Covid-19 testing programs that fail to support the prevention of onward transmission have minimal benefits at best, and are harmful at worst, say Neia Prata Menezes, Katherine Rucinski, and Stefan Baral
Testing has been a cornerstone in covid-19 response strategies and is often heralded as having a central role in returning us to our pre-pandemic lives.1 2
As a tool, testing can be used to screen asymptomatic individuals, diagnose symptomatic infections, and monitor epidemiologic trends in the spread of disease to inform control measures and guide public policy.3 In the case of infectious diseases, testing as an intervention strategy can facilitate connections to prevention, treatment, and care. In sexual health programs, testing is commonly linked to interventions that directly address patients’ health needs and decrease onward transmission risks, including curative antibiotics, antiretroviral therapy for HIV, and decreasing condom-less sex.4 5 For highly transmissible airborne infections, what is the impact of testing if one’s living situation does not allow for isolation, work does not provide paid or unpaid sick leave, family is dependent on income for basic needs, or access to healthcare is conditional on employment?
It has been more than four decades since Wilson and Jungner published the Principles and Practice of Screening for Disease, which highlighted the need to link individuals to appropriate treatments as a requisite for an impactful testing program.6 It underlined our ethical obligations to integrate testing with interventions that are effective and accessible to mitigate the impact of diseases. Without said interventions, the individual level benefits of diagnosis or early detection are rendered useless at best, or harmful at worst. The Tuskegee syphilis study or the Willowbrook experiments highlight horrific instances where physicians and public health agencies opted to observe the natural course of disease after diagnosis, rather than provide curative treatment or implement appropriate preventive measures.7 8 Echoes of these questionable practices linger in the ethical implications of testing research participants for HIV without returning results and supporting referrals to appropriate prevention or treatment services.9
Alongside linking testing with effective treatment, it is also important to ensure that treatment is available and accessible to those in need.6 Historical trends indicate that the populations most vulnerable to disease also face greater barriers to accessing treatment. Covid-19 is no different. However, in the absence of curative therapies, and assuming that people are too well to be admitted to hospital, the primary intervention that needs to happen after testing is supporting the prevention of onward transmission, which necessitates space and time.10 11 Not surprisingly, consistent data have demonstrated sociodemographic and racial inequities in people’s ability to adhere to isolation or quarantine guidelines.12-14 These inequities are not novel. In fact, they mirror existing racial and ethnic and socioeconomic disparities for covid-19 acquisition risks, severe disease or hospitalization, and death.15-19
Fundamentally driving many of these differences in covid-19 outcomes is structural racism, which manifests in overrepresentation within essential service industries, lower socioeconomic status, greater financial hardship, and differential access to healthcare.20 21 It’s no surprise that these factors would similarly converge to impair a person’s ability to self-isolate or quarantine. Furthermore, they may have additional downstream consequences: those who cannot afford to take time off work, or fear being kicked out of shared housing, may be hesitant to present for testing in the first place, exacerbating already disparate outcomes.13 This is compounded by reports of fines or arrests enforced on those who fail to comply with self-isolation or quarantine mandates.22 These policies functionally equate to punishing people for not having enough space in their homes or enough flexibility in their jobs to abide by public health protocols.
These socioeconomic inequities are not unique to covid-19 as they have been consistently observed where studied in previous pandemics of viral respiratory origin.21 23 In other words, we could have anticipated that inequities along socioeconomic lines would play a pivotal role in driving both infections and disparities during covid-19, and designed interventions accordingly.
More than three decades ago, a framework for equity driven programs was published by the World Health Organization, which emphasized that programs have the dual goal of promoting health gains while reducing health inequities.24 Using an equity lens to guide covid-19 strategies therefore means we have to address the living and working conditions that increase risks for some people and not others. Ultimately, if governments and policy makers want to achieve the full potential of testing strategies, they’ll have to implement structural level interventions that support and facilitate people’s adherence to isolation or quarantine.
We can see the importance of these principles of equity, and what happens when they’re neglected, in other aspects of our pandemic response. For while highly effective vaccines arrived far faster than we expected and represent the path out of the covid-19 pandemic, to date, most vaccination programs have been best designed for people with private transport and flexible working conditions. This has resulted in the highest vaccine coverage in the lowest risk communities.25-27
As we start to learn from our various responses to covid-19, it is critical that we explore beyond how many tests were completed and which businesses were closed, and consider what efforts were made to address the specific needs of communities on the margins. Guidance documents dating back decades suggested the need for testing to be linked to interventions and the importance of an equity lens given socioeconomic inequities and structural racism. Ultimately, an enduring lesson of covid-19 will be that our strategies didn’t leverage core surveillance principles, and as a result they—either by design or by accident—better protected wealthier communities. And in that, they have been a resounding success.
Neia Prata Menezes is a PhD student in the Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore. Twitter @Neia_Prata
Katherine Rucinski is an assistant scientist in social and behavioral interventions at the Department of International Health, Johns Hopkins School of Public Health, Baltimore. Twitter @KateRucinski
Stefan Baral is an associate professor and director of the Key Populations Program for the Center for Public Health and Human Rights, Johns Hopkins School of Public Health, Baltimore. Twitter @sdbaral
Competing interests: none declared.
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- World Health Organization. Consolidated guidelines on HIV testing services: 5Cs: consent, confidentiality, counselling, correct results and connection 2015. 2015.
- Marrazzo JM, Cates W. Interventions to prevent sexually transmitted infections, including HIV infection. Clinical Infectious Diseases 2011;53(suppl_3):S64-S78.
- Wilson JMG, Jungner G, World Health Organization. Principles and practice of screening for disease. World Health Organization, 1968.
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- Brandt AM. Racism and research: the case of the Tuskegee Syphilis Study. The Hastings Center Report, 1978; 8(6): 21-29.
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