Did Covid kill the flu? Experts pose intriguing question as flu cases rise by 98% worldwide

10.28.2021 0

Many feared it was the perfect winter storm, a nightmare situation that would push the health service over the edge: " double demia " of influenza, which kills about 10,000 people every year, and a second deadly wave of Covid- 19. According to the latest reports, the number of vaccinations is already the highest ever in people over 65 and young children.

There is only one interesting problem: the flu seems to have almost disappeared.

The disappearing act began when Covid-19 spread at the end of our flu season in March. And how quickly the numbers fell can be seen in the "surveillance" data collected by the World Health Organization (WHO).  Patients are not routinely tested for influenza, even if it is suspected, but a number of hospitals do diagnostic screening for those who have symptoms, and this data gives us the most accurate picture of what % of influenza illnesses actually are. And the numbers give a startling insight into what has become a creeping trend around the world. 

In the Southern Hemisphere, where the flu season falls during our summer months, WHO data indicate that it has never spread at all. In Australia, only 14 positive cases of influenza were recorded in April, compared to 367 in the same month in 2019 - a decrease of 96%.  In June, usually the peak of the flu season, there were none. In fact, Australia has not reported a positive case to WHO since July. In Chile, only 12 cases of influenza were detected from April to October. For the same period in 2019, there were almost 7 thousand. 

And in South Africa, surveillance tests found only two cases early in the season, which quickly dropped to zero over the following month - a total of 99% fewer than the previous year. In the UK, the flu season is just beginning. But since Covid-19 began spreading in March, the WHO has reported just 767 cases, compared to nearly 7,000 from March to October last year.  And while last year, laboratory-confirmed cases of influenza increased by 10 percent between September and October, with the start of the new season this year they increased by only 0.7 percent.

Of course, this is not the total number of flu cases.  According to the Office for National Statistics, we know that hundreds of people die from suspected flu-related pneumonia every week throughout the year - which is why, with a predicted harsh winter ahead, experts agree that vaccination is still vital for those who are eligible. Some flu seasons start earlier than others. But our low flu surveillance figure does indicate the spread of flu in the UK is not yet gathering pace.  Other research by Public Health England has confirmed this. Flu cases worldwide are estimated to be down 98 percent compared to the same period last year.

There's no chance of mistaking one for the other - a piece of viral genetic material from the coronavirus looks like a piece of spaghetti, and the influenza genetic material we're testing looks like eight pieces of penne pasta." Another compelling explanation suggests that SARS-CoV-2, the virus that causes Covid-19 and which is spreading around the world, somehow "displaced" the influenza virus. The theory has gained popularity on Twitter, and this phenomenon has some scientific support. When a person is infected with one virus, they are less likely to become infected with another during that time because of what is called "viral interference".

Both viruses spread the same way: through infected droplets. But people with Covid are considered more contagious and longer-lasting than flu patients. One measure of this is the much-discussed reproduction number, or R number - the number of people to whom one infected person will transmit the virus on average. Covid-19 has a multiplication number of approximately three unless measures are taken to stop its spread. This means that one person will pass it on to three others. Some viruses are more contagious, such as measles, which has an R number of about 15. Influenza, on the other hand, has an R number just over one. The incubation period of influenza is also lower. Once infected, influenza usually causes illness within two days, compared to five days on average for Covid-19.  This means that it is much more likely that people will go about their business unknowingly infecting others with Covid-19 than if they get the flu. 

"All studies of face masks and social distancing are based on preventing flu transmission and have shown huge reductions." Australian officials say their low flu rate can be partly attributed to their vaccination program, which the government has increased by 50 percent, ordering 18 million vaccines instead of the usual 12 million. 

Another question is whether we can trust the flu data at all - most officials say this year's global numbers are not reliable because coronavirus surveillance has been a priority in laboratories.  During the pandemic, fewer people have sought treatment for flu-like symptoms, so fewer suspicious cases are being reported. Public Health England has confirmed that the number of flu tests has been lower this year. However, the organization also claims that the available data shows that the overall flu activity is "low". There is also a danger that in the absence of testing of flu cases in this country and other countries, flu cases could be mistaken for Covid-19.

What will happen to us during the flu season is still unknown. Some say that flu deaths may be reduced as many vulnerable people and the elderly have already died from the coronavirus. But the flu remains a very real danger!