (70%) were cross-reactive with ARAV; seven of the 21 ARAV-positive samples were cross-reactive with MACV. Using an ARAV IgM ELISA, two of the 24 human sera (8.4%) were positive. We captured 322 rodents, including 210 Cricetidae (181 Zygodontomys brevicauda, 28 Oligoryzomys fulvescens and 1 Oecomys trinitatis), six Heteromys anomalus (Heteromyidae), one Proechimys sp. (Echimyidae) and 105 Muridae (34 Rattus rattus and 71 Mus musculus). All rodent sera were negative for both antigens. The 8.4% detection rate of hantavirus antibodies in humans is much higher than previously found in serosurveys in North America, suggesting that rural agricultural workers in northeastern Colombia are frequently exposed to hantaviruses. Our results also indicate that tests conducted with South American hantavirus antigens could have predictive value and could represent a useful alternative for the diagnosis of hantavirus infection in Colombia.

Serologic survey of hantavirus in a rural population from the northern State of Mato Grosso, Brazil

INTRODUCTION: Hantavirus is a genus of ribonucleic acid (RNA) viruses included in the family Bunyaviridae. Hantaviruses are rodent-borne zoonoses that, in the last 18 years, became an emergent public health problem in the Americas, causing a severe cardiopulmonary syndrome. This disease has no specific treatment and has a high case fatality. The transmission of hantavirus to man occurs by inhaling aerosols of rodent excreta. The aim of this study was to determine the prevalence of antibodies to hantavirus in the population of the rural settlement of Tupã in the county of Marcelândia, state of Mato Grosso, Brazil. METHODS: The participants of the serologic survey were visited at their homes and selected randomly among the settlement population. Blood samples of the participants were collected by venopuncture. The serum samples were tested by an IgG-ELISA using an N recombinant protein of Araraquara hantavirus as antigen, using the protocol previously established by Figueiredo et al. RESULTS: IgG antibodies to hantavirus were detected in 7 (13%) of the 54 participants. The positivity was higher among men. It was observed that there was an association of seropositivity to hantavirus within the participants born in the south of Brazil. CONCLUSIONS: The results suggest that, in this rural area, everyone is exposed to the same risk of becoming infected with hantavirus, and, therefore, there is a need to intensify surveillance activities and education of the local people to prevent this viral infection.