Prevalence of non-responsiveness to an indigenous recombinant hepatitis B vaccine: A study among South Indian health care workers in a tertiary hospital.

Background and Aim: Health care workers (HCW) are at higher risk of contracting HBV infection. Non-response to HBV vaccine is one of the major impediments to prevent healthcare associated HBV infection (HAHI). We estimated the prevalence of non-responsiveness to initial 3-dose regimen of an indigenous recombinant HBV vaccine (GeneVac-B) among South Indian HCWs and typed the HLA in non-responders. Study Design and Method: Of the 778 subjects screened over 1 year, 454 completed all three doses of the hepatitis B vaccination. Anti-HBs titers were estimated by microparticle enzyme immunoassay AxSYM AUSAB, (Abbott, Germany). HLA typing was done using SSP-PCR assay AllSet+™ Gold SSP (Invitrogen, USA). Results: The overall seroconversion rate (anti-HBs > 10 mIU/mL) was 98.89% wherein 90.8% had titers >1000mIU/mL, 7.6% had titers 100–1000mIU/mL, 0.43% had titers < 100 mIU/mL and 1.1% were non-responsive (<10 mIU/mL) to the initial 3-dose regimen. Antibody titers <1000 mIU/mL were signifi cantly associated with the highest quartile of body mass index (BMI) (P < 0.001). We found no signifi cant difference in seroprotection rate between gender (P = 0.088). There was no difference in seroprotection rates among various ethnic groups (P = 0.62). Subjects who were non-responsive in our study had at least one HLA allele earlier known to be associated with non-responsiveness to the vaccine. Conclusion: Our fi ndings suggest that non-response to HBV vaccine is not a major impediment to prevent HAHI. Robust seroprotection rates can be achieved using this indigenous HBV vaccine. However, gender and BMI might infl uence the level of anti-HBs titers. We recommend the use of this cost effective HBV vaccine as well as postvaccination anti-HBs testing to prevent HAHI among HCWs.

Superior sagittal sinus and torcula thrombosis in minor head injury.

A 27-year-old man suffered a relatively minor trauma. He developed signs of raised intracranial pressure three days after injury. Investigations revealed superior sagittal sinus and torcular thrombosis.

Preliminary observations on interaction of 14C-metronidazole with macromolecules in vivo and in vitro.

Preliminary studies on the in vivo and in vitro interactions of 14C-metronidazole with macromolecules showed that the agent or its metabolite(s) can interact with nucleic acids and proteins in vivo. In vitro studies suggest that in absence of DNA synthesis trace amount of metronidazole does bind to DNA/protein and addition of metabolic activation system (from mouse liver) generates more reactive species from metronidazole.

Effect of metronidazole on the hepatic mixed function oxygenases (cytochromes b5 and P-450) in Swiss mice.

Effect of metronidazole (MNZ) treatment (oral and ip) on activities of cytochrome b5 and P-450 was studied in male, virgin and pregnant female mice. Activities of both the cytochromes increased in virgin mice treated with 2 mg (ip or PO, per mouse) but not in male and pregnant females. 30 mg dose (per mouse) was toxic in pregnant mice but increased the cytochromes activities in males and virgin females. HPLC analysis of liver MNZ levels showed that virgin females had higher MNZ content than male and pregnant females when treated with ip injection of MNZ (250 mg/kg).