WINTER is here. That means flu, colds and gastro bugs are just around the corner. Of course, travellers aren't the only ones at greater risk from this highly infectious trio (although planes, cruise ships, trains and buses are great disease incubators, including childhood infections like measles). Anyone in a crowded, confined space is vulnerable to winter viruses – students, people in hospitals and nursing homes, office workers, or passengers on public transport.
Regular readers will know that Travelvax Australia recommends all Aussies heading overseas have a seasonal flu shot, regardless of the time of year. That's because more travellers get flu than any other vaccine-preventable disease.
Flu breaks out like a bushfire and spreads just as quickly. At any given time flu outbreaks are occurring in some part of the world and travellers can not only pick up the virus during their flight, but also at numerous places along the way – airport terminals, taxis, hotel lobbies... you get the picture.
You don't even have to breathe in invisible airborne droplets containing the virus. Touching a surface an infected person has touched, sneezed or coughed on is just can transfer the virus from one person to another.
But, unlike the flu virus, there is no vaccine for either the cold virus (a rhinovirus) or noroviruses which, like the flu, thrive in winter. So, prevention is the key.
Flu – the season's about to start
Last week, three Australian experts gave journalists a snapshot of what we can expect from the three viruses this winter. The forum was presented by the Australian Science Media Centre (ASMC).
Dr Ian Barr, the deputy director of the Australian WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, said predicting the severity of the upcoming flu season was 'harder to pick than the Melbourne Cup', although recent southern and northern hemisphere seasons were usually a good guide. Last year's southern season was moderate to severe, while the most recent northern hemisphere season was particularly severe, he said.
So far this year, the number of cases of influenza-like illness reported in Australia is marginally ahead of the tally for the same period last year. (Last year, flu claimed 60 Australian lives, mostly elderly people, and across the country 48 children aged under 15 were admitted to hospital – 23 to intensive care.)
Based on lab tests, the current flu vaccine is well matched to the strains currently circulating, Dr Barr said.
Around half this year's cases to date have been the pandemic A H1N1 strain or 'lineage', a third have been A H3N1 and remainder have been B-strain viruses. Of the latter, there has been an increasing number of cases caused by the Yamagata strain, which is included in this year's seasonal vaccine.
OUR ADVICE: There is still a window of 2-3 weeks in which to be vaccinated before the flu season starts here in earnest. However, the vaccine takes a fortnight to be fully protective, so there's no time to waste! For those who decide against the vaccine, as well as those travellers who want to self-treat if they get symptoms while overseas, anti-viral treatment medications are most effective if taken within 48 hours of flu symptoms appearing.
Rhinovirus – uncommonly easy to pick up
Rhinoviruses are less severe than flu viruses, but still capable of taking the shine off your holiday.
Like flu, colds can occur at any time of year, but thrive when temperatures fall. And, a recent study found our immune systems don't function as efficiently in winter as they do in warmer seasons, making it harder to ward off infection, according to Professor John Upham, Professor of Respiratory Medicine at the School of Medicine and Director of the Lung and Allergy Research Centre at The University of Queensland.
Scientists have found that younger women have a stronger immune response to rhinoviruses than men.
"We think that this is related to hormones," Professor Upham told the forum.
"The difference between women and men is only seen up to the age of 50. Over 50, men and women make a very similar immune response."
Generally mild in most healthy people, a cold can have a more severe impact on those with chronic lung diseases and respiratory conditions like asthma. The viruses are more likely to infect the lungs and take much longer to be cleared from the body.
Scientists suspect that's because of immune system abnormalities in asthmatics. Research is underway to see if inhaling medications containing naturally-occurring proteins, could prevent asthma sufferers having a severe attack, Professor Upham said.
Like flu, the cold virus is easily transferred by touching a hard surface that an infected person has themselves touched, or coughed or sneezed on. All it takes to become infected is to touch the surface and then touch your mouth, nose or eye.
OUR ADVICE: An important way to protect yourself against both colds and flu viruses is to wash your hands regularly, particularly if a family member or work colleague is infected. (See below for more on effective hand hygiene.)
Norovirus – brief but nasty
For travellers, noroviruses are the most likely cause of gastro illness. Very contagious, they are behind virtually every gastro outbreak aboard cruise ships.
Typically, symptoms last 24-72 hours and begin with sudden vomiting, abdominal cramps, nausea and watery diarrhoea, although for a lucky few symptoms can be mild or non-existent. Dehydration is the most common complication, especially among the young and elderly, and most people recover without medication and with no long-term complications.
The bad news is that everyone living in a developed country can expect, on average, one episode of norovirus infection per year, according to Professor Peter White, who led the University of NSW research group that identified the world's newest strain of norovirus, 'Sydney 2012' (each new strain is named after the place where it was identified, and when).
Ironically, after being detected here last year, Sydney 2012 immediately departed NSW. It quickly became the dominant global strain, responsible for more than 80% of outbreaks in hospitals, nursing homes and other institutions, as well as scores of cruise ship outbreaks across the globe.
Sydney 2012's arrival in Western Europe and the USA during the most recent northern winter resulted in major outbreaks. In the UK alone, there were more than a million infections over 3 weeks in December and January.
New Zealand cities, along with Melbourne, also saw significant increases in out-of-season norovirus activity during our 2012-13 summer.
Professor White said that after dodging the norovirus 'bullet' last year, it could be Sydney's turn to experience its namesake virus this winter. The winter peak for norovirus is during October (a month after flu peaks).
"We can expect a lot more Sydney 2012 activity beginning in August and September," Professor White warned. Wards could be closed if a hospital experiences a major outbreak.
He also warned of the potential for extensive outbreaks on cruise ships based in Austalian ports during our norovirus season.
OUR ADVICE: Wash your hands carefully with soap and water regularly – especially after using the toilet or changing nappies, and always before preparing, handling or preparing food. Wash fruit and vegetables and cook seafood thoroughly. If you experience norovirus, don't prepare food for 3 days, thoroughly clean and disinfect contaminated surface, and wash contaminated laundry on the longest cycle before machine drying.
Preventing flu, colds & noroviruses this winter
Whether you are travelling overseas or staying home, here are some tips for avoiding infection from flu, colds and food-borne illnesses this winter.
FLU
Vaccination: Vaccination is the most effective way of avoiding illness caused by the flu virus. Have the vaccine at least 2 weeks before you travel or before the local season begins. Protection lasts for 6+ months.
COLDS AND FLU
Avoid infected: Stay as far as possible from people who are coughing or sneezing. On aircraft, a study confirmed that those sitting in the 'hot zone' – that is two seats in any direction from a flu-infected passenger – had a 7.7% higher chance of being infected.
FLU, COLDS AND NOROVIRUSES
Really clean your hands: Washing your hands thoroughly and regularly greatly improves your chances of avoiding all three viruses. But, observational studies have shown that only around 20% of us wash our hands properly. The gold standard of hand hygiene is soap, warm water and vigorous scrubbing along the full length of the hands and between fingers for 20 seconds. Alcohol-based wipes work for flu and rhinoviruses, but are not as effective in killing norovirus particles because of their particular molecular makeup. However, if soap and water are not available, they're the next best option. Read more on Preventing Norovirus (CDC fact sheet); Effective hand washing (CDC); or watch a hand hygiene clip (YouTube).
Avoid touching your eyes, nose or mouth: Hardy viruses like flu, colds and noroviruses are often spread when a person touches a contaminated surface and then touches his or her eyes, nose, or mouth.
Check your destination for outbreaks: To find out more about these and other disease risks at your destination call Travelvax Australia's travel health information service on 1300 360 164 (toll-free from landlines). We can also advise you on the vaccinations that may be recommended for your trip.
Travellers can also go online to check the current situation with flu. Here are some sites for northern hemisphere countries.
USA - The Centers for Disease Control and Prevention offers activity reports for each state.
CANADA - The Fightflu website allows you to check outbreaks by state or territory.
UNITED KINGDOM - Read the latest National Influenza Reports.
EUROPE - See the influenza activity maps.