Prevalence and genotypes of hepatitis C virus among injecting drug users from Salvador-BA, Brazil

Hepatitis C virus (HCV) is the major infectious disease agent among injecting drug users (IDUs), with seroprevalence ranging from 50-90 percent. In this paper, serological and virological parameters were investigated among 194 IDUs, 94 ex-IDUs and 95 non-IDUs that were sampled by the "snowball" technique in three localities renowned for both intense drug use and trafficking activities in Salvador, Brazil. The majority of the participants were male, but sex and mean age differed significantly between IDUs/ex-IDUs and non-IDUs (p < 0.05). Anti-HCV screening revealed that 35.6 percent, 29.8 percent and 5.3 percent of samples from IDUs, ex-IDUs and non-IDUs, respectively, were seropositive. HCV-RNA detection confirmed that the prevalence of infection was 29.4 percent, 21.3 percent and 5.3 percent for IDUs, ex-IDUs and non-IDUs, respectively. Genotyping analysis among IDUs/ex-IDUs determined that 76.9 percent were infected with genotype 1, 18.5 percent with genotype 3 and 4.6 percent with a mixed genotype; this result differed significantly from non-IDUs, where genotype 3 was the most frequent (60 percent), followed by genotype 1 (20 percent) and a mixed genotype (20 percent). We report a significantly higher prevalence of HCV infection in IDUs/ex-IDUs compared to the control group (p < 0.001). Although the sample size of our study was small, the differences in HCV genotype distribution reported herein for IDUs/ex-IDUs and non-IDUs warrant further investigation.

Distribution of Hepatitis C virus (HCV) genotypes in seropositive patients in the state of Alagoas, Brazil / Distribuição de genótipos do Vírus da hepatite C (HCV) em pacientes soropositivos no Estado de Alagoas, Brasil

We determined the frequency of hepatitis C virus (HCV) genotypes in anti-HCV seropositive patients in the state of Alagoas, Brazil, by means of nested-reverse transcription-polymerase chain reaction (RT-nested-PCR) followed by restriction fragment length polymorphism (RFLP) of amplified fragments of the 5ïNCR. The nested-PCR with genotype-specific primers from the core region was carried out when detection was not possible by the first approach. Detectable HCV-RNA was present in 115 (74.7 percent) of 154 serum samples. Genotype 1 was the most frequent (77.4 percent), against 20.9 percent of genotype 3 and 0.8 percent of genotype 2. Subtype 1b was predominant (65.2 percent), followed by subtypes 1a (8.7 percent), and 3a (6.1 percent). Coinfection (1a/3a) was detected in 0.8 percent of the samples. Indeed, there was no significant differences in the prevalence of genotype 1 compared to what has been obtained from anti-HCV seropositive patients from other locations in Brazil. Here we report for the first time the genotype 2 in the state of Alagoas.

A frequência de genótipos do vírus da hepatite C (HCV) em pacientes soropositivos anti-HCV no estado de Alagoas, Brasil, foi determinada através da RT-PCR aninhada da região 5'NCR seguida pela análise do polimorfismo de comprimento dos fragmentos de restrição (RFLP). A RT-PCR aninhada utilizando primers genótipo-específicos da região core foi efetuada quando não foi possível determinar o genótipo pelo primeiro método. Níveis detectáveis de HCV-RNA estavam presentes em 115 (74,7 por cento) das 154 amostras de soro. O genótipo 1 foi o mais freqüente (77,4 por cento), contra 20,9 por cento do genótipo 3 e 0,8 por cento do genótipo 2. O subtipo 1b foi predominante (65,2 por cento), seguido pelos subtipos 1a (8,7 por cento) e 3a (6,1 por cento). Co-infecção (1a/3a) foi detectada em 0,8 por cento das amostras. Não foram encontradas diferenças significativas quanto à prevalência do genótipo 1 em relação ao que tem sido obtido de pacientes soropositivos anti-HCV de outras localidades do Brasil. Este é o primeiro relato da presença do genótipo 2 no estado.