Pasteurization of dairy products and education regarding fresh cheese must be pursued for eradication of brucellosis. A major risk factor for acquiring brucellosis is the existence of another infected family member. Therefore screening family members of an index case of brucellosis may lead to the detection of additional cases.

Occult hepatitis B virus (HBV) infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen (HBsAg). Occult HBV infection harbors potential risk of HBV transmission through hemodialysis (HD). The aim of this study was to assess the occult HBV infection in hemodialysis patients with isolated hepatitis B core antibody (anti-HBc). A total of 289 HD patients from five dialysis units in Tehran, Iran, were included in this study. Hepatitis B surface antigen (HBsAg), Hepatitis B surface antibody (anti-HBs), anti-HBc, Hepatitis C antibody (anti-HCV), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were tested in all subjects. The presence of HBV-DNA was determined quantitatively in plasma samples of HD patients with isolated anti-HBc (HBsAg negative, anti-HBs negative and anti-HBc positive) by real-time PCR using the artus HBV RG PCR kit on the Rotor-Gene 3000 real-time thermal cycler. Of 289 patients enrolled in this study, 18 subjects (6.2%, 95% confidence interval (CI), 3.5%-8.9%) had isolated anti-HBc. HBV-DNA was detectable in 9 of 18 patients (50%, 95% CI, 27%-73%) who had isolated anti-HBc. Plasma HBV-DNA load was less than 50 IU/ml in all of these patients. Our study showed that detection of isolated anti-HBc could reflect unrecognized occult HBV infection in HD patients. The majority of these infections are associated with low viral loads.

Introduction: Anti-hepatitis B core antibody (Anti-HBc) alone is defined as the presence of anti-HBc in the absence of HBsAg and anti-HBs. The significance of this serological pattern as a predicting factor for occult hepatitis B virus (HBV) infection remains largely unknown. This study aimed to assess the significance of anti-HBc alone in predicting occult HBV infection in high-risk and low-risk individuals. Methodology: A total of 926 individuals were enrolled in this study, including 289 hemodialysis (HD) and 106 HIV-infected patients who were considered as a high-risk group and 531 blood donors who were considered as low-risk. HBsAg, anti-HBs, anti-HBc were tested in all subjects. The presence of HBV-DNA was determined quantitatively in patients with anti-HBc alone by real-time PCR. Results: Of the 395 high-risk patients, 40 cases (10.13%) had anti-HBc alone, while 11 subjects (2.07%) out of 531 blood donors had anti-HBc alone. HBV-DNA was detected in 12 out of 40 (30%) high-risk patients and none of the blood donors with anti-HBc alone. Conclusion: Our study showed that the serological pattern of anti-HBc alone could reflect occult HBV infection in high risk cases but did not presume occult HBV infection in low-risk individuals.

Our study showed that all the blood donors with isolated anti-HBc were negative for HBV-DNA, and occult HBV infection did not occur in the blood donors of this low prevalence region for HBV infection.

HLA-A*33 was closely related with susceptibility to persisting hepatitis B infection, and HLA-DRB1*13 was closely related with protection against persisting hepatitis B in an Iranian population. These findings emphasized that the host HLA polymorphism is an important factor in determining the outcome of HBV infection.