Adherence to the three-component Hepatitis B virus vaccination protocol among healthcare workers in hepatitis B virus endemic settings in Ghana

Background

The WHO and CDC recommend that HCWs who are at risk of HBV infection should vaccinate as adults early in their career by receiving 3 doses of HB vaccine at a schedule of months 0,1,6 and perform post-vaccination serological testing 1-2 months after vaccination. This study assessed adherence to all three components of the HBV vaccination program.

Methods

The study was a hospital-based analytical cross-sectional study involving 340 HCWs who were randomly selected. A pretested questionnaire was used to collect data which was analyzed using SPSS version 21. The proportion of HCWs adhering to the three components of the HBV vaccination protocol was computed. The multivariable analysis procedure identified the factors associated with overall adherence. Odds ratios were estimated with corresponding confidence intervals with the level of significance set at 0.05.

Results

HBV vaccination coverage was 60.9 % and adherence to 3-doses, 0,1,6 vaccination schedules and post-vaccination serological testing were 46.8 %, 38 % and 13 % respectively. Overall adherence was intermediate at the population level with only 6.2 % of the study participants adhering to all three components of the HBV vaccination protocol. HCWs who had low-risk perception for HBV had the lowest odds of completely adhering to all three indicators recommended for HBV vaccination (aOR = 0.15; 95 %CI = 0.04-0.58). Also, male HCWs have lower odds of adhering to all three components of HBV vaccination compared to their female counterparts (aOR = 0.65; 95 %CI = 1.17-2.50).

Conclusion

Adherence to the three components of HBV vaccination recommended for HCWs is low in this study. Failure to receive the recommended three-dose series of HBV vaccine at the recommended 0,1,6 schedule has implications for achieving seroprotection or development of antibodies against HBV. Failure to perform post-vaccination testing 1-2 months after HBV vaccination has implications for timely PEP management following occupational exposures. All three components of an ideal HBV vaccination program are important and should be used collectively to guide facility led HCW vaccination programs. Occupational health and safety programs, Infection prevention and control, as well as health promotion campaigns in health facilities, should promote adherence to all three components of HBV vaccination programs.

Emission characteristics and influencing mechanisms of PAHs and EC from the combustion of three components (cellulose, hemicellulose, lignin) of biomasses

Biomass burning is an important source of polycyclic aromatic hydrocarbons (PAHs) and elemental carbon (EC), but the formation mechanisms are still unclear. Cellulose, hemicellulose, and lignin are the three major components of biomass. In this study, the three-components extracted from three typical biomass raw materials were used for laboratory combustion experiments, to investigate the differences in the emission factors and chemical compositions of PAHs and EC. The average emission factors of the 16 kinds of PAHs were showing as lignin (135 ± 180 mg/kg) > cellulose (97.8 ± 124 mg/kg) > hemicellulose (48.9 ± 65.2 mg/kg), and the average emission factors of EC presented in the descending order of cellulose (1.65 ± 3.02 g/kg), lignin (1.30 ± 1.04 g/kg), and hemicellulose (0.450 ± 0.480 g/kg), respectively. The proportion of naphthalene emitted from cellulose and hemicellulose combustion is higher, while fluoranthene and pyrene accounted significantly higher proportion for lignin. Moreover, the influence of ignition temperature and oxygen content on the emission characteristics of PAHs and EC were also discussed. The influence of ignition temperature on the emission of EC and PAHs is more significant compared to oxygen content, because it obviously promoted the PAHs and EC formations through resonance-stabilized hydrocarbon-radical chain reaction (RSR) pathway. However, correlation analysis combined with cluster analysis showed that the RSR-pathway probably had different effects on PAH growth for the three-components, as the indene-involved RSR-pathway were mainly related to 4-6 ring PAHs for cellulose and lignin (except fluoranthene and pyrene), but 2-4 ring PAHs for hemicellulose. We also found that the fitted results according to the proportion of three-components were significantly higher than the measured values of raw materials for indene, medium-molecular-weight PAHs, and soot-EC. These results presented the different formation pathways for medium-molecular-weight PAHs and the two EC components emitted by biomass combustion, which are worthy of further studies in exploring the generation mechanisms of PAHs and EC.