[Evaluation of HBs Ag, HCV and HIV Ag-Ab Assays using Bio-Rad Elite Microplate Analyzer.]

A study on HIV, Syphilis, and Hepatitis B and C virus infections among female sex workers in the Republic of Congo

BACKGROUND

Female Sex Workers (FSWs) are considered to be at high risk for transmission of Sexually Transmitted Infections (STIs) and are defined as a priority of the national HIV/AIDS response in the Republic of Congo (RoC). However, no data are available regarding STIs in this group. This study aimed to determine the prevalences of HIV, syphilis and hepatitis B and C among FSWs in five cities in the country.

METHODS

A cross-sectional study was conducted from November 2^nd 2011 to May 15^th 2012. Participants were recruited in Brazzaville, Pointe-Noire, Dolisie, Nkayi and Pokola using a respondent-driven sampling method.

RESULTS

A total of 805 FSWs were recruited with an average age of 28.31 ± 9.15 years. The overall prevalences of HIV, syphilis, HBV and HCV were 7.50%, 2.20%, 4.20% and 0.70%, respectively. The age groups 35-39 (20.51% [0%-36.93%], p = 0.0057) and greater than 40 years (16.67% [0%-34.93%], P = 0.016) were positively associated with behaviors at high risk of HIV infection. For syphilis, the most infected age group was the one greater than 40 years, at 6.25% ([1.06% -72.37%] p = 0.04). Pointe-Noire was the most infected city for syphilis and HBV, with 5.15% (p = 0.0061) and 4.22% (p˂0.001), respectively. No risk factors were associated with HCV infection. FSWs practicing in mobile prostitution sites had a significantly higher infection rate (2.1% [0%-11.09%] p = 0.04).

CONCLUSION

This study shows that the prevalence of HIV and other STIs in FSWs is high. Therefore, a combination of individual and structural interventions could reduce the risk of an STI "reservoir" among this population.

Recent trends in hepatitis B virus infection in the general Korean population

BACKGROUND/AIMS

Hepatitis B virus (HBV) is the major cause of chronic liver disease in Korea, but viral prevalence has decreased because of hepatitis B vaccination programs. In this study, we investigated longitudinal changes in HBV in fection in the general Korean population.

METHODS

HBV surface antigen (hepatitis B surface antigen, HBsAg) seropositivity was assessed from the Korea National Health and Nutrition Examination Survey (I to V). In total, 50,140 subjects were tested for serum HBsAg positivity over a period of 12 years (1998 to 2010).

RESULTS

The prevalence of HBsAg seropositivity decreased over the study period. The rates of HBsAg carriers were 4.61% in 1998, 4.60% in 2001, 3.69% in 2005, 3.01% in 2008, and 2.98% in 2010 (p < 0.0001). The reduction in HBV infection rates was more prominent in younger age groups. Among teenagers (10 to 19 years), the percentage of HBsAg carriers decreased from 2.2% in 1998 to 0.12% in 2010 (p < 0.0001). Among those aged 10 to 39 years, the percentage of HBV infection decreased from 4.72% in 1998 to 2.29% in 2010 (p < 0.0001). However, no decreasing trend in HBsAg positivity was observed among those aged 50 or older (p > 0.05). Neither gender nor socioeconomic status were associated with the decreased prevalence of HBsAg carriers.

CONCLUSIONS

HBV infection has decreased in the Korean population since the advent of vaccination programs. However, the decrease is limited to the younger population, and viral persistence remains in the middle-aged and older population.

[Meta-analysis for the pooled sensitivity and specificity of hepatitis B surface antigen rapid tests]

BACKGROUND

Although hepatitis B surface antigen (HBsAg) rapid test based on immunochromatographic assay (ICA) is now widely used, the test has not been evaluated sufficiently enough to validate its performance. Thus, it is important to summarize the clinical performance of the test kits. In this study, we performed meta-analysis for the performance of the HBsAg rapid tests.

METHODS

PubMed database was searched using keywords about the accuracy of diagnostic tests for hepatitis B virus (HBV) infection. Two investigators assessed methodological quality utilizing standards for reporting of diagnostic accuracy studies (STARD) checklist. After performing a heterogeneity test, we obtained pooled sensitivity and specificity. Positive and negative predictive values (PPV and NPV) were simulated according to HBV prevalence.

RESULTS

A total of 38 studies was selected from 10 papers. The quality scores ranged from 3 to 13 (median, 8). Kappa value was good (0.85). The performance of the 38 studies was heterogeneous. When 33 studies with better quality from 7 papers were re-selected, the pooled sensitivity and specificity were 98.07% (95% confidence interval, CI: 97.67-98.47%) and 99.56% (95% CI: 99.21-99.91%), respectively. With an HBV prevalence of 5%, PPV and NPV were predicted to be 92.14% and 99.90%, respectively.

CONCLUSIONS

In view of high HBV prevalence in Korea, it is thought that the HBsAg rapid test can be used for HBV screening in small-sized laboratories or for epidemiologic studies. This study should be helpful in establishing a guideline for the proper performance evaluation of the HBsAg rapid tests.