A case-control study for differences among hepatitis B virus infections of genotypes A (subtypes Aa and Ae) and D

There are two subtypes of hepatitis B virus genotype A (HBV/A) and they are provisionally designated Aa (a standing for Africa/Asia) and Ae (e for Europe). In a case-control study, 78 HBV/Aa, 78HBV/Ae, and 78HBV/D carriers from several countries were compared. The prevalence of HBe antigen (HBeAg) in serum was significantly lower in carriers of HBV/Aa than in carriers of HBV/Ae (31% vs. 49%; P = .033), with a difference more obvious in the carriers aged 30 years or younger (34% vs. 67%; P = .029). HBV DNA levels in the carriers of HBV/Aa (median, 3.46 log copies/mL; 95% CI, 2.93-3.95) were significantly lower than those of carriers of HBV/Ae (6.09 log copies/mL; 95% CI, 4.24-7.64) or of carriers of HBV/D (5.48 log copies/mL; 95% CI, 4.06-7.02), regardless of the HBeAg status (P < .001). The most specific and frequent substitutions in 54 HBV/Aa isolates were double substitutions for T1809 (100%) and T1812 (96%) immediately upstream of the precore initiation codon, which would interfere with the translation of HBeAg in HBV/Aa infections. They were not detected in 57 HBV/Ae or 61 HBV/D isolates examined. The double mutation in the core promoter (T1762/A1764) was more frequent in both HBV/Aa (50%) and HBV/Ae (44%) than in HBV/D isolates (25%; P < .01), whereas the precore mutation (A1896) occurred in HBV/D isolates only (48%; P < .0001). In conclusion, the clearance of HBeAg from serum may occur by different mechanisms in HBV/Aa, HBV/Ae, and HBV/D infections, which may influence clinical manifestations in the Western countries where both genotypes A and D are prevalent

Introduction of Human Immunodeficiency Virus Type 2 Infection in the Philippines

The aim of this study was to describe and document the first case of human immunodeficiency virus type 2 (HIV-2) in the Philippines by using serological and molecular techniques and to compare the diversity of this strain to that of strains from other countries. With the introduction of HIV-2 into the country and the presence of diversified strains of HIV-1, the use of highly sensitive assays to detect all these strains is recommended

Ensuring accurate testing for human immunodeficiency virus in Myanmar

PROBLEM: Until 2005, the quality of rapid diagnostic human immunodeficiency virus (HIV) testing was not monitored and no regular technical support was provided to hospital laboratories in Myanmar. APPROACH: The national reference laboratory introduced a national external quality assessment scheme. The scheme involved (i) training laboratory technicians in HIV testing and in the requirements of the quality assessment system; (ii) implementing a biannual proficiency panel testing programme; (iii) on-site assessments of poorly-performing laboratories to improve testing procedures; and (iv) development of national guidelines. LOCAL SETTING: In 2011, a total of 422 public hospitals in Myanmar had laboratories providing HIV tests. In addition, private laboratories supported by nongovernmental organizations (NGOs) conducted HIV testing. RELEVANT CHANGES: The scheme was started in 65 public laboratories in 2005. In 2012, it had expanded nationwide to 347 laboratories, including 33 NGO laboratories. During the expansion of the scheme, laboratory response rates were greater than 90% and the proportion of laboratories reporting at least one aberrant result improved from 9.2% (6/65) in 2005 to 5.4% (17/316) in 2012. LESSONS LEARNT: National testing guidelines and a reference laboratory are needed to successfully implement quality assurance of HIV testing services. On-site assessments are crucial for all participating laboratories and the only source for insight on the causes of aberrant results; lessons that the reference laboratory can share nationally. Proficiency testing helps laboratory technicians to maintain HIV testing skills by ensuring that they regularly encountered HIV-positive samples