From July 13, confirmatory RT-PCR testing only for symptomatic cases in GhaziabadUpdated: Jul 11, 2020, 00:08 IST
Alarmed by the large number of people testing positive through RT-PCR tests after testing negative during rapid antigen testing in the district, the Ghaziabad health department on Friday said that starting July 13 it will only retest samples of symptomatic patients for the coronavirus disease (Covid-19) through the lab-based reverse transcription-polymerase chain reaction test for “true negatives”.
To expand testing in the district, Ghaziabad administration had started rapid antigen testing on June 26 in containment and non-containment zones. The state government had also given the district a target of collecting 3,000 samples per day for antigen-testing under its special surveillance drive from July 2 to July 12. District health officials said that considering the directions for bulk testing, they had been conducting antigen tests for all, symptomatic as well as asymptomatic persons, during the 10-day long drive. They said they witnessed a high positivity rate of about 15% when RT-PCR tests of those who were found negative during rapid antigen testing were conducted.
“During the special antigen testing drive, we received directions to undertake bulk testing. Hence, we were testing symptomatic as well as asymptomatic persons even during the RT-PCR test in order to find true negative after a negative antigen test. This led to an increase in the number of cases in the last 8-10 days. So, after July 12, we will now adhere to the ICMR guidelines strictly and conduct RT-PCR tests of only symptomatic patients who test negative during antigen testing, ” said Dr NK Gupta, chief medical officer, Ghaziabad.
According to the ‘newer additional strategies’ for Covid-19 testing issued by the Indian Council of Medical Research(ICMR) on June 23, “A positive test should be considered as a true positive whereas all symptomatic individuals testing negative through the rapid antigen test should be confirmed with a real-time PCR test.”
Antigen tests look for specific protein associated with the Sars-Cov-2 virus, the pathogen that causes Covid-19. The new test is highly specific (99.3% to 100%) — meaning a positive result on the test is a “true positive” and does not need any confirmatory test. The sensitivity of the test is between 50.6% to 84% depending on the viral load, meaning those who test negative are not “true negative” and might still have the infection and are advised to go for a test through the more reliable RT-PCR method if they show symptoms of the disease.
“Between June 26 and July 9, we have conducted about 16,634 antigen tests and 477 of these were found positive (positivity rate at 2.8 %). For those found negative during antigen testing, we were getting the samples checked for true negative with the help of RT-PCR test. This was done for all, symptomatic as well as asymptomatic, patients. When we started with the subsequent RT-PCR tests, we found that out of 1,666 test reports received so far, as many as 263 cases have turned positive leaving us with a positivity rate of about 15.78%, ” said Dr NK Gupta, chief medical officer, Ghaziabad.
The district had received a total of 19,000 rapid antigen testing kits before the bulk testing started and has only a few thousands kits left now. Health officials said they have information that 50,000 more antigen test kits will be provided to the Meerut division ( Ghaziabad included) soon, but the date when the additional kits will arrive is not confirmed.
The district has so far conducted a total of about 46,439 tests which including testing methods such as RT-PCR, TrueNat, and rapid antigen kits. Till July 10, Ghaziabad has a total of 2,863 Covid-19 cases which includes 63 deaths, 1,459 discharged patients, and the remaining 1,341 active cases, including 124 cases added on Friday.
The district’s current positivity rate is about 6.1% with the recovery rate at about 59.23 which is lower than UP’s overall recovery rate of 65.28% and the national recovery rate of 62.42% (issued by the union ministry of health & family welfare on July 10) The case-fatality rate in Ghaziabad is about 2.33% now.
Since active cases have been on a constant rise, health officials for the last two days have been checking for the discharge status of patients who have recovered but are were still reflecting as active cases on the state portal.
“In the last two days, we have been able to identify bout 400 such patients who had been discharged from hospitals but their entries were not uploaded over the state portal. After we started calling patients, rectifications are being made. Only July 9, entries of as many as 252 patients were rectified and shown as discharged over the state portal. So, the exercise will bring down our rate of active cases further and we will continue with it,” Dr Gupta added.