Insights into tuberculosis burden in Karachi, Pakistan: A concurrent adult tuberculosis prevalence and child Mycobacterium tuberculosis infection survey.

Pakistan is one of the five highest tuberculosis burden countries globally. We estimated prevalence of adult bacteriologically confirmed pulmonary tuberculosis and annual risk of Mycobacterium tuberculosis (M. tuberculosis) infection in children aged 2-4 years in Karachi, Pakistan. The survey design enabled exploration of tuberculosis burden by whether the population had previously been exposed to widespread tuberculosis active case-finding (ACF) activities or not. We conducted a concurrent adult pulmonary tuberculosis prevalence survey and a child M. tuberculosis infection survey using interferon gamma release assays in four districts (Korangi, South, West and Central). A cluster-based unequal probability random sampling method was employed with the a priori plan to oversample Korangi district which had been the focus of tuberculosis ACF activities since 2011. We defined Korangi district as the 'prior ACF' zone and remaining districts as the 'no prior ACF' zone. Between March 2018 and May 2019, 34,962 adults (78·5% of those eligible) and 1,505 children (59·9%) participated. Overall estimated prevalence of bacteriologically confirmed pulmonary tuberculosis was 387 cases per 100,000 population (95% CI 276-498) with a prevalence of 421 cases [95% CI 276-567] per 100,000 in the 'no prior ACF' and 279 cases [95% CI 155-403] per 100,000 in the 'prior ACF' zone. We estimated the annual risk of M. tuberculosis infection in children to be 1·1% (95% CI 0·7-1·5) in the 'no prior ACF' zone and 0·6% (95% CI 0·3-1·1) in the 'prior ACF' zone. We observed consistent differences in the population distribution of tuberculosis between the 'prior ACF' and 'no prior' ACF zones with a trend towards lower estimates of burden and M. tuberculosis transmission in the 'prior ACF' zone. A plausible explanation is that intensive ACF activities that have been ongoing in Korangi district for the preceding years have noticeably reduced the burden of tuberculosis and transmission.

Correction: Malik et al. Integrated Tuberculosis and COVID-19 Activities in Karachi and Tuberculosis Case Notifications. Trop. Med. Infect. Dis. 2022, 7, 12.

The authors wish to revise the second citation of reference [26] to [27] in the original article main text [...].

Integrated Tuberculosis and COVID-19 Activities in Karachi and Tuberculosis Case Notifications.

As the COVID-19 pandemic surged, lockdowns led to the cancellation of essential health services. As part of our Zero TB activities in Karachi, we adapted our approach to integrate activities for TB and COVID-19 to decrease the impact on diagnosis and linkage to care for TB treatment. We implemented the following: (1) integrated COVID-19 screening and testing within existing TB program activities, along with the use of an artificial intelligence (AI) software reader on digital chest X-rays; (2) home delivery of medication; (3) use of telehealth and mental health counseling; (4) provision of PPE; (5) burnout monitoring of health workers; and (6) patient safety and disinfectant protocol. We used programmatic data for six districts of Karachi from January 2018 to March 2021 to explore the time trends in case notifications, the impact of the COVID-19 pandemic, and service adaptations in the city. The case notifications in all six districts in Karachi were over 80% of the trend-adjusted expected notifications with three districts having over 90% of the expected case notifications. Overall, Karachi reached 90% of the expected case notifications during the COVID-19 pandemic. The collaborative efforts by the provincial TB program and private sector partners facilitated this reduced loss in case notifications.