Occult hepatitis B virus infection in hemodialysis patients in Recife, State of Pernambuco, Brazil

Abstract

INTRODUCTION: Persistence of the hepatitis B virus (HBV) genome in individuals negative for the HBV surface antigen (HBsAg) reflects occult infection. The aim of this study was to identify occult HBV infection among hemodialysis patients at 5 clinics in Recife, State of Pernambuco, Brazil, between August 2006 and August 2007. METHODS: Serum samples underwent enzyme-linked immunosorbent assay to investigate total antibodies against HBcAg (anti-HBc), HBsAg, and antibodies against HBsAg (anti-HBs). Samples that were HBsAg-negative were tested for total anti-HBc, and those that were positive for total anti-HBc were tested for anti-HBs. HBV DNA was investigated with an in-house PCR technique to identify samples positive for total anti-HBc. Subsequently, the samples positive for HBV DNA were sequenced to identify the genotype and mutations. RESULTS: The study population (n = 752) had a mean age of 50 15.1 years and included both sexes. All samples analyzed were negative for HBsAg. The seroprevalence of total anti-HBc was 26.7% (201/752), while that of anti-HBs was 67.2% (135/201). Total anti-HBc alone was detected in 5.7% of the patients. Occult infection was found in 1.5%, comprising genotypes A (33.3%, 1/3) and D (66.7%, 2/3). No mutations were found. CONCLUSIONS: The study detected occult hepatitis B virus infection in hemodialysis patients. Molecular studies on HBV are of fundamental importance because they identify patients that had been considered virus-negative but who, in reality, host the virus and have the ability to transmit it to other patients and staff.

Occult hepatitis B among patients with chronic renal failure on hemodialysis from a capital city in northeast Brazil

“…A low prevalence of chronic HBV infection in Brazil has also been suggested by researchers from the WHO and US Centers for Disease Control and Prevention (CDC), which published a new global estimate of prevalence . The three Brazilian studies published on the dialysis population so far reported OHB prevalence rates of 0%, 15%, and 3% . These discrepancies can be attributed to the selections of samples or differences in the sensitivity of the molecular tests used.…”

“…39 The three Brazilian studies published on the dialysis population so far reported OHB prevalence rates of 0%, 15%, and 3%. 20,24,31 These discrepancies can be attributed to the selections of samples or differences in the sensitivity of the molecular tests used. Indeed, in the study by Motta et al, where the prevalence was 15%, half of the participants were also positive for anti-HCV.…”

“…OHB can be considered a significant problem in patients with chronic renal failure (CRF) being treated with renal replacement therapy (RRT) because they are susceptible to parenteral infection (due to permanent venous access and immunosuppression) and the possibility of reactivating infection when using immunosuppressants after renal transplantation . The prevalence of OHB in patients on hemodialysis is highly variable and has been related to the magnitude of the presence of chronic infection in the regions studied . The aim of this study was to determine the prevalence of OHB in patients on hemodialysis in São Luís, Maranhão state, Brazil.…”

Prevalence of occult hepatitis B in a population from the Brazilian Amazon region

“…Studies conducted in Brazil have reported a higher frequency of subgenotype A1 compared to A2 . Albuquerque et al found a prevalence of OBI of 1.5% among patients undergoing hemodialysis in Recife, northeastern Brazil. Genotypes A (33%) and D (66%) were detected and no mutation was found.…”

Occult hepatitis B virus infection in patients with leprosy

“…Brazil is responsible for 13% of the new cases of leprosy in the world, but it is considered a country of “low” endemicity for HBV, with a prevalence of HBsAg estimated at 0.65% . The prevalence of occult HBV infection is influenced by a number of factors, such as sensitivity of the technique used to detect the HBV DNA and epidemiological characteristics of the population, making it difficult to compare results of different studies …”