Hiv and hcv coiffection: prevalence, associatedfactors and genotype characteriization in the midwest region of Brazil / Coinfecção HIV e HCV: prevalência, fatores associados e caracterização dos genótipos na Região Centro-Oeste do Brasil

A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients.

Estudo transversal sobre a prevalência, fatores associados e distribuição dos genótipos do HCV foi realizado em 848 pacientes infectados pelo HIV, recrutados em centros de referência na Região Centro-Oeste do Brasil. A taxa de prevalência de coinfecção HIV-HCV foi de 6,9% (IC 95%: 5,2-8,6). Na análise multivariada, o aumento da idade, o uso de drogas ilícitas (injetáveis e não injetáveis), história de transfusão de sangue antes de 1994, e ausência de companheiro constante foram fatores associados independentes e significativos para a coinfecção HIV-HCV. A análise filogenética baseada na região NS5B revelou a presença de dois principais genótipos do HCV em circulação: genótipos 1 (58,3%) e 3 (41,7%). A prevalência da coinfecção HIV-HCV foi menor do que as relatadas em estudos realizados com pacientes infectados pelo HIV em diferentes regiões do Brasil, devido ao fato de que o uso de drogas ilícitas não é modo frequente de transmissão do HIV neste Estado do Brasil. Triagem sorológica de pacientes HIV-positivos para HCV antes de iniciar o tratamento antirretroviral, identificação completa dos fatores associados e a implementação de programas eficazes de redução de danos são altamente recomendados para fornecer informações úteis, para o tratamento e para evitar a coinfecção com HCV nestes pacientes.

HIV and HCV coinfection: prevalence, associated factors and genotype characterization in the Midwest Region of Brazil.

A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients.

Genetic diversity of HCV in Brazil.

BACKGROUND: Many studies have documented the molecular epidemiological scenario of HCV within individual Brazilian states, but we still have an incomplete understanding of the dispersion dynamics of the virus in different regions throughout the country. METHODS: A total of 676 HCV NS5B gene sequences of subtypes 1a (n=321), 1b (n=170) and 3a (n=185), isolated from seven different Brazilian states covering four out of five regions were analysed in the present study. We also analysed 22 HCV NS5B gene sequences of minor genetic variants including genotype 2 (n=13), genotype 4 (n=6) and subtype 5a (n=3). Brazilian HCV sequences were aligned with sequences of non-Brazilian origin and subjected to maximum likelihood phylogenetic analyses. RESULTS: These analyses revealed that the Brazilian HCV epidemic resulted from multiple introductions and autochthonous transmission of subtypes 1a, 1b, 3a and genotypes 2, 4 and 5. Brazilian HCV subtype 1a epidemic is dominated by the dissemination of one major clade; while Brazilian HCV subtypes 1b and 3a epidemics are characterized by concurrent dissemination of several independent HCV lineages. Some HCV Brazilian lineages of subtypes 1a, 1b, 2b and 3a were successful in becoming established and disseminated through several regions in the country. Despite significant phylogenetic intermixing of Brazilian sequences, the distribution of HCV strains from different states across lineages was not completely homogeneous. CONCLUSIONS: These results demonstrate the existence of multiple introductions and local propagation of both prevalent and uncommon HCV genetic variants in Brazil and identify some major Brazilian HCV clades with nationwide dissemination. This study also suggests that the observed HCV diversity in Brazil has been shaped by both frequent viral migration among regions and in situ viral dissemination.