• History
  • Firstly gather the travel details. Were there layovers? Did they spend time in other countries either on the way there or on the way back? How long were what the patient there for? When precisely did they return? How long after returning did the fever begin? Are there any co-travellers and how is their health?  Where did they go exactly? Exposure to bushland, scrub, waterholes, rivers, ticks or mosquitos? Was there exposure to animals, local freshwater etc?
  • Gather a timeline of symptoms – vitally important when considering incubation periods of infectious diseases and generating differentials. Typhoid fever and Dengue have shorter incubation periods. Viral infections such as HIV and Hepatitis tend to have weeks of incubation. Infections such as TB have quite lengthy incubation periods
  • Previous health conditions particularly the status of both routine childhood vaccinations as well as travel vaccinations such as Hepatitis A or yellow fever. Did theyobtain travel health advice prior and were they given prophylaxis (such as for Malaria)? Were they compliant before, during and after return?
  • Were they visiting friends or relatives – Travellers may travel to more rural places, take higher risks with local foods when in the company of relatives naturalized in the foreign country
  • Sexual health history is often overlooked and very important
  • Gathering information of specific symptoms such as gastrointestinal, genitourinary, respiratory infections will help to target your differentials. Dermatological symptoms are also important to ask about
  • Utilise resources such as the CDC yellow book for country specific information
• Examination
  • Broad approach required
    • Dermatological – Rash? Bite marks? Scratches?
    • CNS – Evidence of confusion, altered mental status, meningism
    • Thorough abdominal (particularly hepatological) and respiratory examination
    • Other system examination required if the history suggests

• Basic bloods – FBC, UEC, LFT
• Microbiology – blood cultures, urine cultures
• Imaging – Chest X Ray
• ABG – Lactate, Base excess (if patient quite unwell)
• An extra serum specimen may be useful for future serology

Subsequent testing dictated by history and examination:

• • Respiratory infection testing or STI screening may be required if the history dictates
  • Malaria – Thick and thin films required, often 2-3 sets over a couple of days but requires a scientist trained in identification. Rapid antigen tests have been shown to be relatively good at Malaria identification however work best for falciparum malaria and patients with a high parasite load. Following an initial negative smear, films can be collected daily over next 3 days should the patient remain unwell

• In this young man assuming his bloods, chest X Ray and urine specimen, STI screen return unremarkable it is reasonable to consider Typhoid or Dengue Fever.

Typhoid or Enteric Fever

• Infectious Organism
• SalmonellaTyphi or Paratyphi
• Geographic Prevalence
• Although it may occur anywhere outside of the industrialised world, it is endemic in Southeast Asia, where the majority of sufferers contract the illness
• Presentation
• Widely regarded as an enteric illness however very rarely presents with a predominance of gastrointestinal symptoms
• Often there is a non-specific phase lasting approximately a week and then there is a bacteraemic phase consisting of gradually worsening fatigue with fevers and rigors and few other symptoms
• Headache, malaise and anorexia are nearly universal whilst abdominal pain, diarrhoea or constipation is less often reported
• Diagnosis
• Blood culturesare the key diagnostic test
• Complications

A serious complication of Typhoid is intestinal haemorrhage and micro-perforation, occurring 2-3 weeks after contracting the illness. It is easily confused with Malaria and Dengue Fever

Dengue Fever

• Infectious Organism
  • Flavivirus – Dengue Virus (DENV) 1, 2, 3 or 4 transmitted by the Aedes mosquito
• Geographic Prevalence
  • Endemic throughout the tropics and subtropics and is a leading cause of febrile illness among travelers returning from Latin America, the Caribbean, and Southeast Asia
• Presentation
  • Often asymptomatic following an incubation period of approximately one week
  • Classically presents as fevers, arthralgia and sunburn like rash. Frontal headache is quite common
  • Minor haemorrhagic manifestations such as petechial rashes, purpura, bleeding gums or epistaxis may occur, as can haematuria
• Diagnosis
  • Serology. Some laboratories offer NS1 antigen tests, which are positive in the first few days of illness
• Complications
  • Severe dengue occurs in as much as 5% of patients
  • Can be lethal due to wide variety of presentations secondary to haemorrhagic complications or an acute increase in vascular permeability and capillary leak

• First consider your differentials – the main causes of fever in returned traveller are respiratory or gastro-intestinal infections that may simply require supportive care
• Should your differential include conditions such as TB, Meningococcal meningitis or measles (particularly unvaccinated patient) prompt isolation is required
• Does this patient need to be admitted? A stable patient with a recognizable infection may simply be discharged. Often times the diagnosis is less clear and so admission for 24-48 hours is required whilst diagnostic tests return. Empirical treatment of an infectious cause is typically Ceftriaxone 2g if Typhoid is suspected. Dengue fever does not have a specific treatment however a vaccine is coming

• Take a good travel history, exposure history and sexual history
• Use up to date resources in order to limit your differential diagnosis
• Think about Typhoid and Dengue fever – particularly if travelling to endemic areas such as south east Asia and the subcontinent
• Remember common things are common so don’t forget about urinary tract infections and viral respiratory tract infections

• Gherardin, A and Sisson, J. Assessing Fever in the Returned Traveller.Australian Prescriber.2012:1 February,35:10 page 4 
• Centers for Disease Control and Prevention. CDC Health Information for International Travel 2016. New York: Oxford University Press; 2016.