Breakthrough TB among people living with HIV on TB preventive therapy.

BACKGROUND: Zambia has an estimated TB incidence of 319/100,000 population and a HIV prevalence of 11.1%. In 2020, only 49% of new people living with HIV (PLHIV) received TB preventive therapy (TPT) in Zambia. Misconceptions about the reliability of symptom screening and drug resistance among people who develop TB while on TPT are barriers to TPT scale-up. We determined the incidence and predictors of breakthrough TB during TPT among PLHIV in Zambia. METHOD: This was a retrospective analysis of routine TPT programme data among PLHIV collected between October 2016 and October 2019 from select primary health facilities in Zambia. RESULTS: Of 48,581 PLHIV enrolled on TPT, 130 (0.3%) developed breakthrough TB during TPT. Of the 130, 90 client records were accessed. The median age of the breakthrough TB cases was 35 years; 68% were males. Overall, 96% of the breakthrough TB cases had been on antiretroviral therapy (ART) for ⩽3 months; 24% were symptomatic at the beginning of TPT, 22% were asymptomatic and others had missing data. Of the 130 breakthrough TB cases, 79% developed TB in the first month after TPT initiation. The median time to TB diagnosis was 10 days (IQR 4-16). CONCLUSION: Breakthrough TB during TPT is rare among PHLIV on ART, and very rare after the first month of TPT initiation. It should therefore not be a barrier to TPT scale-up.

CONTEXTE: La Zambie a une incidence de TB estimée à 319/100 000 habitants et une prévalence du VIH de 11,1%. En 2020, seulement 49% des nouvelles personnes vivant avec le VIH (PLVIH) ont reçu une thérapie préventive (TPT) contre la TB en Zambie. Les idées fausses sur la fiabilité du dépistage des symptômes et la résistance aux médicaments chez les personnes qui développent une TB alors qu'elles sont sous TPT sont des obstacles à l'extension de la TPT. Nous avons déterminé l'incidence et les facteurs prédictifs de la découverte de la TB pendant la TPT chez les PLVIH en Zambie. MÉTHODE: Il s'agissait d'une analyse rétrospective des données du programme TPT de routine chez les PLVIH recueillies entre octobre 2016 et octobre 2019 dans certains établissements de santé primaire en Zambie. RÉSULTATS: Sur 48 581 PLVIH inscrites au programme TPT, 130 (0,3%) ont développé la TB pendant le TPT. Sur ces 130, 90 dossiers de clients ont été consultés. L'âge médian des cas de TB était de 35 ans ; 68% étaient des hommes. Dans l'ensemble, 96% des cas de TB découvert étaient sous traitement antirétroviral (ART) depuis ⩽3 mois; 24% étaient symptomatiques au début du TPT, 22% étaient asymptomatiques et les autres avaient des données manquantes. Parmi les 130 cas de percée de la TB, 79% ont développé la TB au cours du premier mois après le début du TPT. Le délai médian de diagnostic de la TB était de 10 jours (IQR 4­16). CONCLUSION: La découverte de la TB pendant le TPT est rare chez les PLVIH sous ART, et très rare après le premier mois du début du TPT. Elle ne devrait donc pas constituer un obstacle à la généralisation des TPT.

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.

Performance of Xpert® MTB/RIF and Determine™ TB-LAM Ag in HIV-infected adults in peri-urban sites in Zambia.

SETTING: Peri-urban health facilities providing HIV and TB care in Zambia. OBJECTIVE: To evaluate 1) the impact of Xpert® MTB/RIF on time-to-diagnosis, treatment initiation, and outcomes among adult people living with HIV (PLHIV) on antiretroviral therapy (ART); and 2) the diagnostic performance of Xpert and Determine™ TB-LAM Ag assays. DESIGN: Quasi-experimental study design with the first cohort evaluated per standard-of-care (SOC; first sputum tested using smear microscopy) and the second cohort per an algorithm using Xpert as initial test (intervention phase; IP). Xpert testing was provided onsite in Chongwe District, while samples were transported 5-10 km in Kafue District. TB was confirmed using mycobacterial culture. RESULTS: Among 1350 PLHIV enrolled, 156 (15.4%) had confirmed TB. Time from TB evaluation to diagnosis (P = 0.018), and from evaluation to treatment initiation (P = 0.03) was significantly shorter for IP than for SOC. There was no difference in all-cause mortality (7.0% vs. 8.6%). TB-LAM Ag showed higher sensitivity with lower CD4 cell count: 81.8% at CD4 < 50 cells/mm3 vs. 31.7% overall. CONCLUSION: Xpert improved time to diagnosis and treatment initiation, but there was no difference in all-cause mortality. High sensitivity of Determine TB-LAM Ag at lower CD4 count supports increased use in settings providing care to PLHIV, particularly with advanced HIV disease.