Summer is synonymous with adventure, with millions flocking to exotic destinations to experience different cultures, cuisines and landscapes. But what happens when the souvenir you bring back isn't a fridge magnet or a tea towel, but a new illness?
Author
- Dan Baumgardt
Senior Lecturer, School of Physiology, Pharmacology and Neuroscience, University of Bristol
International travel poses a risk of catching something more than a run-of-the-mill bug, so it's important to be vigilant for the telltale symptoms . Here are the main ones to look out for while away and when you return.
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Fever
Fever is a common symptom to note after international travel - especially to tropical or subtropical regions. While a feature of many different illnesses, it can be the first sign of an infection - sometimes a serious one.
One of the most well-known travel-related illnesses linked to fever is malaria. Spread by mosquito bites in endemic regions , malaria is a protozoal infection that often begins with flu-like symptoms, such as headache and muscle aches, progressing to severe fever, sweating and shaking chills.
Other signs can include jaundice (yellowing of the skin or eyes), swollen lymph nodes, rashes and abdominal pain - though symptoms vary widely and can mimic many other illnesses.
Prompt medical attention is essential. Malaria is serious and can become life threatening. It's also worth noting that symptoms may not appear until weeks or even months after returning home. In the UK, there are around 2,000 imported malaria cases each year.
Travellers to at-risk areas are strongly advised to take preventative measures. This includes mosquito-bite avoidance as well as prescribed antimalarial medications , such as Malarone and doxycycline. Although these drugs aren't 100% effective, they significantly reduce the risk of infection.
Aside from malaria, other mosquito-borne diseases can cause fever. Dengue fever , a viral infection found in tropical and subtropical regions, leads to symptoms including high temperatures, intense headaches, body aches and rashes, which overlap with both malaria and other common viral illnesses.
Most people recover with rest, fluids and paracetamol , but in some instances, dengue can become severe and requires emergency hospital treatment. A vaccine is also available - but is only recommended for people who have had dengue before, as it provides good protection in this group.
Any fever after international travel should be taken seriously . Don't brush it off as something you've just picked up on the plane - please see a doctor. A simple test could lead to early diagnosis and might save your life.
Diarrhoea
Few travel-related issues are as common - or as unwelcome - as diarrhoea. It's estimated that up to six in ten travellers will experience at least one episode during or shortly after their trip. For some, it's an unpleasant disruption mid-holiday; for others, symptoms emerge once they're back home.
Traveller's diarrhoea is typically caused by eating food or drinking water containing certain microbes (bacteria, viruses, parasites) or their toxins. Identifying the more serious culprits early is essential - especially when symptoms go beyond mild discomfort.
Warning signs to look out for include large volumes of watery diarrhoea, visible blood in the stool or explosive bowel movements. These may suggest a more serious infection, such as giardia , cholera or amoebic dysentery .
These conditions are more common in regions with poor sanitation and are especially prevalent in parts of the tropics.
Some infections may require targeted antibiotics or antiparasitic treatment. But regardless of the cause, the biggest immediate risk with any severe diarrhoea is dehydration from copious fluid loss. In serious cases, hospital admission for intravenous fluids may be necessary.
The key message for returning travellers: if diarrhoea is severe, persistent or accompanied by worrying symptoms, see a doctor. What starts as a nuisance could quickly escalate without the right care.
And if you have blood in your stool, make sure you seek medical advice.
Jaundice
If you've returned from a trip with a change in skin tone, it may not just be a suntan. A yellowish tint to the skin - or more noticeably, the whites of the eyes - could be a sign of jaundice , another finding that warrants medical attention.
Jaundice is not a disease itself, but a visible sign that something may be wrong with either the liver or blood . It results from a buildup of bilirubin, a yellow pigment that forms when red blood cells break down, and which is then processed by the liver.
Several travel-related illnesses can cause jaundice. Malaria is one culprit as is the mosquito-borne yellow fever . But another common cause is hepatitis - inflammation of the liver.
Viral hepatitis comes in several forms. Hepatitis A and E are spread via contaminated food or water - common in areas with poor sanitation. In contrast, hepatitis B and C are blood-borne, transmitted through intravenous drug use, contaminated medical equipment or unprotected sex.
Besides jaundice, hepatitis can cause a range of symptoms, including fever, nausea, fatigue, vomiting and abdominal discomfort. A diagnosis typically requires blood tests, both to confirm hepatitis and to rule out other causes. While many instances of hepatitis are viral, not all are , and treatment depends on the underlying cause.
As we've seen, a variety of unpleasant medical conditions can affect the unlucky traveller. But we've also seen that the associated symptoms are rather non-specific. Indeed, some can be caused by conditions that are short-lived and require only rest and recuperation to get over a rough few days. But the area between them is decidedly grey.
So plan your trip carefully, be wary of high-risk activities while abroad - such as taking drugs or having unprotected sex - and stay alert to symptoms that develop during or after travel. If you feel unwell, don't ignore it. Seek medical attention promptly to identify the cause and begin appropriate treatment.
Dan Baumgardt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
