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.

Prevalence and interpretation of Xpert® Ultra trace results among presumptive TB patients.

BACKGROUND: The "trace call" results on Xpert® Ultra indicates extremely low TB levels and may be difficult to interpret. The prevalence of trace results among presumptive TB patients in high TB-HIV infection settings is unknown, as is the significance of divergent "trace call" result interpretations. METHODS: Presumptive TB patients attending a public health facility in Lusaka, Zambia, were prospectively enrolled. Participants underwent several TB investigations, including sputum smear microscopy, Ultra testing, and culture. The diagnostic accuracy of Ultra (culture-based reference) and the number of patients recommended for TB treatment was assessed according to several different interpretation criteria for "trace call" results. RESULTS: Among the 740 participants, 78 (10.5%) were Ultra-positive and an additional 37 (5.0%) had a "trace call" result. The prevalence of trace results did not differ according to HIV status (5.3% vs. 4.8%) or prior TB status (5.6% vs. 4.9%). Differing interpretations of trace results had modest effects on Ultra's sensitivity (range 79.3-82.6%) and specificity (range 94.3-99.2%), but increased the number of patients recommended for treatment by up to 44.9%. CONCLUSIONS: Ultra trace results were common in this setting. The interpretation of trace results may substantially impact TB case yield.

CONTEXTE: La catégorie de résultats « traces ¼ du test Xpert Ultra indique des taux de TB très faibles et peut être difficile à interpréter. La prévalence de résultats traces parmi des patients suspects de TB dans des zones à forte prévalence de TB-VIH est inconnue, tout comme la signification d'interprétations divergentes des résultats traces. MÉTHODES: Les patients suspects de TB consultant dans un centre de soins public de Lusaka, Zambie, ont été inclus de manière prospective. Les participants ont fait l'objet de plusieurs examens de détection de la TB, dont microscopie des frottis d'expectorations, test Xpert® Ultra et culture. La précision diagnostique du test Ultra (par rapport à la culture) et le nombre de patients recommandés pour traitement antituberculeux ont été évalués selon plusieurs critères d'interprétation des résultats traces. RÉSULTATS: Parmi les 740 participants, 78 (10,5%) étaient positifs au test Ultra et 37 autres participants (5.0%) avaient un résultat trace. La prévalence des résultats traces ne différait pas en fonction du statut VIH (5,3% vs. 4,8%) ou du statut tuberculeux antérieur (5,6% vs. 4,9%). Les interprétations divergentes des résultats traces avaient un effet modéré sur la sensibilité du test Ultra (écart 79,3­82,6%) et sur sa spécificité (écart 94,3­99,2%), mais elles augmentaient le nombre de patients à qui un traitement était recommandé de 44,9% maximum. CONCLUSIONS: Les résultats traces au test Ultra étaient fréquents. L'interprétation de ces résultats peut impacter considérablement la détection des cas de TB.

Diagnosed with TB in the era of COVID-19: patient perspectives in Zambia.

INTRODUCTION: Delayed TB diagnosis and treatment perpetuate the high burden of TB-related morbidity and mortality in resource-constrained settings. We explored the potential of COVID-19 to further compromise TB care engagement in Zambia. METHODS: From April to May 2020, we purposefully selected 17 adults newly diagnosed with TB from three public health facilities in Lusaka, Zambia, for in-depth phone interviews. We conducted thematic analyses using a hybrid approach. RESULTS: The majority of participants were highly concerned about the impact of lockdowns on their financial security. Most were not worried about being diagnosed with COVID-19 when seeking care for their illness because they felt unwell prior to the outbreak; however, they were very worried about contracting COVID-19 during clinic visits. COVID-19 was perceived as a greater threat than TB as it is highly transmittable and there is no treatment for it, which provoked fear of social isolation and of death among participants in case they contracted it. Nonetheless, participants reported willingness to continue with TB medication and the clinic visits required to improve their health. CONCLUSION: The COVID-19 pandemic did not appear to deter care-seeking for TB by patients. However, messaging on TB in the era of COVID-19 must encourage timely care-seeking by informing people of infection control measures taken at health facilities.

Coverage of clinic-based TB screening in South Africa may be low in key risk groups.

The South African Ministry of Health has proposed screening all clinic attendees for tuberculosis (TB). Amongst other factors, male sex and bar attendance are associated with higher TB risk. We show that 45% of adults surveyed in Western Cape attended a clinic within 6 months, and therefore potentially a relatively high proportion of the population could be reached through clinic-based screening. However, fewer than 20% of all men aged 18-25 years, or men aged 26-45 who attend bars, attended a clinic. The population-level impact of clinic-based screening may be reduced by low coverage among key risk groups.

Le Ministère de la Santé d'Afrique du Sud a proposé de dépister la tuberculose (TB) chez tous les patients visitant un centre de santé. Parmi d'autres facteurs, le sexe masculin et la fréquentation des bars sont associés à un risque plus élevé de TB. Nous montrons que 45% des adultes dépistés dans la province du Cap Ouest s'étaient rendus dans un centre de santé au cours des 6 derniers mois et c'est pourquoi une proportion relativement élevée de la population pourrait être atteinte à travers un dépistage en centre de santé. Cependant, moins de 20% de tous les hommes âgés de 18­25 ans, ou des hommes âgés de 26­45 ans qui fréquentent les bars, se rendent dans un centre de santé. L'impact sur la population de ce type de dépistage pourrait donc être réduit par une faible couverture parmi les groupes à risque majeur.

El Ministerio de Salud de Suráfrica propuso una detección sistemática de la tuberculosis (TB) a todas las personas que acudían a los consultorios. Entre los factores asociados con un mayor riesgo de padecer TB están el sexo masculino y la frecuentación de bares. El presente artículo pone de manifiesto que 45% de los adultos encuestados en la Ciudad del Cabo había acudido a un establecimiento de salud en los últimos 6 meses, por lo cual se pudo llegar a una proporción relativamente alta de la población mediante esta detección sistemática. Sin embargo, menos del 20% de todos los hombres entre los 18 y los 25 años, o entre los 26 y los 45 años de edad que frecuenta los bares, acudió a los establecimientos de salud. La repercusión a escala de la población de una detección sistemática realizada en los consultorios podría verse atenuada por una baja cobertura de los grupos más vulnerables.

Detection of tuberculosis using digital chest radiography: automated reading vs. interpretation by clinical officers.

SETTING: A busy urban health centre in Lusaka, Zambia. OBJECTIVE: To compare the accuracy of automated reading (CAD4TB) with the interpretation of digital chest radiograph (CXR) by clinical officers for the detection of tuberculosis (TB). DESIGN: A retrospective analysis was performed on 161 subjects enrolled in a TB specimen bank study. CXRs were analysed using CAD4TB, which computed an image abnormality score (0-100). Four clinical officers scored the CXRs for abnormalities consistent with TB. We compared the automated readings and the readings by clinical officers against the bacteriological and radiological results used as reference. We report here the area under the receiver operating characteristic curve (AUC) and kappa (κ) statistics. RESULTS: Of 161 enrolled subjects, 97 had bacteriologically confirmed TB and 120 had abnormal CXR. The AUCs for CAD4TB and the clinical officers were respectively 0.73 and 0.65-0.75 in comparison with the bacteriological reference, and 0.91 and 0.89-0.94 in comparison with the radiological reference. P values indicated no significant differences, except for one clinical officer who performed significantly worse than CAD4TB (P < 0.05) using the bacteriological reference. κ values for CAD4TB and clinical officers with radiological reference were respectively 0.61 and 0.49-0.67. CONCLUSION: CXR assessment using CAD4TB and by clinical officers is comparable. CAD4TB has potential as a point-of-care test and for the automated identification of subjects who require further examinations.

Changes in tuberculosis notifications and treatment delay in Zambia when introducing a digital X-ray service.

SETTING: In August 2009, a digital chest X-ray (CXR) machine was installed at a busy urban health centre in Lusaka, Zambia. OBJECTIVE: To describe the changes in tuberculosis (TB) notifications and treatment delay ≥7 days in Zambia after introducing a digital X-ray service. DESIGN: Operational retrospective research of TB notification, laboratory and CXR data for Q4 2008 (prior to digital CXR) compared to Q4 2009. RESULTS: Notifications for sputum smear-negative TB increased by 8.1%, from 370/527 (70.2%) in Q4 2008 to 425/544 (78.1%) in Q4 2009, despite a 6.7% decrease in sputum smear positivity in Q4 2009. TB treatment delay decreased from 75/412 (18.2%) in Q4 2008 to 52/394 (13.2%) in Q4 2009 (P = 0.05). CONCLUSION: In Q4 2009, sputum smear-negative TB notifications increased and treatment delay decreased. However, accurate diagnosis of TB is challenging in this setting, and misdiagnosis and overtreatment may occur. Moreover, other factors in addition to the introduction of the digital X-ray service could have contributed to these findings. Nonetheless, we found that the digital X-ray service had many advantages and that it may aid in more efficient TB diagnosis.

Comparison of four culture systems for Mycobacterium tuberculosis in the Zambian National Reference Laboratory.

SETTING: National TB Reference Laboratory, Zambia. OBJECTIVE: To compare four TB culture systems when used in a resource-limited setting. DESIGN: Comparison of four culture systems: automated Mycobacterium Growth Indicator Tube (AMGIT) 960, manual MGIT (MMGIT) and two Löwenstein-Jensen (LJ) culture media-commercial (CLJ) and homemade (HLJ). RESULTS: A total of 1916 sputum specimens were received, of which 261 (13.6%) were positive on microscopy. Mycobacterium tuberculosis complex (MTC) was isolated on at least one of the media in 410 (21.4%) specimens: MMGIT recovered 336 (17.5%) MTC, AMGIT 329 (17.2%), CLJ 192 (10.0%) and HLJ 184 (9.6%). The median time to detection for smear-negative specimens was 14 days for AMGIT, 16 days for MMGIT and 34 days for both LJ. Isolation of non-tuberculous mycobacteria (NTM) was more frequent in both MGIT systems (3.5%) than in CLJ (0.9%) and HLJ (0.8%). Contamination rates were high: 29.6% on AMGIT, 23.8% on MMGIT, 14.9% on CLJ and 12.5% on HLJ. CONCLUSION: Despite high contamination rates, either MGIT system considerably improved both the yield and the time to detection of MTC compared to LJ media. Investments in infrastructure and training are needed if culture is to be scaled up in low-income settings such as this.

Costs and cost-effectiveness of tuberculosis cultures using solid and liquid media in a developing country.

SETTING: The expansion of culture has been proposed to aid tuberculosis (TB) control in developing countries. OBJECTIVES: To examine the cost and cost-effectiveness at the Zambian National TB Reference Laboratory of homemade and commercially produced Löwenstein-Jensen culture (HLJ and CLJ) as well as automated and manually read liquid culture (AMGIT and MMGIT). DESIGN: Costs were estimated from the provider's perspective and based on the average monthly throughput. Cost-effectiveness estimates were based on yield during the study period. RESULTS: All techniques show comparable costs per culture (between US$28 and $32). Costs per Mycobacterium tuberculosis specimen detected were respectively US$197, $202, $312 and $340 for MMGIT, AMGIT, CLJ and HLJ. When modelled for the maximum throughput, costs were above US$95 per M. tuberculosis specimen detected for all techniques. When only performed among smear-negative specimens, costs per additionally identified M. tuberculosis would be US$487 for MMGIT and higher for other methods. CONCLUSION: Based on cost-effectiveness grounds, liquid media compare well with conventional solid media, especially where yield of MGIT is substantially higher than that of LJ media. The results indicate high overall costs per culture; the expansion of culture to decentralised levels with lower throughputs may result in even higher costs.