How Can Diseases of Travelers Be Diagnosed?
The diagnoses and tests that seek to identify illness are focused on the area of travel and based on the signs and symptoms.
For Travel To:
- South Asia: Tests for the mosquito-borne diseases–malaria, dengue fever, Japanese encephalitis, Chikungunya fever; typhus and Leishmaniasis from fleas and flies, respectively; typhoid fever (Salmonella), Brucellosis (raw milk), and hepatitis A & E from food/water contamination; and Leptospirosis from infected water. (Polio is endemic in Pakistan and Afghanistan.)
- Africa: Tests for HIV, diarrheal diseases, malaria, tuberculosis, Ebola, yellow fever, Schistomiasis, Lassa fever, foot-and-mouth disease, and typhus.
- South America: Tests for malaria, yellow fever, dengue fever, Chikungunya, West Nile virus, Eastern and Western Equine Encephalitis, and Zika virus.
- Latin America/Caribbean: Dengue fever, cholera, Venezuelan Equine Encephalitis, and leptospirosis,
- Mexico: Tests for dengue, Chikungunya, Zika, malaria, parasites, tuberculosis, traveler’s diarrhea, and hepatitis A.
Depending on the area of travel and the signs and symptoms with which a patient presents, the testing can include blood work, cultures, fecal and urine exams, CT imaging, and at times, biopsies of skin, lung, and liver.
Examination of the blood can reveal red blood cell abnormalities, such as is seen in malaria, stages of parasitic life cycles, evidence of protozoans, and electrolyte abnormalities due to excessive diarrhea or nausea/vomiting.
Examination of stool can demonstrate eggs, worms, and all stages between for parasitic helminths and protozoans.
In rare cases, the diagnosis can remain elusive until actual biopsies are performed to look for evidence of infestation.