Strict adherence to Covid-19 protocols have had one positive spinoff – a significant decline in influenza cases, healthcare experts in the UAE say.
Since the Covid-19 pandemic last year, healthcare specialists and researchers have noted a sudden drop in flu cases, even as SARS COV 2 has been dominating all the headlines.
Dr Shakeel Ahmed Shah , General Practitioner at Aster Clinics, Al Qusais said, “Since the Covid-19 pandemic, we have observed a significant drop in flu cases in our facility. Before the pandemic, around 10 per cent of my patients would be flu cases, but it has dropped to 2 per cent now. The UK and USA are also reporting a similar trend.”
Dr Rajesh Kumar Gupta, Specialist Internal Medicine at Burjeel Specialty Hospital, Sharjah, said: “Flu cases have significantly dropped by 95 per cent, rather vanish from the UAE. There is not a single case reported in last few months in our OPD clinic, as we are getting negative Influenza A & B swab tests in mild suspected cases.”
So, what has led to a sudden drop in flu cases?
Experts say strict adherence to Covid protocols is the main cause for a drop in influenza cases. Dr Ahmed Abdelhameed, Specialist Internal Medicine, Medcare Hospital said “Most experts believe that masks and social distancing, in addition to distance learning and remote working, have helped stop the spread of the influenza virus.”
Dr Reyaz Ahmed Specialist Internal Medicine Prime Center Burjuman also said a focus on Covid protocols has prevented flu transmission. “Flu cases have dropped significantly and the main reasons for this are social distancing, wearing masks, school closures and hand sanitization. Increased flu vaccination last year is also a big factor,” he said.
Considering the present situation, every patient with fever is first tested for Covid-19, as symptoms are similar. “It is very difficult to differentiate between flu and Covid-19 infection because both are having similar symptoms clinically. So every patient is asked to do a RT PCR test for Covid-19 infection” said Dr Sanjay Kumar, Zulekha Hospital.
Covid-19 and influenza
Covid-19 and influenza viruses have a similar disease presentation. They both cause respiratory disease and are transmitted by contact, droplets and fomites. As a result, the same public health measures, such as hand hygiene and good respiratory etiquette, are important actions to prevent infection.
The speed of transmission is an important point of difference. Influenza has a shorter median incubation period (the time from infection to appearance of symptoms) and a shorter serial interval (the time between successive cases) than Covid-19 virus. The serial interval for Covid-19 virus is estimated to be 5-6 days, while for influenza virus, the serial interval is 3 days. This means that influenza can spread faster than Covid-19.
Further, transmission in the first 3-5 days of illness, or potentially pre-symptomatic transmission – transmission of the virus before the appearance of symptoms – is a major driver of transmission for influenza. In contrast, while we are learning that there are people who can shed Covid-19 virus 24-48 hours prior to symptom onset, at present, this does not appear to be a major driver of transmission.
While the range of symptoms for the two viruses is similar, the fraction with severe disease appears to be different. For Covid-19, data to date suggest that 80 per cent of infections are mild or asymptomatic, 15 per cent are severe infection, requiring oxygen and 5 per cent are critical infections, requiring ventilation. These fractions of severe and critical infection would be higher than what is observed for influenza infection.
Those most at risk for severe influenza infection are children, pregnant women, elderly, those with underlying chronic medical conditions and those who are immunosuppressed. For COVID-19, our current understanding is that older age and underlying conditions increase the risk for severe infection.
Mortality for Covid-19 appears higher than for influenza, especially seasonal influenza.