Introduction

Testing for SARS-CoV-2 played a critical role in the global response to the COVID-19 pandemic. Since the onset of the disease in Nigeria in February of 2020, the nation’s testing capability increased progressively because of concerted efforts by governments and partner organizations in scaling-up testing. The country adopted various testing strategies, including the use of antigen-based Rapid Diagnostic Tests (Ag-RDT), molecular polymerase chain reaction (PCR) tests, GeneXpert and genome sequencing for case detection and identification of emerging variants. Ag-RDT is a valuable screening tool for early diagnosis of asymptomatic and symptomatic infections, due to its short turn-around time and reduced cost [1,2]. Early diagnosis is a key factor in preventing community transmission for example by facilitating contact tracing and active monitoring [3,4].

In Nigeria, Ag-RDT was adopted as a strategy for screening and early diagnosis of COVID-19 and to scale-up testing for the virus following the release of a national guideline on its use in January 2021 [3,5]. Its introduction has allowed for expansion and decentralization of testing capacity, utilizing existing health structures and systems. Expansion of testing has resulted in increased uptake; the average daily COVID-19 tests conducted from all diagnostic procedures rose from 2,500 samples in April 2020, to 4,000 samples by December 2020, and 5,250 samples by April 2021 [6]. By December 18^th, 2022, the Nigeria Centre for Disease Control (NCDC) reported a total of 5,812,382 cumulative tests from all diagnostic profiles, of which Ag-RDT constituted 1.8 million (31%) [7].

Programs to decentralize testing for COVID-19 involve task-shifting to community health workers, non-laboratory professionals and/or lay cadres [8]. In Nigeria, community-based decentralization included shifting testing responsibly to Primary Healthcare Workers, Community Pharmacists and Patent Medicine Vendors who often serve as the first point of contact for basic healthcare in the country [9,10]. These decentralization programs aimed to curb the spread of the virus by improving access to testing and diagnosis for those living in poorer communities, or otherwise under-served areas.

Community-based decentralization of COVID-19 testing can improve access and increase uptake of testing as well as strengthen and contribute to COVID-19 surveillance and response. However, risks of decentralized services include service quality; community facilities may not be subject to the same clinical standards as more established health services, buildings may have poorer infrastructure, with potentially lower-skilled, or less trained workers, fewer safety standards, lower adherence to quality standards in testing, reporting, and management of results, as well as poorer testing process, and data management [9,11,12].

To support quality assurance of a community-based decentralized testing model, this study evaluated COVID-19 testing sites in the Federal Capital Territory of Nigeria. The information learned from this study aims to guide optimization of decentralization of COVID19 AG-RDT in Nigeria and other countries where similar models are being implemented.

Methods

Results

Of 148 surveyed facilities, Primary Healthcare Centers made up over half of assessed facilities (53%, 79/148), Community Pharmacies constituted a third of assessed facilities (32%, 48/148), followed by Patent Medicine Stores (14%, 21/148). Two of the facilities (1.4%, 2/148) scored less than 40 thus placed at level ‘0’ on the quality performance rating, both Community Pharmacies. Fifteen facilities (10.1%, 15/148) scored between 40 and 59, thus places at level ‘1’ on the rating, with four Community Pharmacies and nine Patent Medicine Stores falling into this category (Table 1).

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Table 1. Facility average quality performance rating.

https://doi.org/10.1371/journal.pone.0310294.t001

Most facilities scored above 80 on the quality performance rating–corresponding to at least a level 3 on the quality rating—with Primary Healthcare Centers being the most consistent performers in terms of quality. Community Pharmacies and Patent Medicine Stores showed variability in quality performance, with 15 facilities falling below 60 (level 2).

There was strong evidence that Primary Healthcare Centers (median score: 90.2) and Community Pharmacies (83.6) performed better than Patent Medicine Stores (64.6), (p<0.001 for both pairwise comparisons). However, there was no evidence of a difference in quality between Primary Healthcare Centers and Community Pharmacies (p = 0.31) (Fig 1).

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Fig 1. Comparison of COVID-19 RDT service quality performance across health facilities.

Community health facility differences in performance in service quality for COVID-19 RDT. Median scores by facility type are indicated by red dots, alongside upper and lower quartiles. Kruskal-Wallis non-parametric test was used to compare the medians across all facility types. Bonferroni-corrected Mann Whitney U-test p-values for pairwise comparisons between facility types are presented above.

https://doi.org/10.1371/journal.pone.0310294.g001

Within individual domains, Primary Healthcare Centers scored higher in most of these, with physical infrastructure and safety being the domains where they performed better than Community Pharmacies and Patent Medicine Stores (Table 2).

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Table 2. Comparison of COVID-19 RDT quality domains across health facilities.

https://doi.org/10.1371/journal.pone.0310294.t002

The testing phase showed variations across facilities, with Primary Healthcare Centers performing better than the other two types of facilities. Primary Healthcare Centers had the highest median scores for most domains, with a median score of 86 (IQR: 75, 93), for documentation and report, 100 (IRQ: 86, 100) physical infrastructure, and 100 (IRQ: 85, 100) for safety. The median scores for Community Pharmacies and Patent Medicine Stores were lower, with Patent Medicine Stores having the lowest median score of 60 for both post-testing phase and safety.

Discussion

Primary Healthcare Centers are the most consistent performers in terms of quality of COVID-19 Ag-RDT. Primary Healthcare Centers also perform better at documentation and records, physical infrastructure, and safety compared to Community Pharmacies and Patent Medicine Stores. This is encouraging as this level of health facility is critical in health service delivery in Nigeria, essential to the provision of basic and comprehensive health services including disease prevention and control [15].

A previous study in Ekiti, Nigeria, showed lower COVID-19 RDT performance quality scores at secondary and tertiary facilities than at Primary Healthcare Centers. This is unexpected as higher-level facilities are usually considered to have better infrastructure [16]. The higher performance scores in our study could be explained by the extensive support facilities received in the intervention program. However, the modification of the evaluation tool limits the comparability of the results. The convenience sampling strategy also limits external validity, as those community facilities that were available and responded during our assessment, may have been those more likely to perform well in the assessment.

Community Pharmacies and Patent Medicine Stores showed reasonably good quality of COVID-19 RDT testing service, although some sites performed poorly in certain domains. These finding are important as community facilities such as pharmacies and Patent Medicine Stores are often the first level of contact for healthcare services, especially in rural areas where access to Primary Healthcare Centers is limited [17,18]. Community Pharmacies and Patent Medicine Stores have potential to provide quality COVID-19 RDT testing services, there is need for improvement of quality performance to ensure that they meet the required standards. The better performance by primary healthcare facilities is expected as they have better physical infrastructure and safety standards [19]. Additionally, these centers have more resources, medical exposure and training [19]. However, previous research indicates the performance of Patent Medicine Stores can be improved with appropriate training and support [18].

Recommendations for effective and adequate decentralization of COVID-19 testing at community level include provisions for comprehensive training and supervision on safe collection, handling of samples, testing and interpretation of test results [8]. Additionally, adequate, and appropriate biosafety measures including waste management and infection prevention and control (IPC) measures should be put in place. Engagement in quality assurance activities, which can include site supervision and mentorship is also recommended [8].

Conclusion

Our study provides important insights into the quality of COVID-19 Ag-RDT testing delivered at community facilities in Nigeria as part of a decentralized testing strategy. Primary Healthcare Centers and Community Pharmacies can provide quality decentralized testing for COVID-19, while delivery through Patent Medicine Stores may require additional support to improve. The quality of COVID-19 Ag-RDT across health facilities, particularly in Patent Medicine Stores, is critical in ensuring accurate diagnosis, effective treatment, and prevention of the spread of the virus. Training and support such as monitoring, and quality improvement initiatives can improve the performance of community facilities to ensure equitable access to high quality decentralized services for COVID-19 testing.

Supporting information

Acknowledgments

The authors would like to thank the heads and proprietors of the health facilities, and the healthcare providers for granting the permission and consenting to take part in this study. The authors would also like to appreciate the FCT department of Public Health and the FCT Primary Healthcare Board on their guidance and support in undertaking this study and during the joint evaluation visits to the testing sites.