Hepatotropic viruses in the Brazilian Amazon: a health threat: [review]

Viral Hepatitis B, C and D are a serious public health problem in Brazil and other South American countries, mainly in the Amazonian region. Despite the paucity of clinical and epidemiological studies, a high prevalence of Hepatitis viruses has often been described in this area. Genotype F of Hepatitis B and Genotype III of Hepatitis D have been found to be quite prevalent in this area and preliminary studies have implicated both genotypes in carcinogenesis and peculiar pathogenic liver mechanisms. Initial epidemiological studies have further demonstrated a high prevalence of Hepatitis C in the western Brazilian Amazon. The geographic, cultural, ethnic and environmental aspects of this region may favor hepatotropic virus dissemination, as well as rendering difficult the implementation of governmental programs in the treatment of patients and prevention of disease dissemination.

Prevalência de infecção pelo VHB em gestantes atendidas em uma maternidade da região Amazônica brasileira / Prevalence of hepatitis B virus infection in pregnant woman in a referral maternity of Brazilian Western Amazon

Objetivos: A transmissão vertical é responsável por 35 por cento a 40 por cento dos casos novos de hepatite B, sendo a mais importante forma de transmissão nas áreas de elevada prevalência, pois é por meio dela que o vírus é mantido na população e expõe a pessoa aos quadros crônicos mais graves. O objetivo do estudo é determinar a prevalência da infecção pelo vírus da hepatite B em mães e neonatos de uma maternidade da Amazônia brasileira, assim como descrever as características clínico-epidemiológicas das gestantes portadoras do vírus da hepatite B e dos seus respectivos neonatos. Métodos: É um estudo transversal, realizado em uma maternidade do Rio Branco (Acre). Entre outubro e dezembro de 2003 foram estudadas 283 gestantes e seus recém-nascidos. As amostras foram coletadas dos vasos da placenta, por punção direta das artérias e veia. Foram pesquisados o AgHBs e anti-HBs em todos os pacientes. Resultados: A prevalência de mães AgHBs positivas foi de 2,1 por cento (6/283). O AgHBs foi encontrado em 16 por cento (1/6) das amostras dos seus neonatos. A infecção pelo VHB não se associou ao uso de drogas endovenosas, transfusão sanguínea, realização de sorologia contra a hepatite B no pré-natal e história vacinal contra o vírus da hepatite B. 83 por cento (5/6) das mães portadoras do VHB não sabiam ser portadoras da hepatite B. Conclusões: É elevada a prevalência de mães portadoras do AgHBs nesta região do Brasil, mesmo após o pré-natal. A presença de AgHBs no sangue da artéria umbilical, demostra o papel da transmissão vertical intra-uterina

Serological markers of hepatitis A, B and C viruses in rural communities of the semiarid Brazilian Northeast

In the village of Cavunge, located in a dry tropical, semiarid rural region of the state of Bahia, Brazil, a sentinel study on viral hepatitis is underway. We report on the first part of the study. The objective of this study was to determine the prevalence of serological markers for hepatitis A, B and C in the village. Cross sectional study. Blood samples were tested for serological markers of hepatitis A (HAV), B (HBV) and C (HCV) through ELISA-III assay. In HBsAg and anti-HCV carriers, HCV-RNA and HBV-DNA were checked by PCR. The prevalence of anti-HAV IgG was 83.3 percent (1,210/1,452), being higher among residents from the village (87.4 percent) than in residents from the rural area (79.5 percent); it also higher among individuals older than 10 years of age. The prevalence of HBsAg was 2.6 percent (38/1,476), 9.3 percent anti-HBc (137/1,476) and 10.5 percent (155/1,476) anti-HBs of. In more than half (58.1 percent; 90/155) of anti-HBs carriers, this was the only serological marker found. In 3.7 percent of the population, (55/1,476), anti-HBc was the only serological marker found. All HBV carriers were infected by genotype A. Only 0.4 percent (6/1,536) presented anti-HCV antibodies and only one of them was viremic, being infected with genotype 1. The prevalence of patients with antibodies against hepatitis A virus in the village of Cavunge was high, but the prevalence of B virus was moderate, with only genotype A among HBV carriers. The prevalence of C virus was very low, contrasting with the situation in large Brazilian urban centers.

Very low prevalence of hepatitis C virus infection in rural communities of northeastern Brazil with a high prevalence of schistosomiasis mansoni

Alguns autores passaram a rejeitar a hipótese da maior susceptibilidade dos equistossomóticos com a forma clínica hepatosplênica ao vírus da hepatite C, justificando que a associação foi descrita em pacientes hospitalizados ou acompanhados em serviços de saúde e, conseqüentemente, mais expostos à transmissão destes vírus, durante os procedimentos diagnóstico e/ou terapêuticos. Desse modo, o objetivo foi verificar se há ocorrência de associação da esquistossomose mansônica e marcador do VHC em moradores de Catolândia (Bahia, Brasil). Neste estudo transversal, os anticorpos anti-VHC foram pesquisados (ELISA-II) em 1.228 (85,8%) moradores, com os seguintes resultados: Seis (0,5%) soropositivos, oito (0,6%) inconclusivos e 1.214 (98,9%) soronegativos. Todavia, somente em um soro ELISA-positivo (0,08%) os anticorpos foram confirmados pelo RIBA-II e dois outros (ELISA-II positivos) apresentaram RIBA-II indeterminado esses três casos, durante período de seguimento (1976 1996), sempre tiveram a forma hepatointestinal da esquistossomose mansônica. Em conclusão a hipótese de associação entre a esquistossomose mansônica e o VHC nesta área endêmica foi rejeitada, especialmente entre os portadores da esquistossomose mansônica com a forma clínica hepatosplênica.

Very low prevalence of hepatitis C virus infection in rural communities of Northeastern Brazil with a high prevalence of Schistosomiasis mansoni

The association of hepatitis C virus (HCV) infection and the hepatosplenic form of schistosomiasis mansoni (SM) has been claimed to result in the concomitant evolution o the two pathologies, with a poor prognosis due to aggravated liver disease. Recently, however, some authors have begun to reject the hypothesis of a higher susceptibility of hepatosplenic schistosomal patients to HCV. The aim of the present transverse study carried out between July and August 1990 was to determine the possible association between SM and HCV markers in residents of CatoLândia, in the state of Bahia, Brazil. Anti-HCV markers were assayed by ELISA-II and RIB-II in serum samples obtained from 1,228 residents (85.8 por cento).The anti-HCV antibody (ELISA II) was positive in six (0,5por cento) individuals, eight (0.6por cento) cases were inconclusive, and 1,214(98.9por cento) were negative. However, only in one ELISA-positive serum sample (0.08por cento) were antibodies confirmed by /RIBA-II, while two other samples assayed by RIBA-II were indeterminate. These three patients presented the hepatointestinal form of SM during the follow-up period (1976 to 1996),In conclusion, no association was observed between HCV and SM in the endemic area studied especially among patients with the hepatosplenic form of the disease

HCV Infection in Northeastern Brazil: unexpected high prevalence of genotype 3a and absence of African genotypes

The genomic diversity of HCV embraces 6 genoptypes and at least 52 subtypes with clinical and epidemiological correlations. There is a paucity of studiens assessing HCV genotypes and biomolecular epidemiology in Brazil. We studied genotypes distribution and epidemiological aspects in 232 HCV carriers, 133 ( 57,9 per cent) males and 99 (42,1 per cent) females, followed in the liver disease referral unit in Salvador, BA, northeastern Brazil. All of them were anti-HCV positive by 3rd generation ELISA assay, and HCV infection showed that 93 (40 per cent) had past blood transfusion, 14 (6 per cent) intravenous drug use, 19 (8 per cent) inhalation of cocaine, 28 (12 per cent) tattooing, 15 (7 per cent) were health care workers, 5 (2 per cent) had reused disposable syringes, 5 (2 per cent) had multiple risk factors and in 53 (23 per cent) no risk factor was determined.Genotypes 1a was observed in 75 (32 per cent), 1b in 72 (31 per cent), 3a in 61 (26 per cent), 2b in 14 (6 per cent): 5 (2.5 per cent) had mixed genotypes and 5 (2.5 per cent) were undetermined. Patients with genotype 1 had a higher mean age (P<0.05) and no particular risk factors were associated with a specific genotype. Genotype 1 largely predominates in northeast Brazil followed by genotype 3 which, in this population, does not seem to be related to intravenous drug abuse, in contrast to some European studies. Although 80 porcentage of the Salvador population comprise African-Brazilians, no Africa genotype was identified, which way mean that HCV was introduced into this region via European immigration. This study demonstrated some peculiarities of HCV epidemiology in Brazil and strongly suggests that HCV introduction to this region was probably related to European immigration.