Booster Dose of Bacille Calmette-Guérin Vaccine for Tuberculosis in Low and Middle-Income Countries: A Systematic Review

Background: The Bacille Calmette-Guérin (BCG) vaccine, given as a single dose, offers variable protection against Tuberculosis (TB). It is plausible that repeat doses could improve the effectiveness of the BCG vaccine in settings where the population remain at risk of the disease. Objective: To assess the effectiveness of BCG revaccination as a booster dose in preventing TB in Low- and Middle- Income Countries (LMICs). Methods: We searched the electronic databases without language or publication restrictions and followed the procedures for preparing systematic reviews, including assessing the risk of bias as outlined in the Cochrane handbook. We included randomised controlled trials (RCTs) conducted in LMICs involving children and adults receiving one or more BCG vaccine doses after the primary BCG vaccination. The incidence of severe forms of TB, active TB and adverse events were the primary outcomes. Results: Five RCTs were included in this systematic review. Revaccination with BCG probably makes little or no difference to the risk of active TB measured after five years (Relative risk (RR) 1.16, 95% CI 0.88 to 1.51; 348,083 participants; one study, moderate certainty evidence) or nine years post-revaccination (RR 0.96, 95% CI 0.82 to 1.12; 348,083 participants; one study, moderate certainty evidence). In populations with HIV co-infection, revaccination probably increases the risk of pulmonary tuberculosis compared to placebo (RR 1.74, 95% CI 1.00 to 3.01; 46,764 participants; one study, moderate certainty evidence). Conclusion: The available evidence suggests that BCG revaccination probably makes little or no difference in preventing tuberculosis disease in LMICs

Awareness and utilization of personal protective equipment among small-scale welders in Cross River State, Nigeria: a descriptive cross-sectional study: Awareness and utilization of PPE among welders

Objective: Rapid urbanization and industrialization in the many low- and middle-income countries means that there is a growing demand for the welding industry. Previous studies in Nigeria, and other low- and middle-income countries have reported a significant discrepancy between awareness and consistent and appropriate use of personal protective equipment (PPE). This study assessed the awareness and utilization of PPE among small-scale welders in Calabar South, Cross River State, Nigeria. Methods: This study was conducted in Calabar South Local Government Area using a descriptive cross-sectional design. Data collection was with an interviewer-administered semi-structured questionnaire, and an observation checklist was used to monitor the use of PPE among small-scale welders. Results:  One hundred and sixteen small-scale welders were surveyed with a mean age of 34.9 ±9.1 years. Almost 90% of respondents had completed at least primary education. Eighty-one respondents (69.8%) were aware of PPE. Three-quarters of respondents (61/81) knew PPE protected the user from injury. The most frequently identified type of welding PPE among the respondents aware of PPE, were safety goggles (38.3%), hand gloves (25.9%), safety boots (19.8%), and coveralls (9.9%). 83.6% had access to PPE at work. However, only 14.4% reported using PPE consistently. Observation revealed that the PPE most frequently used, sunglasses, were not the recommended welding goggles. Conclusion:  The low utilization of PPE calls for stricter enforcement of occupational health and safety regulations among welders in the informal sector, including implementing PPE awareness programs