Molecular and epidemiological study on nosocomial transmission of HCV in hemodialysis patients in Brazil

Abstract

An epidemiological and molecular study of hepatitis C virus (HCV) infection was carried out in Brazilian hemodialysis centers. A total of 1,095 patients in all 15 hemodialysis centers in the State of Goiás, Brazil, were studied. All patients were interviewed for possible risk factors to HCV infection and serum samples tested for anti-HCV by ELISA and for HCV RNA by nested RT-PCR of the 5' NC region. For sequence analysis, HCV RNA amplification for the NS5B region (nt 8,279-8,619) was performed. The phylogenetic tree was generated with MrBayes, and clusters with support values above 0.85 were considered epidemiologically related. Of the 1,095 patients, 180 were anti-HCV and/or HCV RNA positive, resulting in an overall prevalence of 16.4% (95% CI: 14.3-18.7). The prevalence of HCV infection in the dialysis centers ranged from 0% to 47.7%. Multivariate analysis of risk factors revealed that history of blood transfusion not screened for anti-HCV and length of time on hemodialysis were independently associated with HCV infection in this population. One hundred six samples could be amplified and sequenced in the NS5B region. Among them, plylogenetic tree analysis revealed that 69 sequences form 13 separated clusters, which were supported by credibility intervals ranging from 85% to 100%, indicating a very close relationship among the HCV isolates and therefore a likely transmission of the virus between patients. By combining phylogenetic analysis with epidemiological data, routes of transmission between the clustered-related-patients could be suggested. These findings provide evidence for nosocomial transmission of HCV in Brazilian hemodialysis centers.

Hepatitis C virus infection in Brazilian long-distance truck drivers

“…Phylogenetic analysis of full-length or partial sequences of HCV isolates has led to the identification of six genotypes (1 to 6), each comprising multiple subtypes (designated a, b, c, etc) [3]. These genotypes and subtypes have distinct geographical distributions, and information on their distribution is needed to perform effective molecular and epidemiological HCV surveillance [4,5]. …”

“…Regarding blood transfusion, HCV infection was associated with this procedure before the introduction of screening for anti-HCV antibodies in Brazilian blood banks [4]. In fact, the anti-HCV-positive truck drivers reported having undergone blood transfusions with blood that had not been screened for anti-HCV antibodies (before November 1993).…”

Dissection of familial correlations in hepatitis C virus (HCV) seroprevalence suggests intrafamilial viral transmission and genetic predisposition to infection

“…Of the 96 strains, 95 (99%) were genotype 4 while the remaining one was genotype 1. The NS5B region is commonly analysed to distinguish between related and unrelated isolates of the same subtypes especially in HCV nosocomial transmission that occurred over a period of several years 21 – 23. This region is known to be stable over time24 and was recommended for the study of ancient HCV transmission events 25.…”

Hepatitis C virus genotypes in hemodialysis patients in the Federal District, Brazil

“…These patients have an increased tendency to become HCV chronic carriers and also to be a potential reservoir for its transmission, possibly contributing to the nosocomial spread of HCV in dialysis centers 5,13 . In addition, hepatitis C seems to increase the mortality rate in this group of patients 4,20 .…”