Time trend in incidence and mortality of tuberculosis and characteristics of notified tuberculosis patients in urban area of Mongolia

Abstract

Recent Mongolian political, social and economic changes have had a great impact on its health care system and tuberculosis control program. The objective of this study is to assess time trend in incidence and mortality of tuberculosis and characteristics of notified tuberculosis cases in Mongolia. 1) Data on statistics of tuberculosis are obtained from reports of the National Tuberculosis Center in Mongolia. The mortality of tuberculosis in Mongolia shows a downward trend during 1985-1995. The number of notified tuberculosis cases had gradually decreased during 1985-1989. It suddenly dropped in 1990 and was the lowest in 1993. After that, about two fold increase in the notified cases was observed in recent three years from 1993 to 1995. Such a large fluctuation in the number of notified cases after 1990 is unlikely to be associated with the epidemiologic situation of tuberculosis, but rather due to a reporting bias. The shortage of drugs and economic hardship prevented patients from consulting medical facilities. The shortage of drugs also prevented doctors from notifying patients to the tuberculosis registry, because the notification did not lead to treating the disease. The improvement of health care system and the supply of essential drugs since 1994 seems to contribute to the increase in the number of notified cases. 2) The study subjects include 618 patients who were diagnosed as active tuberculosis at ten tuberculosis specialized facilities in Ulaanbaatar, Mongolia from May 1995 to March 1996. Patients were interviewed about their demographic factors and their medical records were reviewed. Fifty one percent of the cases were female. The mean age was 26.9 years old. Ninety percent of the cases underwent chest X-ray examination, while 72% of the cases underwent bacteriological examination and only 21% were confirmed bacteriologically. It is necessary to improve the quality control of sputum smear examination and the validity of diagnosis of tuberculosis in Mongolia. As for treatment regimens, only 29% of the cases were being treated with at least four drugs (isoniazid, rifampicin, pyrazinamide, ethambutol and/or streptomycin). It is needed to provide directly observed treatment using the WHO recommended standard regimen to at least smear positive tuberculosis cases.