الملخص
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 occupationallyacquired PTB in the country.
Keywords: Risk factors, pulmonary TB, health care workers, Ibadan, Nigeria
Résumé
Les données sur les programmes de contrôles des infections du TB sont limitées dans plusieurs pays ou la tuberculose est un problème majeur. Nous avons effectué une étude épidémiologique croisée sur un an (Jan-Déc. 2008) pour déterminer le taux de la tuberculose pulmonaire acquise occupationnellement par les personnels de santé à Ibadan au Nigeria. Cette information est importante pour planifier les stratégies de prévention. Tous les personnels consentant dans 2 centres a Ibadan : Centre Hospitalier Universitaire (UCH) et l’hôpital de Jéricho étaient recrutés dans cette étude, un questionnaire bien structuré était utilise pour recueillir les informations sur les caractéristiques sociodémographiques des sujets incluant les données médicaux et sociales. Trois (3) échantillons de salive étaient collectes de chaque malade/sujet et analyses pour AFB et cultive dans un milieu sélectionné. Les Isolats étaient confirmes ayant le M. tuberculosis par les analyses biochimiques standards. Des 271 sujets recrutes, neuf (3.3%) avaient de salive positive au AFB alors que six (2.2%) étaient positif après la culture. Les sujets de plus de 20ans, femelles et personnels non qualifies avaient un risque plus élevé du TBP que ceux de moins de 20 ans, male et personnels qualifies. (OR = 1.9, 95% d’intervalle de confiance, 95% CI = 0.23-16.3, 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 ) respectivement. L’analyse de régression logistique démontrait que les sujets qui recevaient le vaccin BCG étaient moins prédisposes au TBP que ceux sans vaccination (OR = 0.86, 95% CI= 0.20-3.6, p = 0.83 pour la microscopie ; OR= 0.76, 95% CI = 0.13-0.14, p= 0.76 pour la culture). Bien que les risques occupationnels du TBP étaient faibles chez ces sujets qui ont passés moins de 2 ans dans leurs unités, la relation n’était pas statistiquement importante (OR = 0.84, 95% CI =0.20-3.5, p = 0.82 pour la microscopie et OR= 1.21, 95% CI=0.22-0.65,P=0.82 pour la culture). Il est nécessaire de développer et d’implémenter des stratégies de control des infections de la tuberculose moins cher au Nigeria afin de réduire la souffrance de la tuberculose occupationnelle acquise dans le pays.
Correspondence: Dr. A.O. Kehinde, TB Unit, Department of Medical Microbiology and Parasitology, College of Medicine, University College Hospital, University of Ibadan, Ibadan Nigeria. E-mail: aokehinde@yahoo.com
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