By Dr Eddy Bajrovic*
Australia’s flu season is shaping up as a severe one, a panel of experts has warned.
Despite almost 50% more confirmed flu cases than at the same time last year, many Australians remain unprotected, partly because stocks of the vaccine arrived later than usual.
The good news is there’s no shortage now and it’s not too late to be protected. But, you need to have the vaccine soon to get the maximum benefit this winter.
The bad news is that we now know ‘silent spreaders’ are just as likely to infect you as someone sneezing and coughing.
Silent spreaders are people who appear well but are either newly infected or just over their symptoms. They can pass on the flu simply by talking to you or breathing into the air close by.
Travelling holds extra flu risks
For travellers, planes, trains, buses, or airport terminals are all risk areas for flu, according to Professor Mary-Louise McLaws. An epidemiologist in infectious diseases control with the School of Public Health and Community Medicine at Sydney’s University of NSW, Professor McLaws was one of three experts who took part in the flu forum last week.
“We know flu particles are spread by large droplets which fall quickly, as well as small particles which can float in the air and can spread up to 2.5 metres from someone with the virus,” she told the Travelvax Report in an interview after the forum.
“But, a person doesn’t have to have obvious signs of illness to be very contagious.
“They can pass it on for up to 3 days before their symptoms first appear and for a day or two after they recover simply by talking or breathing.
“They can be sitting next to you in a plane, on a train or bus, or at work and can infect you very quickly if you haven’t been vaccinated or don’t have antibodies from a previous infection with that particular strain or a similar one.”
It’s easy to ‘pick up’ flu
Unprotected travellers can also literally pick up the virus off hard surfaces around them, such as fold-down trays, arm rests or the fixtures in toilets.
“We know from our research that humans touch their face 23 times an hour,” Prof McLaws said.
“Around half of those contacts involve touching our nose or mouth, where the virus enters the body. So, someone in the early, mid or late stages of a flu infection will transfer virus particles from their hands to surfaces that lots of people will touch.”
Aircraft also present a unique risk for flu because in the cabin’s low humidity flu virus-containing particles can remain alive for up to 24 hours on the hard surfaces, especially in high-traffic areas like toilets.
Cabin’s low humidity adds to flu risk
“We know from studies that if someone has the flu on a plane they can infect people two seats away in any direction,” Professor McLaws said.
“What adds another dimension to the risk on planes is the very low humidity in the cabin – around 12% compared with 50-60% in most buildings. Flu viruses spread very effectively at 60% or less humidity.
“When you are sitting for long periods in a low humidity atmosphere the mucous membranes in our nose or mouth dry out, which also increases the likelihood of acquiring respiratory infections like flu.
“Whether you’re travelling for leisure or business, the last thing you want after you’ve bought an expensive ticket is to get sick. Flu has a short incubation period of 1-4 days so getting it will certainly impact your work or disrupt your holiday for up to a week.”
Travel creates a flu melting pot
Flu is THE most common vaccine-preventable travel disease, regardless of whether you’re visiting a developed or developing country, or the time of year. In the tropics, flu circulates year-round and travellers bring different strains from all points of the compass.
It can take up to two weeks to fully recover, possibly stopping you from boarding a flight or disrupting your holiday activities or business meetings. And, if you need treatment, seeing a doctor overseas can be costly.
No-one is immune from flu: Even young, fit people are felled by flu, but it’s more likely to be severe for infants, the elderly, and people with immune suppressive disorders or chronic medical conditions. The vaccine is free for those at higher risk.
Flu can be lethal: It kills an average 2500 Australians each year – about the same number as die on our roads. Another 300,000 need to see their GP for treatment, while around 18,000 are hospitalised.
Don’t believe the myth that having the vaccine can give you the flu: It simply isn’t true. The three-strain and new four-strain vaccines contain purified and inactivated (‘killed’) influenza viruses that prime your immune system and protect for 6-12 months.
For travellers, a flu shot is pretty cheap insurance for enjoying your holiday or getting to an important work assignment.
* Dr Bajrovic is the Medical Director of Travelvax Australia.
Got a question about flu or other vaccinations for an upcoming overseas trip? Call Travelvax Australia’s telephone advisory service on 1300 360 164 (toll-free from landlines) for no-obligation, country-specific advice. You can also make an appointment at your nearest Travelvax clinic to obtain vaccinations, medication to prevent or treat illness, and accessories for your journey.