College Health May Be Full of Surprises: International Travelers and Tropical Diseases

TREATMENT / MANAGEMENT
Malaria
The treatment of malaria varies depending on the severity of disease and the probability the organism is resistant to antimalarial drugs. The likelihood of drug resistance is determined based on the species of malaria parasite and the location where the infection occurred.²⁴

Malaria is considered severe if one or more of the following are present: neurologic sequelae, renal failure, severe anemia, ARDS, jaundice, or parasite burden greater than 5%.⁸ Patients with severe malaria are treated with parenteral (IV) antimalarials; the two options for parenteral medication are quinine and artesunate.⁷ All patients treated with parenteral antimalarial agents should take a full course of oral medication for malaria as well. Oral antimalarial medications include, but are not limited to, quinine sulfate, atovaquone/proguanil, artemether-lumefantrine, doxycycline, clindamycin, sulfadoxine/pyrimethamine, chloroquine, and primaquine. The oral medications most commonly used to treat nonfalciparum malaria are chloroquine followed by primaquine.⁷ Chloroquine is not typically used for falciparum malaria due to widespread resistance.⁷

In cases of malaria caused by P vivax or P ovale infection, the likelihood of parasitic infection lying dormant in the liver must be considered. Additional treatment is often needed to eradicate this type of infection.⁷ The relapse of symptoms can occur years after the acute attack.²⁵ Primaquine is the only approved medication for preventing and treating parasitic relapse associated with dormant infection.²⁵

Dengue fever
The typical course of dengue follows three phases: febrile, critical, and convalescent.¹⁴ Dengue is usually a self-limiting febrile illness and typically resolves within one week after symptom onset without major complications.¹¹ During the critical phase, most patients begin to improve, but up to 5% of cases develop concerning warning signs and symptoms that could represent a life-threatening condition that requires intense treatment and close monitoring.¹⁴ Warning signs for worsening disease are caused by marked increase in vascular permeability and include narrow pulse pressure, pleural effusions, ascites, and hemorrhagic manifestations (hematemesis, melena, menorrhagia).¹⁴

Treatment of most cases of dengue involves use of acetaminophen for comfort and fever reduction, hydration, and rest.²⁶ Treatment of worsening dengue includes inpatient admission and possibly ICU admission for close observation and frequent monitoring.¹⁴ It is important to avoid aspirin and other NSAIDs due to the risk for bleeding complications in severe dengue.¹⁴ There are no approved antivirals for treatment of dengue. To reduce the risk for transmission of dengue, febrile patients should avoid further mosquito bites.¹⁴

Clinicians should be aware of warning signs of worsening illness with dengue fever. Signs of worsening dengue fever include postural hypotension, thrombocytopenia, decrease in serum albumin, and rising hematocrit.¹⁰

Chikungunya
CHIKV illness is usually a self-limiting condition. Diagnosis of chikungunya may take time, and providers should assume the chikungunya patient may have dengue, which has the potential to be more pathologic. Accordingly, they must watch for warning signs of dengue until CHIKV is confirmed.²⁷

Management focuses on supportive care, including hydration and rest. Typically, the medications used are antipyretics (acetaminophen and ibuprofen) and analgesics; no antiviral medication for chikungunya is available.²² Aspirin is avoided due to the risk for Reye syndrome. Antihistamines may be helpful for patients who have an associated pruritic rash. Cold compresses can be beneficial for joint pain and swelling. Additionally, it is important to keep patients under mosquito nets during the febrile phase to decrease the risk for disease transmission.

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