- The risk of contracting SARS-CoV-2 while using public transport has remained low, but it can happen.
- Evidence, however, suggests that wearing a face mask, and good ventilation can help.
- A new study shows that mask-wearing and distancing during peak hours can reduce infection by up to 98%.
The rapid spread of the Covid-19 virus in 2020, and the consequent lockdowns, led to a reduction in the use of public transport.
In South Africa, there were concerns that the minibus taxi industry, including taxi ranks, could become Covid-19 super-spreaders.
As restrictions eased, the number of people using public transport has risen steadily. Under level 4 restrictions, bus, taxi, and train services were allowed to operate at 100% capacity, News24 reported – a move criticised by some of the country’s top scientists.
But what are the risks of catching and spreading SARS-CoV-2, the virus that causes Covid-19, for those who use public transport?
Considering the risk
Using public transport increases the risk of getting and spreading the virus, as a result of people being in close physical contact with others – often for prolonged periods – and exposed to frequently-touched surfaces, notes the US Centers for Disease Control and Prevention (CDC).
Although airborne transmission of the virus has increasingly been recognised during the pandemic, fomite transmission (picking up the virus from objects) has not been ruled out.
In January 2020, very early in the Covid outbreak, 67 Buddhist passengers and a driver boarded a bus in Ningbo, China, and since the disease was so new, no passengers were wearing a mask. Just days later, 24 people who had been on the bus fell ill, Health24 reported.
A study based on this event, and published in JAMA Internal Medicine, showed that it took one infected person to spread the virus to more than a third of the passengers during a trip that took one hour and 40 minutes.
Using sophisticated modelling, scientists from the University of Southampton examined the chances of catching Covid in a train carriage carrying an infectious person and established that there was an increased risk of Covid transmission on trains.
Other studies have suggested that while public transit may not be a "superspreader", it doesn't mean there's zero risk of passengers spreading and contracting the virus.
What you can do to protect yourself and others
Millions of people in South Africa do not have access to cars and rely on taxis, buses, and trains.
The best protocols to reduce transmission of the virus are wearing a mask correctly, physical distancing – where possible – and keeping windows wide open to ensure good ventilation.
The researchers of the University of Southampton study commented: “A person’s seat location and travel time in relation to an infectious person can make a big difference as to whether [the virus] is passed on … It is important to reduce the density of passengers and promote personal hygiene measures, the use of face coverings and possibly carry out temperature checks before boarding.”
Research published last year showed that the safest way for two people to lower the risk of transmitting the virus while travelling in a car was to keep all four windows down and the passenger to sit as far as possible from the driver (in the rear seat and on the opposite side to the driver), Health24 reported.
It is also best to avoid touching handrails and other surfaces while using public transport, but if you do, then it is important to practise hand hygiene (hand washing or sanitising).
Importance of face masks
The latest research by researchers in South Korea, published in the journal Science, measured the impact of the aforementioned policies on virus transmission on public transport. Specifically, they simulated how passengers encountered and infected each other during their journeys on public transport by tracking the movements of passengers.
They concluded that wearing masks exhibited effects similar to maintaining a two-metre distance in preventing Covid: “Mandatory wearing of masks and practising physical distancing with masks during peak hours reduced infection rates by 93.5 and 98.1%, respectively,” they wrote.
The CDC’s guidelines echo this: “Wearing masks that completely cover the mouth and nose reduces the spread of Covid-19."
In communities where case numbers are high, the health agency advises that fully vaccinated people should consider wearing a mask for activities involving close contact with others who are not fully vaccinated, such as public transport settings.
As of 24 October 2021, around 11.5 million people in South Africa had been fully vaccinated with the Johnson & Johnson or Pfizer-BioNTech vaccines.READ | How 7 people conquered their needle phobia and got vaccinated against Covid-19
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