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.

Padronização da PCR em Tempo Real para o Diagnóstico da Hepatite B / Standardization of real-time PCR for the hepatitis B diagnosis

A hepatite B é uma doença de interesse em saúde pública, acometendo cerca de 2 bilhões de pessoas no mundo, das quais aproximadamente 350 milhões tornam-se portadoras crônicas. Os ensaios quantitativos de detecção do DNA viral são empregados para avaliar a infectividade do vírus e para o monitoramento do tratamento, sendo importante para avaliar a progressão da doença. O objetivo deste estudo foi padronizar a técnica de amplificação quantitativa em tempo real (PCR em tempo real) do DNA do vírus da Hepatite B e comparar a técnica com métodos comerciais (COBAS AmpliPrep/COBAS TaqMan® e COBAS AmpliPrep/COBAS TaqMan®). A amostragem foi constituída por 397 amostras de soro ou plasma recebidas e estocadas no laboratório de hepatites virais do Centro de Virologia do Instituto Adolfo Lutz, no período de 2009 a 2011. Do total de amostras, 345 foram utilizadas para a comparação com os testes comerciais disponíveis e 52 amostras foram utilizadas para o teste de especificidade, sendo 27 amostras HIV positivas e 25 amostras HCV positivas, todas com AgHBS e Anti-HBc total não reagentes. Estas amostras foram inicialmente analisadas por testes comerciais e posteriormente pela técnica padronizada. Para o controle da quantificação, uma curva padrão foi construída em todas as reações, utilizando-se padrões internacionais produzidos pela Organização Mundial de Saúde, em diluições seriadas. Para a extração do DNA das amostras e padrão, foi utilizado kit comercial (QIAGEN®), seguindo os procedimentos descritos pelo fabricante. Os testes foram realizados empregando o método do TaqMan – PCR, em um equipamento ABI 7300 (Applied Biosystems, Foster City, CA). Os “primers” e sondas utilizadas para a padronização foram selecionados a partir da literatura e os que apresentaram melhores resultados nos testes iniciais foram escolhidos para o estudo. A técnica de sequenciamento foi realizada nas amostras com carga viral quantificável...

Hepatitis B is a disease of public health concern. Worldwide, it affects approximately 2 billion people, of whom approximately 350 million become chronic carriers. Quantitative assays for the detection of viral DNA are used to evaluate the infectivity of the virus and to monitor treatment, which is crucial to evaluate the progression of the disease. The aim of this study was to standardize real-time (real-time PCR) quantitative amplification of the DNA of hepatitis B and to compare this technique with commercial methods (COBAS AmpliPrep / COBAS ® TaqMan and COBAS AmpliPrep / COBAS TaqMan ®). The sample consisted of 397 serum or plasma samples received and stored at the laboratory of viral hepatitis from the Center of Virology, Instituto Adolfo Lutz, from 2009 to 2011. Of the total samples, 345 were used for comparison with the available commercial tests and 52 samples were used for the specificity test. Of these, 27 were HIV positive and 25, HCV positive, and all were HBsAg and anti- HBc nonreactive. These samples were initially analyzed by commercial tests and later by the standardized technique. To control the quantification, a standard curve was constructed in all reactions using international standards established by the World Health Organization, in serial dilutions. For the extraction of DNA samples and standard, a commercial kit used was (QIAGEN ®) according to the manufacturer’s instructions. The tests were performed using the TaqMan method - ABI 7300 PCR system (Applied Biosystems, Foster City, CA). Primers and probes used for standardization were selected from the literature and those presenting better results in initial tests were chosen for the study. Sequencing technique was performed on samples with measurable viral load. The standardized real-time PCR technique yielded satisfactory results...

Prediction of fibrosis progression in chronic viral hepatitis

Prediction of liver fibrosis progression has a key role in the management of chronic viral hepatitis, as it will be translated into the future risk of cirrhosis and its various complications including hepatocellular carcinoma. Both hepatitis B and C viruses mainly lead to fibrogenesis induced by chronic inflammation and a continuous wound healing response. At the same time direct and indirect profibrogenic responses are also elicited by the viral infection. There are a handful of well-established risk factors for fibrosis progression including older age, male gender, alcohol use, high viral load and co-infection with other viruses. Metabolic syndrome is an evolving risk factor of fibrosis progression. The new notion of regression of advanced fibrosis or even cirrhosis is now strongly supported various clinical studies. Even liver biopsy retains its important role in the assessment of fibrosis progression, various non-invasive assessments have been adopted widely because of their non-invasiveness, which facilitates serial applications in large cohorts of subjects. Transient elastography is one of the most validated tools which has both diagnostic and prognostic role. As there is no single perfect test for liver fibrosis assessment, algorithms combining the most validated noninvasive methods should be considered as initial screening tools.

Artículo de revisión: hepatitis viral B y su manejo / Review article: viral hepatitis B and its handling

La Hepatitis B es causada por el virus del mismo nombre (VHB). El paciente presenta ictericia, acolia, coluria, astenia, adinamia, anorexia, distensión abdominal, lienteria, náuseas y vómitos sin fiebre. Blumberg y colaboradores detectaron y caracterizaron al nuevo Virus. Además de hepatitis postranfusional puede causar epidemias por trasnmisión sexual, alimentos y en las zonas endémicas, perinatal. Trabajos en Asia, América y África demostraron relación del VHB con cirrosis macro y micronodular, hepatocarcinoma. Se presenta una parte de nuestra modesta contribución en Colombia. Varias vacunas están en uso clínico y se describen en el artículo. El tratamiento con Inmunomoduladores como interferones y antivirales inespecíficos como rivabirina, isoprinosine, lamivudina, adefovir, entecavir, tenofovir, emtricitabina, clevudina, alamifovir se comenta en el artículo. La respuesta a antivirales depende del subtipo y genotipo del VHB y mutaciones inducidas por el tratamiento. Esto y progresos en métodos diagnósticos en los cinco últimos años renovaron el interés por estudiar las mutaciones naturales y espontáneas del VHB, sus genotipos, subtipos y respuesta inmune que se revisan.

Hepatitis B is caused by the virus with the same name (HBV). The patient has symptoms of jaundice, acolia, dark urine, fatigue, weakness, anorexia, abdominal distension, lienteria, nausea and vomiting without fever. Blumberg and his colleagues identified and characterized the new virus. Besides postranfusional hepatitis, it can cause epidemics by sexual transmission, food, and in endemic areas, perinatal. Studies in Asia, America and Africa showed a relationship between the HBV and macro and micronodular cirrhosis, hepatocellular carcinoma. We present a part of our modest contribution in Colombia. Several vaccines are being used clinically and they are described in the article. In the article, we discuss the treatment with immunomodulators such as interferons and non-specific antiviral drugs such as isoprinosine, lamivudina, adefovir, entecavir, tenofovir, emtricitabina, clevudina, alamifovir. The response to antiviral drugs depends on the HBV subtype, genotype and mutations induced by the treatment. This and advances in diagnostic methods in the last five years renewed the interest in studying the natural and spontaneous mutations of HBV, its genotypes, subtypes, and the immune response that is analyzed here.

Hepatitis A vaccination in chronic liver disease: is it really required in a tropical country like India?

Vaccination against hepatitis A virus (HAV) has been recommended in patients with chronic liver disease to prevent any decompensation due to superinfection. This may not hold good in high endemic areas for hepatitis A like India. The aim of this study was to find out the seroprevalence of anti-HAV antibodies in patients with chronic liver disease and to justify the need for vaccination against hepatitis A virus in these patients. One hundred and thirty three consecutive patients with cirrhosis of liver attending Gastroenterology department of our Institute between June 2004 and June 2005 were enrolled. Seventy-five healthy persons were taken as controls. The diagnosis of cirrhosis was based on clinical profile, biochemical, radiological (ultrasound abdomen) and endoscopic findings. The etiology of cirrhosis was based on presence of viral markers, history of significant alcohol consumption, autoimmune and metabolic workup. All patients and controls were tested for antiHAV (total) antibodies using commercially available enzyme-linked immunosorbent assay kits. Data from patients and control group were compared by unpaired 't' test and Chi square test. All subjects were in the age group 11 to 75 years. Etiology of chronic liver disease was as follows: HBV- 29.3%, HCV - 14.28%, HBV+HCV dual -1.5%, alcohol- 21.8%, Cryptogenic -23.3%, Wilson"s Disease -1.5% and Budd chiari -1.5%. The prevalence of HAV was 93.2% in patients with cirrhosis of liver and 94.6% in controls. The prevalence was almost similar irrespective of the etiology. In view of high seroprevalence of HAV antibodies among cirrhotic patients in our study and the high cost of the vaccine, the hepatitis A vaccination may not be routinely required in this part of the world.