The role of human T cell lymphotrophic virus type 1, hepatitis B virus and hepatitis C virus coinfections in leprosy

Leprosy spectrum and outcome is associated with the host immune response against Mycobacterium leprae. The role of coinfections in leprosy patients may be related to a depression of cellular immunity or amplification of inflammatory responses. Leprosy remains endemic in several regions where human T cell lymphotrophic virus type 1 (HTLV-1), hepatitis B virus (HBV) or hepatitis C virus (HCV) are also endemic. We have evaluated the evidence for the possible role of these viruses in the clinical manifestations and outcomes of leprosy. HTLV-1, HBV and HCV are associated with leprosy in some regions and institutionalization is an important risk factor for these viral coinfections. Some studies show a higher prevalence of viral coinfection in lepromatous cases. Although HBV and HCV coinfection were associated with reversal reaction in one study, there is a lack of information about the consequences of viral coinfections in leprosy. It is not known whether clinical outcomes associated with leprosy, such as development of reactions or relapses could be attributed to a specific viral coinfection. Furthermore, whether the leprosy subtype may influence the progression of the viral coinfection is unknown. All of these important and intriguing questions await prospective studies to definitively establish the actual relationship between these entities.

Occult hepatitis B virus infection among injecting drug users in the Central-West Region of Brazil

The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil's Central-West Region.

Molecular characterisation of hepatitis B virus in the resident Chinese population in Panama City

Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.