Abstract
The Korea Disease Control and Prevention Agency has been promoting a “Public-Private Mix Tuberculosis Control Project (PPM Project)” with the “Korean Academy of Tuberculosis and Respiratory Diseases” since 2011. In 2021, 182 PPM institutions participated in the PPM Project, and managed 82.1% of tuberculosis (TB) patients. This study analyzed 35 TB management indicators based on the reported data of TB patients from 182 institutions that participated in the PPM Project in 2021. The final treatment results were confirmed through five-quarter observation by dividing the reported date by quarters. The sputum smear test rate, sputum culture test rate, and sputum MTB PCR test rate reported by PPM institutions in 2021 were 95.9%, 95.6%, and 91.5%, respectively. The rapid drug susceptibility test rate was 87.7% in 2021, an increase from 66.5% in 2020. In 2021, the rates of treatment completion within 12 months, stopped, failure, and still on treatment were 76.5%, 2.3%, 0.06%, and 7.2%, respectively. The mortality rate was 14.0%. In 2021, the household contact investigation rates in adults and children were 92.0% and 93.0%, respectively, down from 94.5% and 94.4% in 2020. On the other hand, the treatment rates for latent TB infection were 74.1% and 95.1% in adults and children, respectively, an increase from the corresponding 69.3% and 91.9% in 2020. The rates of sputum smear tests and sputum culture tests for suspected TB patient among contacts were 47.7% and 42.9%, respectively. Since more than 80% of TB patients are managed by PPM institutions, quality control of PPM institutions is important.
Keywords: Tuberculosis, Public-Private Mix, Latent tuberculosis infection, Tuberculosis control project, Tuberculosis management indicators
Key messages
① What is known previously?
The KDCA has been promoting the PPM Project since 2011. The PPM Project is to educate TB nurses and check the TB management status at PPM institutions. The TB management indicators are used for evaluating PPM Projects.
② What new information is presented?
There were 182 PPM institutions in 2021, managing 82.1% of TB patients. The rates of sputum test and rapid drug susceptibility test reported by PPM institutions in 2021 were improved year-on-year. The contact investigation rate decreased, but the LTBI treatment rate were improved year-on-year.
③ What are implications?
Since more than 80% of TB patients are managed by PPM institutions, quality control of PPM institutions is important.
Introduction
The Korea Disease Control and Prevention Agency (KDCA) has been collaborating with the Korean Academy of Tuberculosis and Respiratory Diseases since 2011 to implement the Public-Private Mix Tuberculosis Control Project (PPM Project) aimed at improving the treatment success rate in patients with tuberculosis (TB) at private healthcare facilities [1]. The PPM Project involves deploying TB management personnel to both healthcare facilities and local government agencies (e.g., city or provincial health departments and health centers) and encouraging collaboration among staff to ensure comprehensive TB patient management. Under the PPM Project, the KDCA provides training, including standard operating procedures, to TB management personnel (e.g., specialized nurses for TB management) assigned to each healthcare facility and regularly monitors the TB management status at healthcare facilities participating in the PPM Project (hereinafter referred to as PPM healthcare facilities) to support the systematic management of TB patients and their contacts. Additionally, the KDCA selects and regularly analyzes and reviews TB management indicators to maintain the quality of TB management in PPM healthcare facilities.
In this article, we examine the results of the TB management indicators at PPM healthcare facilities in 2021 and aim to propose future policy directions for TB management.
Methods
The TB management indicators for PPM healthcare facilities are broadly classified into two main categories: indicators for monitoring the adequacy of TB patient management and indicators for monitoring the adequacy of TB contact management. In this study, we analyzed the TB management indicators at PPM healthcare facilities in 2021 and compared the results with findings from the previous five years (2017–2021). A total of 22 TB management indicators (12 for TB patient management and 10 for contact management) were analyzed for cases reported from 2017 to 2019, and 40 TB management indicators (30 for TB patient management and 10 for TB contact management) were analyzed for cases reported from 2020 to 2021. In the present study, we focused on comparing 35 of these indicators (25 for TB patient management and 10 for contact management).
The data used for this analysis in this study was obtained from reports submitted by PPM healthcare facilities to the KDCA. Data analysis was conducted by dividing the reported TB cases into quarterly segments based on the date of reporting, and the data were then tracked for a minimum of one year over the subsequent five quarters. In this study, we utilized the latest available data, which corresponds to the fifth quarter analysis. In other words, cases of TB patients reported during the first quarter of 2021 (from January to March 2021) and their contacts were tracked and analyzed until the first quarter of 2022 (from January to March 2022). Similarly, cases of TB patients reported in the fourth quarter of 2021 (from October to December 2021) and their contacts were tracked and analyzed until the fourth quarter of 2022 (from October to December 2021).
As the data were collected from reports submitted by healthcare facilities, duplicate reports of the same patient (for reasons such as transfer to another healthcare facility) were included as separate cases for analysis.
Results
1. PPM Healthcare Facilities
The number of PPM healthcare facilities increased from 164 in 2020 to 182 in 2021. Moreover, the number of specialized nurses for TB management in these PPM healthcare facilities also increased from 297 in 2020 to 341 in 2021.
The proportion of PPM healthcare facilities responsible for TB management increased from 77.4% in 2020 (19,628 out of 25,350 patients) to 82.1% in 2021 (18,810 out of 22,904 patients), representing a 4.7%p increase. In terms of newly reported cases, the proportion of PPM healthcare facilities responsible for TB management increased from 79.3% (15,816 out of 19,933 patients) in 2020 to 83.3% (15,280 out of 18,335 patients) in 2021, marking a 4.0%p increase (Table 1).
Table 1. TB notification cases and rates and status of the TB patient management under the PPM Project, 2017–2021.
| Variable | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Total TB cases, ratesa) | 36,044 (70.4) | 33,796 (65.9) | 30,304 (59.0) | 25,350 (49.4) | 22,904 (44.6) |
| New TB cases, ratesa) | 28,161 (55.0) | 26,433 (51.5) | 23,821 (46.4) | 19,933 (38.8) | 18,335 (35.7) |
| PPM institution | |||||
| Total TB cases, percentage management (n, %) | 24,296 (67.4) | 23,500 (69.5) | 23,145 (76.4) | 19,628 (77.4) | 18,810 (82.1) |
| New TB cases, percentage management (n, %) | 19,349 (68.7) | 18,698 (70.7) | 18,624 (78.2) | 15,816 (79.3) | 15,280 (83.3) |
| No. of hospitals | 127 | 127 | 161 | 164 | 182 |
| No. of TB specialist nurses | 200 | 198 | 258 | 297 | 341 |
TB=tuberculosis; PPM Project=Public-Private Mix Tuberculosis Control Project. a)Rates: person/100,000 population.
2. Adequate TB Patient Management
To comprehensively understand the epidemiological characteristics of TB patients and to systematically manage their contacts such as family members and individuals in mass group facilities, a case investigation (individual epidemiological investigation) is conducted for all reported TB cases. Case investigations for TB patients are carried out by the local public health center when cases of TB patients are reported by public health centers and non-PPM participating healthcare facilities. When TB cases are reported by PPM healthcare facilities, the specialized nurses for TB management at the respective institution conduct the investigation, and the local public health center oversees the final management. The case investigation for TB patients is based on the “Enforcement Rules of the Tuberculosis Prevention Act” and are stipulated to be conducted within three days of reporting by the “National TB Control Guidelines.”
In 2021, the rate of case investigations for patients described by PPM healthcare facilities was 96.8%, with a compliance rate for the investigation period of 99.7%. The rate of case investigations excludes cases for which specialized nurses for TB management were unable to conduct investigations within the designated period, such as when the patient dies or when the diagnosis changes to a non-TB disease during the investigation period. Further, case investigations were considered as “not performed” if the local public health center conducted the investigation in cases wherein the specialized nurses for TB management at the PPM healthcare facility are not employed or are absent. Thus, the actual rate of case investigations may be underestimated.
For the rapid and accurate diagnosis of TB, a nucleic acid amplification test (NAAT) should be performed along with sputum smear and culture tests when TB is suspected. In cases where a prompt determination of drug susceptibility is required, Xpert MTB/RIF testing should be performed [2]. In our analysis of TB management indicators, we analyzed the rate of sputum testing among patients with respiratory TB, including pulmonary, laryngeal, tracheal, and bronchial TB, while excluding extra-pulmonary TB, such as TB meningitis and bone and joint TB.
For cases of TB patients reported by PPM healthcare facilities, the rates of sputum smear tests, sputum culture tests, and NAAT (including sputum Xpert MTB/RIF) were higher in 2021 (95.9%, 95.6%, and 91.5%, respectively) than in 2020. In particular, the rate of Xpert MTB/RIF testing, which can detect genetic mutations causing rifampicin resistance within 2 hours, increased by 9.2%p, from 58.1% in 2021 to 48.9% in 2020 (Figure 1). As patients in cases with “positive” sputum test results (smear test, culture test, and NAAT) are managed as having infectious TB, sputum testing is not only crucial for TB diagnosis but also for management of patients and their contacts.
Figure 1. Status of the sputum test for tuberculosis patient under the PPM Project, 2017–2021.
PPM Project=Public-Private Mix Tuberculosis Control Project.
Drug susceptibility testing (DST) is performed to determine whether the TB bacillus Mycobacterium tuberculosis is resistant to anti-TB drugs, and the test results are crucial in determining the treatment regimen. The “Korean Guidelines for Tuberculosis” recommend rapid DST for both isoniazid and rifampicin, in addition to routine DST for isoniazid, rifampicin, and other antibiotics, for the first culture strain in all TB patients [2].
In PPM healthcare facilities, the rate of DST in patients with positive culture results reported in 2021 (rapid DST, routine DST, or both) was 93.7%. Although the rate of standard DST remained at a similar level in 2021 (92.8%), the rate of rapid DST increased by 21.2%p, from 66.5% in 2020 to 87.7% in 2021 (Figure 2). In 2021, the notification cases of multidrug-resistant TB was 3.6%, that of rifampicin-monoresistant TB was 1.4%, and that of isoniazid-monoresistant TB was 7.0% in patients who underwent DST.
Figure 2. Status of the DST for tuberculosis patient under the PPM Project, 2017–2021.
DST=drug susceptibility test; PPM Project=Public-Private Mix Tuberculosis Control Project.
The compliance rate with initial treatment guidelines is an indicator used to assess adherence to the standard prescription presented in the “TB Treatment Guidelines” for TB patients (excluding isoniazid or rifampicin resistance), such as isoniazid (H)-rifampicin (R)-ethambutol (E)-pyrazinamide (Z) and isoniazid (H)-rifampicin (R)-ethambutol (E). In 2021, the compliance rate with initial treatment guidelines for TB patients was 93.0%.
Regarding treatment outcomes for TB patients in 2021, PPM healthcare facilities reported that the 12-month treatment success rate was 76.5%, mortality rate was 14.0%, treatment discontinuation rate was 2.3%, and treatment failure rate was 0.06%. The proportion of patients whose final outcomes were not reported even after 1 year of treatment initiation (i.e., the treatment incompletion rate/treatment default rate) was 7.2%.
The transfer-out rate, which represents the proportion of TB patients who transferred to other healthcare institutions during their treatment, was 14.8% (Table 2).
Table 2. Status of the TB patient management under the PPM Project, 2017–2021.
| Variable | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| Case investigation | |||||
| Rate of Investigation performed | 98.7 | 98.5 | 98.1 | 97.8 | 96.8 |
| Period compliance rates | 99.6 | 99.7 | 99.7 | 99.7 | 99.7 |
| Sputum AFB smear test | |||||
| Rate of tests performed | 93.4 | 94.9 | 94.8 | 95.2 | 95.9 |
| Rate of positive results | 29.6 | 29.0 | 28.7 | 28.6 | 29.7 |
| Sputum AFB culture test | |||||
| Rate of tests performed | 92.2 | 94.6 | 94.4 | 94.8 | 95.6 |
| Rate of positive results | 60.1 | 60.8 | 60.3 | 59.1 | 59.7 |
| Sputum MTB PCR test (include Xpert MTB/RIF test) | |||||
| Rate of tests performed | 89.4 | 91.5 | |||
| Rate of Xpert MTB/RIF performed | 48.9 | 58.1 | |||
| Rate of positive results | 53.7 | 54.8 | |||
| Rate of Xpert MTB/RIF results | 59.4 | 57.8 | |||
| DST | |||||
| Rate of total DST performed | 93.2 | 93.6 | 93.8 | 93.5 | 93.7 |
| Rate of conventional method DST performed | 91.9 | 92.7 | 93.2 | 92.9 | 92.8 |
| Rate of rapid DST performeda) | 66.5 | 87.7 | |||
| Rates of drug-resistant TB casesa) | |||||
| Rate of multidrug-resistant TB cases | 4.2 | 3.6 | |||
| Rate of rifampicin-resistant TB cases | 1.2 | 1.4 | |||
| Rate of isoniazid-resistant TB cases | 7.0 | 7.0 | |||
| Compliance rate of initial standard treatment regimen | 93.7 | 93.6 | 93.6 | 93.4 | 93.0 |
| Treatment outcomesa),b) | |||||
| Treatment completion (within 12 mo) | 76.2 | 76.5 | |||
| Treatment stopped | 2.0 | 2.3 | |||
| Treatment failed | 0.03 | 0.06 | |||
| Died | 13.3 | 14.0 | |||
| TB caused or contributed to death | 2.5 | 2.6 | |||
| TB incidental to death | 10.7 | 11.4 | |||
| Still on treatmentc) | 8.4 | 7.2 | |||
| Transferred out ratea) | 15.6 | 14.8 |
Values are presented as percent. TB=tuberculosis; PPM Project=Public-Private Mix Tuberculosis Control Project; AFB=acid fast bacilli; DST=drug susceptibility test. a)Expanded analysis of reported patients in 2020. b)The sum of the percentages does not equal 100% because of rounding. c)Percentage still being treated after 12 month of treatment.
3. Adequate TB Contact Management (Including Family)
When a TB patient is identified, conducting investigations among family members and close contacts aims to identify additional TB cases and latent TB infections (LTBI) early, thus preventing the spread of TB. According to the criteria for contact screening, individuals aged ≤65 years should undergo chest X-ray examinations and LTBI testing (either tuberculin skin test or interferon-gamma release assay). For individuals aged ≥66 years, chest X-ray examination is mandatory, while LTBI testing is optional.
The average number of family members and cohabitants (hereinafter referred to as “family contacts”) of TB patients reported by PPM healthcare facilities in 2021 was 2.1, and the contact screening rate for family contacts was 92.0% among adults (age ≥19 years) and 93.0% among children (age <19 years; Figure 3). The rate of LTBI refers to the proportion of contacts who were diagnosed with LTBI among those who underwent LTBI testing according to the contact screening criteria. Among individuals who underwent family contact screening in 2021, the rate of LTBI was 25.7% among adults and 22.2% among children. After excluding those with a history of TB treatment (individuals who did require treatment) or contacts of a patient diagnosed with multidrug-resistant TB for which there is no standard treatment regimen (untreatable individuals), the rate of treatment initiation for LTBI was 74.1% in adults and 95.1% in children (Figure 4).
Figure 3. Status of the household contacts investigation rate under the PPM Project, 2017–2021.
PPM Project=Public-Private Mix Tuberculosis Control Project.
Figure 4. Status of the initiated LTBI treatment rate for household contacts under the PPM Project, 2017–2021.
LTBI=latent tuberculosis infection; PPM Project=Public-Private Mix Tuberculosis Control Project.
Among family contacts of TB patients who were described by PPM healthcare facilities and underwent chest X-ray examinations in 2021, 3.7% were suspected to have TB (including cases in which TB was confirmed). The rates of sputum smear tests and sputum culture tests among suspected and confirmed TB patients were 47.7% and 42.9%, respectively, and the rate of positive test results was 9.8% and 14.0%, respectively.
In 2021, total of 157 family contacts who underwent contact investigations were ultimately diagnosed with TB (Table 3).
Table 3. Status of the household contacts management under the PPM Project, 2017–2021.
| Variable | 2017 | 2018 | 2019 | 2020 | 2021 |
|---|---|---|---|---|---|
| No. of individuals in an average household | 2.0 | 2.0 | 2.0 | 2.1 | 2.1 |
| Rate of contacts investigation/rate of LTBI/rate of initiated LTBI treatment (%) | |||||
| Adult | |||||
| Contacts investigation rate | 87.0 | 89.5 | 91.9 | 94.5 | 92.0 |
| LTBI screening rate | 25.7 | 27.6 | 26.3 | 25.1 | 25.7 |
| Initiated LTBI treatment rate | 53.3 | 48.1 | 59.8 | 69.3 | 74.1 |
| Child | |||||
| Contacts investigation rate | 89.4 | 93.1 | 93.4 | 94.4 | 93.0 |
| LTBI screening rate | 18.8 | 20.3 | 21.3 | 23.4 | 22.2 |
| Initiated LTBI treatment rate | 81.9 | 85.8 | 90.0 | 91.9 | 95.1 |
| Proportion of suspected TB after contacts investigation (%) | |||||
| Proportion of suspected TB in chest X-ray | 3.6 | 3.5 | 3.5 | 3.1 | 3.7 |
| Sputum smear test for suspected TB (%) | |||||
| Rate of tests performed | 50.7 | 47.9 | 45.1 | 48.1 | 47.7 |
| Rate of positive results | 5.5 | 4.9 | 4.9 | 6.7 | 9.8 |
| Sputum culture test for suspected TB (%) | |||||
| Rate of tests performed | 42.2 | 42.2 | 41.3 | 44.4 | 42.9 |
| Rate of positive results | 6.9 | 10.1 | 6.0 | 7.6 | 14.0 |
| Final diagnosis of household contact investigation program (n) | |||||
| Normal | 11,271 | 12,938 | 14,434 | 12,965 | 15,420 |
| TB | 104 | 88 | 94 | 96 | 157 |
| LTBI (include inactive TB) | 4,282 | 4,570 | 4,492 | 4,066 | 4,804 |
| Other diseases | 285 | 388 | 429 | 418 | 590 |
| Not a contact | 1 | 0 | 0 | 0 | 0 |
PPM Project=Public-Private Mix Tuberculosis Control Project; LTBI=latent tuberculosis infection; TB=tuberculosis.
Discussion
In this study, we analyzed TB management indicators and compared the results with findings from the previous five years to determine the status of TB patient and contact management reported in PPM healthcare facilities in 2021.
For cases of TB patients reported by PPM healthcare facilities, the rates of sputum smear tests, sputum culture tests, and NAAT were all ≥90% in 2021 (95.9%, 95.6%, and 91.5%, respectively) compared to the rates in 2020, indicating the consistent performance of TB tests. Notably, the rate of Xpert MTB/RIF testing, which enables rapid detection of M. tuberculosis genes as well as determination of rifampicin resistance, increased by 9.2%p, from 48.9% in 2020 to 58.1% in 2021. This suggests an improvement in the rapid determination of rifampin resistance and early detection of M. tuberculosis, indicating enhanced rapid detection of drug-resistant strains.
Furthermore, the rate of DST conducted for culture-positive cases of TB patients was 93.7% in 2021, similar to previous levels. However, the rate of rapid DST among culture-positive patients significantly improved from 66.5% in 2020 to 87.7% in 2021 (a 21.2%p increase). The addition of rapid DST to the evaluation criteria for adequate TB management conducted by the Health Insurance Review and Assessment Service in 2021 likely contributed to this significant improvement.
The ultimate goal of TB management is not only to restore the quality of life and productivity of TB patients by curing the disease but also to reduce TB transmission and prevent TB recurrence and emergence and spread of drug resistance [2]. The 12-month treatment success rate among TB patients reported in PPM healthcare facilities in 2021 was 76.5%, which is similar to the previous year’s rate of 76.2%. The rates of treatment discontinuation and failure were not high, at 2.3% and 0.06%, respectively, but the high mortality rate (14.0%) and treatment incompletion rate (7.2%) were barriers to increasing treatment success.
Considering that the mortality rate for TB patients aged ≥65 years is approximately 25% in the Republic of Korea [3], the annual increase in the proportion of older adults (≥65 years) among new TB patients [4] may be a limiting factor in improving treatment success rates. However, efforts to reduce treatment discontinuation, treatment failure, and treatment incompletion rates should continue. In particular, although minor, the treatment discontinuation rate rose 0.3%p from 2.0% in the previous year, indicating the need for continued investment and attention to proactively detect, support, and manage patients at high risk for treatment discontinuation. In addition, as the standard TB treatment duration typically ranges from 6 to 9 months, it is important to analyze the reasons underlying treatment incompletion, which refers to failure to complete treatment even after 12 months of initiation.
The contact screening rate for family contacts of adult and pediatric TB patients reported by PPM healthcare facilities slightly decreased from 94.5% and 94.4% in 2020 to 92.0% and 93.0% in 2021, respectively. However, the proportion of family contacts (adults and children) initiating treatment for LTBI increased from 69.3% and 91.9% in 2020 to 74.1% and 95.1% in 2021, respectively. Family contacts with suspected TB findings on chest X-ray examination underwent sputum testing, but the rates of sputum smear and sputum culture testing were <50%, at 47.7% and 42.9%, respectively, highlighting the need for improvement. Additionally, the rate of positive sputum smears and cultures increased from 6.7% and 7.6% in 2020 to 9.8% and 14.0% in 2021, respectively, and were the highest in the previous five years, warranting continuous surveillance.
In light of the finding that the risk of TB was 7.4 times higher among family contacts who did not undergo screening than among those who did, and the risk for TB was 7.29 times higher among people with LTBI who did not receive treatment than among those who completed treatment [5], it is imperative to screen and treat LTBI in family contacts of TB patients for early detection and treatment of TB, as they are at high risk for TB.
In March, the KDCA unveiled the “Third National Strategic Plan for TB Control in Republic of Korea (2023–2027)” in an effort to minimize the TB disease burden and establish the foundation for TB eradication. To accomplish one of the key initiatives of the plan, “More detailed patient care and management,” it is crucial to improve the patient care capacity of healthcare facilities by facilitating early diagnosis of TB through healthcare professional training, prescribing effective TB medications based on rapid and accurate DST, and increasing the treatment success rate by minimizing factors that contribute to treatment discontinuation and delay. As >80% of TB patients in the Republic of Korea are managed by PPM healthcare facilities, efforts to improve TB management in these facilities are of paramount importance, and poor TB management indicators should be continuously improved. Changes in TB management indicators can serve as evidence for determining the effectiveness of the PPM project.
Acknowledgments
None.
Supplementary Materials
Supplementary data are available online.
Declarations
Ethics Statement: Not applicable.
Funding Source: None.
Conflict of Interest: The authors have no conflicts of interest to declare.
Author Contributions: Conceptualization: CES. Data curation: JTK. Formal analysis: JTK. Investigation: JTK, SYK, CES. Methodology: CES, JTK, SYK, JSM, JSK, JSP. Supervision: HYC. Writing–original draft: CES. Writing–review & editing: CES, JTK, SYK, HYC, JSM, JSK, JSP.
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