Related Subjects:
|Fever in a traveller
|Malaria Falciparum
|Malaria Non Falciparum
|Viral Haemorrhagic Fevers (VHF)
|Lassa fever
|Dengue
|Marburg virus disease
|AIDS HIV
|Yellow fever
|Ebola Virus
|Leptospirosis
|Crimean-Congo haemorrhagic fever
|African Trypanosomiasis (Sleeping sickness)
|American Trypanosomiasis (Chagas Disease)
|Incubation Periods
|Notifiable Diseases UK
🌡️ Fever = ≥38°C.
Any patient returning from a malarial area in the past 3 months with flu-like symptoms must be assumed to have falciparum malaria until proven otherwise.
🦟 Always send urgent thick & thin films. Hours matter. Mortality can occur before the post-take ward round.
👉 Non-falciparum malaria may present up to 1 year later, but falciparum rarely after 3 months.
⚠️ Red Flags & Key Rule-Out
- 🦟 Malaria = most important diagnosis to exclude → thick & thin blood films, repeat if negative.
- 🧍♂️ Ask: Does this patient need isolation? (e.g. Ebola, MERS, VHF).
- 💊 Think antimicrobial resistance if hospitalised in Africa/Asia/Middle East.
🌍 Common Causes of Fever in Travellers
| Pattern | Main Causes |
|---|
| 🧩 Systemic febrile illness | Malaria, Dengue/Zika/Chikungunya, Typhoid, Rickettsia, Acute HIV, Leptospirosis |
| 🧠 CNS involvement | Cerebral malaria, Meningococcal meningitis, Japanese encephalitis, Trypanosomiasis, Rabies |
| 🫁 Respiratory symptoms | Influenza, Pneumonia, TB, Histoplasmosis, Q fever, MERS-CoV |
| 🌸 Fever + Rash | Dengue, Chikungunya, Zika, Measles, Varicella, Rickettsia, Typhoid (rose spots), EBV/CMV |
⏳ Incubation Period Clues
| Timeframe | Likely Conditions |
|---|
| < 14 days | Falciparum malaria, Dengue/Zika/Chikungunya, Rickettsia, Meningococcal disease, MERS |
| 1–4 weeks | Vivax/ovale malaria, Typhoid, Leptospirosis, EBV/CMV, Acute HIV, Ebola, Lassa |
| Weeks–months | Relapsing malaria, Schistosomiasis, Amoebic liver abscess, Hepatitis A/E, TB, Leishmaniasis |
🧪 Investigations
- 📊 FBC, Differential WCC, U&E, LFTs, Glucose, CRP
- 🦟 Malaria: rapid antigen test + thick/thin films (repeat 12–24 hrs if negative)
- 💉 Blood cultures (aerobic & anaerobic)
- 🧫 Urine MCS, Stool culture (esp. Salmonella/typhoid)
- 🫁 CXR (pneumonia/TB), Abdominal USS (abscess, hepatosplenomegaly)
- 🧬 HIV, viral serologies as indicated
- ♀️ Pregnancy test (guides imaging/drug safety)
💡 Teaching Pearls
- 🦟 Malaria = until proven otherwise. Never send home a febrile traveller without excluding it.
- ⏱️ Repeating films is vital → parasites may not be detectable initially.
- 🌍 Always ask: where, when, how long, exposures (mosquitoes, fresh water, animals, food)?
- 👩⚕️ If uncertain, isolate first, then investigate → protect staff & public health.
- 📚 Non-falciparum malaria (vivax/ovale) may relapse months later due to dormant liver hypnozoites.
Cases — Fever in a Traveller
- Case 1 — Malaria (Falciparum):
A 30-year-old man returns from Nigeria with fever, sweats, and headache. He took no prophylaxis. Exam: febrile, mild jaundice, splenomegaly. Blood film: trophozoites of *Plasmodium falciparum*.
Diagnosis: Malaria.
Management: Admit; treat with IV artesunate if severe, or oral artemisinin-based combination therapy if uncomplicated.
- Case 2 — Typhoid Fever:
A 25-year-old woman returns from India with 7 days of fever, abdominal pain, and constipation. Exam: relative bradycardia, “rose spots” on abdomen, tender hepatosplenomegaly. Blood culture: *Salmonella typhi*.
Diagnosis: Enteric fever.
Management: IV ceftriaxone (or azithromycin if sensitive); supportive fluids and monitor for intestinal perforation.
- Case 3 — Dengue Fever:
A 22-year-old student returns from Thailand with fever, severe myalgia (“breakbone fever”), retro-orbital pain, and a blanching rash. Platelets 95 ×10⁹/L, haematocrit rising.
Diagnosis: Dengue fever.
Management: Supportive care, fluids, avoid NSAIDs/aspirin; admit if warning signs (abdominal pain, bleeding, rising haematocrit).
- Case 4 — Rickettsial Infection (African Tick Bite Fever):
A 35-year-old safari traveller in South Africa presents with fever, headache, and an eschar at the site of a tick bite. Exam: generalised rash and lymphadenopathy.
Diagnosis: Rickettsial infection.
Management: Doxycycline, supportive care. Usually rapid response.
- Case 5 — Acute Schistosomiasis (Katayama Fever):
A 28-year-old backpacker returns from Uganda after swimming in Lake Victoria. He has fever, eosinophilia, cough, and urticaria.
Diagnosis: Acute schistosomiasis (Katayama fever).
Management: Symptomatic initially; definitive therapy with praziquantel once infection established.
Teaching Commentary 🌍
Fever in a returning traveller is always malaria until proven otherwise. Key initial steps: detailed travel history (location, exposures, prophylaxis, vaccines), prompt malaria film/RDT, and infection control if viral haemorrhagic fever possible.
Important differentials: malaria, enteric fever, dengue, rickettsial infections, viral hepatitis, schistosomiasis, HIV seroconversion.
Red flags: altered mental state, hypotension, jaundice, bleeding, severe thrombocytopenia. Early recognition and empiric management (while awaiting confirmation) saves lives.
