There’s so much to remember before heading off on an overseas holiday that it can be easy to forget to sort out one of the most essential items: travel health.

With a recent spate of disease outbreaks in popular destinations, such as Bali and Brazil, public health experts advise taking precautions well ahead of your departure.

Here are some of the most common infectious diseases that plague holiday hotspots – and how can you protect yourself against them.

Influenza and measles

Flu is one of the most common illnesses to infect travellers, Dr Deb Mills, medical director of the Travel Medicine Alliance clinics, said.

“One per cent of travellers to the tropics contract influenza.”

She recommends getting the seasonal flu vaccine ahead of your trip.

“Travel exposes you to lots of people. You don’t know who’s on the plane with you, so it makes sense to get vaccinated.”

Measles is also highly contagious and the risk is greater when travelling to countries with lower vaccination rates, Dr Mills said.

“You only need to be in the room where a measles sufferer was two hours ago and you could catch it,” she said.

Earlier this year, Victorian health officials issued a travel warning after a man fell ill on returning to Melbourne from Bali.

In March, Western Australia’s health department followed, issuing a measles alert after several people fell ill in Bali.

Medical epidemiologist Dr Gary Dowse said then that WA had had more than 20 cases of measles in returning Bali visitors since 2013 – more than for any other overseas travel destination.

“Unfortunately, it is not unusual for Australians to be infected with measles overseas, including in Bali,” he said in March.

“The increase in the number of cases in WA and other states in recent weeks suggests there may be an increased risk of catching measles in Bali at present.”

Dr Mills said travellers should ensure their normal childhood vaccines were up to date before travelling.

People born between 1966 and 1994 might require booster measles jabs as they commonly only had one in childhood.

Zika virus

Zika’s first large human outbreak was recorded in 2007, but its biggest outbreak was in Brazil in 2015.

It is a mosquito-borne disease that can infect children in the womb. Infection can lead to birth defects, including impaired brain development and deformities. There is no preventative medication or vaccine.

Anyone who is pregnant or planning to be should avoid unnecessary travel to areas with Zika, Dr Mills said.

“Women should avoid the tropics if trying to get pregnant. If you put your toe into Thailand, you should not get pregnant for two months,” Dr Mills said.

High-risk regions include much of Asia, the Pacific Islands, and some African countries, according to the US Centers for Disease Control and Prevention.

Parts of South and Central America, the Caribbean and Mexico are also danger zones. Full list here.

The Zika warning also extends to men, Dr Mills said.

“Zika can be transferred sexually. Men who travel can pick up Zika and not realise,” she said. The virus can remain in their body for eight weeks.

The CDC recommends that couples who are expecting and have visited Zika areas use condoms during sex for the remainder of the pregnancy.

Avoiding travel to hotspots and preventing mosquito bites were the most effective ways to reduce risk of infection, Dr Mills said.

“You can keep away from mosquitos, and that’s a good idea because of dengue and yellow fever and other insect-borne diseases,” she said.

The CDC also recommends using insect repellent, wearing long-sleeved shirts and long pants, and choosing accommodation with air-conditioning and insect screens.

Yellow fever,  dengue and malaria

Malaria is one of a host of other mosquito-borne diseases. People who spend time outdoors, including sleeping outside, are at greater risk of catching it.

Symptoms – fever, chills, and flu-like aches – usually appear within a few weeks of infection but can take up to a year. Prevention may involve taking anti-malarial medicines some weeks before travel.

Yellow fever is common in parts of South and Central America, the Caribbean and Africa.

In early 2017, the Brazilian Ministry of Health reported outbreaks in several eastern cities, including Rio de Janeiro and Sao Paolo.

A yellow fever vaccination is recommended at least 10 days before travel to these regions. Some airlines will also require proof of vaccination if returning from these regions.

Dengue fever is common in the tropics, including Queensland. Like Zika, it has no vaccine or preventative medication. Infection can be prevented by avoiding or protecting against mosquito bites.

Symptoms can take up to a fortnight to develop. They include fever, headache, nausea, vomiting, rash, eye pain, joints, and muscles, and minor bleeding.

Typhoid

Typhoid is a particularly nasty illness that can cause fever, constipation, diarrhoea and, sometimes, death. It is spread through contaminated food and water.

Dr Anita Heywood from UNSW School of Public Health & Community Medicine said most Australians became infected when visiting family overseas. Her research found the majority of Australian cases were in migrants returning from India.

“The vaccine only lasts for about two years, and many migrants may think they are protected from disease as a child prior to migration or from a previous vaccine,” Dr Heywood said.

“Some regions of the world are seeing multidrug resistant strains of typhoid, meaning that treatment may not work, making prevention even more important.”

Pakistan is in the midst of a typhoid outbreak. Earlier this year, three cases of drug-resistant typhoid fever were reported in travellers returning to Britain and the US.

Rabies

Rabies is preventable by vaccination before and after exposure to an infected animal bite or scratch.

However, Dr Mills said it was common for the after-bite jab not to be available, particularly in Bali (where monkeys carry the virus).

There are reports that 14 people exposed to rabies in Bali – mostly from monkey bites – were treated in Mackay in 2016.

A November 2018 analysis by the GeoSentinel Global Surveillance Network found that Bali was the most common location for exposure to potentially rabid animals. But few travellers received immediate treatment.

By contrast, travellers exposed in Thailand, Sri Lanka and the Philippines were more likely to receive rabies immunoglobulin – a stopgap measure – in the country of exposure, the researchers wrote.

Dogs, cats and bats also carry the virus.

The rabies vaccine is recommended before travel in three doses a month apart.

Before you travel

“Ignorance is not bliss when it comes travel health,” Dr Mills said.

The Department of Health recommends visiting a travel specialist or your doctor six to eight weeks before jetting off. Some vaccines take weeks to become effective, and some require boosters.

But Dr Mills said only 4 per cent of Australians visited a travel medicine specialist.

“Many people will ask someone who has no particular expertise in travel medicine, such as a travel agent,” she said.

Other advice: “Take your regular medications, have the right check-ups and vaccinations, have your dental work before you go, because you don’t want to have dental problems while overseas.

“If you’re going to the tropics, it’s worth asking the questions to see if there’s a particular need for vaccines.”