By Dr Eddy Bajrovic, Medical Director of Travelvax Australia
“I’m travelling overseas. Should I be worried about Ebola?”
It’s a question Travelvax Australia’s travel health specialists have been asked repeatedly in recent weeks. And, not just by people heading to West Africa where the deadly disease has infected 1848 people in Guinea, Sierra Leone, Liberia and most recently in Nigeria, killing 1013 of them, according to the latest World Health Organization (WHO) figures.
Yes, that’s despite the WHO declaration last week that the eight-month long outbreak now constitutes a ‘Public Health Emergency of International Concern’ and America’s Centers for Disease Control and Prevention advising against non-essential travel.
How can that be given that outbreaks are spreading to new regions of West Africa?
Because, the reality is that it’s actually quite difficult to become infected with Ebola.
EBOLA CAN ONLY BE PASSED ON through direct contact (generally through broken skin or mucous membranes in the nose) with bodily fluids, such as blood, saliva, faeces, or semen of an infected person (or animal) already very sick with its very obvious symptoms, or by handling their infected bodies after death. Touching objects contaminated with infected body fluids is another form of transmission.
EBOLA CANNOT BE PASSED ON from casual contact with someone who has been exposed to the disease but isn’t sick yet. Despite what you may hear, you cannot catch Ebola by breathing it in, from handling everyday items, drinking local tap water, swimming in a pool, or bites from mosquitoes or other insects.
The risk of contracting Ebola is much lower than for any of the more common diseases that you might encounter during travel. Indeed, respiratory diseases and gastro infections are far more likely because they are far more contagious.
Many airborne diseases are highly contagious
Just what makes a disease contagious?
The answer is complex: It’s based on factors such as how it passes from person to person (in the air, in blood or bodily fluids, etc.), what systems are in place in the country to detect and control infection, how much contact the infected person has with others, and (if the disease is vaccine preventable) the level of vaccination coverage in the local population.
To determine just how contagious a disease is, infectious diseases experts* take these and other factors into account when determining the average number of people an infected person might infect. It is called the basic reproductive rate or number and it’s an estimate only, likely to vary from one country to another.
While Ebola is spread by contact with blood or body fluids, diseases such as measles, diphtheria, whooping cough, and influenza are mainly airborne. They are most commonly transmitted through face-to-face contact with an infected person – no physical contact is needed, as with Ebola.
Risks higher in developing countries
When comparing the reproductive rates of various diseases, a vulnerable person anywhere is at much higher risk of encountering one of the following more common viral and bacterial infections – especially if travelling in a developing country.
Measles: 12-18 people (likely to be infected by a single case)
The highly infectious measles virus is spread through the air when an infected person coughs or sneezes. If exposed to infected droplets, anyone not already immune through vaccination or previous exposure is very likely to become infected. Measles rates have risen sharply worldwide in recent years and outbreaks involving hundreds of cases have become commonplace in countries with vaccination coverage below 95%.
Whooping cough (pertussis): 5-17 people
Whooping cough is a bacterial disease which is also spread by infected airborne droplets. Highly contagious, it attacks the respiratory system, making it difficult to breathe and often causing a racking cough. Most deaths occur among infants, who are particularly vulnerable up until the age of six months, when they can be fully vaccinated.
Diphtheria: 6-7 people
Diphtheria is also caused by bacteria passing from person to person, usually by coughing or sneezing.
Polio: 2-20 people
The virus is spread through infected faeces or from droplets from a sneeze or cough. Objects contaminated with the virus can also spread the disease.
Mumps: 4-7 people
Another viral disease, mumps is spread by droplets of mucus or saliva when an infected person talks, coughs, or sneezes.
Influenza: 1-4 people
This all-too-familiar viral disease is the most common vaccine-preventable disease among travellers. They become infected by breathing in contaminated droplets in the air, or by literally picking up the virus from hard surfaces they touch during the northern and southern hemisphere flu seasons.
Vaccines protect travellers
Thankfully, all of these childhood diseases can be prevented through vaccination.
Despite the proven protection vaccines provide, vaccine-preventable diseases such as measles and whooping cough have made a comeback worldwide in recent years – even in countries with traditionally high rates of immunisation, such as Australia.
One reason has been vaccine-refusal, which has led to a slight, but worrying, fall in childhood vaccination levels.
To protect themselves, as well as family, friends, and the wider Australian community they return home to, Travelvax recommends Australians travelling overseas check their immunisation status for measles, diphtheria, whooping cough, mumps, and polio at least 6 weeks prior to travel. (Combination vaccines also enable travellers to receive boosters for rubella, diphtheria, and tetanus, too.)
The 6-week gap is ideal in case other vaccines are recommended for your specific journey and need to be scheduled before you leave.
Why an Ebola outbreak is unlikely in Australia
In contrast, Ebola’s reproductive rate would be very low – virtually zero – in Australia or other countries with advanced healthcare systems.
If a case was to occur here, the patient would be diagnosed quickly and treated in strict isolation under the very highest levels of barrier protection and infection control. Anyone who had been in direct contact with them would also be traced rapidly and placed in quarantine for the disease’s incubation period, which can be as long as 21 days.
Despite the best efforts of the WHO and partner organisations, this level of tracing and infection control has proven very difficult in West Africa and outbreaks have continued to spread.
Since Ebola first appeared in Africa in 1975, virtually everyone infected has been a close family member caring for a sick relative at home, exposed during burial ceremonies, or a healthcare worker treating the sick. (Of the estimated 140 to 150 healthcare workers infected, 80 have died.)
So, while most travellers and expats are at low risk of infection, the possible exceptions may be:
- People visiting family or relatives in a region where cases are occurring and who will be in family homes, particularly those staying for an extended period.
- Healthcare workers based in hospitals or other facilities where the sick are being treated.
As always, remember good hygiene
All travellers visiting regions of West Africa where outbreaks are occurring should avoid:
- Direct contact with blood or bodily fluids or with objects possibly contaminated with them, such as needles.
- All contact with wild animals. (Don’t eat ‘bush meat’: If improperly cooked, the meat may harbour the virus.)
- Unprotected sex. (People who have recovered from Ebola can pass on the virus through unprotected sexual contact for up to seven weeks.
Finally, and perhaps most importantly, practice careful personal hygiene, including thorough hand washing after using the toilet and before eating.
Good hygiene also helps to protect against those most common of germs – the ones that cause traveller’s diarrhoea.
*REFERENCE: Vaccines (6th Edition) by Stanley Plotkin, Walter Orenstein, Paul Offit.
For more advice on the health risks and possible vaccinations recommended for your next overseas destination, please call Travelvax Australia’s free travel health advisory service on 1300 360 164.