Chikungunya virus

Background

Member of the Alphavirus genus within the Togaviridae family
- Closely related to o’nyong-nyong virus
Four genotypes: East-Central-South African, West African, Indian Ocean, and Asian

The primary vectors are Aedes aegypti and Aedes albopictus mosquitoes
Endemic in most of Africa, Southeast Asia, the Philippines, and South and Central America
- There has been autochthonous transmission in Italy and Frace

Incubation period of 1 to 12 days
Fever, rash, and arthralgias
Fever may be "saddleback", with remittance at 4 to 8 days followed by recrudescence for 2 weeks
Arthritis is typically a symmetrical polyarticular arthritis that involves small joints and knees
- Resolves over months to a year (sometimes longer), but arthralgias (± arthritis) can persist for years
Rash is macular or maculopapular, and more often central but can involve palms and soles
Other common symptoms include headache, fatigue, nausea, vomiting, and conjunctivitis
Bloodwork shows leukopenia, thrombocytopenia, hypocalcemia, and mild to moderate transaminase elevation
Children are more likely to develop neurological symptoms (status epilepticus, complex seizures, and encephalitis) and dermatologic symptoms (bullous rash)