The World Health Organisation (WHO) recently released a report about COVID-19 on the new territories that have reported cases of COVID-19, but what was perhaps more interesting was the included Q&A about the differences between COVID-19 and influenza or the common flu. While it is kinda difficult to make sense of all the medical jargon in WHO’s report, thankfully MIT Technology Review reporter Tanya Basu has written a great piece that breaks down the report.
As WHO has declared that COVID-19 is a pandemic, and our very own Malaysian government has issued a Movement Control order, it is important to educate ourselves better with the differences between the coronavirus and influenza. Here are the six main differences between these two viruses according to the WHO.
COVID-19 spreads slower than influenza
The speed of transmission between these two viruses is the key to differentiate them. There are two reasons to explain it. Firstly, the novel coronavirus’s serial interval (time between the successive cases) is around five to six days and flu is more likely to have a three-day gap between the cases. As coronavirus appears to take longer serial interval time, this means researchers are having hard time to identify and study the epidemiological links (how diseases occur in different groups of people and why) between cases. Serial intervals can serve as an important boundary to design infection prevention and control strategies (IPC) in epidemic transmission models.
Another important reason is the incubation period or the length of time between catching the virus and beginning to have symptoms of the disease. Coronavirus’s incubation period is range from one to 14 days, most commonly around five days while for a flu is only about 24 hours to three days. It is important to differentiate the incubation period between them because it will help determine the clues about the sources of an outbreak.
Although these two viruses are transmitted at different speeds, COVID-19 and influenza viruses spread in similar ways. They are both viruses that attack the respiratory system and could cause death. Moreover, both viruses spread through contact, droplets and fomites. Therefore, keeping respiratory and hand hygiene, as well as cough etiquette is important actions in preventing the infection from spreading.
Someone with COVID-19 can spread the virus before showing symptoms
Unlike the flu, COVID-19 can spread without an infected person showing symptoms. This is because the virus in an infected person starts to shed, or reproduce virus progeny (offspring), to the surrounding before that particular person shows any symptoms. A study in The Lancet showed that survivors continued to shed the coronavirus for around 20 days or until death.
This has made it completely different with influenza that sheds in the first or two days after symptoms have started. Most of the time, influenza will only shed for up to a week. This also suggests that coronavirus patients remain contagious for a longer time compared to patients with influenza.
More than one secondary infection
When you’ve successfully battled a secondary infection for a flu, it is unlikely for you to contract the same infections twice. This is because the immune system has already recognised and created antibodies to fight against the same virus.
However, there are higher risks for COVID-19 patients to experience more than one secondary infection. Researchers have estimated that COVID-19 patients have a higher reproductive number, between 2 and 2.5, compared to the common influenza. A reproductive number is used to denote the average number of secondary infections generated from one infected individual.
But it is still difficult to make direct comparison between these two diseases due to context and time differences. For example, researchers find it difficult to get a clear comparison when infected patients—who are struggling from COVID-19—are having other health conditions.
Adults have higher possibility passing the coronavirus
For influenza it is often passed from a child to another child through sneezing or coughing. However, it is suggested that adults are most likely be the actors in transmitting COVID-19 compared to children. Older people or people who have serious chronic medical conditions such as heart disease, diabetes or lung disease are also at higher risks of getting really sick if they are infected.
Yet, this doesn’t mean that children won’t get infected with COVID-19. According to the Chinese Center for Disease Control and Prevention, there is only one death in someone younger than 20 and no deaths among children below the age of 10 out of the 45,000 confirmed cases in China. But, CNN Health also reports that even though cases involving children typically wouldn’t be as severe as adults, it doesn’t mean that their cases won’t be serious too.
Deadlier than influenza
#COVIDー19 Statistik seluruh dunia dikeluarkan WHO, 17 Mac 2020.— KKMPutrajaya (@KKMPutrajaya) March 17, 2020
Jumlah kematian keseluruhan 6,442 dengan purata kadar kematian 3.55%.
Kadar kematian tertinggi Itali (6.47%), Iran (4.83), China (3.95%) dan Sepanyol (2.9%).
Wabak COVID-19 Korea Selafan makin terkawal. pic.twitter.com/vkixeEDG45
In the latest statistics from the Malaysian Health Ministry, there are currently 181,556 confirmed cases and 6,442 death cases across the globe. From the report, WHO has indicated a data that calculated that the crude mortality ratio is between 3 to 4% while for seasonal influenza it usually goes below 0.1%.
This means that COVID-19 is much more deadlier than influenza because about 3 to 4% of people who were infected, have died, while seasonal flu has killed less than 1% of infected people globally.
No cure or vaccine for coronavirus
Although there are no vaccines for the novel coronavirus yet, they’re working on it now. People are suffering from the new virus because no one has immunity to it yet. On the other hand, most people globally have already built up their immunity to their influenza and there are already flu vaccines that will help protect the human body against the influenza viruses.