A 5-year-old black male has had fever, headache, abdominal pain, and muscle aches for the preceding 3-4 days. His temperature is $103.4^{\circ} \mathrm{F}$, heart rate is 130, and respirations are 40 per minute. He appears acutely ill and dehydrated. He has no rash. No history of tick bite is obtained, and the child had recently been camping in rural Wisconsin. Laboratory findings include WBC count of $2,300 / \mathrm{mm}^3, 24 \%$ segmented neutrophils, $65 \%$ bands, $8 \%$ lymphocytes, and platelet count $57,000 / \mathrm{mm}^5$. Elevations in serum AST (465 IU/L; normal, 0-40 IU/L) were also present. A peripheral blood smear reveals small blue clusters of bacterialike bodies in an aggregate within the cytoplasm of $1 \%$ of circulating mononuclear WBCs. What is the most appropriate diagnosis?

A 5-year-old black male has had fever, headache, abdominal pain, and muscle aches for the preceding 3-4 days. His temperature is $103.4^{\circ} \mathrm{F}$, heart rate is 130, and respirations are 40 per minute. He appears acutely ill and dehydrated. He has no rash. No history of tick bite is obtained, and the child had recently been camping in rural Wisconsin. Laboratory findings include WBC count of $2,300 / \mathrm{mm}^3, 24 \%$ segmented neutrophils, $65 \%$ bands, $8 \%$ lymphocytes, and platelet count $57,000 / \mathrm{mm}^5$. Elevations in serum AST (465 IU/L; normal, 0-40 IU/L) were also present. A peripheral blood smear reveals small blue clusters of bacterialike bodies in an aggregate within the cytoplasm of $1 \%$ of circulating mononuclear WBCs. What is the most appropriate diagnosis?

Which of the following is true concerning measles?

What percentages of poliovirus infections are inapparent?

Which is true concerning antiviral treatment of varicella-zoster virus infections?

Which is not a complication of influenza?