Tuberculosis is a global public health problem. It causes high morbidity and mortality. However its incidence in KSA has declined in recent years. During the second school semester 1999 five cases of smear positive pulmonary tuberculosis were diagnosed among female secondary school students in the city center of Riyadh. A state of anxiety and phobia spread among the students and teachers of the affected schools. An investigation was conducted to define the magnitude and the source of the outbreak and to suggest appropriate control measures.
Methodology
The cases were interviewed and a case definition was developed. School health records were revised. Questionnaire was completed with the cases and contacts. Passive and active case finding was conducted. Household and school contacts underwent tuberculin testing and chest x-ray.
Results
The five cases were attending five different schools in the city center. The father of the first case had history of incompletely treated pulmonary tuberculosis. The fifth case was treated from tuberculosis three years ago. Among 178 contacts the infection rate was 52.2%, of them 29% were household and 91% were school contacts. The risk factors for positive tuberculin included being household contacts (O.R.=2.49, C.I.=1.09-5.74); non-Saudi nationality (O.R.=2, C.I.=1.05-3.83); living in Al-Dira (O.R.=5.57, C.I.=1.19-28.23) and Ghubera (O.R.=3.73, C.I.=1.19-11.96) and fathers' occupation as drivers (O.R.=6.93, C.I.=1.71-30.38).
Conclusion
The outbreak was most likely due to more than one source. The infection rate among contacts was 52.2%. Being a house-hold contact, non-Saudi, and a resident of Al-Dira and Ghubera and fathers' occupation as driver were risk factors for tuberculosis infection. Proper screening of school contacts and management of cases and infected contacts were recommended, along with raising the suspicion index for TB and promoting public health education.