Omicron: Most patients in Guj needed re-test

Parth Shastri & Sachin Sharma | TNN

Ahmedabad/Vadodara: 21.12.2021

What was common about the cases recorded in Vadodara on Monday and in Ahmedabad on Sunday? The patients had tested negative with RT-PCR tests twice — but the third test detected the presence of Covid-19 and subsequently genomic sequencing found the Omicron variant.

In the case of a 27-yearold woman in Vadodara, she developed symptoms such as low-grade fever after returning from the UK last week. “She underwent the RT-PCR test before boarding the flight according to the requirements. Upon arrival in Mumbai, she again took the test and the result was negative,” said a senior health department official. “She then returned to Vadodara. As she developed symptoms, she was advised another test and the presence of the virus was detected.” In the case of a couple from Tanzania, the chance discovery was due to a preprocedure RT-PCR test that gave the positive result. They had tested negative in Mumbai and Ahmedabad and even at the time of boarding the flight. Experts pointed out that the milder symptoms or the lack of symptoms make detection all the more difficult. Senior state health department officials were not available for comment on whether multiple testing could be the norm for passengers from ‘at risk’ countries.

Dr Mukesh Maheshwari, an Ahmedabad-based pathologist, said that the way in which the samples are collected matters as much as the kits do. “Both nasal and throat swabs can give results, but if the viral load is low, the virus may not get detected immediately,” he said. “It’s possible that the first two tests are carried out at a short interval, and by the third test the viral load required for detection is achieved.”