Estimating tuberculosis burden and case detection in Pakistan

BACKGROUND: The National Tuberculosis Control Programme (NTP) in Pakistan has officially achieved a tuberculosis (TB) case detection rate of 64% in 2011, with an estimated incidence rate of 230 per 100 000 population, but is likely to be missing an unknown number of patients, particularly in the private sector.

SETTING: All public and private sector providers in 12 randomly selected districts of Pakistan were included.

OBJECTIVE: To estimate TB incidence and TB notification rates in Pakistan in 2012.

DESIGN: A surveillance system was established among all eligible non-NTP providers in selected districts from January to March 2012. Record linkage and capture-recapture analysis was conducted.

RESULTS: Of 8346 TB cases identified after record linkage, 6061 were registered with the NTP. The estimated number of unobserved TB cases was 10 030 (95%CI 7800–12 910), which meant that the proportion of notified cases was 32% (95%CI 17–49). The calculated annual incidence was 878 000 cases (95%CI 573 000–1 675 000), corresponding to a rate of 497/100 000 (95%CI 324–948) annually in the population.

CONCLUSION: The study estimated that the proportion of cases notified to the NTP was low, with actual incidence rates being higher than official estimates. TB surveillance should be strengthened to reduce under-reporting.