Differential Diagnosis for Fever in a Return Traveller from Taiwan
When considering a fever in a return traveller from Taiwan, several diagnoses come to mind, categorized based on their likelihood and potential impact.
- Single Most Likely Diagnosis
- Influenza: Given Taiwan's geographical location and the global prevalence of influenza, this is a common cause of fever in travellers. The justification for this being the single most likely diagnosis is based on the high incidence of influenza worldwide and its ease of transmission.
- Other Likely Diagnoses
- Dengue Fever: As Taiwan is an area where dengue fever can occur, especially during outbreaks, a return traveller with fever should be considered for this diagnosis, particularly if they have been exposed to mosquitoes.
- Enteric Fever (Typhoid or Paratyphoid): Although less common in Taiwan compared to other parts of Asia, enteric fever is still a consideration for travellers who have consumed contaminated food or water.
- Respiratory Tract Infections (including pneumonia): These can be caused by a variety of pathogens and are common in travellers due to close quarters and shared air on planes.
- Do Not Miss Diagnoses
- Malaria: Although Taiwan is not typically considered a high-risk area for malaria, the disease can be deadly if not treated promptly. It's essential to consider malaria in any febrile traveller returning from an area where malaria is present, even if the risk is low.
- Japanese Encephalitis: This viral infection is prevalent in parts of Asia, including Taiwan, and can cause severe neurological symptoms. Vaccination is available, but not all travellers may be vaccinated.
- SARS-CoV-2 (COVID-19): Given the ongoing pandemic and Taiwan's proximity to areas with high transmission rates, COVID-19 should always be considered in a febrile return traveller.
- Rare Diagnoses
- Leptospirosis: This bacterial infection can be acquired through contact with contaminated water and is more common in certain occupational or recreational exposures. It's a rare but potential cause of fever in a return traveller from Taiwan.
- Melioidosis: Caused by the bacterium Burkholderia pseudomallei, melioidosis is rare in Taiwan but can be found in Southeast Asia. It's typically associated with exposure to contaminated water or soil.
- Scrub Typhus: Transmitted by chiggers (larval mites), scrub typhus is found in parts of Asia, including Taiwan. It's a rare cause of fever but should be considered in travellers with exposure to rural or grassy areas.