Why are so many tourists getting sick in Asia? The golden rules of travel we’ve forgotten

(It may sit uncomfortably to have to reach for the single-use plastic bottles – look for water in recyclable aluminium containers.)

Many good hotels now have sophisticated in-house filtration systems for water cleaning, so their salad-washing and ice making may be safe. Outside those, the general rule is to eat only foods that are cooked (which counts out oysters a la natural – oops).

Some authorities suggest also avoiding food that has been sitting on a buffet for a while – but you’d expect good hotels and resorts to keep their buffets safe.

And of course, you should be washing your hands often with soap and water, especially after using the bathroom and before eating, using an alcohol-based hand sanitiser in between times, and keeping your hands away from your mouth.

But tummy bugs aren’t just viral and bacterial. They can come in the form of parasites. And fun fact: parasites burrow into bare feet.

“An example is strongyloidiasis,” says Dr Lau. That’s roundworms. “The transmission is through walking around barefoot in a contaminated muddy area, or the soil contaminated with those parasites. And once you’ve got them, you may have them for the rest of your life.”

Wear reef shoes when wading in streams, especially in areas where there is even a chance of mammal faeces.

Our group walked through a freshwater stream, along which there was a dubious private “zoo”. It took the walkers by surprise. And it was too late – they were all barefoot. (I didn’t like the look of it in the first place and was back by the roadside drinking a fresh coconut. I didn’t get sick. Hot tip: follow those kinds of instincts.)

Dr Lau says you can also get parasites, though, through other areas of exposed skin, if swimming in contaminated water, even chlorinated swimming pools – do your research before you dip.

Mosquitoes are another source of some nasty, persistent illnesses. Carry personal repellent – and use it often.

Other health tips that should go without saying but perhaps need to be repeated are: use face masks in close quarters. Be discerning about street food. And be aware of what’s going on around you when you’re taking photos – those horror stories of people getting hit by cars, or plunging to their deaths while taking selfies aren’t all made up.

Most destinations no longer require proof of COVID-19 vaccination. That doesn’t mean you should travel without your boosters being up-to-date.

And there are plenty of other vaccinations to consider.

For instance, “People may not even recall when they last had a tetanus shot, and measles is on the rise,” says Dr Lau. “If you travel regularly, make sure you’re up-to-date with the flu vaccine. Also, the whooping cough vaccine, especially if you look after young children.”

Typhoid and cholera shots are imperative in some destinations. And if he had to pick one non-negotiable vaccine for travelling to developing countries? “The hepatitis A vaccine would be top of my list.”

Dr Lau recommends getting informed and prepared by making an appointment with a travel doctor such as he before you set off.

But he also points out, “More motorcyclists are killed by road traffic accident than all infectious diseases combined.” So don’t stop enjoying your travels due to fear of falling ill – just wear a helmet on that moped.