Covid-19: India faces shortage of test kits. New research may reduce dependence on China

Covid-19: India faces shortage of test kits. New research may reduce dependence on China

India's fight against Covid-19 outbreak is hampered due to shortage of testing kits. India largely depends on import from China to meet the requirements. New research may reduce its dependence on China to fight Covid-19 outbreak.

A medical professional collecting swab samples from throat of a Covid-19 suspect in Mumbai earlier this month. (Photo: PTI)

HIGHLIGHTS

  • New research may reduce India's dependence on Chinese testing kits
  • India faces shortage of swab transport and Covid-19 diagnosis kits
  • Researchers find saliva samples better, no need for RNA extraction kits

India is now 15th worst-affected country in terms of novel coronavirus cases. The number stood at over 31,330 with close to 1,900 being fresh cases as on Wednesday morning. Around 22,630 are active cases.

The ICMR (Indian Council of Medical Research) and the government say the rate of increase in coronavirus cases has stabilised but the stable number is not small. This calls for more testing to better ascertain the scale of Covid-19 outbreak in the country.

This is where Indian government, health agencies and healthcare professionals fighting novel coronavirus pandemic in India feel constrained. There are not enough testing kits. Local production of test kits is far behind the requirement. India is dependent on import of kits, mostly from China, to test coronavirus infection.

The rapid test kits, imported from China, were faulty and now have been withdrawn. India's sole testing method now is RT-PCR test. This is a complex test which requires swab collection sticks, storage solution, RNA extraction kits and PCR kits.

There is growing shortage of storage solution and RNA extraction kits world over. India too has this problem. Reports suggest at the current rate of testing (around 35,000 a day), India does not have enough stock of RNA extraction kits to last more than a week.

Each Covid-19 test requires one RNA extraction kit. Without RNA extraction kits, RT-PCR test cannot happen under the current testing methods.

Now, a solution has come up. A group of researchers have developed a new testing method called, "dry swabbing, extraction-free" technique.

This method does not require the special chemical solution used for storage of swab samples before these are transferred to the RNA extraction kits for separation of RNA strands. Thereafter the PCR kit conducts genetic testing for SARS-CoV-2, the coronavirus which causes Covid-19.

The "dry swabbing, extraction-free" procedure, in fact, performed better that the existing method for coronavirus testing during the experiment conducted in the US. The new method correctly detected novel coronavirus RNA in nine out of 11 samples, taken Covid-19 patients.

In comparison, the existing methods showed positive results for only eight of the 11 cases.

"Using paired mid-turbinate swabs self-collected by 11 individuals with previously established SARS-CoV-2 positivity, we performed a comparison of conventional (swab-UTM--RNA extraction--RT-qPCR) vs. simplified (direct elution from dry swab--RT-qPCR) protocols. Our results suggest that dry swabs eluted directly into a simple buffered solution (TE) can support molecular detection of SARS-CoV-2 via endpoint RT-qPCR without substantially compromising sensitivity," the research paper, which is yet to be peer reviewed, said.

There is more.

Last week, researchers found that human spit samples could be the solution to shortage of long swab sticks and special chemical required for storage of samples. Researchers have found that a coronavirus-infected person's saliva works better in tests than the conventional method of swabbing from back of the throat or deep into the nose.

The researchers in the US collected both saliva and throat swab samples from hospitalised Covid-19 patients. "We found that saliva yielded greater detection sensitivity and consistency throughout the course of infection," the research paper, yet to be peer reviewed, said.

What surprised the research team is that they could not detect the novel coronavirus in some of the Covid-19 patients, whose throat-swab samples had been collected for testing. The same persons were found to be carrying the novel coronavirus infection in the samples of their saliva.

The paper says, "Saliva is a promising candidate for SARS-CoV-2 diagnostics because (1) collection is minimally invasive and can reliably be self-administered and (2) saliva has exhibited comparable sensitivity to nasopharyngeal swabs in detection of other respiratory pathogens, including endemic human coronaviruses, in previous studies."

Findings of both the researches have the potential to resolve India's handicap in conducting more and more tests for novel coronavirus.

India has received praise for early and stricter lockdown but has faced criticism for its conservative testing policy, which was primarily guided by the limited number of testing kits it has had. Earlier this week, Indore - one of the big Covid-19 hotspots - reported that it had less than 800 RNA extraction kits.

India is heavily dependent on the import of viral transport medium kits (having storage solution) and RNA extraction kits. The ICMR expects 30 lakh RNA extraction kits and 10 lakh viral transport medium kits to arrive soon. The order were placed weeks ago.

China, South Korea and Singapore are the major suppliers of coronavirus testing kits to India. But arrival of medical supplies has been slow. New research offers a solution.

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Posted byPrabhash Kumar Dutta