HBsAg subtype distribution among different populations of HBsAg carriers in Spain

Abstract

Data concerning the HBsAg subtype distribution in Spain are out-of-date and confined to a restricted geographical area. Furthermore, the complex distribution observed in the countries surrounding Spain prevents any prediction. To obtain further data on HBsAg subtype distribution among Spanish HBsAg carriers, subtyping analysis (d and y determinants) was performed in 670 samples from subjects belonging to various epidemiological risk groups and coming from different geographical areas of the country. Similar frequencies were found for both mutually exclusive d/y subtype determinants among non-risk, normal HBsAg carriers from almost all geographical areas studied. In contrast, the ay subtype was clearly predominant (79-87%) among intravenous drug users, irrespective of their geographical origin. Thirteen different institutions for mentally retarded patients behaved as closed communities for HBV circulation, showing independent subtype distributions. Thus, no significant geographical variations were found for HBsAg subtype distribution in Spain. The prevalence of each particular subtype is mainly dependent on the epidemiological characteristics of the carriers studied. Subtype distribution was independent of the presence of HBeAg or HDV infection serum markers when homogeneous groups were considered separately. Atypical HBsAg phenotypes, either with coexistence or absence of both subtype determinants, were found in some cases.

Serum levels of β2-microglobulin, neopterin, TNF-α and soluble receptors of TNF-α and interleukin-2 in intravenous drug abusers according to HIV-1 status and stage of the HIV-1 infection

“…The influence of co‐infection with other viruses on the level of surrogate markers could be important, due to the frequency of this co‐infection in HIV‐positive IVDAs. Our cohorts showed rates of co‐infection with HBV and HCV of 20% and 83%, respectively These figures were similar to those measured in IVDAs in other studies [20–24], although the HBV ratio was higher than expected. The prevalence of HBsAg in IVDAs ranged between 5% and 15% [20,21].…”

“…Our cohorts showed rates of coinfection with HBV and HCV of 20% and 83%>, respectively These figures were similar to those measured in IVDAs in other studies [20-241, although the HBV ratio was higher than expected. The prevalence of HBsAg in IVDAs ranged between 5% and 15% [20,21]. Infections with other viruses such as HTLV-I, HTLV-I1 and HIV-2 are currently very unusual in Spain and were not studied [25-271.…”

Molecular epidemiology of hepatitis B virus in Spain: Identification of viral genotypes and prediction of antigenic subtypes by limited sequencing

“…Together with the 13 genotype A strains from patients native from Spain displaying Asn 207 and Leu 209 , these 19 strains represented 8.2 % of the 231 HBV strains from autochthonous carriers in the present study, which demonstrates the emergence of exotic HBV strains in the country. This is already known for the American genotype F strains [Echevarría et al, 1995;Rodríguez-Frías et al, 1995;Sola et al, 2002;Echevarría and León, 2004] and has also been suggested for African strains belonging to genotype E . Our data regarding genotype A strains confirm the spread of HBV strains originating from sub-Saharan Africa in the Spanish population.…”

“…Data on characteristics of HBV strains in Spain was derived from reports on HBsAg subtypes [Pedreira et al, 1974[Pedreira et al, , 1975Echevarría et al, 1994Echevarría et al, , 1995 and reports on HBV genotypes [Rodríguez-Frías et al, 1995;Sá nchezTapias et al, 2002;Echevarría and León, 2004]. These studies showed similar prevalence for the subtypes ad and ay, and a dominance of genotypes D and A was noted among the HBV carriers.…”

Hepatitis B surface antigen detection using pooled sera: A cost-benefit analysis

“…The distribution of the two major subtypes of HBsAg (ad and ay) in our environment is approximately 50% for each one, ay being more frequent in drug addicts who use the parenteral route (22). We have demonstrated that the pooling method improves sensitivity, that is, decreases the detection limit of an immunoassay used for the determination of the two major HBsAg subtypes.…”