With India currently seeing a rise in both Covid and influenza cases, many people are likely to be co-infected by the viruses, which can turn fatal if not treated on time, health experts said on Friday.
Increasing genome surveillance and active follow-up may also help, they noted.
"Covid and influenza can coexist in some patients. Flu and all viral infections are virulent if not detected on time and can lead to severe problems, including hospitalisation, " Kuldeep Kumar Grover, head of critical care & pulmonology at C.K. Birla Hospital, Gurugram, told IANS.
"While both are primarily viral infections, with the dual infection patients will be having more cough and nasal symptoms. But if the patients are immunocompromised and their immunity is low, they are more likely to have respiratory issues such as breathlessness. These patients normally end up in ICU with severe complications, " he added.
A pre-print study, meaning not yet peer-reviewed, reported the case of a 10-year-old girl from Kerala, who was co-infected with SARS-CoV-2 Omicron variant and influenza A-H3N2 last year.
The school-going girl was taken to the primary health centre with symptoms of low-grade fever associated with cough and cold. There was no associated chest pain or dyspnea, and her vitals were normal with clear chest. She was given symptomatic treatment and all the symptoms subsided after three days.
"The patient presented in this study was co-infected with the SARS-CoV-2 Omicron variant and the influenza A-H3N2 virus, as confirmed through genome sequencing data. She recovered quickly with symptomatic treatment without developing any complications, " said the researchers in the study, including from ICMR-NIE Chennai, CSIR Institute of Genomics and Integrative Biology, District Medical Office, Kasaragod, Kerala, and Department of Microbiology, Government Medical College Calicut, Kerala.
The report highlighted the importance of genomic surveillance of SARS-CoV-2 co-infections with other respiratory illnesses for understanding the prevalence of co-infections and thus their rapid detection and prevention.
According to biologist Vinod Scaria, the estimates of co-infection between Covid and influenza "are variable, and possibly not so rare as we believe it could be".
"Co-infections have been associated with a higher rate of morbidity and mortality. It is estimated that 16 per cent of paediatric influenza deaths during 2021-2022 were in patients who were co-infected with SARSCoV2, " Scaria, a scientist at CSIR-Institute of Genomics and Integrative Biology (IGIB), said in a tweet.
He stressed the importance of "active case surveillance, follow-up and molecular confirmation of infection".
"With wider availability of molecular tools, including genome sequencing , it is possibly the right time we think of having a diagnosis for all outbreaks. Let us make 'mystery disease' a history, " he said.