Tracking tuberculosis control using detailed population health and satellite luminosity data: findings from Kazakhstan

Abstract

Following the collapse of the Soviet Union, Kazakhstan, like many other formerly socialist countries, experienced a surge in tuberculosis (TB). Despite the successful efforts of Kazakhstan’s Ministry of Health in reducing TB related mortality, analysis of TB risk factors in Kazakhstan remains incomplete. This study takes advantage of detailed district-level population health data, and links TB to the presence of man-made environmental damage from the Semipalatinsk Nuclear Test Site and the desiccation of the Aral Sea. Using both propensity score matching and regression models, along with census and satellite nightlight (SNL) data, we examine TB incidence and prevalence from 2000 to 2018, focusing on regions affected by acute environmental disasters. Areas severely exposed to ionizing radiation have converging TB incidence and prevalence. In contrast, regions most affected by the Aral Sea’s desiccation continue to have elevated TB levels. Our results suggest that areas officially recognized as “zones of ecological catastrophe” and “zones of ecological crisis” have about 40% and 30% higher prevalence and incidence of TB, respectively. Further analysis of time trends reveals that the significantly elevated TB incidence in these areas appears to be driven by dynamics during 2000–2012 and is not present in more recent years. TB prevalence in the zones of ecological catastrophe and crisis also demonstrates a converging trend, though relative rates remain much higher.