INFECTIOUS DISEASETHE FEBRILE TRAVELERA 60-year-old ill-appearing woman presents with high fevers followed
by drenching sweats a week after returning from visiting relatives in
West Africa. What diagnostic test should be sent and (if positive) what
treatment should be initiated?
Thick and thin smears; quinidine gluconate and doxycycline.Malaria
■ Plasmodium falciparum, P. vivax, P. ovale, and P.malariae
■ Transmitted by Anophelesmosquito bite
■ Globally endemic
SYMPTOMS/EXAM
■ Incubation period: 1–4 weeks
■ Longer with partial immunity or antimalarial use
■ Begins with flulike prodrome
■ Frequently presents with misleading symptoms (eg, chest pain, abdominal
pain, vomiting, diarrhea, arthralgias, etc.)
■ Progresses to high fever, chills, and rigor
■ Classic febrile cycles (from RBC lysis) frequently absent
■ Symptoms/exam
■ High fever
■ Tachycardia
■ Pallor/anemia
■ Splenomegaly
■ P. falciparumresponsible for most mortality
■ MostP. falciparumcases acquired in sub-Sahara Africa
■ Hepatomegaly, icterus, peripheral edema, seizures (cerebral malaria)
DIFFERENTIAL
■ Influenza, hepatitis, viral syndromes, multiple other infections
DIAGNOSIS
■ Basic labs: Normochromic normocytic anemia, thrombocytopenia, hypo-
glycemia, mild LFT abnormalities
■ Definitive diagnosis: Plasmodial parasites on Giemsa-stained thick and
thin smears
■ Speciation important as P. falciparuminfections should be hospitalized
(mixed infections uncommon in travelers)
TREATMENT
■ DEET and mosquito nets for prevention
■ See Table 8.17 for treatment regimens.
■ Admit for:
■ SuspectedP. falciparum
■ Significant hemolysis or parasitemia >3% on smear
■ Significant comorbid conditions
As malaria symptoms are
often nonspecific, consider the
diagnosis in any febrile
person with a history of travel
to the tropics.