New Delhi: India
Nearly 25-30% of those with respiratory diseases have tested positive for Covid-19 on average during the pandemic, according to central government officials familiar with the development.
The numbers highlight the need to continue aggressive screening of respiratory disease cases to pick up early signs of a Covid-19 surge, and better disease management
The cases tested were classified as severe acute respiratory infection (SARI)/influenza-like illness (ILI).
“The conversion has been usually in the range of 25-30% so far, with some states reporting more Covid-19 positives among SARI and ILI cases than others. SARI/ILI monitoring is a part of Covid-19 surveillance and will continue in a robust manner,” said a senior official aware of the matter, on condition of anonymity.
In a recent order to states, Union health secretary, Rajesh Bhushan, also directed that such severe respiratory cases in all health establishments need to be monitored.
“Monitoring of influenza-like illness & SARI cases must be taken up in all health facilities on a regular basis for early warning signals of the spread of infection,” wrote Bhushan in his letter.
Preventing clustering through strict monitoring of SARI and ILI cases has always been the government strategy as part of its initial efforts to track an unusual jump in cases in certain pockets, and stop the further spread of infection.
Initially, random testing was done among SARI and ILI patients in each district of the country to gauge disease prevalence.
Even now, while the number of Covid-19 cases in the country has reached an all-time low, cases in several countries are on the uptick. RT-PCR testing of respiratory cases in India therefore will continue and samples of positive cases will be sent for whole genome sequencing, said one of the people mentioned above.
“Samples of all those patients who test positive for Covid-19 will be sent for whole-genome sequencing in one of the designated laboratories as part of the INSACOG network. If a caseload of a particular district exceeds testing capacity of the designated lab, then samples can be diverted to other nearby labs,” said the official cited above.
Tracking SARI and ILI cases is one of the key surveillance measures also proposed by epidemiologists to determine the disease spread because of the similarity of symptoms. Government has established close to 300 sentinel sites and a network of about 40 laboratories that do advanced testing.
Experts say this is the best preventive strategy to adopt in the current scenario as WHO recently informed that the proportion of reported sequences designated more transmissible BA.2 has been increasing relative to BA.1 in recent weeks, at the global level.
“When talking about effective surveillance, whole genomic surveillance is the best way to track and contain new and sub variants that may emerge in the future. And large-scale genomic sequencing can be quickly done when numbers are low as a higher volume of cases tends to slow down the process. This is just the right time to conduct those studies, said Dr. Navin Kumar, head of department and consultant clinical microbiology and infection control, Manipal Hospitals.