In the light of the limited testing protocol charted out by the Ministry of Health and Family Welfare for the novel coronavirus (Covid-19), a Maharashtra-based physician faced a strange dilemma while treating a patient with severe multi-organ failure and pneumonia at the ICU of a rural hospital.

SP Kalantri, Professor of Medicine at Mahatma Gandhi Institute of Medical Sciences, in Wardha, said: “We are unable to figure out who the villain is — bacteria or viruses (in this case). The regional lab refused to test his sample for Covid-19 because he lacked a travel history.” Kalantri wondered if the testing criteria for Covid-19 are too restrictive.

Balram Bhargava, Head, Indian Council of Medical Research (ICMR), and Secretary, Department of Health Research, is emphatic that only those who have a travel history, and those who have come in contact with them, and then have gone on to develop the symptoms of cough, cold, fever, breathlessness and so on will be tested for Covid-19.

Largely inadequate

India has activated 67 laboratories for conducting the first test, and 51 of those are equipped to conduct confirmatory tests, which is not even one lab per district. India has 732 districts.

At present, cases are being reported from 13 States and Union Territories. In a country with a population of 1.3 billion, till now, only 6,500 throat swab samples from 5,900 individuals have been sent to these labs; at least 107 have tested positive.

“In the entire collective network of 51 labs we have run only as many as 60 to 70 samples per day, whereas each lab singularly has a capacity to run up to 90 samples per day. We, thus, have huge reserve capacity,” said Nivedita Gupta, scientist, Epidemiology and Communicable Diseases, ICMR.

The current cost of testing each sample is upward of ₹5,000, she confirmed.

The question is whether India will expand its testing protocol to cover those who are symptomatic of Covid-19 but do not have a travel history or have not been zeroed in on through contact tracing. South Korea, which has allowed universal screening free of cost for any patient showing symptoms,for instance, has tested up to 2.5 lakh samples.

Local transmission

Not yet, said R Gangakhedkar, Head of Epidemiology and Communicable Diseases, ICMR. “We have not yet reached the stage of mass testing, where the virus spreads unfettered in community. We are at Stage Two of local transmission,” he said.

From March 15 onwards, Gupta said 51 regional labs will collect 20 samples every week from people with influenza-like illnesses and severe acute respiratory infections, who do not have any travel or contact history, and test them for Covid-19 to rule out community transmission. This means testing close to 120 random samples every week as part of an Integrated Disease Surveillance Programme (IDSP).

Primers and probes

So what does it take to conduct these tests? Bhargava said the main requirement is that of primers and probes. A pair of primers are used to hybridise with the sample DNA (in this case the suspect sample) and define the region of DNA to be amplified in a polymerase chain reaction, which is used for running diagnostic tests. A probe, on the other hand, is used to search for the virus DNA sequence.

“We have enough supplies of primers, but not enough probes. Probes are being imported from Germany,” said Bhargava.

The coronavirus situation in India is fast evolving and protocols are being revised on a weekly basis, but there’s still some wait-and-watch when it comes to revising testing guidelines, he added.

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