In fight against Covid-19, increased testing and better infra critical

Updated on May 07, 2020 06:36 AM IST

Diagnostic testing is an important weapon in Covid-19 fight. It helps to identify infected individuals and treat them; also it helps in breaking the chain of transmission and supports decision making on easing restrictions.

A doctor wearing a protective gear takes a swab from a woman to test for coronavirus disease (COVID-19), in Dharavi, one of Asia’s largest slums, in Mumbai.(Reuters File Photo)
A doctor wearing a protective gear takes a swab from a woman to test for coronavirus disease (COVID-19), in Dharavi, one of Asia’s largest slums, in Mumbai.(Reuters File Photo)
New Delhi | ByPriyanka Aggarwal, Kshitij Vijayvargiya and Siddharth Jain

Diagnostic testing for Covid-19 has been the topic du jour in India – from government offices to boardrooms to online chatrooms. Debates range from whether we are doing enough testing to whether we are testing the right people. Continuous media coverage on availability of test kits, quality of the kits and effectiveness of testing protocols has often led to confusion on how to expand testing capacity.

It is now well accepted that we are in a marathon fight against the Covid-19 pandemic. India has been in a nationwide lockdown since March 25 that has been extended twice -- to May 17 -- with some relaxations in restrictions. This was essential and well-timed -- helping reduce the spread of the disease ( the doubling rate of cases, 3.4 days prior to the lockdown, is 11 days currently) and providing time to ramp up the healthcare infrastructure. However, in this battle between lives and livelihoods, we cannot ignore the crippling impact the lockdown has had on India’s economy. Already the unemployment rate has risen to 23%, from 8.4 % in mid-March.

Diagnostic testing is an important weapon in this fight. It helps to identify infected individuals and treat them; also it helps in breaking the chain of transmission and supports decision making on easing restrictions. Countries like South Korea have already shown how large-scale testing can control the disease without resorting to a nationwide lockdown.

India: Current state of testing

Covid testing in India has evolved rapidly. Until mid-March, testing was focused on only symptomatic international travellers or symptomatic contacts of such travellers in the belief that the spread was largely restricted to international travellers. Over time, with identification of cases with no travel-related history, these guidelines evolved to include symptomatic local patients, healthcare workers, asymptomatic contacts of confirmed cases and patients exhibiting SARI (severe acute respiratory infection) and influenza like symptoms. Currently, Indian testing guidelines stand in line with those of countries like South Korea and Germany.

With the new guidelines in place, testing has been ramped up by over 35 times during the last five weeks from an average of 2,000 tests / day (last week of March) to more than 70,000 tests (early May). A heartening indicator is that with the scaling-up of testing, positivity rates have remained one of the lowest in the world at -- 4%.

This increase has been driven by multiple government interventions. More than 150 testing labs have been additionally approved in the last four weeks. Pooled testing protocols in locations with low positivity rates have been created and testing has been included in the Pradhan Mantri Jan Arogya Yojana (PMJAY) package.

Shifting to the next gear

Viewed this way, the overall picture does not seem as grim as many have claimed. However, reviewing the state- wise status of testing, it is seen that there are wide disparities which point to the need for urgent segmented action. Refer to Exhibit 2

States in Quadrant I (e.g. West Bengal) are seeing low testing rates despite high positivity and need to immediately ramp up testing to understand the true spread. States in Quadrant II (like Delhi and Maharashtra) show a high spread while having high testing rates. These geographies have had many outbreaks in clusters and need to continue large-scale testing to identify and treat patients. Many states fall in Quadrant III (e.g. Bihar) where testing has been sub-scale. While they currently see low positivity, they need to enhance testing to understand the spread and support decisions to open up gradually.

While cumulative cases in India have exceeded 40,000, a granular review shows eight cities contribute over 45% of cases, while 250+ districts have no reported cases. This, in addition to the concentration of growth of Covid-19 in particular areas, allows for a regional review to decide on lifting lockdown restrictions. This could be supported with thorough testing to enable informed decision making.

This is where the different available testing options lend themselves to appropriate use cases. We have the gold standard RT-PCR (reverse transcriptase polymerase chain reaction) tests that detect the presence of a viral genome in the body; they can be deployed largely in identification of infected patients and treatment. These are expensive and need specialised molecular diagnostic equipment and trained professionals to operate the equipment.

On the other hand, serological tests detect the presence of antibodies (that develop in the body as an immune response) and are useful to detect past infections. While such tests are less useful in immediate response (and should not be used for clinical diagnosis), they can be used to track disease development. They could also assess individuals who are immune and can be safely brought back to the workforce. Antibody kits were added to our testing regime, but were challenged due to a few faulty kits. With additional kits getting approved, the quality of test kits should be regularly confirmed through periodic quality checks

We should think of these tests as weapons in our arsenal, and deploy a segmented approach for testing in India, which is customized by region depending on the current level of disease spread. See Exhibit 3

* High disease spread and high growth: Continue large scale RT-PCR testing to support identification of cases. Deploy rapid testing in hotspots to quickly assess community immunity

* High disease spread but low growth: Leverage combination of antibody tests to test herd immunity coupled with RT-PCR tests for diagnosis

* Low disease spread and high growth: Leverage pooled testing at scale to quickly identify new hotspots

* Low disease spread and low growth: Leverage RT-PCR tests for Influenza-like-illnesses /SARI cases and healthcare workers and serological testing to monitor disease surveillance

Operationalising the ramp-up

The testing value chain is complex and has several bottlenecks. Starting from sample collection where it is crucial to ensure availability of skilled phlebotomists (people trained to draw blood from a patient) with full protective personal equipment (PPE). Subsequently, the lab testing process requires availability of technicians with training in molecular biology, infrastructure such as biosafety rooms, sufficient kits and reagents and finally RT-PCR machines – the most critical equipment needed in the current molecular testing regime.

While government interventions have ensured sufficient supply of kits (with enough stocks to conduct 100,000 tests / day for the next two months and ramp-up beyond this as needed), PCR machines, sample collection process and regional lab availability may emerge as future bottlenecks.

Given this, it is recommended to focus on four priorities:

* Lab Capacity: Address regional disparities in lab capacity. States like Jharkhand and Chattisgarh have less than five labs while labs in Gujarat are near capacity with current disease spread. Private sector collaboration can help plug these gaps

* PCR machines: ~400 PCR machines are available in approved labs in India currently. This is sufficient to conduct 70-80,000 tests / day in the public sector and 30-40,000 tests / day in the private sector. The positive side is that India already has a sufficient installed base (1400+ machines) across public and private sector and capacity can be ramped up even more by adding these machines to the approved list

* Setup of fever clinics to enable sample collection: Taking learnings from South Korea and other countries, India should set up fever clinics in each locality to do screening and sample collection

* Leverage innovations: Innovations like pooled testing, nano-reaction based tests and RT-LAMP {Reverse Transcription Loop-Mediated Isothermal Amplification) technology could further enhance capacity

Diagnostic testing is crucial to the fight against Covid. As we move into a post-lockdown era and contemplate recovery, government officials, corporate leaders and healthcare experts will all have to confront the need for testing. Unfortunately, it is neither simple to implement nor a panacea to all problems. It will be important that all stakeholders (public and private sector) work jointly to address this challenge and bring forth their respective strengths to help win this fight.

The article is written by Priyanka Aggarwal, Managing Director and Partner at BCG, Kshitij Vijayvargiya, Partner at BCG and Siddharth Jain, Project Leader at BCG. Views expressed are personal.

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