Despite World Health Organization’s (WHO) recent report describing a decline in tuberculosis (TB) morbidity and mortality, the disease remains an acute threat to global public health . The increase in tuberculosis case notification rates (CNRs) across much of the former Soviet Union (FSU) since its dissolution has been well-documented [2, 3]. Following the break-up of the Soviet Union, Kazakhstan experienced a dramatic increase in tuberculosis infections. Incidence rates reported to the WHO in 1995 (135/100,000 population), 2000 (196/100,000), and 2004 (223/100,000) chronicled this increase, which spurred the country’s public health sector to introduce new approaches to tuberculosis control . Starting in 1998, Kazakhstan’s Ministry of Health (MoH) began implementing Directly Observed Therapy Short Course (DOTS) through the then newly created National Tuberculosis Program (NTP), which continues to oversee TB care and treatment in the country today.
In several FSU republics including Kazakhstan, multidrug resistant forms of the disease increasingly threaten TB control efforts [5, 6]. The NTP provides free TB treatment for its residents via a centralized network of TB dispensaries, hospitals, and polyclinics. While polyclinics may perform tentative TB diagnosis and later serve as local sites for continued treatment, they initially refer all suspected cases to NTP facilities . The NTP system currently consists of 315 microscopy laboratories and funding was recently allocated to the network to improve diagnostic capacities. In the first quarter of 2012, the NTP reported that Kazakhstan was the only Central Asian republic where all of the oblasts had the capacity to perform drug resistance testing, citing a testing rate of 98.2% of new TB cases and 98.9% of retreatment cases covered by DOTS . However, TB drug resistance testing of all cases has not been fully achieved within Kazakhstan’s prison system. Hein genotyping analysis is currently being piloted in 10 out of 14 oblasts. Despite these advances in TB control efforts, in practice, TB diagnosis is often based on x-ray rather than bacteriological analysis.
TB incidence peaked in Kazakhstan in 2003 and 2004, since then the NTP has attained some success in restraining further increases; however, MDR-TB presents a growing challenge to controlling TB. The WHO reports that 14% (range 11-18%) of all newly diagnosed TB cases in Kazakhstan are multidrug resistant. Among retreatment cases, 45% test positive for MDR-TB . Since such statistics were first recorded in 1998, the country’s success rates for treatment of new TB cases have consistently fallen below the WHO-recommended ≥85% cure rate. In fact, success rates declined to 62% in 2009 after achieving an earlier high of 79% [9, 10]. The problem is compounded by high MDR-TB rates in prisons, where CNRs may be five times higher than in the general population .
Interest in the social, economic, and environmental determinants of TB has grown as CNRs have risen during the past two decades. The contextual milieu in which individuals live and work is critical to understanding and stemming the disease . A literature review identified several global risk factors for TB. Individual risks include age, sex, smoking, alcoholism, diabetes, HIV status, marital status, ethnicity, homelessness, incarceration, drug use, and migrant status [13–18]. Socioeconomic and environmental risk factors take into account deprivation, financial insecurity, and housing conditions. [13, 14, 19] While these risk factors may play a role in increasing Kazakhstan’s overall TB burden and intensifying MDR-TB, they have not been adequately examined.
This study presents the first comprehensive description of the spatial and temporal burden of TB disease constructed from data obtained from the Kazakhstani national TB surveillance system. Study findings identify salient risk factors for TB disease as well as MDR-TB at the oblast (provincial) level in Kazakhstan. Reported incident CNRs and prevalence vary by oblast, thus the study investigated which determinants contribute to this regional variation. By analyzing aggregate and individual case records provided by the country’s National Institute of Geography and the National Tuberculosis Program, we compared burdens among oblasts and identified significant risk determinants.