Undernotification and underreporting of tuberculosis in Zambia: a national data quality assessment

BACKGROUND

Despite national implementation of several high impact interventions and innovations to bolster tuberculosis (TB) detection and improve quality of TB services in Zambia, notifications have been declining since 2004. A countrywide data quality assessment (DQA) of Zambia's National TB and Leprosy Programme (NTLP) was undertaken to quantify the degree to which undernotification and underreporting of TB notifications may be occurring.

METHODS

The NTLP conducted a retrospective DQA of health facilities in high burden districts in all ten Zambian provinces. Multiple routine programmatic data sources were triangulated through a multi-step verification process to enumerate the total number of unique TB patients diagnosed between 1st January and 31st August 2019; both bacteriologically confirmed and clinically diagnosed TB patients were included. Undernotification was defined as the number of TB patients identified through the DQA that were not documented in facility treatment registers, while underreporting was defined as the number of notified TB cases not reported to the NTLP.

RESULTS

Overall, 265 health facilities across 55 districts were assessed from which 28,402 TB patients were identified; 94.5% of TB patients were ≥ 15 years old, 65.1% were male, 52.0% were HIV-positive, and 89.6% were a new/relapse case. Among all TB cases, 32.8% (95%CI: 32.2-33.3) were unnotified. Undernotification was associated with age ≥ 15 years old (adjusted prevalence odds ratio [aPOR] = 2.4 [95%CI: 2.0-2.9]), HIV-positive status (aPOR = 1.6 [95%CI: 1.5-1.8]), being a new/relapse TB case (aPOR = 17.5 [95%CI: 13.4-22.8]), being a clinically diagnosed TB case (aPOR = 4.2 [95%CI:3.8-4.6]), and being diagnosed at a hospital (range, aPOR = 1.5 [95%CI: 1.3-1.6] to 2.6 [95%CI: 2.3-2.9]). There was substantial heterogeneity in the proportion of unnotified TB cases by province (range, 18.2% to 43.6%). In a sub-analysis among 22,199 TB patients with further data available, 55.9% (95%CI: 55.2-56.6) were notified and reported to the NTLP, 32.8% (95%CI: 32.2-33.4) were unnotified, and 11.3% (95%CI: 10.9-11.7) went unreported to the NTLP.

CONCLUSIONS

The findings from Zambia's first countrywide TB programme DQA demonstrate substantial undernotification and underreporting of TB cases across all provinces. This underscores the urgent need to implement a robust and integrated data management system to facilitate timely registration and reporting of all TB patients who are diagnosed and treated.

ERRATUM: Rapid and Simple Detection of Isoniazid-Resistant Mycobacterium tuberculosis Utilizing a DNA Chromatography-Based Technique

Volume 74, no.3, p.214-219, 2021. Page 214, affiliation "¹TBA Co., LTD, Sendai; ²Hokkaido University Research Center for Zoonosis Control, Sapporo; ³Hokkaido University, GI-CoRE Global Station for Zoonosis Control, Sapporo; ⁴Zambia National Public Health Institute, Ministry of Health, Lusaka, Zambia; ⁵Department of Pathology and Microbiology, University Teaching Hospital Ministry of Health, Lusaka, Zambia; and ⁶Ministry of Health, Ndeke House, Lusaka, Zambia." should read "¹TBA Co., LTD, Sendai, Japan; ²Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan; ³Hokkaido University, GI-CoRE Global Station for Zoonosis Control, Sapporo, Japan; ⁴Zambia National Public Health Institute, Ministry of Health, Lusaka, Zambia; ⁵Department of Pathology and Microbiology, University Teaching Hospital Ministry of Health, Lusaka, Zambia; and ⁶Ministry of Health, Ndeke House, Lusaka, Zambia".

A comparison of vitamin D and cathelicidin (LL-37) levels between patients with active TB and their healthy contacts in a high HIV prevalence setting: a prospective descriptive study

BACKGROUND

Studies from Asia and Europe indicate an association between vitamin D deficiency and susceptibility to TB. We performed an observational case-control study to determine vitamin D and cathelicidin (LL-37) levels and their association with active TB in newly diagnosed and microbiologically confirmed adult TB patients in Zambia, a high HIV prevalence setting.

METHODS

Both total vitamin D and LL-37 were measured using ELISA from serum and supernatant isolated from cultured whole blood that was stimulated with heat-killed Mycobacterium tuberculosis. Statistical analysis was performed using STATA statistical software version 12.

RESULTS

The median vitamin D in TB patients and healthy contacts was 28.7 (19.88-38.64) and 40.8 (31.2-49.44) ng/ml, respectively (p<0.001). The median LL-37 in TB patients compared with healthy contacts was 1.87 (2.74-8.93) and 6.73 (5.6-9.58) ng/ml, respectively (p=0.0149). Vitamin D correlation with LL-37 in healthy contacts was R2=0.7 (95% CI 0.566 to 0.944), p<0.0001. Normal vitamin D significantly predicted a healthy status (OR 4.06, p=0.002).

CONCLUSIONS

Significantly lower levels of vitamin D and LL-37 are seen in adults with newly diagnosed active TB. Longitudinal studies across various geographical regions are required to accurately define the roles of vitamin D and LL-37 in preventive and TB treatment outcomes.

Rapid and Simple Detection of Isoniazid-Resistant Mycobacterium tuberculosis Utilizing a DNA Chromatography-Based Technique

Despite the availability of anti-tuberculosis drugs, the treatment of tuberculosis has been complicated by drug-resistant tuberculosis. The early detection of drug resistance makes early treatment possible. However, the available tools are mainly for rifampicin resistance detection, and the existing isoniazid resistance detection method is expensive, highly technical, and complicated, making it unsustainable for use in developing nations. This study aimed to develop a simple, rapid, and low-cost diagnostic kit for isoniazid-resistant tuberculosis using the single-stranded tag hybridization method to target an isoniazid resistance-conferring mutation. Specificity and sensitivity were assessed using DNA extracted from 49 isoniazid-resistant and 41 isoniazid-susceptible Mycobacterium tuberculosis clinical isolates cultured in mycobacterial growth indicator tubes. Positive signals were observed on mutant and wild-type lines with 100% sensitivity and specificity compared with Sanger sequencing results. In contrast, no positive signal was observed for non-tuberculosis mycobacteria. The detection limit of this method was 10³ CFU or less. The STH-PAS system for isoniazid-resistant M. tuberculosis detection developed in this study offers a better alternative to conventional phenotypic isoniazid resistance determination, which will be of both clinical and epidemiological significance in resource-limited nations.