Pulmonary tuberculosis among health care workers at two designated DOTS Centers in urban city of Ibadan, Nigeria.

Background & objectives: Tuberculosis (TB) infection control interventions are not routinely implemented in many Sub-Saharan African countries including Nigeria. This study was carried out to ascertain the magnitude of occupationally-acquired pulmonary TB (PTB) among health care workers (HCWs) at two designated DOTS centers in Ibadan, Nigeria. Methods: One year descriptive study (January-December 2008) was carried out at the University College Hospital and Jericho Chest Hospital, both located in Ibadan, Nigeria. A pre-tested questionnaire was used to obtain socio-demographic data and other relevant information from the subjects. Three sputum samples were collected from each subject. This was processed using Zeihl-Neelsen (Z-N) stains. One of the sputum was cultured on modified Ogawa egg medium incubated at 37°C for six weeks. Mycobacterium tuberculosis was confirmed by repeat Z-N staining and biochemical tests. Results: A total of 271 subjects, 117 (43.2%) males and 154 (56.8%) females were studied. Nine (3.3%) had their sputum positive for acid fast bacilli (AFB) while six (2.2%) were positive for culture. The culture contamination rate was 1.8 per cent. Significantly, all the six culture positive samples were from males while none was obtained from their female counterparts. About half of the AFB positive samples were from subjects who have spent five years in their working units. Eight AFB positive cases were from 21-50 yr age group while students accounted for seven AFB positive cases. Interpretation & conclusions: The study shows that occupationally-acquired PTB is real in Ibadan. Further studies are needed to ascertain and address the magnitude of the problem.

Risk factors for pulmonary tuberculosis among health-care workers in Ibadan, Nigeria

Data on TB infection control programs is limited in many of the TB high burden countries. We carried out a one-year cross sectional epidemiological study (January-December, 2008) to determine the prevalence of occupationally-acquired pulmonary tuberculosis (PTB) among Health- Care Workers (HCWs) in Ibadan, Nigeria. This information is important for planning preventive strategies. All consenting HCWs at two TB centres in Ibadan--the University College Hospital (UCH) and Jericho Chest Hospital were enrolled into the study. A well structured questionnaire was used to obtain information on socio-demographic characteristics of the subjects including their medical and social data. Three sputum samples collected from each subject were processed for acid-fast bacilli (AFB) and culture on selective medium. Isolates were confirmed as M. tuberculosis by standard biochemical tests. Of the 271 subjects recruited, nine (3.3%) had their sputum positive for AFB while six (2.2%) were positive for culture. Subjects aged 20 years and above, female gender and unskilled professionals had higher risk for occupationally-acquired PTB than those who were 20 years and below, male gender and skilled professionals (Odd Ratio OR = 1.9, 95% Confidence Interval, 95% CI = 0.23-16.3, Fisher's exact P = 0.37; OR = 1.1, 95% CI = 0.28-4.0, p = 0.01; OR = 1.05, 95% CI = 1.02-1.08, p = 3.43) respectively. Multivariate logistic regression analysis showed that subjects who received BCG vaccination were less likely to have occupationally-acquired PTB than those without vaccination (OR = 0.86, 95% CI = 0.20-3.6, p = 0.83 for microscopy; OR = 0.76, 95% CI = 0.13- 0.44, p = 0.76 for culture). Even though the risk for occupationally-acquired PTB was lower in subjects who had not spent up to two years in their units, the association was not statistically significant (OR = 0.84, 95% CI = 0.20-3.5, p = 0.82 for microscopy and OR = 1.21, 95% CI = 0.22-0.65, p = 0.82 for culture). There is a need to develop and implement affordable and cost-effective TB infection control strategies in Nigeria in order to reduce the burden of occupationally-acquired PTB in the country