A case-control study on the association of hepatitis B virus infection and hepatocellular carcinoma in Northeast Brazil

Hepatitis B virus (HBV) serological markers were investigated in 40 incident cases of hepatocellular carcinoma (HCC) and in two age and sex matched control groups, comprising 40 patients with other cancers and 80 healthy individuals, resident in Bahia, Brazil. Serologic tests were done by radioimmunoassay. The study observed high proportion of seropositivity to HBsAg (42.5%) and of those presenting HBsAg or antiHBc (65.0%) among HCC cases, higher in men than women and in those aged 17 to 30 years old. HBsAg seropositivity among HCC patients was greater than in the control group with other cancers (7.5%) and in healthy controls (2.5%), corresponding to odds ratio estimates of 15.0 (95% CI 3.29, 68.30) and 33.0 (95% CI 9.13, 119.28), both statistically significant. HBeAg was not observed and antiHBe was present in 41.2% of cases, suggesting the absence of viral replication, possibly with viral DNA intergration into the hepatocyte genome. The presence of cirrhosis was associated with HBsAg seropositivity among HCC cases. A history of chronic alcoholism is shown to be more frequently related to those cases with cirrhosis. This study highlights the relevant association between HCC and HBV in Northeast Brazil, particularly for young individuals, and the high risk of development of HCC for HBsAg carriers.

HEPATITIS B VIRUS INFECTION PROFILE IN CENTRAL BRAZILIAN HEMODIALYSIS POPULATION

Hepatitis B has proved to be a major health hazard in hemodialysis patients. In order to investigate the hepatitis B virus (HBV) infection profile in the hemodialysis population of Goiânia city - Central Brazil, all dialysis patients (N=282) were studied. The prevalence of any HBV marker (HBsAg, anti-HBs, and anti-HBc) was 56.7% (95% CI: 51.1-62.7), ranging from 33.3% to 77.7% depending on dialysis unit. HBV-DNA was detected in 67.6% and 88.2% of the HBsAg-positive serum samples, in 91.3% and 100% of the HBsAg/HBeAg-positive samples, and in 18.2% and 63.6% of the HBsAg/anti-HBe-reactive sera by hybridization and PCR, respectively. The length of time on hemodialysis was significantly associated with HBV seropositivity. Only 10% of the patients reported received hepatitis B vaccination. The findings of a high HBV infection prevalence in this population and the increased risk for HBV infection on long-term hemodialysis suggest the environmental transmission, emphasizing the urgent need to evaluate strategies of control and prevention followed in these units.

Prevalence of hepatitis B and C in the sera of patients with HIV infection in São Paulo, Brazil

The objective of this study was to evaluate the prevalence of hepatitis B and C viruses in a group of HIV infected patients, followed at a single institution since 1996. 1,693 HIV positive patients (1,162 male, 531 female) were tested for HBV infection. Virological markers for HBV included HBsAg and total anti-HBc by ELISA. 1,457 patients (1,009 male, 448 female) were tested for HCV infection. Detection of HCV antibodies was carried out by ELISA. A sample of HCV antibody positive patients was tested for HCV by PCR to confirm infection. Of 1,693 patients tested for HBV, 654 (38.6%) and 96 (5.7%) were anti-HBc and HBsAg positive, respectively. Of 1,457 patients tested for HCV, 258 (17.7%) were anti-HCV positive. 82 of these patients were also tested by PCR and 81 were positive (98%). Of 1,411 patients tested for HBV and HCV 26 (1.8%) were positive for both viruses.

Hepatitis C virus seroprevalence and risk factors among patients with HIV infection

The objective of this study was to evaluate the prevalence and risk factors associated with HCV infection in a group of HIV seropositive patients. We analyzed the medical records of 1,457 patients. All patients were tested for HCV infection by third generation ELISA. Whenever possible, a sample of the positive patients was also tested for HCV by PCR. HCV positive patients were analyzed according to their risk factors for both infections. The prevalence of anti-HCV positive patients was 17.7% (258 patients). Eighty-two (82) of these patients were also tested by PCR and 81 were positive for HCV virus (98%). One hundred fifty-one (58.5%) were intravenous drug users (IDU); 42 (16.3%) were sexual partners of HIV patients; 23 (8.9%) were homosexual males; 12 (4.7%) had received blood transfusion; 61 (17.5%) had promiscuous sexual habits; 14 (5.4%) denied any risk factor; 12 (4.7%) were sexual partners of IDU. Two hundred four patients mentioned only one risk factor. Among them, 28 (10.9%) were sexual partners of HIV-positive patients. Although intravenous drug use was the most important risk factor for co-infection, sexual transmission seemed to contribute to the high HCV seroprevalence in this group of patients.

Liver histology in co-infection of hepatitis C virus (HCV) and Hepatitis G virus (HGV)

As little is known about liver histology in the co-infection of hepatitis C virus (HCV) and hepatitis G virus (HGV), HGV RNA was investigated in 46 blood donors with hepatitis C, 22 of them with liver biopsy: co-infection HCV / HGV (n = 6) and HCV isolated infection (n = 16). Besides staging and grading of inflammation at portal, peri-portal and lobular areas (Brazilian Consensus), the fibrosis progression index was also calculated. All patients had no symptoms or signs of liver disease and prevalence of HGV / HCV co-infection was 15.2%. Most patients had mild liver disease and fibrosis progression index, calculated only in patients with known duration of infection, was 0.110 for co-infection and 0.130 for isolated HCV infection, characterizing these patients as "slow fibrosers". No statistical differences could be found between the groups, although a lesser degree of inflammation was always present in co-infection. In conclusion co-infection HCV / HGV does not induce a more aggressive liver disease, supporting the hypothesis that HGV is not pathogenic.

Seasonal variation of hepatitis A virus infection in the city of Rio de Janeiro, Brazil

Hepatitis A virus (HAV) infection constitutes a major public health problem in Brazil. The transmission of HAV is primarily by fecal-oral route so the water is an important vehicle of HAV dissemination. There is a great incidence of acute cases of hepatitis A in some areas of Brazil however the seasonal variation of these cases was not documented. The aim of this study was to determine the seasonality of HAV infection in Rio de Janeiro. From January 1999 to December 2001, 1731 blood samples were collected at the National Reference Center for Hepatitis Viruses in Brazil (NRCHV). These samples were tested by a commercial enzyme-immunoassay to detect anti-HAV IgM antibodies. Yearly positive rates were 33.74% in 1999, 32.19% in 2000, and 30.63% in 2001. A seasonal variation was recognized with the highest incidence in spring and summer. Furthermore a seasonal increase in incidence of HAV infection was found during the rainy season (December to March) because the index of rains is very high. It is concluded that HAV infections occur all year round with a peak during hot seasons with great number of rains.

Seroprevalence of hepatitis B virus infection in individuals with clinical evidence of hepatitis in Goiânia, Goiás: detection of viral DNA and determination of subtypes

The presence of serological markers for hepatitis B virus (HBsAg, anti-HBc IgM and Anti-HBc total) was investigated in the serum of 1,396 individuals who had clinical suspect of hepatitis. It was observed that 50.7% of the individuals were positive and, from the total of the studied individuals, 14.5% were positive for HBsAg. From these, 8.5% were also positive for anti-HBc IgM. The analysis in relation to gender showed a higher seroprevalence index among male individuals (p < 0.0001). It was observed the occurrence of subtypes adw2 (62.7%), ayw3 (23.5%), ayw2 (9.8%) and adw4 (3.9%). The viral DNA was detected in 61 (33.9%) HBsAg positive samples and in one sample positive only for anti-HBc total. These results indicate an important incidence of the HBV infection in this population, and reinforce previous studies regarding this virus in the central west region of Brazil.

Serological, epidemiological and molecular aspects of hepatitis C virus infection in a population from Londrina, PR, Brazil, 2001-2002

Serological, epidemiological and molecular aspects of hepatitis C virus (HCV) infection were evaluated in 183 subjects from Londrina, Paraná, Brazil, and adjacent areas. Serum samples which tested anti-HCV positive by microparticle enzyme immunoassay (MEIA) obtained from eight patients with chronic hepatitis C, 48 blood donors, and 127 patients infected with the human immunodeficiency virus (HIV) were submitted to another enzyme immunoassay (ELISA) and to the polymerase chain reaction (PCR). About 78.7% of samples were also reactive by ELISA, with the greater proportion (70.8%) of discordant results verified among blood donors. A similar finding was observed for HCV-RNA detection by PCR, with 111/165 (67.3%) positive samples, with higher rates among HIV-positive subjects and patients with chronic hepatitis than among blood donors. Sixty-one PCR-positive samples were submitted to HCV genotyping, with 77.1, 21.3 and 1.6% of the samples identified as types 1, 3 and 2, respectively. Finally, analysis of some risk factors associated with HCV infection showed that intravenous drug use was the most common risk factor among HIV/HCV co-infected patients, while blood transfusion was the most important risk factor in the group without HIV infection. The present study contributed to the knowledge regarding risk factors associated with HCV infection and the distribution of HCV genotypes in the population evaluated.

Seroprevalence for hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná , Brazil

A cross-sectional study was carried out among 996 volunteer blood donors enrolled from May 1999 to December 1999 to determine the seroprevalence of hepatitis E virus (HEV) infection among volunteer blood donors of the Regional Blood Bank of Londrina, State of Paraná, Brazil, and to evaluate whether the rate of seroprevalence of IgG anti-HEV antibodies is associated with sociodemographic variables and with seropositivity for hepatitis A virus (HAV) infection. All participants answered the questionnaire regarding the sociodemographic characterisitcs. Serum samples were tested for IgG antibodies to HEV (anti-HEV) by an enzyme linked immunoassay (ELISA). All serum samples positive for anti-HEV IgG and 237 serum samples negative for anti-HEV were also assayed for IgG anti-HAV antibodies by ELISA. Anti-HEV IgG was confirmed in 23/996 samples, resulting in a seroprevalence of 2.3% for HEV infection, similar to previous results obtained in developed countries. No significant association was found between the presence of anti-HEV IgG antibodies and the sociodemographic variables including gender, age, educational level, rural or urban areas, source of water, and sewer system (p > 0.05). Also, no association with seropositivity for anti-HAV IgG antibodies was observed (p > 0.05). Although this study revealed a low seroprevalence of HEV infection in the population evaluated, the results showed that this virus is circulating among the population from Londrina, South Brazil, and point out the need of further studies to define the clinical and epidemiological importance of HEV infection and to identify additional risk factors involved in the epidemiology and pathogenesis of this infection in this population.

Prevalence of hepatitis C virus infection in quilombo remnant communities in Central Brazil

In order to determine the prevalence of hepatitis C virus (HCV) infection in quilombo remnant communities in Central Brazil, 1,007 subjects were interviewed in all 12 communities existing in Mato Grosso do Sul State, Central Brazil. Blood samples were collected and sera were tested for anti-HCV by enzyme-linked immunosorbent assay. Positive samples were retested for confirmation using a line immunoassay and were also subjected to HCV RNA detection. The prevalence of HCV infection was 0.2%. This finding shows a low prevalence of HCV infection in quilombo remnant communities in Central Brazil.

Influence of human t-cell lymphotropic virus type 1 (HTLV-1) Infection on laboratory parameters of patients with chronic hepatitis C virus

Hepatitis C virus (HCV) and human T-cell lymphotropic virus type 1 (HTLV-1) share routes of transmission and some individuals have dual infection. Although some studies point to a worse prognosis of hepatitis C virus in patients co-infected with HTLV-1, the interaction between these two infections is poorly understood. This study evaluated the influence of HTLV-1 infection on laboratory parameters in chronic HCV patients. Twelve HTLV-1/HCV-coinfected patients were compared to 23 patients infected only with HCV, in regard to demographic data, risk factors for viral acquisition, HCV genotype, presence of cirrhosis, T CD4+ and CD8+ cell counts and liver function tests. There was no difference in regard to age, gender, alcohol consumption, smoking habits, HCV genotype or presence of cirrhosis between the groups. Intravenous drug use was the most common risk factor among individuals co-infected with HTLV-1. These patients showed higher TCD8+ counts (p = 0.0159) and significantly lower median values of AST and ALT (p = 0.0437 and 0.0159, respectively). In conclusion, we have shown that HCV/HTLV-1 co-infected patients differs in laboratorial parameters involving both liver and immunological patterns. The meaning of these interactions in the natural history of these infections is a matter that deserves further studies.

Seroprevalence of hepatitis B and C infection markers among children and adolescents in the southern Brazilian region

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. The aim of this study was to determine the prevalence of HBV and HCV serological markers among children and adolescents and verify the epidemiology of the HBV infection over than a decade of the introduction of vaccination program. Serologic markers to HBsAg, total anti-HBc and anti-HCV had been tested in 393 samples. The seropositivity for HBsAg was 0.76% and for total anti-HBc was 1.02%. Copositivity between HBsAg and total anti-HBc was verified in 0.76% of the analyzed samples. There was no seropositivity for anti-HCV marker. The seroprevalence of HBV infection markers among children and adolescents in the southern Brazilian region is high compared to that reported in other countries. Preventive measures, such as educational activities in addition to the universal childhood HBV vaccination, should be initiated in order to reduce the morbimortality and the economic burden associated with the disease.