International travel is part of contemporary life like never before, and it is not unusual for the 21st century traveller to explore regions where one might need to consider additional precautions in order to preserve good health. Outbreaks of disease, even preventable disease like measles and pertussis (whooping cough), can occur anywhere in the world and leave the unvaccinated vulnerable. But certain countries, particularly where sanitation and the quality of available drinking water are variable, and where mosquitos and other vectors pose a very real threat to humans, often provide pathogens with the perfect conditions in which to multiply and proliferate. If you know these risks well in advance, you can take sensible steps to keep yourself safe. Thorough preparation for an international trip involves a detailed examination of your medical history and your current levels of immunity, especially if you’re going to regions where diseases aren’t typically controlled by modern medicine.
This guide serves as a general resource for the appropriate health cautions to take before and during international travel. The golden rule is to endeavour to receive ALL locally recommended vaccinations or their relevant boosters before considering regionally-specific immunisation. If you’re not sure what you’ve previously been immunised against, or have lost your vaccination records, you can obtain a serology report by having a simple blood test. This will show the active antibodies you have circulating in your body, antibodies that are not present, and the required boosters. This is what they’ll be looking for:
Measles, Mumps, Rubella and Varicella – MMRV Vaccine
Recently, measles has been resurgent in Australia after infecting unvaccinated young travellers who in turn give the disease a free ride back to Australia. It then goes on to infect others. Measles is usually controlled quite quickly, with quarantines and community alerts occurring without delay, but the more unvaccinated people the disease is exposed to the greater the number of people who are affected. Mumps and Rubella are relatively rare these days, but be aware that immunity can fade over time, and you may require a booster shot. Rubella is a particular concern for pregnant women, or women planning a pregnancy.
The varicella (chickenpox) vaccine has been available in Australia since 2000, and is saving millions of people from the itchy welts and scabs that characterise the disease. In healthy children, varicella is a mild, albeit unpleasant, virus. In adults and vulnerable children, however, it can have severe complications and is potentially fatal. If you’ve not had chickenpox and have never been immunised, vaccination should be a priority. Typically, we have a lower incidence of these diseases than some other countries and communities, so travellers who are unsure of their levels of immunity should be tested.
Diphtheria, Tetanus and Pertussis – dTpa Vaccine
A booster shot is recommended for anyone who has not been immunised or re-immunised in the previous 10 years.
Diphtheria is an extremely rare respiratory condition that can be severely debilitating and can cause complications leading to death in around 10% of cases. Thankfully diphtheria is almost never seen in developed countries since the advent of the vaccine.
Tetanus is a type of bacteria transmitted from the natural environment into broken skin, and can cause horrible symptoms including lockjaw and convulsions. Everyone is potentially at risk of exposure, but particularly those who have frequent contact with dirt, dust and animal manure. The vaccine has made this disease a rare occurrence, but given the nature of transmission, we should not become complacent.
Pertussis, or whooping cough, is less controlled, partly owing to the incremental mutations in the disease as it spreads, and also due to less than ideal levels of vaccination in some parts of the country. An adult booster shot of dTpa is recommended for this reason. It’s particularly dangerous to young babies prior to their scheduled vaccination, but adults whose immunity has weakened by time or by medical circumstance can also be at risk.
The potential consequences of contracting hepatitis B include liver disease and cancer, so this is one to avoid. It is more prevalent in certain parts of the world, so immunisation for travellers is a crucial part of your preparation. Three doses of the vaccine are given, but coverage is generally quite good after the second. Hepatitis B is more commonly reported in parts of Central and South America, Asia, Africa and in the South Pacific.
Pneumococcal and Meningococcal
The pneumococcal vaccine protects against dozens of strains of the potentially deadly bacteria, which can cause pneumonia, meningitis and septicaemia. It’s also given over three doses, so aligning each dose with the Hepatitis B schedule makes good sense.
Closely related is the meningococcal bacterium, and a vaccine for meningococcal strain C is now available for the Australian schedule after successful testing in Europe. Note that a vaccine for meningococcal B has recently become available, but is not currently on the Pharmaceutical Benefits Scheme. Meningococcal vaccination should be prioritised for anyone travelling to sub-Saharan Africa or Saudi Arabia.
Influenza circulates globally, and is usually associated with the colder months. The flu mutates as it moves through populations, so virology experts have to work quickly year round to determine what sorts of strains will be prevalent in the near future. As such, the influenza vaccine is a little different each year, and if you are vulnerable to illness, including as a traveller, you are encouraged to stay immunised again the current circulating strains. Note that cruise ships, buses, and large crowds make ideal conditions for spreading influenza quickly.
The dreaded disease that crippled healthy children up until the mid-twentieth century is thankfully almost never seen in the developed world. Since the vaccine was first licensed in 1962, incidences of disease fell at an astonishing rate. Today, polio remains elusive, but pockets of active disease remain in some war-torn and undeveloped regions. Since the World Health Organisation lists the vaccine as an essential medicine, travellers should ensure they are protected. Travellers to Africa or the Middle East should be vigilant. You can check where the disease is currently active here.
VACCINES FOR TRAVELLERS
If you were asked to picture the deadliest creature on Earth, what would come to mind? Whichever image you’ve created, there’s a good chance it looks nothing like the humble mosquito, an insect that is responsible for the deaths of millions around the globe. In Australia, the insect is unlikely to cause anything beyond an itchy bite, but for warmer, wet climates, the mosquito symbolises death and disease. The dramatic environmental differences between countries are just one reason to be aware of the health risks of travelling, the available vaccinations, and what you need to do to keep yourself safe. The following is a list of diseases that you may encounter on your travels.
Disease prevalence: Africa, Asia, Papua New Guinea, South and Central America, Fiji
Malaria is caused by a parasite called Plasmodium, which is transmitted via affected mosquitoes. The parasites multiply in the liver and infect red blood cells. Symptoms of malaria are varied, and usually appear 10 to 15 days after the mosquito bite. They include fevers, headache and vomiting, and the disease can quickly become life-threatening by disrupting blood supply to vital organs.
While no vaccine exists for malaria, it is recommended to implement appropriate prevention techniques. These include acquiring prophylaxis against malaria, using insect repellents and sleeping with mosquito nets installed.
Disease prevalence: Recent outbreaks have occurred in Nigeria, Haiti, Dominican Republic, Venezuela, Democratic Republic of Congo, Somalia, India, Sierra Leone, Cuba, Iraq, Nepal, Pakistan, Iran, Bangladesh, Myanmar, Laos, Cambodia, Vietnam, Afghanistan, China, Kenya, Uganda, Zambia, Angola, Ethiopia, Mozambique, Ghana, Ukraine, Guinea, Mali and Niger.
Cholera is a bacterial infection characterised by severe diarrhoea and vomiting, leading to dehydration and electrolyte imbalances. Though exposure can be limited by carefully avoiding contaminated food and water, an oral vaccine is available for those travelling to at-risk regions or participating in disaster recovery. The vaccine is taken in two doses, at least a week apart.
Disease prevalence: Africa, Asia, South and Central America, regions of Europe.
Hepatitis A is a liver disease that is most commonly transmitted through contaminated water and food. Symptoms can last from a few weeks to a few months, and include nausea, fatigue, loss of appetite, jaundice and diarrhoea. It is mostly found in developing countries, but is not exclusive to them – recent outbreaks have also occurred in the United States, for example. Because its presence is so wide spread, this is one of the most common diseases that travellers vaccinate for.
Disease prevalence: South East Asia, East Asia, Papua New Guinea
Japanese Encephalitis is a mosquito-borne virus that is typically harboured by wild birds and pigs. Although the vast majority of cases are asymptomatic, the presentation of symptoms can lead to horrific disability and death. Fatigue, fever and headache can quickly descend into rigidity, convulsions and coma, often leaving survivors with permanent brain damage. Travellers spending time in rural areas of Asia, particularly during the wet season, should consider vaccination. This is given in two doses, one month apart, and immunity lasts up to three years.
Disease prevalence: Africa, Asia, South America, parts of Eastern Europe
Rabies is a virus that is transmitted to humans from animals, usually dogs or bats (but also foxes and monkeys), via a bite or scratch. The virus eventually travels to the central nervous system, causing severe neurological defects that present as significant behavioural disturbances, hallucinations, partial paralysis, delirium, and eventually coma. Although transmission via bats is rare, countries with stray dog problems such as India experience outbreaks far more commonly. The available vaccine does not provide comprehensive immunity, but it does ensure management of the condition after exposure is simpler and more effective. Rabies can be treated up to the point it reaches the central nervous system. The vaccine is given in three intravenous doses over the course of one month. Travellers spending more than a month in endemic regions, or who are planning to be in contact with animals, should consider the vaccine.
Disease prevalence: Africa, South and Central America
Yellow fever is an often-fatal viral diseases transmitted by mosquitos. Infection results in fever, jaundice, hemorrhage, and kidney failure. The single-dose vaccine is only recommended for travellers who are visiting or passing through areas with recent or active outbreaks, or who are particularly prone to mosquito bites. Some countries require proof of yellow fever immunisation from an approved World Health Organisation clinic. Contact your local health department for the nearest approved clinic if you require this vaccine.
Disease prevalence: Primarily the Baltic States, Russian Federation, Slovenia. Also Albania, Austria, Belarus, Bosnia, Bulgaria, China, Croatia, Denmark, Finland, Germany, Greece, Hungary, Italy, Mongolia, Norway, Poland, the Republic of Korea, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Turkey and Ukraine.
As the name suggests, tick-borne encephalitis is transmitted through the blood-seeking ticks, but can also potentially pass through unpasteurised dairy products. It initially presents with influenza-like symptoms until the infection reaches the central nervous system, at which point the symptoms can include respiratory problems, confusion, seizures and partial-paralysis. The virus has a mortality rate of 1-2%. The vaccine for tick-borne encephalitis is difficult to get in Australia as it’s only available through the Special Access Scheme, but travellers can be vaccinated once they reach Europe. At the highest risk are those planning high-altitude treks or extended periods of hiking or camping.
Disease prevalence: Africa and Asia, though it is globally present. High concentrations are in Mozambique, Zimbabwe, Marshall Islands, Djibouti, Lesotho, Namibia, Sierra Leone, South Africa and Swaziland.
Tuberculosis, or TB, is a bacterial infection that primarily affects the lungs. It is both preventable and treatable. It’s an airborne disease transmitted from an infected person, typically through the inhalation of infected mucous from a cough or sneeze. Symptoms include coughing, fever and sweats, and left untreated, around two-thirds of those with active disease will die from it. The majority of these deaths occur in developing countries. Those who have access to treatment in the form of antimicrobial drugs usually recover fully. For travellers, the BCG vaccine for tuberculosis is only recommended for those who have a negative TB test (Mantoux or blood serology) and who are spending extended periods of time in high-risk areas.
Disease prevalence: Africa, Southern Asia including Indonesia, Peru, India, Papua New Guinea, and some South Pacific nations. Assume a potential risk in all area of poor sanitation and untreated drinking water.
Typhoid fever is a bacterial infection transmitted via contaminated food and water, and occasionally, via fecal/oral transmission. Symptoms include fever, headache, weight loss and insomnia. Severe cases can also include abdominal symptoms, brain involvement and pneumonia, which results in a fatality rate of 12-30%. The available vaccine is a single-dose injection, or a course of three capsules is also available. Vaccination is recommended for all travellers to high-risk areas.
WHAT ELSE CAN YOU DO TO KEEP SAFE?
Before You Travel
Research your destination. Consider general sanitation, water quality, food hygiene, current or recent epidemics, access to quality healthcare. This will help you determine what diseases you may encounter, if you can vaccinate against them, and what services you can access if you become unwell.
Consider your likely activities. Will you be spending a lot of time in the great outdoors, in rural areas, with animals (particularly wild animals)? Will you be sleeping, trekking, or camping outdoors in tropical or sub-tropical regions?
Are You a High-Risk Traveller? Pregnancy, age (babies, toddler, and elderly persons), current state of health and medical history are all factors to consider when planning your travel. You may need to give particular consideration to the level of access to health care you’ll have during your trip, and tailor your plans accordingly.
Visit your primary care physician. Your doctor will help you prepare for your travel by implementing a vaccination schedule that allows for the full course to be given prior to travel. This must be done as early as possible –aim for two to three months prior to travel to maximise your immunity, and to ensure vaccinations have enough time to produce the desired antibodies. Your doctor can also provide you with further information on how best to protect yourself from disease exposure as you travel, and what to do in case of a medical emergency.
Secure Reputable Travel Insurance. Despite taking all possible precautions, there is no guarantee against accident or illness. Ensure that if something happens to you or your fellow travellers overseas, you are fully covered for treatment. Compare travel insurance providers well before you leave to ensure the best possible rate.
Once You’ve Arrived
You will know from your research whether mosquito-borne diseases pose a risk in your destination country. If so, you will need to be particularly diligent to ensure you don’t get bitten. Mosquito repellent should be used at all times, and should contain the active ingredient DEET or Picaridin. Extend coverage to your feet, hands, ears, back of the next and behind the knees. You can take further precautions by wearing long-sleeved clothing, forgoing perfumes and colognes, keeping doors and windows closed when nets are not present, and using bed nets overnight.
Exercise extreme caution around animals where rabies and ticks are known to have infected humans. Countries that have problems with stray dogs, or wild animals in urban areas may be a rabies risk. A vaccine is available and recommended for those travelling to parts of Asia, Africa and South America, and particularly India.
Poor local sanitation often allows bacteria to feed into water supplies and to come into contact with food during handling. Avoiding undercooked meat, unpasteurised dairy products, ice, reheated foods, salads likely to have been washed in tap water and food that is exposed to flies are sensible ways to limit exposure. Boiling water prior to drinking, washing food or cleaning dishes is also advised.
Intravenous and Sexually-Transmitted Disease
Differing standards of hygiene and poor understanding of infection control can lead to transmission of disease through the use of unclean needles. Tattoos are often a cheap holiday souvenir, but they are also a very good way to contract hepatitis. In non-sterile environments, tattoo needles are a high-risk vector for disease.
Unprotected sexual activity is also high-risk behaviour, and travellers should be aware of these risks and prepare accordingly. Carrying and using condoms is the best way to protect yourself from chlamydia, gonorrhoea, HIV/AIDS, syphilis, HPV and Hepatitis.
When You Return Home
You should be conscious of the fact that some diseases take days or weeks to incubate and present symptoms. If you are in any way unwell within the first few weeks of returning home, it’s extremely important that you present to your doctor. Signs to look out for include respiratory problems, swollen glands, fever, diarrhoea or vomiting, rash or lesions, unexplained bleeding or loss of consciousness. Even if you are just generally unwell for more than a couple of days, it’s better to be thoroughly examined than to wait for more serious ailments.