The arrival of the month of June signals the onset of peak influenza season in Singapore. Amidst the furore that the COVID-19 pandemic has raised in the first half of 2020, awareness of the potency and danger of the influenza virus has declined sharply among not only Singaporeans, but populations all across the globe.
Influenza, which is more commonly known as the flu, has been a formidable enemy for many decades to count. The virus first rose to infamy during what has come to be known as the Spanish flu epidemic of 1918, where it infected a whopping one third of the world’s population and took 50 million lives globally.
For decades after, it continued to be the reason for many deaths, especially in vulnerable populations – the World Health organisation estimates that even today, the flu virus causes severe illness in 3 to 5 million people and causes 250,000 to 500,000 deaths worldwide.
In 2020, with all attention having been taken off the flu virus momentarily and directed towards the COVID-19 pandemic, it is all the more important to educate yourself on the risks of influenza and how you can keep yourself and your loved ones safe during flu season or even a flu pandemic.
What is the influenza virus?
There are four types of the flu virus (A, B, C and D) but it is primarily types A and B that cause infection in most individuals. These two types are more commonly known as the seasonal flu since there are specific periods of the year in which they infect large masses of people.
These periods vary according to many factors, but primarily according to season. In temperate countries, winter and colder months of the year are usually the months in which there are the most outbreaks as the cold facilitates the spread of the virus. However, in tropical countries like Singapore, transmission may occur throughout the year, with there being certain peak periods.
The WHO has determined that the flu has rapid transmission since it can be spread through droplets, which are emitted when an infected person coughs or sneezes. What makes the flu particularly contagious is that the droplets in question, when dispersed into the air, can travel up to one meter.
Moreover, when an infected person touches any surface with hands that are contaminated with the virus, the virus transfers to these surfaces and the surfaces then become fomites. Fomites are inanimate objects that facilitate the transfer of the flu virus between persons – this is because when a health person touches a fomite, he or she picks up the virus as well and becomes prone to infection.
Seasonal influenza often causes a rapid onset of symptoms including a fever, cough, sore throat, runny nose, muscle aches and malaise among others. These symptoms can last up to 2 weeks. Although most healthy people can recover from the flu without any treatment or hospitalisation, certain groups of the populace can become severely ill – ill enough to need hospitalisation and sometimes even ill enough to cause death.
Who are at risk of being severely affected by the flu?
The WHO has identified a set of risk factors in a person that may cause him or her to become severely ill from the flu. The individual may need hospitalisation and may even pass away due to complications from the flu, if infected.
These are the groups of people who are most at risk of developing severe complications from the infection:
- The elderly (65 years and above)
- Young children (below 6 years)
- Those with chronic medical conditions (cardiac, pulmonary, renal, hematologic etc.)
- Those who are immunocompromised (HIV-positive, undergoing chemotherapy etc.)
- Pregnant women
- Healthcare workers (due to repeated exposure to virus and increased viral load)
The list is not exhaustive and those who have a higher risk should be identified on a case-by-case basis after a consultation with a travel health nurse or a doctor.
Prevention: the flu vaccine
Decades of research has gone into developing and then modifying the flu vaccine so that it offers better protection against the flu virus. The flu vaccine is modified to protect the populace against the latest circulating strains of influenza. This protection is primarily against Influenza types A & B, since these are the seasonal types that cause outbreaks across the world.
When you receive the flu vaccine, your risk of contracting the disease is reduced by between 40% and 60%, according to the US Centres for Disease Control and Prevention (CDC). This is quite a significant amount of protection, especially for groups of people who have a higher risk of developing severe complications from the illness.
Flu vaccine strains are updated seasonally, usually in March and October, so that they offer protection against the latest circulating strains of the flu. The vaccine that is manufactured for release in March usually covers strains of the flu circulating in the Southern Hemisphere and the one manufactured for release in October covers Northern Hemisphere strains – this makes the coverage comprehensive. You should aim to get a flu vaccine every year, especially if you are part of the risk population.
Receiving the flu vaccine during the COVID-19 pandemic also offers additional benefits: it saves you the anxiety of contracting the flu and assuming that it is COVID-19 and it allows healthcare workers to better diagnose you.