Background

The coronavirus disease (COVID-19) resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has led to significant mortality and morbidity since its initial reporting in December 2019. While the global health emergency has transitioned, the lessons learned regarding diagnostic infrastructure remain vital for health system strengthening. Testing, along with isolation, contact tracing, and the use of personal protective equipment (PPE), was essential to the response. While nucleic acid amplification testing (NAAT) is the diagnostic reference, antigen-detection rapid diagnostics tests (Ag-RDTs) are also recommended due to their ease of use and rapid results. [1] Ag-RDTs are particularly suited for resource-constrained settings since shortages of NAAT testing supplies, limited skilled laboratory personnel, high costs, and logistical challenges are common. The practice and knowledge related to SARS-CoV-2 Ag-RDTs could serve as a foundation for the timely identification of other endemic diseases and new variants. [2]

Guaranteeing affordable diagnostic access for everyone in sub-Saharan Africa is essential to prevent access disparities based on socioeconomic status. In the post-pandemic era, empirical data on patient-side costs is required to design sustainable health policies. In contexts where patients incur out-of-pocket expenses, these costs can discourage individuals from getting tested. Affordable testing diminishes these barriers, encouraging individuals to pursue testing without the weight of financial burden.

The existing literature on the patient-side economic burden of SARS-CoV-2 Ag-RDTs in sub-Saharan Africa is scarce. A study examined the cost and cost-effectiveness of implementing SD Biosensor antigen-detecting SARS-CoV-2 diagnostics tests in Kenya but estimated this cost for testing in a hospital only [3]. Another study looked at the health system costs of SARS-CoV-2 testing in Mozambique [4]. However, there is a lack of multi-country evidence comparing different delivery modalities, such as community pharmacies versus public clinics, from the patient’s perspective.

In this study, we sought to understand which Ag-RDT testing modalities may be lowest-cost and thus most affordable for the majority of the population in three different sub-Saharan African settings that share a need for expanded community-based SARS-CoV-2 testing and persistent challenges in integrating such testing into routine public health services: Nigeria, Malawi, and Zimbabwe. Specifically, we aimed to assess (i) the cost incurred by patients per SARS-CoV-2 Ag-RDT test in different healthcare settings from the patient’s perspective, and (ii) the affordability of the tests in these settings. By providing a retrospective analysis of these costs, this study helps understand the socioeconomic barriers to diagnostic uptake and the patient-side costs of different rapid testing modalities in Sub-Saharan Africa.

Methods

Study overview

This study, implemented by various health development partners and supported by Ministries of Health (MOH) in Nigeria, Malawi, and Zimbabwe, evaluated the implementation of SARS-CoV-2 Ag-RDT strategies including self-testing and linkage to treatment and prevention for symptomatic participants and asymptomatic contacts who were contacts of a known case. The implementation projects aimed to evaluate the professional use of SARS-CoV-2 Ag-RDTs for diagnostic testing of symptomatic patients presenting to primary care facilities (Nigeria, Malawi), Female Sex Worker Clinics (Zimbabwe), PHS New Start Centers (Zimbabwe) or community pharmacies/drug stores (Nigeria). Community pharmacies are licensed retail pharmaceutical outlets operated by trained pharmacists and authorized to dispense prescription and over-the-counter medicines. Drug stores (also referred to as patent and proprietary medicine vendors in some settings) are retail outlets that sell over-the-counter medicines and basic health commodities but are typically staffed by non-pharmacist personnel and operate under more limited regulatory scope. SARS-CoV-2 Ag-RDTs self-testing was also evaluated in all primary healthcare facilities in Zimbabwe and both community and drug stores in Nigeria (Table 1).

Download:

• PNG
  larger image
• TIFF
  original image

Table 1. SARS-CoV-2 Ag-RDT strategies in the different countries.

https://doi.org/10.1371/journal.pone.0350288.t001

Results

Study demographic characteristics

A total of 644 clients participated in the study, with 199 in Nigeria, 106 in Malawi, and 339 in Zimbabwe. The median age of the participants ranged from 27 to 32 years. In all three countries, more than half of the participants were females, and the majority had completed senior secondary school and/or had some higher education. The participants represented a diverse range of occupations, with approximately 30% of them being unemployed in Malawi and Zimbabwe. The proportion of the responding population declaring they were in an income-earning occupation (excluding unemployed, students, homemakers and retired individuals) was 75% in Nigeria, 63% in Malawi and 62% and 66% in Zimbabwe’s PHS New Start Centers and Female Sex Worker clinics respectively. These figures are similar to the national figures for employment in the working age population in 2022–2023 in these countries, which were estimated at 78% and 80% in Nigeria in 2022 and 2023, at 64% in Malawi, and at 59% in Zimbabwe [8]. Among the participants, Nigerian respondents had the lowest monthly income (M = US$84.0, SD = US$87.0), while Zimbabwean participants had the highest monthly income (M = US$207.5, SD = US$344.4). However, in Nigeria, only 40% of the participants expressed concerns about food insecurity in the last week, while approximately 59% and 73% were worried about food insecurity in Zimbabwe and Malawi, respectively (Table 2).

Download:

• PNG
  larger image
• TIFF
  original image

Table 2. Demographic characteristics of respondents (N = 644).

https://doi.org/10.1371/journal.pone.0350288.t002

Cost of accessing SARS-CoV-2 Ag-RDTs test (patients’ perspective)

The mean cost of accessing a SARS-CoV-2 Ag-RDT test was lower in Malawi (M = US$2.7, SD = US$3.8; 95% CI: 2.0–3.4) and Zimbabwe (M = US$2.7, SD = US$3.6; 95% CI: 2.3–3.1) compared to Nigeria (M = US$4.2, SD = US$16.0; 95% CI: 2.0–6.4). The relatively large standard deviation observed in Nigeria reflects substantial variability in patient-incurred costs, driven primarily by differences in travel expenses and productivity losses across testing locations. The cost per positive case of SARS-CoV-2 Ag-RDT testing was US$416.1 in Nigeria and US$915.3 in Zimbabwe. We were not able to calculate this cost in Malawi since none of the participants tested positive (Table 3).

Download:

• PNG
  larger image
• TIFF
  original image

Table 3. Cost of accessing SARS-CoV-2 Ag-RDTs test (patients’ perspective).

https://doi.org/10.1371/journal.pone.0350288.t003

Scenario analyses

In Nigeria, testing at primary healthcare facilities was associated with a much higher cost (US$9.6) compared to drug stores (US$1.8) and community pharmacies (US$0.6). Additionally, professional testing was associated with a higher client cost compared to self-testing (US$9.8 vs. US$1.3) in Nigeria. Conversely, in Zimbabwe, professional testing was associated with lower client costs compared to self-testing (US$2.3 vs. US$3.2) (Table 4).

Download:

• PNG
  larger image
• TIFF
  original image

Table 4. Cost of testing at different use cases or different scenarios.

https://doi.org/10.1371/journal.pone.0350288.t004

Affordability of SARS-CoV-2 Ag RDT Testing

The assessment of the potential catastrophic impact of SARS-CoV-2 Ag RDT testing revealed that approximately 28.6% of the 199 individuals in Nigeria, 40.6% of the 106 individuals in Malawi, and 5.7% of the 339 individuals in Zimbabwe may experience catastrophic health expenditures to access SARS-CoV-2 Ag RDT testing (Fig 1).

Download:

• PNG
  larger image
• TIFF
  original image

Fig 1. The potentially catastrophic impact of SARS-CoV-2 Ag RDT testing.

https://doi.org/10.1371/journal.pone.0350288.g001

In Nigeria, a higher percentage of participants at primary healthcare facilities potentially experienced catastrophic health expenditures (approximately 32%), compared to those who tested in drug stores (approximately 29%) or those who tested in private pharmacies (approximately 25%). In Nigeria again, a higher percentage of participants who chose professional testing potentially experienced catastrophic health expenditures compared to participants who opted for self-testing. The same situation was also observed in Zimbabwe (Table 5)

Download:

• PNG
  larger image
• TIFF
  original image

Table 5. Percentage of persons that could potentially experience catastrophic health expenditure in the different socio-economic strata in Nigeria, Malawi, and Zimbabwe.

https://doi.org/10.1371/journal.pone.0350288.t005

Discussion

In our study, we found that clients spent between US$2.7 – US$4.2 to test for SARS-CoV-2. While these data reflect a specific epidemiological window (late 2022 to early 2023), they provide a critical baseline for understanding the hidden economic barriers that persist in post-emergency diagnostic systems. Malawi and Zimbabwe had the lowest client cost while Nigeria had the highest. The high cost per positive case detected (from US$416.1 in Nigeria to US$915.3 in Zimbabwe) underscores the economic challenge of maintaining testing programs as prevalence drops, arguing for the integration of SARS-CoV-2 testing into broader, multiplexed respiratory surveillance systems. Our findings also show that even within the “post-emergency” phase, a significant proportion of individuals in Nigeria, Malawi, and Zimbabwe faced catastrophic health expenditures to access Ag RDTs. While we applied a standard threshold of 10% of household income to define catastrophic health expenditure, this threshold may not fully capture the extent of financial hardship across diverse socioeconomic contexts. In low-income settings, even smaller expenditures may impose a substantial burden on households, suggesting that our estimates may underestimate the true economic impact of testing. Overall, these findings indicate that “free” testing at the point of care is insufficient for achieving diagnostic equity if indirect costs like transport and productivity loss remain unaddressed. These barriers are not unique to SARS-CoV-2 and will likely hinder the uptake of diagnostics for future pathogens of pandemic potential.

In relation to similar studies, the two other studies on SARS-CoV-2 Ag-RDT testing costs in sub-Saharan Africa primarily focused on health systems costs [3,4]. However, the study in Kenya also estimated patient costs for the SARS-CoV-2 Ag-RDT test, with a median cost of US$2.92 [3]. This cost aligns with our estimated patient cost in health facilities in Malawi (US$2.7) and Zimbabwe (US$3.3) but is lower than the patient cost estimated in Nigeria (US$4.2). Building the literature on patient costs of accessing SARS-CoV-2 rapid testing should help with future work on costs and cost-effectiveness in sub-Saharan Africa [9] . The cost of approximately US$2.7 to US$4.2 for a SARS-CoV-2 test can be a significant amount for individuals in countries where, at a poverty headcount ratio of US$2.15 per day and based on 2017 purchasing power parity, approximately 31% of Nigerians, 40% of Zimbabweans, and 68% of Malawians live below the poverty line [10]. Therefore, integrating client costs in decision-making regarding the choice of diagnostic modalities and locations is crucial to ensure equitable access to testing and design “people-centred” diagnostic networks.

Perhaps the most important finding for future health policy is that utilizing testing facilities beyond the traditional hospitals or primary health care centers, such as community pharmacies and drug stores, was associated with lower costs. Further review of the client cost details in Nigeria showed that travel cost and productivity loss were higher in primary health centers compared to community pharmacy or drug store. Retail pharmacies and drug stores are more abundant than clinics and are often situated in high-traffic areas, ensuring easy accessibility for the general population [11]. Moreover, it is well-documented that wait times in primary healthcare facilities can be lengthy. [12,13] leading to increased productivity losses. Diagnostic delivery at more accessible locations, such as private pharmacies and drug stores, can substantially reduce travel time and wait times for the client, a finding that could be adapted to other endemic diseases or future outbreaks.

It is important to note that the choice of testing method (self-testing or professional testing) is not consistently associated with lower costs. For example, self-testing was associated with lower costs in Nigeria but was associated with higher costs in Zimbabwe. One might expect that clients choosing self-testing would spend more time on the testing process, potentially resulting in increased opportunity costs and higher client expenses if other costs, such as travel costs or wait times, are similar. In Nigeria, the time lost due to testing was lower with self-testing because the majority of clients who opted for self-testing participated in the study at private pharmacies (41%) and drug stores (59%), which are closer to clients than healthcare centers (less than 1% of the study participants who opted for self-testing did so through primary healthcare facilities). Conversely, in Zimbabwe, the higher cost of self-testing compared to professional testing is primarily driven by higher travel cost, higher lost earnings due to testing, and higher non-medical costs. Client costs associated with testing are therefore not systematically higher or lower for professional vs. self-testers. Instead, they seem associated with other drivers, including the specific location and accessibility of testing (self-testing was more accessible than professional testing in Nigeria but not in Zimbabwe), the profile of the patients being tested (self-testers were slightly wealthier on average in Zimbabwe than professional testers, i.e., daily income of US$9 versus US$8 respectively) and other drivers including wait times (56 minutes for self-testers in Zimbabwe vs. 27 minutes for provider-testing), time spent getting familiar with the test and travel cost.

While testing in pharmacies and drug stores was cheaper in Nigeria, establishing public-private partnerships (PPP) with these providers to enhance SARS-CoV-2 testing accessibility demands careful consideration, as numerous concerns are associated with this arrangement. Successfully implementing PPPs can be challenging when there are no formal contracts with private providers outlining their roles, a lack of oversight and consequences for inadequate governing body capabilities, and financial viability concerns [14,15]. It is essential to acknowledge that in the latter case, private service providers not employed by the government must be remunerated for the services they provide. These challenges were observed in several low- and middle-income countries (LMICs) during health sector reforms from the mid-1980s to the late 1990s in response to calls from the World Bank and the International Monetary Fund (IMF) to adopt PPPs for strengthening struggling health systems [15]. Notably, the PPP implemented in Tanzania to enhance healthcare delivery did not fully achieve the expected outcomes, contrary to popular belief [16]. Hence, each testing modality considered has to be carefully considered in a specific country context and properly overseen. More cost data collection in additional countries would help better understand the complexity of SARS-CoV-2 Ag-RDT client costs in different settings.

Although our analysis focused on cost and affordability, individuals seek SARS-CoV-2 testing for personal and public health benefits, including early care-seeking, informed self-isolation, reduced transmission, and reassurance before travel, social events, or work. Similarly, the decision not to test may derive from fear of restrictive measures and social harms, or misperceptions about COVID-19. Cost is only one dimension of access; improving uptake also requires raising awareness of benefits, increasing convenience, and aligning services with individuals’ reasons for testing [17].

While this study provides important insights across three sub-Saharan African countries, future research involving a larger number of countries would be valuable to generate a more comprehensive regional picture of patient-level costs and affordability of diagnostic testing. Such broader analyses could further inform context-specific and region-wide strategies to improve equitable access to diagnostics.

This study presents a number of limitations. It utilized a limited number of test settings and was conducted in only three countries, which may limit the generalizability of findings across the broader sub-Saharan African region. While Nigeria, Malawi, and Zimbabwe were selected to reflect diverse implementation contexts, a larger multi-country study would provide a more comprehensive understanding of patient costs and affordability across different health systems in the region. We were not able to test the exact same testing modalities across all countries. For practical reasons, study sites were selected in collaboration with health authorities to be representative of SARS-CoV-2 testing setting; however, they did not constitute a random sample of all healthcare centres in the country. As a result, there may be some discrepancy between the patients in the targeted facility and all facilities. A more important potential bias relates to generalizability to the entire country’s population. By design, we sampled individuals seeking care at health facilities and in need of SARS-CoV-2 testing. This excludes individuals who did not seek care, potentially due to affordability or access constraints. As a result, our findings likely underestimate the true economic burden of testing, particularly for more vulnerable populations who face greater barriers to accessing care. Consequently, our estimates of patient costs and affordability, including catastrophic health expenditure, should be interpreted as conservative. Individuals who are unable to access testing may incur even higher relative costs or forgo testing altogether due to financial barriers. For costs expressed in terms of working time lost, we may have underestimated loss of working time, and at the same time overestimated the income of those who may need SARS-CoV-2 testing (as people with lower incomes are less likely to seek care). In addition, productivity loss estimates relied partly on standardized assumptions based on minimum wage rates, particularly for accompanying individuals or where self-reported income data were unavailable. While this approach improves consistency, it may not fully capture individual-level variations in income. We did not conduct formal sensitivity analyses to assess the robustness of these assumptions. Furthermore, the high variability observed in cost data, particularly in Nigeria, reflects real-world heterogeneity but may limit comparability across settings. The survey was conducted between October 2022 to May 2023, and changes in public health trends since then may affect the applicability of the findings to current conditions. Finally, the use of a 10% threshold to define catastrophic health expenditure, while widely adopted, may not adequately reflect financial hardship across heterogeneous income groups, particularly among the poorest populations. In addition, household income data were self-reported and may be subject to recall bias or misreporting, which could affect the accuracy of catastrophic expenditure estimates.

Despite the limitations, the study provides valuable insights into the financial burden faced by individuals seeking SARS-CoV-2 testing and helps compare alternative testing scenarios that may offer cost-effective options for those in need of testing.

Conclusions

This study provides retrospective yet vital knowledge for integrating diagnostics into routine primary care in LMICs. We demonstrate that the financial burden associated with SARS-CoV-2 Ag-RDT testing remains a threat to diagnostic equity. However, a promising solution lies in differentiated testing modalities. By expanding testing options to community pharmacies and drug stores, we can provide low-cost alternatives that are more accessible to a broader segment of the population. These settings offer convenience and affordability, as they are often conveniently located and equipped to provide testing services at competitive prices. This approach not only reduces the financial strain on individuals but ensures that as many people as possible have the opportunity to get tested, contributing to the collective effort to control the spread of the virus and protect public health. Any decision on testing modalities should however be informed by the specific country context and associated constraints.

Supporting information

Acknowledgments

The authors acknowledge the country study teams from Zankli Research Center in Nigeria, the Centre for Sexual Health, HIV and AIDS Research in Zimbabwe (CeSHAAR), and the Health Economics Policy Unit at the Kamuzu University of Health Sciences in Malawi that conducted the field study.