Fever in the returned traveller

Today we discussed issues related to fever in the returned traveller

Some points that came up:

The red herring effect:
Do not be completely distracted by the travel history and its accompanying exotic possibilities; remember to look for and exclude the common causes of fever (i.e. common bacterial and viral infections, etc).

Important points on history:
-detailed travel itinerary (for location, activities) and dates (for incubation periods)
-whether pre-travel advice and appropriate prophylaxis was obtained
-specific exposures: sexual history, fresh water, animals, mosquitos

The VFR effect
Travellers "visiting friends and relatives" (i.e. VFR) are a particularly high risk group for serious travel-related illness; they are less likey to seek pre-travel counselling and take indicated prophylaxis. In contrast, they are more likely to have high-risk exposures and waning immunity due to prolonged absence.

Selected features of specific diagnoses (not intended to be exhaustive!)

Malaria- any fever in returned traveller from tropics is malaria until proven otherwise. Diagnosis by thick (sensitive) and thin (specific) smears; send multiple. Falciparum is the most virulent type

5 Malaria Questions:
1) Where it was acquired, and the resistance patterns there
2) What type is it? (much more worried if falciparum)
3) What is the degree of parasitemia (% of RBCs carrying); > 5% can be fatal
4) Was the pt on prophylaxis, taking it properly?
5) Is this "severe malaria"; coma, severe prostration, anemia, ARF, severe jaundice, resp failure, hypoglycemia, shock

Dengue- Wide spectrum of clinical manifestations. Retrobulbar h/a, muscle and joint pain "break bone fever"; rash in 50%. Leukopenia and thrombocytopenia common. Dengue Hemorrhagic Fever is feared complication; more common in previously exposed.

Typhoid- Abdo pain, fever, chills. Evanescent "rose spots" on abdomen or trunk. Relative bradycardia for fever is classic. Diarrhea or constipation. May have leukopenia or leukocyosis, anemia, transaminitis. Diagnosis by blood or stool cultures. Bone marrow Bx is 98% sensitive.

Others: schistosomiasis, leptospirosis, rickettsial diseases, hepatitis A, hepatitis B, HIV seroconversion reaction...

Some useful links

Click here for VFR paper from JAMA
Click here for GeoSentinel survey for conditions by geographical location
Click here for Gideon website- input location, symptoms, duration and receive weighted probabilty of different diagnoses
Click here for CDC website