Fast Five Quiz: Bites and Stings

Richard H. Sinert, DO


April 29, 2019

In most cases, Zika virus infection causes a mild, self-limited illness. The incubation period is probably 3-12 days. Because of the mild nature of the disease, more than 80% of Zika virus infection cases may go unnoticed. The spectrum of Zika virus disease overlaps with that of arboviral infections, but rash (maculopapular and likely immune-mediated) typically predominates. Aside from rash, the most common symptoms of Zika virus infection include fever, arthralgia (involving the small joints of the hands and feet), retroocular headache, and conjunctivitis. Symptoms last from 2 to 7 days.

Most patients with malaria have no specific physical findings, but splenomegaly may be present. Symptoms of malarial infection are nonspecific and may manifest as a flulike illness with fever, headache, malaise, fatigue, and muscle aches. Some patients with malaria present with diarrhea and other gastrointestinal symptoms. Immune individuals may be completely asymptomatic or may present with mild anemia. Nonimmune patients may quickly become very ill. In children, malaria has a shorter course, often rapidly progressing to severe malaria. Children are more likely to present with hypoglycemia, seizures, severe anemia, and sudden death, but they are much less likely to develop renal failure, pulmonary edema, or jaundice.

Patients with dengue will have a history of living in, or recent travel to, a region where the disease is endemic. The incubation period is 3-14 days (average, 4-7 days); symptoms that begin more than 2 weeks after a person departs from an endemic area are probably not a result of dengue. Many patients experience a prodrome of chills, erythematous mottling of the skin, and facial flushing (a sensitive and specific indicator of dengue fever). The prodrome may last for 2-3 days. Children younger than 15 years usually have a nonspecific febrile syndrome, which may be accompanied by a maculopapular rash. Classic dengue fever begins with sudden onset of fever, chills, and severe (termed breakbone) aching of the head, back, and extremities, as well as other symptoms. The fever lasts 2-7 days and may reach 105.8°F (41°C). Fever that lasts longer than 10 days is probably not a result of dengue.

Chikungunya fever is an acute febrile illness with an incubation period of 3-7 days. It affects all age groups and both sexes equally, with an attack rate (percentage of individuals who develop illness after infection) of 40%-85%. Patients present with abrupt onset of high-grade fever often reaching 102°-105°F (38.9°-40.6°C), with shaking chills that last 2-3 days. The fever may return for 1-2 days after an afebrile period of 4-10 days, and hence is termed a saddle-back fever. Prodromal symptoms are uncommon. However, sore throat, headache, abdominal pain, constipation, and retro-orbital pain have been reported during the acute phase of the illness.

Read more about Zika virus.


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