The Rural Front Line

Why testing for surveillance—not universal testing—is necessary to contain COVID-19

A doctor wearing a protective suit stores a swab in a test tube to test for COVID-19 in Mumbai on 8 April 2020. In the eyes of many, universal testing has become the primary proxy for action against coronavirus. Prashant Waydande / REUTERS

This is the third piece in a series titled “The Rural Front Line,” by Yogesh Jain and Naman Shah, about the COVID-19 pandemic. Jain and Shah are both doctors working with Jan Swasthya Sahyog, a public-health initiative based in rural Chhattisgarh, who are writing the pieces in their individual capacities. Over the course of the series, they will address the issues they witness on the ground while dealing with the virus, and discuss how policy decisions affect the lives of India’s rural residents. Disclosure: Shah is a part of the national task force on COVID-19’s research group for epidemiology and surveillance. 

Perhaps no aspect of this pandemic has caught the public’s eye as testing has. At Jan Swasthya Sahyog, in Ganiyari village in Chhattisgarh’s Bilaspur district, testing for coronavirus remains a challenge. We are a 100-bedded hospital, providing essential health services in a land where there is not much else for the marginalised. We try to do it well and at low cost, with a lean workforce. Around two weeks back, three of our staff fell ill—two nurses, who are roommates, and a young doctor developed fevers and coughs. It could have been any respiratory infection, including COVID-19; they needed tests. With testing, we could reasonably rule out the disease. Or else, we would quarantine these frontline staff, losing their services for 14 days. 

Our hospital has the right recipe for testing. The lab is advanced, even rich, for a rural hospital. Dedicated, experienced technicians and a talented young microbiologist run the show. All manners of body fluids pass through and they detect all varieties of diseases. While a real-time polymerase chain reaction machine—used for testing coronavirus—is missing, we have the GeneXpert, which can detect minuscule amounts of tuberculosis in samples, fortunate for a society overflowing with that disease. A COVID-19 cartridge for the GeneXpert is now available, but it can only be procured from a faraway place that we cannot reach and at a price we cannot afford. 

At the least, we hoped to collect and send our own samples for testing—swabs of the back of the nose and throat. We had the containers and transport liquid. The unexpected roadblock was the device used to swab—a 15-centimetre long stick with a wad of sterilised, synthetic fibres at the end. It was out of stock in local markets. We contacted the district health authorities for help, but the state has its own supply issues. It was even sold out on the e-commerce platform Amazon. These are strange shortages in strange times. 

Our staff went to the nearest sample-collection centre in Bilaspur town, 45 minutes away. From what the nurses and the young doctor told us, the centre was easy to find—in a well-marked building, separated from the rest of the medical college campus. It is always interesting to receive healthcare when one delivers it daily. They found the doctor examining them was kind and knowledgeable. They were aghast when no one took a temperature, blood pressure, or heart rate—aptly named vital signs. There are recommendations to maintain a distance from suspected patients except for the physical exam, but no one suggests forgoing the exam altogether. The doctor did not even apply a stethoscope.

After a careful review of symptoms, risks and travel questions, the centre’s doctor recommended COVID-19 testing. The lab in-charge rejected the idea. Confusion ensued. Many calls were made. Until recently, only symptomatic healthcare workers who were managing respiratory distress or severe acute respiratory illness were eligible for testing. With rapidly changing advisories, the testing centre understandably struggled. Finally, with the intervention of the district health officer, the lab collected samples. From there, the sample travelled for another three hours to the state capital Raipur. Our staff returned and remained quarantined for two days until the reports came. Negative. We breathed a sigh of relief. We wondered if this is the situation at our hospital, where we have long-standing relationships with cooperative, local networks, what happens to others? 

For our staff, and for anyone else, receiving a test result is satisfying. In the eyes of many, universal testing has become the primary proxy for action against coronavirus. This belief exists due to the media, approaches used in other countries, and what just seems right. It is in line with an assumption we all may hold—that more information is always better. But testing might not improve outcomes for patients. 

To understand the value of testing better, we need to know its scope. Scaling it up in a controlled manner—which does not necessarily mean testing everyone, indiscriminately—will improve disease surveillance and help in making better policy decisions. 

In controlling infectious diseases, testing serves two distinct purposes. It can be for surveillance—to know where the disease is, in whom and to what extent. This data then informs public-health responses. For instance, it could indicate where to target insecticidal spraying to reduce malaria.

The second purpose, the one we most often think of, is to diagnose the individual patient. In certain outbreaks with distinct and established symptoms—for example, dengue, diphtheria, or cholera—once we confirm the first few cases with testing, signs and symptoms alone can suffice for both surveillance and diagnosis. But testing is important when the symptoms of the disease are too general to make the diagnosis based on them alone.

COVID-19 presents as a varied illness. Between five-percent and 80 percent people who test positive with COVID-19 can be asymptomatic or have mild symptomatic. It could just be a cough with a headache, a sore throat or fever and congestion—an experience we have all been through. It is not possible to distinguish COVID-19 from other respiratory infections, even if it can be swift and fatal. 

How do tests work? Tests operate on one of two principles. They can look for the agent causing the illness or the body’s immune response to it. The current COVID-19 testing looks for the virus, specifically the parts which contain its genetic code, using nasal swabs. New blood tests can test for current infection or show evidence of previous infection and immunity, but only work seven to 10 days after the start of being ill. It sometimes takes 14 days for the tests to come back positive. 

How well do tests work? There is no such thing as a 100-percent accurate test. Screening tests catch almost all positive cases but people without the disease may test positive. Confirmatory tests are stricter. They may not identify all those with the disease, but those diagnosed positive are truly infected. The reverse transcription-polymerase chain reaction test, or RT-PCR—used for COVID-19—is usually a very accurate method, but in this case one out of three people who have the disease may test negative. The causes can be multiple. Staff may not have collected samples properly, or tested patients later in their illness when the body sheds less virus, the collected virus might have degraded because of storage, or the test itself has some limitations in kit manufacturing. The accuracy of blood tests is still unknown, but we know some kits are made with poor quality. 

What are the benefits of getting tested? For epidemic control, testing helps policymakers understand the spread of the virus, and to direct isolation and quarantine work. This is disease surveillance. For COVID-19, we need more testing to accept the extent of its transmission and take actions. Once that level is achieved, more testing is not better. 

For patients, there are no benefits. It is hard to understand the need for increased, focused testing whose aim does not apply to your illness episode but to the need for surveillance. A laboratory test result does not change one’s treatment. There are no effective antiviral therapies yet; the treatment is supportive. Among the hospitalised sick, it can help rule out other treatable causes of respiratory distress—a person showing fever and having difficulty breathing will not unnecessarily be treated for scrub typhus, a deadly infection in many rural areas, if we know she has COVID-19. 

Who should get tested? The government recommends only testing the contacts of positive cases, the seriously ill and health workers. Testing is not yet recommended for the public. The lesson from Italy and the United States is to stay at home and to go to health centres only if your symptoms are severe. Otherwise, you could end up with the disease since health facilities have been vectors of disease spread. 

Our patients here, at the JSS hospital, face additional complications. Testing is even riskier for them. To reach a testing centre, one needs public transport, which may or may not be available. They may need to stay overnight before returning home. For those who become sick at home, it may be too late to reach anywhere that can help. There are almost no private centres for testing or care in our villages. In our experience, other than informal practitioners—who provide variable services of questionable quality—private healthcare does not expand access. It concentrates only where public services already exist and from which it can divert patients and resources.

A policy understanding of the importance of access to easy diagnostics and medical aid exists. In 1996, India created its first list of essential medicines with 279 drugs. It grew over time and recently expanded to include medical devices, such as cardiac stents. The list has been successful in assisting procurement and price controls to improve access to life-saving treatments. Although even medicines cannot work if we do not know who needs them—thus the need for more testing. Last year, the Indian Council of Medical Research, the nodal body framing India’s COVID-19 policy, released the first list of essential diagnostics for improving access to these tests. It was a welcome move. But in rural India, many basic tests remain unavailable. Just as we need tests to differentiate the novel coronavirus, the need also holds for malaria, dengue and many other infections. 

Our expectation from medical tests is high. In a way, that expectation is a victim of certain successes. We possess world-class academic labs and a thriving biotechnology industry. In another way, the expectations are blinded to certain failures. These vaunted institutions are often unresponsive to the needs of those who live around them. We pioneer experiments with stem cells but forget to find better medicines for leprosy. This is a cause for deep reflection. We should strive for a future where any test, COVID-19 or not, is sufficiently available. A future where we do not boast on projections of might, let alone projections from millennia past, but on doing simple things well, for all.