Impact of COVID-19 Pandemic on the National PPM Tuberculosis Control Project in Korea: the Korean PPM Monitoring Database between July 2019 and June 2020

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions to healthcare systems and endangered the control and prevention of tuberculosis (TB). We investigated the nationwide effects of COVID-19 on the national Public-Private Mix (PPM) TB control project in Korea, using monitoring indicators from the Korean PPM monitoring database.

Methods: The Korean PPM monitoring database includes data from patients registered at PPM hospitals throughout the country. Data of six monitoring indicators for active TB cases updated between July 2019 and June 2020 were collected. The data of each cohort throughout the country and in Daegu-Gyeongbuk, Seoul Metropolitan Area, and Jeonnam-Jeonbuk were collated to provide nationwide data. The data were compared using the χ² test for trend to evaluate quarterly trends of each monitoring indicator at the national level and in the prespecified regions.

Results: Test coverages of sputum smear (P = 0.622) and culture (P = 0.815), drug susceptibility test (P = 0.750), and adherence rate to initial standard treatment (P = 0.901) at the national level were not significantly different during the study period. The rate of loss to follow-up among TB cases at the national level was not significantly different (P = 0.088); however, the treatment success rate among the smear-positive drug-susceptible pulmonary TB cohort at the national level significantly decreased, from 90.6% to 84.1% (P < 0.001). Treatment success rate in the Seoul metropolitan area also significantly decreased during the study period, from 89.4% to 84.5% (P = 0.006).

Conclusion: Our study showed that initial TB management during the COVID-19 pandemic was properly administered under the PPM project in Korea. However, our study cannot confirm or conclude a decreased treatment success rate after the COVID-19 pandemic due to limited data.

Keywords: Coronavirus; Public-private Sector Partnerships; Quality Indicators; SARS Virus; Treatment Outcome.

Fig. 1. Sputum AFB smear test coverage among pulmonary TB cases, which were initially registered for the third and fourth quarters of 2019 and the first and second quarters of 2020.

Sputum AFB smear test coverage was calculated as the number of patients who had sputum smear test performed divided by the number of patients with pulmonary TB. Cohort data from the third and fourth quarters of 2019 and the first and second quarters of 2020 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). AFB = acid-fast bacilli, TB = tuberculosis.

Fig. 2. Sputum AFB culture test coverage among pulmonary TB cases, which were initially registered for the third and fourth quarters of 2019 and the first and second quarters of 2020.

Sputum AFB culture test coverage was calculated as the number of patients who had sputum culture test performed divided by the number of patients with pulmonary TB. Cohort data from the third and fourth quarters of 2019 and the first and second quarters of 2020 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). AFB = acid-fast bacilli, TB = tuberculosis.

Fig. 3. Adherence to initial standard anti-TB treatment recommended by the guidelines among TB cases, which were initially registered for the third and fourth quarters of 2019 and the first and second quarters of 2020.

Adherence to initial standard anti-TB treatment was calculated as the number of patients treated with initial standard regimens, including H+R+E+Z, H+R+E, H+E+Z+Rfb, or H+E+Rfb, divided by the number of patients eligible for initial standard anti-TB treatment recommended by the guidelines. Patients with isoniazid-resistant TB, RR-TB, and MDR-TB were excluded. Patients whose data regarding anti-TB drugs were not entered in the Korean National TB Surveillance System were excluded. Patients registered as “treatment after failure” were excluded. Cohort data from the third and fourth quarters of 2019 and the first and second quarters of 2020 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). TB = tuberculosis, H = isoniazid, R = rifampicin, E = ethambutol, Z = pyrazinamide, Rfb = rifabutin. RR = rifampicina resistant, MDR = multidrug resistant.

Fig. 4. Drug susceptibility test coverage among culture-confirmed TB cases, which were initially registered for the second, third, and fourth quarters of 2019 and the first quarters of 2020.

Drug susceptibility test coverage was calculated as the number of patients with culture-based or molecular drug-susceptible test results divided by the number of patients with culture-confirmed TB cases. Cohort data from the second, third, and fourth quarters of 2019 and the first quarter of 2020 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). TB = tuberculosis.

Fig. 5. Treatment success rate among the smear-positive drug-susceptible pulmonary TB cohort, which were initially registered for the third and fourth quarters of 2018 and the first and second quarters of 2019.

Treatment success rate was calculated as the number of smear-positive drug-susceptible pulmonary TB cases that were successfully treated divided by the number of smear-positive drug-susceptible pulmonary TB cases registered as treatment success, treatment failed, loss to follow-up, died, and still on treatment. Smear-positive pulmonary TB cases are defined by ICD-10 codes (A15.00 or A15.01) and positive results of sputum AFB smear tests. Patients with RR-TB and MDR-TB were excluded. Patients who were “transferred out” to another treatment unit, returned to their home country, and died of non-TB-related causes were excluded. Cohort data from the third and fourth quarters of 2018 and the first and second quarters of 2019 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). TB = tuberculosis, ICD = International Classification of Diseases, AFB = acid-fast bacilli, RR = rifampicina resistant, MDR = multidrug resistant.

Fig. 6. Loss to follow-up rate among TB cases, which were initially registered for the third and fourth quarters of 2018 and the first and second quarters of 2019.

Loss to follow-up rate was calculated as the number of TB cases that were registered as loss to follow-up divided by the number of TB cases registered as treatment success, treatment failed, loss to follow-up, died, and still on treatment. Patients with RR-TB and MDR-TB were excluded. Patients who were “transferred out” to another treatment unit, returned to their home country, and died due to non-TB-related causes were excluded. Cohort data from the third and fourth quarters of 2018 and the first and second quarters of 2019 were collected and updated between July 2019 (the third quarter of 2019) and June 2020 (the second quarter of 2020). TB = tuberculosis, RR = rifampicina resistant, MDR = multidrug resistant.