Adopting conventional strategies may not work in India given its highly heterogeneous character.
This is part I of a two-part series.
As India enters a decisive phase in its fight against novel Coronavirus (Covid19), at least two cases of possible community transmission have emerged in Tamil Nadu and Maharashtra. In both states, Patient X had contact with many people while carrying the virus: one through a 24 hour travel by train to Chennai, and the other while attending a wedding. It is clear that the containment part of India’s strategy via border/air travel check has only been partially successful.
It would now be safe to assume that India has entered the phase of community transmission and should prepare for the worst. Adopting conventional strategies, however, may not work in India given its highly heterogeneous character; so far, novel coronavirus transmission has primarily been occurring in urban centres. Furthermore, India has its unique strengths (for example, most remained disciplined amidst the impact of demonetisation — something perhaps no other democracy in the world would have tolerated as easily) and weaknesses as well (example, our healthcare systems are hobbled by scarce resources, such as ventilators and ICU beds, and personal protective equipment for health workers).
This author proposes specific strategies for facing the pandemic. These measures are a combination of pharmaceutical, administrative and diagnostic testing strategies.
Japan has been able to contain Coronavirus at around 1,000 cases and 35 deaths primarily by aggressive social distancing (everybody wears masks, and they are repurposed and reused via various strategies) despite having a low number of tests per capita. Face masks have been shown in some modelling studies to contain spread assuming a large number of infections.
Everybody should wear masks (particularly in urban centres and in hospitals) or cover their faces with scarves or bandanas as have been recommended by the US Centers for Disease Control and Prevention (CDC) as well. They may offer limited protection, but then most healthy people will not face high-risk contacts.
The government should order manufacturing companies to produce masks, gowns, gloves and other protective equipment on a war footing. It is a war, indeed, and healthcare workers are in the frontlines. They need personal protection not only for themselves but also to ensure that they do not infect others as what happened in Wuhan where 40 percent of people had hospital-acquired infection. Further, Wuhan, similarly constrained by limited resources, allowed the symptomatic workers to continue working. This resulted in further spread till replacements were brought in.
Serological assays must be done to find which people have acquired immunity, or even innovative approaches like recruiting healthcare workers from China who have developed immunity (which is long lasting). Those who have recovered, including healthcare workers, can re-join the work force or trained to serve patients as they will be at lesser risk of contracting the virus again.
The current RT-PCR test used by WHO and the CDC has a higher threshold of Covid RNA detection. It is slow and has a high rate of false negatives (at 30-40 percent, using throat swabs). Compared to conventional Respiratory Panel developed by commercial agencies for RSV and H1N1 with false negative rates in range of 1-3 percent, these numbers compare poorly.
India should be sourcing faster and more accurate tests with higher sensitivity as a higher rule-out value would lead to more downstream testing, and the current approach which is inefficient in terms of repeated testing can then be ruled out. The way out is to build a better PCR test. At the time of writing, new bedside PCR test (similar to second generation PCR CBNAAT test for diagnosing resistant Tuberculosis (TB) which can be used at Point of Care in Fever Clinics and gives results in 30 minutes) has been approved by the US Food and Drug Administration (FDA). India has multiple such machines at TB centers and the know-how is present as well. Whether these existing machines can be repurposed for faster point of care (not needing sophisticated lab environment) should be assessed.
Different states in India may have different levels of transmission. Since the current RT-PCR test is not effective in ruling out infection in the population because of possible high number of false negatives, the test has the maximum chance of detecting patients when they become symptomatic and have maximum viral load. This is currently at the heart of ICMR's and CDC's testing strategy (which, in addition, is done on high-risk patients). This strategy can prove to be effective for states and cities with low level of transmission.
South Korea initially adopted this same strategy. When community transmission started to occur due to the recklessness of some patients, they switched to a different approach utilising drive-through PCR test, which is known as “Test, Test and Test” strategy through a massive PCR roll-out. It required testing all asymptomatic suspects at regular intervals since a single negative test might prove to be a false negative.
While this strategy is resource-intensive, it also may be required when some states or cities begin showing many patients without obvious traveler contacts, implying community transmission. This is why the testing strategy has to be adapted to the regional requirements.
Randomly testing people with high public interaction (healthcare workers, grocery stores, police personnel, and politicians) should also be done if prevalence continues to rise as they can act as central nodes with high transmission value.
Until the world has to do with a currently imperfect test (RT-PCR), other triaging strategies — use of Symptoms, Complete Blood Count and CT Chest Scans before use of PCR — that were employed by China to handle their load can be adopted. Fortunately, India has sufficient CT scanners available across the country. A fast high-resolution CT scan can be used to rule out Covid19 in both symptomatic and asymptomatic patients. In the Diamond Princess cruise ship, 54 percent of asymptomatic patients showed Ground Glass opacities in their CT Scans. Therefore, CT scans can be used to augment current triaging strategies.
CT scans are hampered by cleaning/sterilisation issues, and in these cases partial scans can be used to triage 50 percent of asymptomatic patients (who should be sent in fully protected gear to avoid spread) thus optimising of Covid19 screening capacity.
Serological tests, at this point, can be used to see if people who are immune can return to the workforce.
Part II will focus on initiatives on organisation of healthcare as well as administrative and pharmacological approaches to handle the extreme pressure that Covid19 will put on the healthcare delivery system.
The views expressed above belong to the author(s). ORF research and analyses now available on Telegram! Click here to access our curated content — blogs, longforms and interviews.
Anupam Singh MD is an Assistant Professor of Medicine at Santosh Medical College. He is a member of the coronavirus outbreak response committee of Ghaziabad ...Read More +