Hepatitis B virus infection in immigrants to the southern Brazilian Amazon

Prevalence of hepatitis B and D virus infection in a district of Mato Grosso, bordering Amazonas and Rondônia states

INTRODUCTION:

Brazil’s western Amazon basin has the highest prevalence of hepatitis B virus (HBV) infection in the country. Coinfection with hepatitis D virus (HDV) is also endemic. To estimate the prevalence of HBV and HDV markers in a population inhabiting the northwest portion of Mato Grosso state in the western Amazon.

METHODS:

We performed a cross-sectional study of the seroprevalence of antibodies against HBV core antigen (anti-HBc) in the Três Fronteiras District northwest of Mato Grosso. Anti-HBc-positive subjects were tested for HBV surface antigen (HBsAg). Those positive for this marker were tested for HDV antibodies. Anti-HBc-negative participants were tested for anti-HBsAg. All tests were performed by EIA.

RESULTS:

A total of 623 individuals in the community were assessed; the majority (67.6%) were male, with a mean age of 30.8 ± 15.4 years. Two hundred and fourteen individuals (34.3%) were anti-HBc-positive, and 47 (7.5%) were HBsAg carriers. Only one individual was anti-HDV-positive. Among the 409 individuals without HBV infection, 18.3% were anti-HBsAg-positive. There was no association between HBV infection and known risk factors.

CONCLUSIONS:

The study area had intermediate-to-high endemicity for HBV infection, but a low prevalence of HDV. Our serological results suggesting low vaccination-induced protection indicate a need for reinforced immunization programs in the populations of northwest Mato Grosso.

What is known about sexual and reproductive health in Latin American and Caribbean mining contexts? A systematic scoping review

Background

Latin America and the Caribbean (LAC) has experienced an unprecedented mining boom since the mid-2000s with unknown effects on sexual and reproductive health (SRH). This study takes the essential first steps of summarizing the available literature regarding SRH in mining contexts in LAC, identifying critical gaps in knowledge, and discussing main implications for future research.

Methods

We conducted a scoping review with a systematic search of health literature in four databases, reference lists of selected papers, and citations in Google Scholar.

Results

The systematic search yielded 592 primary references and 16 articles from LAC. The 11 papers finally selected were conducted in gold-mining contexts in Brazil, Venezuela, Guyana, Peru, and Colombia, between 1995 and 2016. Ten studies centered on measuring HIV/STD prevalence among mineworkers and other populations; few examined associated risk factors. Eight studies reported high HIV/STD prevalence in the study population. None of the studies explored broader SRH issues.

Conclusions

Available research is scarce and provides limited evidence on SRH in LAC mining contexts. Critical gaps include little knowledge on (1) broader SRH impacts besides HIV/STDs, (2) SRH in settings different from gold-mining contexts in Amazon countries, (3) mechanisms shaping SRH in LAC mining contexts, and (4) effective interventions in these scenarios. Future research must consider the distinctive demographic, environmental, socioeconomic, and gender dynamics triggered by the mining economy in the analysis of the relationship between mining and SRH, particularly in a period of extractive boom.

[Long-term use of lamivudine for treating chronic hepatitis B in the State of Mato Grosso]

To assess the results from lamivudine treatment (100 mg or 150 mg) for chronic hepatitis B, 34 patients were followed at a clinic in Cuiabá, Mato Grosso, Central Brazil. Among them, 21 (62%) had liver cirrhosis and 24 (70%) were HBeAg-positive. The viral genotype was determined for 18 patients, among whom genotype A was the most prevalent (12). The median follow-up was 27 months (range from 7 to 64 months). Among the total, 23 (67%) presented a biochemical response after 2 to 24 months of treatment. Among the 24 HBeAg-positive subjects, 13 (54%) became HBeAg-negative during the follow-up. Among the anti-HBe-positive patients, 70% obtained normalization of aminotransferase levels. Fourteen (41%) did not present any initial biochemical or serological response or presented breakthrough. The L180M and M204V mutations were found in six of the non-responders. Four patients died after at least 21 months of lamivudine and three patients with liver cirrhosis developed liver cancer after 24 months. From the third year onwards, complications such as digestive system hemorrhage or liver cancer started to emerge. The present findings suggest that an early response to lamivudine treatment may be associated with better control over chronic hepatitis B.

[Soroepidemiological survey of hepatitis B virus among HIV/AIDS patients in Belém, Pará--Brasil]

The objective of this investigation was to study the prevalence of hepatitis B virus infection in a sample of 406 adult patients with human immunodeficiency virus infection who attended at the public health care in the city of Belém, Pará, Brazil, as well as analyzing possible risk factors for hepatitis B virus infection. The overall prevalence of hepatitis B virus infection was 51% (CI: 46.1 - 55.8), with 7.9% (CI: 5.3 - 10.5) for HBsAg, 45.1% (CI: 40.3 - 49.9) for anti-HBc and 32.3% (CI: 27.5 - 36.8) for anti-HBs. After adjustment using logistic regression, hepatitis B serological markers were associated with the following variables: age, marital status and sexual preference. The frequency of hepatitis B markers was 28.7% in heterosexuals and 68.8% in homo/bisexuals (CI: 3.50 - 9.08; OR: 5.63; p=0.000). In married people the frequency was 31% and 58.7% in single people (CI: 1.29 - 3.63); OR: 2.16; p=0.003). Multivariate analysis showed no association between hepatitis B virus infection and illicit injectable drug use.

A hepatite B e os movimentos migratórios no Estado de Mato Grosso, Brasil

A hepatite B é a principal causa de doença hepática na Amazônia, sendo um de seus maiores problemas de saúde pública. A partir dos anos 70, intensificou-se a migração para o sul da Amazônia. No norte do Estado de Mato Grosso, Brasil, foram identificados surtos de hepatite B comunitária e alta prevalência de seus marcadores entre os migrantes após meses da chegada. Análise de subtipos do antígeno de superfície do virus sugere que os migrantes trouxeram o agente infeccioso de suas regiões de origem. Fatores ambientais e comportamentais provavelmente facilitaram a rápida disseminação do vírus da hepatite B nessas comunidades. Dados mais recentes demonstram que a manutenção de vacinação e vigilância nas regiões mais acometidas está diminuindo a incidência da infecção. O aumento do número de casos de hepatite delta entre os portadores do vírus B no norte do Estado de Mato Grosso começa a ser detectado, provavelmente resultante do maior contato com os Estados vizinhos, que têm alta prevalência de hepatite delta.

Relation between hepatitis B carrier status and antibody against synthetic Plasmodium falciparum erythrocyte surface (pf155 - RESA) antigen

A survey on Plasmodium infection was carried out in gold mine camps located in the Brazilian Amazon. Antibody against P. falciparum ring-infected erythrocyte surface antigen (RESA) was quantified by an enzyme-immunoassay in order to assess P. falciparum exposure. Hepatitis B, a common infection in this area, was also investigated by serologic markers. Among 520 sampled subjects, 517 (99.4%) admitted previous symptomatic malaria, 106 (20.4%) had positive thick smears for malaria, 82.9% had HBV markers, and 7.1% were HBsAg positive. Anti-RESA titers was significantly lower in HBV carriers than in people with resolved HBV infection suggesting that the anti-RESA immune response could be supressed by HBV carrier status. Moreover, immunedeficient responses to both infections may take place in some subjects causing concomitant lower anti-RESA response and incapacity to clear HBV.

Prevalence of hepatitis B and C virus markers among malaria-exposed gold miners in Brazilian Amazon

Hepatitis B and C virus markers were assessed during a survey on malaria in gold mine camps in southern Brazilian Amazon in order to identify risk factors associated to these viral diseases. The study comprised 520 subjects, most of them were gold miners. Missing subjects totaled 49 (8.6%). Among these 520, 82.9% had HBV markers and 7.1% were HBsAg positive. Previous hospitalization, surgery, sexually transmitted diseases and incarceration were quite common among surveyed people, but there is no association between total HBV markers and these factors. On other hand, HBsAg was independently associated to history of sexually transmitted diseases and history of surgery after adjustment. The most frequent HBsAg subtypes identified, adw2 (59%), predominates in populations of Northeast Brazil. The most surveyed people were immigrants coming from that area suggesting that immigrants carried HBV themselves to the study area. Immunoblot (RIBA) confirmed-anti-HCV were found in 2.1%. The only variable associated to anti-HCV in multivariate analysis was illicit intravenous drug. Lack of HCV infection in subjects with such a high HBV markers prevalence reinforces the opinion that HCV is transmitted by restricted routes when compared to HBV. Furthermore, gold miners in Amazon may be considered as a risk group for HBV infection, but not for HCV.

[Hepatitis Delta in the State of Mato Grosso, Brazil: report of 5 cases]

Five cases of hepatitis B and D superinfection in teenagers from the northernmost region of Mato Grosso State are reported. Hepatitis B is high prevalent there, but not hepatitis D. The proximity to the States of Acre and Amazonas and intense migration may be introducing the virus into the region. Necessity for the surveillance of hepatitis D in northern Mato Grosso is emphasized.

Hepatitis C virus prevalence among an immigrant community to the southern Amazon, Brazil

A community-based random survey was conducted in a southern Brazilian Amazonian county aiming to investigate hepatitis C virus (HCV) infection prevalence and the association of demographic variables and lifestyle behaviours. Seven hundred eighty individuals were serologically screened with a third generation enzyme-linked immunosorbent assay to detect anti-HCV antibodies between 1994/1995. Positive samples were retested for confirmation with a line immunoassay (LIA, Inno-LIA HCV Ab III). Most of these subjects were low income and came from southern Brazilian states (65.8). Two point four percent (IC 95% 1.2%- 4.6%) of the subjects had LIA-confirmed anti-HCV antibodies reactivity. The age-specific prevalence of HCV antibodies slightly increased with age, with the highest prevalence after the age of 40 years. The results of multivariate analysis indicate a strong association between HCV antibodies and previous surgery and history of intravenous drug use. There were no apparent association with gender, hepatitis B virus markers, blood transfusion, and sexual activity. Mean time living in Amazon did not differ between confirmed and negative anti-HCV individuals. The present data point out an intermediate endemicity of HCV infection among this immigrant community to the Amazon region and that few HCV infected participants presented known risk factors.