A Retrospective Survey of Rodent-borne Viruses in Rural Populations of Brazilian Amazon.

INTRODUCTION: The Amazon tropical rainforest has the most dense and diverse ecosystem worldwide. A few studies have addressed rodent-borne diseases as potential hazards to humans in this region. METHODS: A retrospective survey was conducted using enzyme-linked immunosorbent assay for detecting mammarenavirus and orthohantavirus antibodies in 206 samples collected from rural settlers of the Brazilian Western Amazonian region. RESULTS: Six (2.91%) individuals in the age group of 16 to 36 years were found to possess antibodies against mammarenavirus. CONCLUSION: Evidence of previous exposure to mammarenavirus in the rural population points to its silent circulation in this region.

A Retrospective Survey of Rodent-borne Viruses in Rural Populations of Brazilian Amazon

Abstract INTRODUCTION: The Amazon tropical rainforest has the most dense and diverse ecosystem worldwide. A few studies have addressed rodent-borne diseases as potential hazards to humans in this region. METHODS: A retrospective survey was conducted using enzyme-linked immunosorbent assay for detecting mammarenavirus and orthohantavirus antibodies in 206 samples collected from rural settlers of the Brazilian Western Amazonian region. RESULTS: Six (2.91%) individuals in the age group of 16 to 36 years were found to possess antibodies against mammarenavirus. CONCLUSION: Evidence of previous exposure to mammarenavirus in the rural population points to its silent circulation in this region.

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.

Seroprevalence of rodent-borne viruses in Afro-descendent communities in Brazil.

During the Brazilian slavery period, many African migrants were brought to the American continent. Historically, some of these migrants escaped from the Brazilian gold mines and farms to which they had been brought and settled in remote valleys and this was the main mode of resistance to the slavery system. These runaway-slave descendant communities are called quilombos, a group with distinct ethnic identity, specific behavioral habits, including geographic isolation and conservative practices. The objective of this study was to investigate the prevalence of rodent-borne viruses in two Afro-descendent communities from Mato Grosso do Sul State, Midwestern Brazil. A total of 319 individuals from rural and urban quilombola communities were enrolled. Twelve (3.76%) had anti-rodent-borne virus IgG antibodies. Seven (2.19%) were anti-mammarenavirus reactive and nine (2.82%) had anti-orthohantavirus antibodies. The literature includes limited data on the health status of quilombola communities, but all the studies emphasize the disparity of attention of local healthcare personnel to these communities compared to the general population. The findings of this study highlight the vulnerability and the precarious health conditions of quilombola groups, especially those living in rural areas and thus, point to the need of preventive measures to improve access to healthcare for this ethnic group.

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

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.

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.

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

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.

Standardization of an ELISA test using a recombinant nucleoprotein from the Junin virus as the antigen and serological screening for arenavirus among the population of Nova Xavantina, State of Mato Grosso.

INTRODUCTION: Arenavirus hemorrhagic fever is a severe emerging disease. METHODS: Considering that the levels of antibodies against arenavirus in the Brazilian population are completely unknown, we have standardized an ELISA test for detecting IgG antibodies using a recombinant nucleoprotein from the Junin virus as the antigen. This protein was obtained by inserting the gene of the Junin virus nucleoprotein into the genome of Autographa californica nucleopolyhedrovirus, using the Bac-to-Bac baculovirus expression system. This recombinant baculovirus was used to infect S. frugiperda cells (SF9). RESULTS: The infection resulted in synthesis of high concentrations of recombinant protein. This protein was detected on 12.5% polyacrylamide gel and by means of Western blot. Using the standardized ELISA test, 343 samples from the population of Nova Xavantina were analyzed. We observed that 1.4% of the serum samples (five samples) presented antibody titers against arenavirus. CONCLUSIONS: These results show the population studied may present exposure to arenavirus infection.

Standardization of an ELISA test using a recombinant nucleoprotein from the Junin virus as the antigen and serological screening for arenavirus among the population of Nova Xavantina, State of Mato Grosso / Padronização de um teste de ELISA utilizando a nucleoproteína recombinante de vírus Junin como antígeno e triagem sorológica para Arenavírus na população de Nova Xavantina, Estado do Mato Grosso

INTRODUCTION: Arenavirus hemorrhagic fever is a severe emerging disease. METHODS: Considering that the levels of antibodies against arenavirus in the Brazilian population are completely unknown, we have standardized an ELISA test for detecting IgG antibodies using a recombinant nucleoprotein from the Junin virus as the antigen. This protein was obtained by inserting the gene of the Junin virus nucleoprotein into the genome of Autographa californica nucleopolyhedrovirus, using the Bac-to-Bac baculovirus expression system. This recombinant baculovirus was used to infect S. frugiperda cells (SF9). RESULTS: The infection resulted in synthesis of high concentrations of recombinant protein. This protein was detected on 12.5 percent polyacrylamide gel and by means of Western blot. Using the standardized ELISA test, 343 samples from the population of Nova Xavantina were analyzed. We observed that 1.4 percent of the serum samples (five samples) presented antibody titers against arenavirus. CONCLUSIONS: These results show the population studied may present exposure to arenavirus infection.

INTRODUÇÃO: A febre hemorrágica por Arenavirus é uma severa doença emergente. MÉTODOS: Considerando que os níveis de anticorpos contra Arenavirus na população brasileira é totalmente desconhecido, nos padronizamos um teste de ELISA para detecção de anticorpos IgG usando uma nucleoproteína recombinante do vírus Junin como antígeno. Esta proteína foi obtida pela inserção do gene da nucleoproteína do vírus Junin no genoma do vírus Autographa californica nucleopolyhedrovirus, utilizando o sistema de expressão em Baculovírus, Bac-To-Bac. Este baculovirus recombinante foi utilizado para infecção de células de S. frugiperda (Sf9). RESULTADOS: A infecção resultou na produção de altas concentrações de proteína recombinante. Esta proteína foi detectada em gel de poliacrilamida 12,5 por cento, e em Western blot. Utilizando o teste de ELISA padronizado, foram analizadas 343 amostras provenientes da população de Nova Xavantina. Observamos que 1,4 por cento dos soros (5 amostras) apresentavam títulos de anticorpos contra arenavírus. CONCLUSÕES: Estes resultados sugerem que a população estudada pode estar sendo exposta a infecções por arenavírus.

Clinical case definitions for Argentine hemorrhagic fever.

Argentine hemorrhagic fever (AHF) is a potentially lethal infection in Argentina. The case-fatality ratio is >15%, but treatment reduces the mortality rate to <1%. Diagnosis is based on clinical and laboratory criteria, but no case definition has been validated. A chart review was conducted for patients hospitalized with suspected AHF. Individuals with a fourfold rise in antibody titer were classified as cases. The combination of a platelet count of <100,000/mm3 and a white blood cell (WBC) count of <2,500/mm3 had a sensitivity and specificity of 87% and 88%, respectively, thus suggesting that the use of these criteria in a case definition would be helpful for epidemiological studies of AHF. The combination of a platelet count of <100,000/mm3 and a WBC count of <4,000/mm3 had a sensitivity of 100% and a specificity of 71%; the use of these criteria in a case definition should be helpful for screening patients for therapy with immune plasma in the region where AHF is endemic.

[Venezuelan hemorrhagic fever: eight years of observation]. / Fiebre hemorrágica venezolana: ocho años de observación.

Venezuelan hemorrhagic fever (VHF) is a severe disease characterised by fever, malaise, sore throat, followed by abdominal pain, diarrhea, a variety of hemorrhagic manifestations and convulsions. The arenavirus Guanarito is the causal agent and the virus natural reservoir is the rodent Zygodontomys brevauda (cane mouse). The disease affect agricultural male workers, between 14-54 years of age, mainly from Guanarito municipality of Portuguesa state and adjacent regions of Barinas State. Since VHF emergency in 1989 up till 1997, 220 cases have been reported with a fatality rate of 33%. Epidemiological informations suggest that VHF has a cyclic behaviour, with epidemic periods of high incidence, every 4-5 years. During the interepidemic periods few VHF cases are reported.

Fiebre hemorrágica Venozolana: ocho anos de observacion / Venezuelan hemorrhagic fever: eight of observation

La fiebre hemorrágica Venezolana (FHV) es una enfermedad severa, caracterizada por fiebre, malestar general, dolor de cabeza dolor de garganta, seguida por dolor abdominal, diarrea, una variedad de manifestaciones hemorrágicas y convulsiones. El agente causal es el arenavirus Guanarito, el cual es mantenido en la naturaleza por el roedor de la especie Zygodontomys brevicauda: ratón de la caña de azúcar. La enfermedad afecta principalmente a agricultores del sexo masculino, en edades comprendidas entre 14- 54 años, procedentes del Municipio Guanarito del estado Portuguesa y áreas adyacentes del Estado Barinas. Desde la emergencia de la FHV en 1989 hasta 1997, se han reportado 220 casos con una letalidad del 33 por ciento. Tiene un comportamiento epidemiológico cíclico, registrándose periodos epidémicos cada 4-5 años, e interepidémicos con un numero reducido de casos.

[Laboratory-acquired human infection with SP H 114202 virus (Arenavirus: Arenaviridae family): clinical and laboratory aspects]. / Infecção humana adquirida em laboratório causada pelo virus SP H 114202 (Arenavirus: família Arenaviridae): aspectos clínicos e laboratoriais.

Here in is described the clinical and laboratorial findings of a laboratory-acquired infection caused by the virus SP H 114202 (Arenavirus, family Arenaviridae) a recently discovered agent responsible for a viral hemorrhagic fever. The patient was sick for 13 days. The disease had an abrupt onset characterized by high fever (39 degree C.), headache, chills and myalgias for 8 days. In addition, on the 3rd day, the patient developed nausea and vomiting, and in the 10th, epigastralgia, diarrhea and gengivorrhagia. Leucopenia was seen within the 1st week of onset, with counts as low as 2,500 white cells per mm3. Counts performed after the 23rd day of the onset were within normal limits. With the exception of moderate lymphocytosis, no changes were observed in differential counts. An increase in the titer of antibodies by complement fixation, neutralization and ELISA (IgM) was detected. Suckling mice and baby hamsters were inoculated intracerebrally with 0.02 ml of blood samples collected in the 2nd and 7th days of disease. Attempts to isolate the virus were also made in Vero cells. No virus was isolated. This virus was isolated before in a single occasion in São Paulo State, in 1990, from the blood of a patient with hemorrhagic fever with a fatal outcome. The manipulation of the virus under study, must be done carefully, since the transmission can occur through aerosols.