Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil

Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004. These first cases were followed by two fatal cases, one in the municipality of Maués in 2005 and another in Itacoatiara in 2007. In this study, we investigated the antibody levels to hantavirus in a population of 1,731 individuals from four different counties of AM. Sera were tested by IgG/IgM- enzyme-linked immune-sorbent assay using a recombinant nucleocapsid protein of the Araraquara hantavirus as an antigen. Ten sera were IgG positive to hantavirus (0.6 percent). Among the positive sera, 0.8 percent (1/122), 0.4 percent (1/256), 0.2 percent (1/556) and 0.9 percent (7/797) were from Atalaia do Norte, Careiro Castanho, Itacoatiara and Lábrea, respectively. None of the sera in this survey were IgM-positive. Because these counties are distributed in different areas of AM, we can assume that infected individuals are found throughout the entire state, which suggests that hantavirus disease could be a local emerging health problem.

Combining diagnostic procedures for the management of leishmaniasis in areas with high prevalence of Leishmania guyanensis / Procedimentos diagnósticos combinados no manejo da leishmaniose em áreas com alta prevalência de Leishmania guyanensis

BACKGROUND: The Amazon region corresponds to approximately 40 percent of the cases of leishmaniasis in Brazil. We report a prospective study with 180 patients conducted in a health care unit that diagnoses 10 percent of the cases of leishmaniasis in the Brazilian Amazon. The study addresses how a combination of procedures improves diagnosis in areas with high prevalence of Leishmania guyanensis. OBJECTIVES: to evaluate diagnostic methods in areas with high prevalence of Leishmania guyanensis. METHODS: All subjects were amastigote-positive by direct microscopic examination of lesion scarifications. We conducted skin biopsy and histopathology, polymerase chain reaction and parasite cultivation. RESULTS: Polymerase chain reaction detected almost ninety percent of infections when two amplification protocols were used (mini-exon and HSP-70). HSP-70 specific polymerase chain reaction matched the sensitivity of parasite cultivation plus histopathology. CONCLUSION: The best combination was polymerase chain reaction plus histopathology, which increased diagnostic sensitivity to 94 percent. Species discrimination by polymerase chain reaction disclosed prevalence of human infections with Leishmania guyanensis of 94 percent and with Leishmania braziliensis of 6 percent for this region.

FUNDAMENTOS: O Amazonas corresponde a aproximadamente 40 por cento dos casos de leishmaniose do país. Nós reportamos um estudo prospectivo com 180 pacientes de uma unidade de saúde que diagnostica 10 por cento dos casos de leishmaniose da amazônia brasileira, com combinação de métodos diagnóstico em área de alta prevalência de Leishmania guyanensis. OBJETIVOS: avaliar métodos diagnóstico da Leishmaniose em área endêmica para Leishmania Amazonensis. MÉTODOS: Todos os pacientes tiveram exame direto positivo com presença de amastigotas. Foi feita também biópsia cutânea, com realização de exame histológico, reação em cadeia da polimerase e cultura. RESULTADO: A reação em cadeia da polimerase detectou aproximadamente 90 por cento de infecção quando foram usados duas técnicas de amplificação (mini-exon and HSP-70). A reação em cadeia da polimerase com HSP-70 foi mais sensível que a cultura associada à histopatologia. CONCLUSÃO: A melhor combinação foi a reação em cadeia da polimerase com histopatologia, com sensibilidade de 94 por cento. A discrimanação das espécies causadoras de infecção humana nessa região mostrou Leishmania guyanensis em 94 por cento dos casos e Leishmania brasiliensis em 6 por cento.

HIV-associated tuberculous lymphadenitis: the importance of polymerase chain reaction (PCR) as a complementary tool for the diagnosis of tuberculosis - a study of 104 patients / Linfadenite tuberculosa associada ao HIV: a importância da reação em cadeia de polimerase (PCR) como ferramenta complementar para o diagnóstico da tuberculose - estudo de 104 pacientes

BACKGROUND: Lymphadenitis is common in HIV-positive patients. Diagnosis of the infections associated with this condition is complex, particularly in the case of tuberculosis. Rapid and specific detection of Mycobacterium tuberculosis (M. tuberculosis) is fundamental in ensuring adequate treatment. In addition, frequent causes of lymphadenitis such as those associated with lymphoma and histoplasmosis, among others, must be eliminated as possible causes. OBJECTIVES: To evaluate the accuracy of polymerase chain reaction as a tool for the diagnosis of lymphadenitis resulting from M. tuberculosis. METHODS: In this study, a protocol was developed using the following procedures: direct microscopy using Ziehl-Neelsen staining, culture in Lowenstein-Jensen medium, histology and polymerase chain reaction. RESULTS: A total of 104 patients were included in the study. According to histopathology, 38 patients (36 percent) were found to have nonspecific chronic lymphadenitis, 27 (26 percent) had tuberculous lymphadenitis, 11 patients (10.5 percent) had lymphoma and 9 (8.7 percent) had histoplasmosis. When Lowenstein-Jensen culture was performed, positive tests for tuberculous lymphadenitis increased by 30 percent. With polymerase chain reaction, M. tuberculosis DNA was detected in 6 out of 38 samples of non-specific chronic lymphadenitis. Three of these patients were followed up, developed symptoms of tuberculosis and were cured following specific treatment. CONCLUSION: The data obtained in this study suggest that all cases of lymphadenopathies should be submitted to histopathology, Lowenstein-Jensen or Ogawa culture and polymerase chain reaction. Polymerase chain reaction may prove to be useful in providing an early and accurate detection of cases of extrapulmonary tuberculosis in HIV-positive patients with lymphadenopathies, avoiding empirical treatment and the possible development of resistant strains.

FUNDAMENTOS: A linfadenite é comum em pacientes HIV-positivos. O diagnóstico das infecções associadas a essa condição é complexo, especialmente em relação à tuberculose. A detecção rápida e específica do Mycobacterium tuberculosis (M. tuberculosis) é essencial para o tratamento adequado. Além disso, frequentes causas de linfadenites tais como as relacionadas a linfoma, histoplasmose, e outras, devem ser afastadas. OBJETIVOS: Avaliar a importância da biópsia cirúrgica excisional das linfadenites e realização dos exames histopatológicos, exames baciloscópicos (Ziehl-Neelsen), cultura (Lowenstein-Jensen) e reação em cadeia da polimerase (PCR) com finalidade diagnostica MÉTODOS: Desenvolveu-se um protocolo para biópsias excisionais de linfonodos, adotando-se os seguintes procedimentos: exame direto de esfregaços corados pelo método de Ziehl-Neelsen, cultura em meio de Lowenstein-Jensen, exame anátomo-patológico e PCR. RESULTADOS: Ao todo foram incluídos 104 pacientes, e o exame histopatológico evidenciou 36 por cento (n = 38 pacientes) de casos de linfadenite crônica inespecífica, 26 por cento (n = 27) de linfadenite tuberculosa, 10,5 por cento (n =11) de linfoma e 8,7 por cento (n = 9) de histoplasmose. Através da cultura no meio de Lowenstein-Jensen, os casos positivos para linfadenite tuberculosa aumentaram para 30 por cento. A PCR detectou M. tuberculosis em 6 das 38 amostras de linfadenite crônica inespecífica. Três desses pacientes foram acompanhados, exibiram sintomas de tuberculose e foram curados após tratamento específico. CONCLUSÃO: Os dados obtidos neste trabalho sugerem que em todos os casos de linfadenopatia deve-se realizar exame histopatológico, cultura em Lowenstein-Jensen ou Ogawa e reação em cadeia da polimerase. A reação em cadeia da polimerase pode ser útil na detecção precoce e acurada de casos de TB extrapulmonar nos pacientes HIV-positivos com linfadenopatias, evitando-se o uso de tratamentos empíricos e o eventual desenvolvimento de cepas resistentes.

Hepatite crônica B oculta: prevalência e aspectos clínicos em população de elevada endemicidade de infecção pelo vírus da hepatite B na Amazônia Ocidental Brasileira / Occult hepatitis B: prevalence and clinical characteristics in a population with high endemicity of hepatitis B infection in the western Brazilian Amazon region

Recentemente é descrito estado de persistência do vírus da hepatite B denominado hepatite crônica B oculta. Sua prevalência e fisiopatologia são desconhecidas. O objetivo deste estudo foi avaliar a ocorrência dessa entidade clínica em pacientes da Amazônia brasileira. De 51 pacientes anti-HBc total reativos testados pela reação em cadeia da polimerase, 17 por cento foram positivos. Não observamos associação com fatores de risco clássicos de infecção pelo vírus da hepatite B, testes bioquímicos, hematológicos e histopatologia. No entanto, os pacientes ictéricos e reativos para o anti-HIV apresentaram associação com a presença do ADN-vírus da hepatite B. Os resultados demonstram a ocorrência da hepatite crônica B oculta, entre nossos doentes, porém, com taxas de prevalência abaixo do esperado para a região. Acreditamos que, apesar do tamanho da amostra avaliada ser pequeno, sua ocorrência poderia ter sido maior se empregássemos primers para a região S, C e X do genoma do vírus da hepatite B, aumentando a sensibilidade do teste.

A persistent form of the hepatitis B virus called occult chronic hepatitis B has recently been described. Its prevalence and physiopathology are unknown. The aim of this study was to evaluate the occurrence of this clinical entity among patients in the Brazilian Amazon region. Out of 51 anti-HBc total-positive patients who were tested using the polymerase chain reaction, 17 percent were positive. We did not find any associations with classical risk factors for hepatitis B virus infection or with biochemical tests, hematological tests or histological patterns. However, the jaundiced and HIV-positive patients showed a statistical association with the presence of hepatitis B virus-DNA. The results demonstrated that occult hepatitis B occurred among our patients, but at prevalence rates lower than expected for this region. We believe that despite the small sample size, the occurrence might have been found to be greater if we had used primers for the S, C and X regions of the hepatitis B virus genome, thereby increasing the sensitivity of the test.

Characterization of HBeAg-negative chronic hepatitis B in western Brazilian Amazonia

The present study was conducted with 55 patients native from western Brazilian Amazonia, who were HBV-DNA positive after seroconversion of HBeAg. It is a descriptive case study, with the patients separated into two groups: with hepatitis and without hepatitis on histological examination. The aim of the present study was to describe the clinical and molecular characteristics of patients who are chronic carriers of HBsAg. The prevalence of hepatitis was 63.64 percent, with a predominance of males (41.82 percent) and a mean age of 42.5 years, occurring mostly in natives of the southeast sub-region (32.73 percent). Time was a variable proportional to the course of the disease and the most frequent symptoms were: dyspepsia, asthenia and loss of libido with the majority of the patients having history of prior contact with HBV or positive family history. Splenomegalia was the most frequent sign (40 percent). Among the tests, platelet count, serum albumin and prothrombin activity were significant in the diagnosis of hepatitis. Alpha-fetoprotein was greater in patients with hepatitis, and hepatocellular carcinoma was detected in 3.63 percent of the patients with hepatic cirrhosis. Three types of HBV genotypes were diagnosed: A, D and F in the samples amplified for gene S. Genotype A (AA) was observed in 54.54 percent of the cases with hepatitis, in contrast to other studies showing the predominance of genotype F in this region. We observed mutations in 36.36 percent, with a predominance of the mutations in the core promoter region (31.81 percent), due to the greater prevalence of genotype A in this study.