Progress toward tuberculosis control and determinants of treatment outcomes--Kazakhstan, 2000-2002

In Kazakhstan, during 1995-2002, the annual notification rate per 100,000 population for new cases of tuberculosis (TB) increased from 67.1 to 165.1. Beginning in 1998, public health authorities have used the national case management strategy (DOTS) promulgated by the World Health Organization (WHO) to control TB. Intended goals of DOTS include achieving a cure rate of >85% for persons with newly detected pulmonary TB sputum-smear-positive (PTB+) cases and having PTB+ represent >65% of all PTB cases among adults. Surveillance data collected during 2000-2002 were analyzed to evaluate progress toward achieving these goals and identify factors associated with specific treatment outcomes.

Surveillance data included the following nonidentifiable information on persons with newly reported cases of PTB: dates of disease onset and treatment initiation; methods of diagnosis; treatment outcomes; HIV status; and selected demographic, socioeconomic, and behavioral characteristics. Cure rates and proportions of PTB+ cases were calculated on the basis of the TB case definition and treatment outcome classification format outlined in DOTS guidelines issued by WHO. Denominator data to calculate rates were obtained from the National Census Office of Kazakhstan. Logistic regression was employed to investigate factors associated with treatment outcomes using Epi Info version 3.2.

During 2000-2002, a total of 65,011 new cases of PTB were detected in Kazakhstan. The average annual countrywide notification rate per 100,000 population was 146.0; provincial notification rates varied (range: 65.1-274.0). The countrywide cure rate for newly detected PTB+ was 72.2%; provincial rates varied (range: 65%-81%). Of 59,905 cases of PTB among adults during 2000-2002, a total of 26,804 (44.7%) were PTB+. Unfavorable treatment outcome of new PTB+ cases was associated with alcohol abuse, homelessness, and previous incarceration.

The cure rate for new PTB+ cases and the proportion of cases of PTB+ among all adults with PTB were below targeted goals. This might, in part, be explained by the 1998 adoption of DOTS. Improving program indicators requires evaluation of detection efforts, laboratory diagnostic capabilities, and adherence to treatment regimens, especially in provinces in which rates are high and among persons at high risk for unfavorable treatment outcomes.