Post-Travel Illness: What Returning Travellers Need to Know and When to Seek Urgent Help

Reviewed by GPhC Pharmacist at Priory Pharmacy, York

Pre-travel health preparation receives the clinical attention it deserves at Priory Pharmacy in York. The return from travel deserves equal clinical attention and receives far less of it.

Infections acquired abroad can present days, weeks, or months after return. Some, particularly falciparum malaria, can be rapidly fatal without prompt diagnosis and treatment. A returning traveller with fever is a medical emergency until malaria has been excluded by blood film testing, regardless of whether antimalarial tablets were taken during travel.

Fever in a Returning Traveller: An Emergency Until Proved Otherwise

Plasmodium falciparum malaria can progress from early symptoms to cerebral malaria, multi-organ failure, and death within 24 to 48 hours. No antimalarial regimen offers complete protection: patient compliance, drug resistance, and intensity of exposure all affect prophylactic efficacy.

Any returning traveller who develops fever within three months of return (95 percent of cases show symptoms within the first month) from a malaria risk country requires urgent clinical assessment and a malaria blood film, regardless of antimalarial compliance. This applies even if the traveller feels only mildly unwell.

Other important febrile illnesses in returning travellers include:

• Dengue fever – high fever, severe myalgia, retro-orbital pain, and characteristic rash, typically presenting within two weeks of exposure
• Typhoid fever – sustained fever developing one to three weeks after return, often with abdominal pain
• Chikungunya – fever with severe and potentially prolonged arthralgia
• Viral haemorrhagic fever – in travellers returning from sub-Saharan Africa with specific exposure risk

Common Post-Travel Illnesses and Their Presentations

Gastrointestinal: Most Common Category

Traveller’s diarrhoea usually resolves within 7 to 14 days with oral rehydration and dietary adjustment.

Persistent diarrhoea beyond two weeks warrants stool microscopy and culture to exclude parasitic infections, including:

• Giardia duodenalis
• Entamoeba histolytica
• Cryptosporidium

Specific antibiotic or antiparasitic treatment depends on the organism identified.

Dermatological: Frequently Overlooked

• Cutaneous larva migrans – a serpiginous tracking rash caused by hookworm larvae penetrating skin from contaminated sand. Common in returning beach travellers
• Myiasis (botfly larvae) – produces boil-like lesions
• Tinea versicolor – causes pale or dark patches on the trunk

None are dangerous, but all require identification and appropriate treatment.

Post-Travel Testing: When and What to Request

Not all post-travel illnesses present with acute symptoms.

• Any traveller who has had freshwater contact in sub-Saharan Africa, the Nile system, or other endemic areas should have schistosomiasis serology tested eight to twelve weeks after return, even in the absence of symptoms
• Unexplained eosinophilia on a blood count in a traveller is a signal to investigate for helminthic infection

Go directly to an emergency department if:

• You have a fever and have visited a malaria risk country in the past three months
• You have a fever with a petechial or purpuric rash (possible meningococcal disease)
• You have altered consciousness following tropical travel

See a GP urgently for:

• Any fever within four weeks of return from a tropical destination
• Diarrhoea persisting beyond two weeks
• Blood in urine after freshwater contact in Africa
• An unexplained rash after return

Priory Pharmacy can provide initial advice and direct you to the appropriate clinical pathway.

What to Tell Your Clinician

When seeking medical attention after travel, provide your clinician with:

• A complete itinerary including every country and region visited
• Dates of departure and return
• All antimalarial medications taken and compliance
• Any unusual exposures, including freshwater contact, animal bites, sexual contact abroad, or wild food consumption
• Any vaccination documentation

This information significantly accelerates the differential diagnosis and ensures appropriate investigations are requested promptly.

This article is for general information only and does not constitute individual clinical advice. Please book a travel consultation at Priory Pharmacy in York to discuss your individual requirements before travel.