1-in-11,000 chance of contracting COVID-19 on trains
TWO studies into the spread of COVID-19 on railways have found that the chance of contracting the disease by travelling on a train is extremely low.
The RSSB (formerly the Rail Safety and Standards Board) estimates that the risk of infection per passenger journey is only 1-in11,000 journeys.
The modelling is based on a Hitachi Class 800 carriage used by LNER, loading 44 passengers travelling for 30 minutes, with 22 passengers alighting and replaced by another 22, then travelling for a further 30 minutes. The figure does not include any mitigating effect of wearing face coverings.
RSSB is now developing scenarios involving different types of train, more complex journeys, and variations in the number of passengers travelling.
Meanwhile, a German study has found “little or no evidence” that the disease has been triggered by a train journey.
The research for German train operator Deutsche Bahn concluded: “We see remarkably few infections in trains. No infections occurred in persons on board with a stay of less than ten hours. Not a single contact tracing has been identified in Germany and Austria as having been triggered by an infection on the train journey.”
It also found that the infection rate in air-conditioned carriages was lower than in vehicles without air-conditioning. It reported: “The air flow is essentially vertical rather than horizontal, which makes direct distribution of the virus by the airflow rather unlikely.”
DB employees must wear face coverings and the company strongly recommends passengers to wear them. It found that “they appear to significantly reduce the risk of infection in public areas and on trains”.
The research said the number of infected DB train attendants has been below the age-corrected infection rate of COVID-19 cases in Germany as a whole.
It concluded: “No increased risk of infection for employees on board long-distance trains can be deduced from these figures.”
However, a study of Chinese railways, conducted by population mapping experts from the University of Southampton, found different results. It concluded that for passengers sitting within three seats across and five rows apart, the average rate of transmission was 0.32%.
The study, using data from highspeed G Train services, showed that passengers travelling in seats directly adjacent to a patient with Coronavirus suffered a higher level of transmission, with an average 3.5% contracting the disease. But only 0.075% of people who used a seat previously occupied by a
patient went on to contract it.
The study used data collected between December 19 2019 and March 6, covering more than 2,000 patients and 72,000 contacts.
Dr Shengjie Lai, a Research Fellow at the University of Southampton, said: “Although there is an increased risk of COVID-19 transmission on trains, a person’s seat location and travel time in relation to an infectious person can make a big difference as to whether it is passed on.”
The researchers concluded that a safe social distance of more than one metre is required for one hour spent travelling together. After two hours of contact, they considered a distance of less than 2.5 metres may be insufficient to prevent transmission.
Others have questioned the validity of this Chinese research, given that the German study drew upon a wider pool of evidence and reached a different conclusion.
The Southampton paper seems to assume that if people sit together on a train, then the transmission occurred on the train, even though families or friends generally sit together when travelling. RAIL approached the University for comment, but none was received before going to press.
The Deutsche Bahn researchers reported that UIC, the international union of railways, had not encountered any other proof of infection during train journeys. It found the highest incidence of infection came from contact within a household, at 10%, whereas incidence on trains was at most 0.1%.
Simon Fletcher, Europe Director for UIC, told RAIL: “We find every country has a different approach to dealing with the virus. A few countries stopped trains completely. SNCF in France required every passenger to wear a face covering from May, but then stopped also requiring social distancing.
“We propose to publish a set of international standards later this year. They will not be mandatory - we don’t do that - but this will enable countries to understand what others are doing.”
Christopher Irwin, who sits on the European Passengers’ Federation board and previously chaired the European Railway Agency, said: “There is scant evidence that public transport has been the source of infection clusters anywhere in the world. One reason is that fewer people are travelling.
“The pandemic has catapulted many people along the path of behavioural change - working from home, staggered hours, substituting digital conferencing for business travel. This is a fundamental challenge - the vast majority feel they have managed quite well without easy access to the railway.”