Evaluation of the multidrug-resistant tuberculosis surveillance system in the centre region, Cameroon, 2020-2021

¹Cameroon Field Epidemiology Training Program (CAFETP), MOH, Yaounde, Cameroon, ²Department of Disease, Epidemics and Pandemics Control, MOH, Yaounde, Cameroon, ³Department of Public Health and Social Sciences, Faculty of Medicine and Pharmaceutical Sciences of Sangmelima, University of Ebolowa, Ebolowa, Cameroon, ⁴National Tuberculosis Control Program (NTCP), MOH, Yaounde, Cameroon

^&Corresponding author
Evaristus Ncham, Cameroon Field Epidemiology Training Program (CAFETP), MOH, Yaounde, Cameroon

Introduction    

TB remains a major public health problem [1]. The global pandemic of TB is growing as a result of the spread of HIV infection, breakdown in health services, and the emergence of multidrug-resistant TB [2,3]. Multidrug-resistant TB is defined as resistance to rifampicin (RIF) and isoniazid (INH), with or without resistance to the other first-line drugs [4]. In 2019, there were about 10.4 million new TB infections with 1.4 million deaths worldwide. The African region had about a quarter of the world's cases and the highest incidence [1]. World Health Organization (WHO) estimates that 3.3% of newly diagnosed TB cases and 18% of retreatment TB cases have MDR-TB. The prevalence of MDR-TB in Cameroon is estimated at 3.5 per 100,000 inhabitants. An analysis of the 2021 national TB data shows that the majority of cases, both drug-sensitive and MDR-TB cases, were concentrated in the Centre and Littoral regions of the country. The Centre region alone accounted for more than 20% of cases notified in 2021, with 4,695 out of 21,533 drug-sensitive TB cases, and 35 out of 175 MDR-TB cases notified.

In Cameroon, MDR-TB surveillance is done in all the 307 TB diagnostic and treatment centres (DTCs) of the country. Suspected MDR-TB cases are sent to GeneXpert sites where resistance testing can be done. Data from these sites is collected and forwarded to the regional level for compilation and onward transmission to the National Tuberculosis control program. One of the objectives of the National Strategic Plan (NSP) for tuberculosis 2020-2024 is to increase by 100% the number of MDR-TB cases notified by 2024 [5]. In order to attain this objective, a reliable surveillance system is essential. This study was carried out to describe and to evaluate the acceptability, simplicity, representativeness, data quality, stability, and sensitivity of the MDR-TB surveillance system in the centre region of Cameroon.

Methods     

Study setting: this study was carried out in the Centre region of Cameroon, the second-largest region in the country. It has a population of about 4.9 million inhabitants distributed across 32 health districts. There are over 1748 registered health facilities, 62 of which are TB diagnosis and treatment centers. There are 15 GeneXpert sites where testing for MDR-TB can be done. More than half of these GeneXpert sites are located within the urban centre of Yaounde.

Study design and study population: we conducted a cross-sectional study from March to April 2022. The study population comprised all surveillance personnel working at GeneXpert sites and MDR-TB treatment centers in the Centre region.

Sample size and sampling technique: we used purposive sampling to select three surveillance personnel from each structure visited. In structures where one person performed more than one of these functions, the person was selected to answer the corresponding questions. At the district level, the district medical officer (DMO), the chief of bureau for health (CBH), and the district focal point for surveillance (DFPS) were selected. At the GeneXpert sites, the head of the TB unit, the laboratory, and the health facility focal point for surveillance were selected.

Data sources, tools, and procedures: we used the CDC-updated guidelines for evaluating a public health surveillance system [6]. A structured questionnaire was used to collect data on the acceptability, simplicity, and stability of the system. A data collection form was used to collect data from MDR-TB reports for the Centre region from January 2020 to December 2021. This data was used to evaluate the data quality, representativeness, and sensitivity of the system.

Data analysis: we designed an evaluation grid with specific scores to evaluate the attributes. Data were analyzed using MS Excel 2016.

Surveillance system attributes and variables

Simplicity: the simplicity of the surveillance system of MDR-TB referred to both its structure and ease of operation. It was evaluated with the following criteria: knowledge of testing targets, ease in filling reporting forms, time taken to complete notification forms, and knowledge of the circuit of transmission of reports.

Data quality: it was defined as the completeness and validity of the MDR-TB surveillance data. Completeness of data was calculated by dividing the number of spaces correctly filled on the reporting forms by the total number of spaces to be filled for the period from January 2020 to December 2021. Data completeness was considered to be satisfactory if it was greater than or equal to 80%. Validity was considered to be the proportion of reports verified by a second person before their transmission to the next level. It was considered satisfactory if the proportion of double-signed reports was greater than 80%.

Stability: stability referred to the reliability and availability of the MDR-TB surveillance system. Reliability was defined as the ability to collect, manage, and provide data properly without failure, while availability was the ability of the system to be operational when it is needed. It was evaluated by the availability of a district surveillance focal point for MDR-TB, availability of reporting forms, functional GeneXpert machines and cartridges, and a computer for data analysis at the district level.

Timeliness: timeliness was considered to be how quickly identified cases were notified within the surveillance system. It was considered satisfactory if the timeliness of reports was at least 80%.

Ethical considerations: we received authorization from the permanent secretariat of the National Tuberculosis Control Programme (No0224/MINSANTE/SG/DLMEP/PNLT/SP/CSM). Written informed consent was obtained from each participant before administering the questionnaire.

Results     

Description of the surveillance system: identification of suspected MDR-TB cases occurs at the community level and at the DTCs. These cases have a high likelihood of MDR-TB and include positive TB cases classified as treatment failures, relapses, or retreatment cases, as well as symptomatic patients who have been in contact with a confirmed MDR-TB case. Other patients, such as children under 5 years, prisoners, and people living with HIV (PLWHIV), are systematically tested for MDR-TB. These patients are tested using GeneXpert, which allows for the detection of RR-TB. In centers where GeneXpert is not available, specimens are collected and sent to a laboratory with such capacity. At the end of each trimester, data are collected from the testing and treatment centers and forwarded to the regional level before the 5^th of the following month. At the regional level, the data collected from the various diagnostic and treatment centers is aggregated in an Excel sheet, then entered into the DHIS2 platform and forwarded to the central technical group (CTG) by the 15^th of the month. At the central level, the data from the regional level is aggregated into a validated Excel sheet and in DHIS2. At both the regional and central levels, the quality of the data is assessed and feedback given to the lower level.

Sociodemographic analysis: a total of 33 surveillance personnel were interviewed. Most of the personnel involved in MDR-TB surveillance in the Centre region were nurses in charge of DTCs (36%) and laboratory technicians (33%). Two out of the thirty-three (6.06%) were DMOs, and 2/33 (6.06%) were district focal point persons for surveillance.

Analysis of surveillance system attributes

Simplicity: eighty-two percent (27/33) of personnel interviewed found the MDR-TB reporting form easy to fill out, and 88% (29/33) admitted they used less than 10 minutes to complete it. Only 27% (9/33) of persons interviewed could clearly identify suspected MDR-TB cases, and 64% (21/33) knew the next level of transmission of reports (Table 1).

Stability: only 16.7% (2/12) of sites had a focal point person for MDR-TB surveillance. Fifty-eight percent (7/12) of sites were functional at the time of the study, while 42% (5/12) of sites had reserve Xpert-RIF cartridges. There were no tools dedicated to the analysis of MDR-TB data at the level of the RTG-TB for the Centre region (Table 1).

Data quality: all GeneXpert sites in the Centre region are involved in MDR-TB surveillance. However, only 10/48 expected reports were submitted, giving a completeness of reports of 21%. Of the 10 reports submitted, there were 100 spaces to be filled, and 86/100 spaces were effectively filled, giving 86% data completeness. None of the reports was cross-checked by a second person before submission.

Timeliness: of the 48 reports expected, only 4 were received on time, giving an overall timeliness of 8.3%.

Discussion     

Surveillance for MDR-TB is done within the framework of tuberculosis surveillance in Cameroon by the National Tuberculosis Control Program. The second expected result of the national strategic plan is to increase by more than 100% the number of MDR-TB cases notified with respect to the 2018 baseline; in a bid to close the gap between the estimated number of MDR-TB cases and the number notified each year. Surveillance for MDR-TB is done in the Gene-Xpert sites, where the diagnosis of MDR-TB is made. In the Centre region, this is done in all 12 GeneXpert sites. The surveillance system for MDR-TB is not well structured, as it does not respect the district health system of the country. Data from the DTCs is forwarded directly to the regional level, thereby making it difficult for the district health service to directly supervise the activities of the DTCs.

The surveillance system for MDR-TB was moderately simple. In order to effectively carry out surveillance for MDR-TB, it is important that all the personnel involved in the system can clearly identify suspected cases and the steps to follow when a case is suspected. This is not a reality in the Centre region, where only a quarter of the personnel were able to identify suspected MDR-TB cases, and only two-thirds knew the next level for the transmission of reports. This can be explained by the fact that neither case definitions nor any guidelines on the diagnosis of MDR-TB in any of the facilities. Although data completeness was good (86%), the validity of the data was doubtful due to the fact that none of the reports was verified before submission. This can also be explained by the poor implication of the hospital administration in the surveillance of MDR-TB.

The MDR-TB surveillance system is timely if it can react promptly to outbreaks. This depends on how fast information is made available to the decision makers within the system. Timeliness of the MDR-TB surveillance system in the Centre region was very poor, with only 8% overall timeliness of reports. This can be attributed to poor supervision. A stable performance is necessary for the viability of the MDR-TB surveillance system. The MDR-TB surveillance system was found to be unstable, with only 58% of the GeneXpert machines functional and only 42% have reserve GeneXpert cartridges. This makes the system unreliable and can delay or prevent necessary public health actions.

Conclusion     

Surveillance of MDR-TB is done within the framework of TB surveillance in Cameroon. This evaluation showed that in the Centre region of Cameroon, the system is moderately simple, though most of the personnel do not master the case definitions. It is essentially passive and does not respect the health pyramid of the country. MDR-TB data is transmitted directly from the DTCs to the regional level. We recommend staff training and a restructuring of the system to respect the health pyramid of the country. Surveillance for MDR-TB should be more active, and the NTCP should scale up the diagnosis of MDR-TB to more DTCs.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Evaristus Ncham, Linda Esso, Armel Evouna, and Abdoul Wahhab conceived and designed the study; Evaristus Ncham collected, analysed data, and wrote the manuscript. Evaristus Ncham, Linda Esso, Armel Evouna, Abdoul Wahhab, and Antoine-De-Padue Etoundi critically reviewed and edited the manuscript. All the authors have read and approved the final version of this manuscript.

Acknowledgments     

Our gratitude goes to all the study participants for consenting to participate in the study and for responding to the questionnaire. We also acknowledge the Department of Disease, Epidemics and Pandemics Control, the Cameroon Field Epidemiology Training Program, and the National Tuberculosis Program of Cameroon for their support in the implementation of the study. Dr Els Matheu and Anne Griggs for editing the manuscript.

Table     

Table 1: attributes of the MDR-TB surveillance system in the Centre region of Cameroon, April 2022

References