Fever in a returned traveller
From IDWiki
History
- Pretravel
- Vaccinations
- Prophylaxis, e.g. malaria
- Vector protection, including bed nets and mosquito spray
- Travel
- Make explicit timeline of locations visited, for how long
- Assess activities and exposures in each location
- Food (especially street food) and water sources
- Recreational water
- Animals
- Insect bites
- Sex and other body fluid exposures
- Combine timeline of exposures with incubation periods to rule out diseases
- Dengue: 3-5 days
- Malaria: 7-21 days
- Hepatitis A: 6 days to 6 weeks
- Hepatitis B: 1-6 months
- Typhoid: 7-21 days
- Non-typhoidal Salmonella: 3-7 days
Differential Diagnosis
Most common conditions
| Disease | % | Incubation | Diagnosis |
|---|---|---|---|
| Malaria | 20-30% | 7-30 days, or longer | thick-and-thin blood film examination or rapid antigen test |
| Acute diarrhea or gastroenteritis, including traveller's diarrhea | 10-20% | days | bacterial stool cultures but primarily clinical diagnosis |
| Respiratory infections, including influenza | 10-15% | days | NP swab for respiratory viruses |
| Dengue | 5% | 4 to 7 days | serology or PCR |
| Enteric fever | 2-7% | 6-30 days | blood culture |
| Skin and soft tissue infections | 2-11% | ||
| Rickettsioses, including African tick bite fever and Mediterranean spotted fever | 3% | 1-2 weeks | serology or PCR |
| UTI or STI | 2-3% | urinalysis and culture, urine NAAT for G&C | |
| Viral hepatitis | 3% | 6 days to 6 weeks (HAV) 1-6 months (HBV) |
serology or PCR |
| Mononucleosis or viral syndrome | 4-25% | 30 to 50 days | Monospot (if young), serology (EA-IgG/VCA-IgM), or PCR |
Most common by location of travel
- Sub-Saharan Africa: malaria, respiratory infections, diarrhea, skin and soft tissue infections
- Southeast Asia: dengue, respiratory infections, diarrhea, malaria
- South Central Asia: enteric fever, dengue, malaria, diarrhea
- South America: diarrhea, respiratory infections, dengue, malaria
- Central America and Caribbean: diarrhea, respiratory infections, dengue, malaria
Life-threatening infections
| Disease | Incubation | Distribution | Exposures | Diagnosis |
|---|---|---|---|---|
| Viruses | ||||
| Avian influenza | 2-8 days | East and Southeast Asia | poultry | PCR |
| MERS-CoV | 2-14 days | Arabian peninsula | infected humans or camels | PCR |
| Ebola, Lassa fever, or Marburg hemorrhagic fever | up to 22 days | Africa | infected humans and animals | PCR |
| Crimean-Congo hemorrhagic fever | 1-9 days (tick) or 3-13 days (contact) | southern Europe, Middle East, Africa, northwestern China | Ixodes ticks or infected humans or animals | PCR |
| Yellow fever | 3-8 days | South America and Africa | Aedes mosquitoes | PCR or IgM |
| Japanese encephalitis | 5-15 days | Asia and western Pacific | Culex mosquitoes | IgM |
| Rift Valley fever | 2-6 days | Africa and the Arabian peninsula | mosquitoes, or blood from infected animals | PCR or IgM |
| Rabies | 20 to 60 days (usually 4 weeks) | worldwide | animal bite | saliva PCR; serum/CSF RFFIT; skin biopsy PCR or RFFIT |
| Bacteria | ||||
| Anthrax | 1 day (cutaneous) to 1-7 days (pulmonary) | Africa and Asia | infected animals or animal products | bacterial culture or PCR |
| Enteric fever | 6-30 days | South and Southeast Asia | fecal-oral transmission | bacterial culture |
| Epidemic typhus | 7-14 days | Central Africa, Asia, North and South America | Human body lice, flying squirrel parasites, possibly ticks | IgM/IgG and PCR |
| Leptospirosis | 2-29 days | worldwide but particularly South and Southeast Asia and South America | urine of infected animals | IgM/IgG and PCR |
| Louse-borne relapsing fever | 4-14 days | Ethiopia, Eritrea, and Sudan | Human body lice | blood film examination, IgM/IgG, or PCR |
| Melioidosis | 1-21 days (but up to years) | South and Southeast Asia, northern Australia, and case reports from Africa and South America | contaminated soil or surface water | bacterial culture |
| Endemic typhus | 7-14 days | worldwide but particularly Southeast Asia | rodent fleas | IgM/IgG or PCR |
| Oroya fever or Carrion disease | 10 days to 7 months | South America, particularly Peru | Sandflies | bacterial culture |
| Scrub typhus | 6-20 days | Asia and northern Australia | chiggers | IgM/IgG or PCR |
| Rickettsial spotted fever | 2-14 days | worldwide | mostly ticks | IgM/IgG or PCR |
| Plague | 2-6 days (bubonic) or 1-3 days (pneumonic) | remote Africa, Asia, and South America | rodent fleas | bacterial culture |
| Protozoa | ||||
| East African sleeping sickness | 7-21 days | eastern and southern Africa | tsetse flies | blood film examination, lymph aspirate exam, or chancre biopsy |
| Falciparum malaria | 7-30 days, or longer | African, Asia, South America | Anopheles mosquitoes | thick-and-thin blood film examination or rapid antigen test |
| Knowlesi malaria | 10-14 days | Southeast Asia, particularly Borneo | Anopheles mosquitoes | thick-and-thin blood film examination |
Investigations
- First-line
- CBC
- Liver enzymes and function, for viral hepatitis
- Electrolytes, urea, and creatinine
- Urinalysis, for proteinuria that would suggest Leptospirosis
- Blood cultures x2, for enteric/typhoid fever
- Thick and thin smears x3 over 3 days, for malaria
- Based on history and lab results
- Urine culture
- Stool culture and O&P
- Hepatitis serologies
- Serology for Zika, chikungunya, and dengue viruses, with repeat in 14 days if negative
- C. difficile toxin
- NP swab for influenza and other respiratory viruses that may circulate non-seasonally in other countries
Further Reading
- Freedman DO, et al. Spectrum of Disease and Relation to Place of Exposure among Ill Returned Travelers. N Engl J Med 2006; 354:119-130. doi: 10.1056/NEJMoa051331
- Boggild A, et al. Fever in the Returning International Traveller Initial Assessment Guidelines. CCDR. 2011;37(ACS-3):1-15. doi: 10.14745/ccdr.v37i00a03
