What to watch for after your trip and when to seek medical attention.
See a doctor promptly if you experience any of the following within 12 months of returning from overseas travel — even if symptoms appear weeks or months after your return:
Fever: Any fever after returning from a malaria-risk area is a medical emergency. Go to a hospital emergency department immediately — don't wait for a GP appointment. Malaria can be fatal within days if untreated.
Persistent diarrhoea: Travellers' diarrhoea that lasts more than a few days, contains blood, or is accompanied by fever. Parasitic infections like giardia can persist for weeks.
Skin problems: Unusual rashes, sores that won't heal, insect bites that become infected, or any skin changes you didn't have before travel.
Respiratory symptoms: Persistent cough, difficulty breathing, or chest pain — especially if you visited areas with TB risk.
Fatigue and weight loss: Unexplained fatigue, weight loss, or night sweats that persist after returning.
Always inform your doctor about your travel history, even if you think your symptoms are unrelated. Include: which countries you visited and when, rural vs urban areas, activities (trekking, swimming in freshwater, animal contact), whether you took malaria prophylaxis, any vaccinations received before travel, and whether you had any illness during the trip.
The most common post-travel infections include travellers' diarrhoea (usually bacterial or parasitic), dengue fever (onset 4-14 days after a mosquito bite), malaria (can present weeks to months after exposure), respiratory infections, and skin infections from insect bites or wounds. Most are treatable if diagnosed promptly.
Knowing the incubation period of common travel-acquired infections helps you and your doctor narrow down the cause of post-travel illness. Symptoms that appear too early or too late for a particular disease can rule it out.
Travellers' diarrhoea: Symptoms typically begin during the trip or within a few days of return. Most cases resolve in 3–5 days. If it persists beyond a week or contains blood, see a GP — bacterial causes (campylobacter, shigella) and parasites (giardia, cryptosporidium) require different treatment.
Dengue fever: Onset 4–14 days after a mosquito bite. High fever, severe headache (especially behind the eyes), muscle and joint pain ("breakbone fever"), and a rash that often appears 3–4 days into the illness. Most cases recover but a small proportion progress to severe dengue with bleeding or shock — go to ED if you have high fever after returning from a dengue-risk area.
Chikungunya and Zika: Similar mosquito-borne profile to dengue with shorter incubation. Chikungunya causes severe joint pain that can persist for months. Zika is generally mild but is a serious concern in pregnancy.
Malaria: Most P. falciparum infections present within a month of return; P. vivax and P. ovale can present months later (up to a year), particularly if antimalarial prophylaxis was used. Any fever after travel to a malaria-risk area is a medical emergency — same-day testing is mandatory.
Typhoid: Onset usually 1–3 weeks after exposure. Sustained fever rising over several days, headache, abdominal pain, and sometimes a rose-coloured rash on the trunk. Often misdiagnosed initially as influenza or gastroenteritis.
Hepatitis A: Incubation 2–6 weeks. Jaundice, dark urine, fatigue, and right upper quadrant pain. Most adults recover completely but illness can last weeks.
Tuberculosis: Most exposed travellers do not develop active disease but can develop latent TB infection that may reactivate years later. Persistent cough, night sweats, weight loss, and unexplained fatigue warrant TB testing if you have travelled to high-burden countries (Indonesia, Philippines, India, much of sub-Saharan Africa).
Schistosomiasis: Acquired by swimming in freshwater lakes and rivers in Africa and parts of Asia and South America. Acute symptoms (Katayama fever) can appear 4–8 weeks after exposure; chronic infection can present years later with urinary or bowel symptoms.
Strongyloides: A persistent intestinal worm endemic in many tropical and subtropical regions. Can persist asymptomatically for decades and become life-threatening if the patient later receives immunosuppressive therapy.
Go to the Emergency Department if you have: Fever after travel to a malaria-risk area (any temperature ≥38°C), shortness of breath, chest pain, severe abdominal pain, signs of dehydration that you cannot manage with oral fluids, jaundice, neurological symptoms (confusion, seizure, severe headache), or any rapidly worsening illness.
Book a GP appointment within 1–3 days for: Persistent diarrhoea (over a week), unusual skin lesions, mild persistent fever in a non-malaria area, mild fatigue, post-travel respiratory infection, or any symptom that has not resolved as expected.
Tell every clinician your travel history — including the specific countries, rural vs. urban areas, activities (freshwater swimming, animal contact, sexual contact), and whether you took prophylaxis. Many travel-acquired infections are uncommon enough in Australia that they are missed unless travel is volunteered.
If a GP suspects an unusual tropical infection, referral to a specialist travel-medicine or infectious-diseases service may be appropriate. Major centres include the Victorian Infectious Diseases Service (Royal Melbourne Hospital), the Sydney Travel Health Clinic (RPAH), the Wesley Travel Medicine Centre (Brisbane), and the Doherty Institute (which runs Melbourne's reference laboratory for tropical pathogens). Emergency presentations should always go to the nearest hospital ED first.
Last updated: April 2026