Fever in the returning traveler








Most common

Cosmopolitan infections (common cold, sinusitis, upper respiratory tract infections, urinary tract infections, etc.)

Malaria

Enteric fever (typhoid and paratyphoid)

Atypical pneumonia, acute respiratory tract infections (bacterial and viral pneumonia)

Hepatitis (hepatitis A, hepatitis E)

Rickettsial infections

Arboviral infections (dengue, chikungunya, yellow fever, Western equine encephalitis [WEE], Eastern equine encephalitis [EEE], and others)

Bacterial diarrhea or dysentery

Viral gastroenteritis

Protozoal diarrhea (giardiasis or amebiases)

Amebic liver abscess

Sexually transmitted diseases
Less common

African trypanosomiasis

Tuberculosis

Human immunodeficiency virus (HIV)

Brucellosis

Leptospirosis

Histoplasmosis

Atypical pneumonia (Legionnaires’ disease, pulmonary histoplasmosis, psittacosis)

Acute schistosomiasis (Katayama fever)

Leptospirosis

Filariasis

Drug fever
Uncommon

Visceral leishmaniasis (kala-azar)

Cutaneous leishmaniasis

Lyme disease

Relapsing fever (borreliosis)

Melioidosis

Viral hemorrhagic fevers

Tropical pulmonary eosinophilia

Cutaneous larva migrans

Endocarditis

Noninfectious causes (malignancy, autoimmune)



Careful assessment of travelers with fever must involve a detailed history, a thorough examination, and targeted laboratory investigations. The following are essential in the clinical management of fever in the returning traveler:



1. A comprehensive history:

a. Symptoms, time of onset, duration and progression and evolution of symptoms over time. Try and localize symptoms to organ systems.

b. Travel history – destinations, type of accommodation, prophylaxis measures taken, activities (e.g., game viewing, camping, farms, caves, swimming in lakes/rivers, sex, drug abuse, consumption of uncooked or semi-cooked food, and water source), bites (insects, ticks, fleas, lice, mites, animal, other).

2. A complete physical examination of all systems:

Clinical features to look for are: skin rash (maculopapular, petechiae, ecchymosis), skin lesions (eschars, insect bites, erythema nodosum, boils, erysipelas), lymphadenopathy, hepatomegaly, splenomegaly, jaundice, wheeze, crackles, crepitations, joint or muscle involvement, stiff neck, photophobia, conjunctivitis, neurologic signs, or evidence of bleeding.

3. Urgent investigations:

a. Full blood count

b. Malaria thin and thick blood films including rapid malaria diagnostic test

c. Blood culture

d. Urine culture and dipstix analysis (blood, protein, sugar)

e. Stool – bacteriology, virology, and parasitology (ova, cysts, and parasites)

f. Blood biochemistry (C-reactive protein, urea, electrolytes, creatinine, and liver function tests)

g. Chest x-ray

h. Specific PCR tests on clinical specimens for those suspected of having rapidly fatal diseases e.g., arboviruses, viral hemorrhagic fevers (VHF), Middle East respiratory syndrome (MERS)-coronavirus.

4. Other investigations in persisting fever:

a. Serology – bacterial, viral, fungal, spirochetal (save serum for paired serology)

b. Bone marrow and/or lymph node aspirates – microscopy and culture may be required if fever persists without localizing signs.

c. Further imaging – CT scan, PET, PET/CT scans.

The most common tropical fevers in travelers are malaria, enteric fever, hepatitis, amebic liver abscess, and rickettsial and arboviral infections.


Malaria


Malaria is the most important potentially fatal cause of fever in travelers returning from the tropics. Thus, all febrile travelers returning from malaria endemic areas must be evaluated for malaria, even those who have taken appropriate malaria chemoprophylaxis. Antimalarial prophylaxis regimens cannot be considered fully protective.


Nearly all malaria due to Plasmodium falciparum present with fever within 4 weeks of returning but could present several months after leaving a malarious area. Plasmodium vivax and Plasmodium ovale malaria may occur up to 3 years after exposure due to persistence of hypnozoites (latent parasites) in the liver. Plasmodium malariae, which does not have a latent liver phase, is the least common species causing fever in travelers, but may present up to a year or longer (up to 20 years) after first infection. Typical symptoms are high fever, shaking, chills, sweats, headache, and myalgias. Symptoms may be modified or masked according to the immune status, as in an immune native of an endemic area, or by the use of prophylactic antimalarial drugs. Severe Plasmodium falciparum infections can rapidly lead to such lethal complications as cerebral malaria, renal failure, severe hemolysis, and adult respiratory distress syndrome.


Diagnosis is by appropriately prepared and carefully examined Giemsa-stained thin and thick malaria smears. A single negative set of smears cannot rule out malaria; smears should be repeated at 6-hour intervals for at least 24 hours. Rapid malaria antigen detection tests are now available. Specific prophylaxis and therapy for malaria is discussed in Chapter 200, Malaria.


Enteric fever (typhoid and paratyphoid)


Typhoid and paratyphoid fevers can be contracted from contaminated food or water where the prevalence of these bacteria is high. Typhoid vaccines offer protection to no more than 70% of recipients. Enteric fever should be suspected in travelers returning from an endemic area with fever, headaches, abdominal pain, diarrhea, or cough. Symptoms may not develop until several weeks after return. Diagnosis is confirmed by positive blood, stool, or urine culture. The agglutinin test (Widal) lacks sensitivity and specificity and is not recommended. Newer rapid serologic tests that detect IgM antibodies to Salmonella typhi antigens are available. Blood and bone marrow cultures have the highest yield within 1 week of symptoms and urine and stool cultures become positive after the first week.

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Jun 18, 2016 | Posted by in INFECTIOUS DISEASE | Comments Off on Fever in the returning traveler
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