Hepatitis B Virus Infection among People Who Use Illicit Drugs: Prevalence, Genotypes and Risk Factors in the State of Amapá, Northern Brazil.

Background: Several records of high prevalence of HBV have been made in northern Brazil. Among risk groups for viral infection, people who use illicit drugs (PWUDs) stand out, especially if they inject drugs and engage in risky sexual behavior. Objectives: In this study, the prevalence, genotype distribution and factors associated with hepatitis B virus (HBV) exposure in PWUDs were estimated. Methods: This cross-sectional study used snowball sampling from nine different sites. Socio-demographic, economic, drug use and health-related information were collected of 308 PWUDs from nine municipalities in the state of Amapá, northern Brazil. Blood samples were tested for the presence of HBV using enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Logistic regressions were run to identify factors independently associated with HBV exposure. Results: In total, seventy (22.7%) PWUDs were exposed to HBV, and 12 (3.9%) had DNA HBV. Genotypes A (58.4%), D (33.3%) and F (8.3%) were identified. Age ≥35 years, use of injectable drug, daily use of drugs, use of drugs over 12 years, unprotected sex, exchange sex for money/drugs, and >12 sexual partners in the last 12 months were associated with exposure to HBV. Conclusions: This study identified important information on the epidemiological scenario of HBV infection in PWUDs, highlighting the high prevalence of HBV exposure and the urgent need for measures for control and prevention, especially vaccination against this hepatotropic virus.

Phylogeny, molecular dating and zoogeographic history of the titi monkeys (Callicebus, Pitheciidae) of eastern Brazil.

The titi monkeys belong to a genus of New World primates endemic to South America, which were recently reclassified in three genera (Cheracebus, Plecturocebus and Callicebus). The genus Callicebus, which currently includes five species, is endemic to eastern Brazil, occurring in the Caatinga, Savanna, and Atlantic Forest biomes. In the present study, we investigated the validity of these species and inferred their phylogenetic relationships, divergence times, and biogeographic patterns based on the molecular analysis of a concatenated sequence of 11 mitochondrial and nuclear DNA markers, derived from 13 specimens. We ran Maximum Likelihood (ML) and Bayesian Inference (BI) analyses, and estimated genetic distances, divergence times. Ancestral areas were estimated on BioGeoBears. Our results suggest that at about twelve million years ago, the ancestor of all titi monkeys inhabited a wide area that extended from the Amazon forest to the South of the Atlantic forest. A first vicariant event originated Cheracebus in the West of the Amazon and the ancestor of Callicebus and Plectorocebus which, later were separated by a second one. The diversification of Callicebus occurred during the Plio-Pleistocene (beginning at 5 Ma) probably influenced by climatic fluctuations and geological events. Therefore, the results of the present work confirmed the existence of five species that currently inhabit forested areas under increasing threat from human activities. Thus, a reliable diagnosis of the taxonomic status of species living in endangered environments is extremely important for the development of conservation measures.

Detection and Genetic Characterization of Hepatitis B and D Viruses: A Multi-Site Cross-Sectional Study of People Who Use Illicit Drugs in the Amazon Region.

Hepatitis B (HBV) and delta (HDV) viruses are endemic in the Amazon region, but vaccine coverage against HBV is still limited. People who use illicit drugs (PWUDs) represent a high-risk group due to common risk behavior and socioeconomic factors that facilitate the acquisition and transmission of pathogens. The present study assessed the presence of HBV and HBV-HDV co-infection, identified viral sub-genotypes, and verified the occurrence of mutations in coding regions for HBsAg and part of the polymerase in HBV-infected PWUDs in municipalities of the Brazilian states of Amapá and Pará, in the Amazon region. In total, 1074 PWUDs provided blood samples and personal data in 30 municipalities of the Brazilian Amazon. HBV and HDV were detected by enzyme-linked immunosorbent assay and polymerase chain reaction. Viral genotypes were identified by nucleotide sequencing followed by phylogenetic analysis, whereas viral mutations were analyzed by specialized software. High rates of serological (32.2%) and molecular (7.2%) markers for HBV were detected, including cases of occult HBV infection (2.5%). Sub-genotypes A1, A2, D4, and F2a were most frequently found. Escape mutations due to vaccine and antiviral resistance were identified. Among PWUDs with HBV DNA, serological (19.5%) and molecular (11.7%) HDV markers were detected, such as HDV genotypes 1 and 3. These are worrying findings, presenting clear implications for urgent prevention and treatment needs for the carriers of these viruses.