Zika virus infection in Adult
Twenty to twenty-five percent of patients infected with Zika virus develop clinical manifestations. After being bitten by an infected mosquito, it takes approximately 3-14 days for symptoms to appear. The diagnostic criteria of Zika virus disease include a widespread erythematous macular and papular rash (involving the face, trunk, extremities, palms, and/or soles) and at least one of the following manifestations: fever, arthralgia, arthritis, and/or conjunctivitis. Other symptoms may include myalgias, headache, sore throat, cough, vomiting, and diarrhea.
Symptoms are typically mild, short-lasting (2-7 days), and self-limited. In a 2019 review, rash was seen in 90% of 240 cases. Mucocutaneous hemorrhage occurred in approximately 8% of individuals, and conjunctivitis was seen in just over one-third of individuals. Zika viral infection in pregnant patients has been associated with microcephaly in infants (see congenital Zika virus infection). There are also cases of fetal loss in women who were infected with Zika virus. It is thought that these outcomes are the result of congenital infection with Zika virus. Additionally, Guillain-Barré syndrome and other neurological disorders have been reported in patients after exposure to Zika virus.
Because the clinical presentation overlaps with those of other arboviruses, such as dengue fever and chikungunya, cases may be mistaken for another arboviral infection.
Zika virus has the potential to cause outbreaks, but cases in travelers returning to nonendemic areas are infrequently reported. While Zika virus is spread by the bite of an infected mosquito, there have been reports of it being spread human to human via sexual transmission as well as via blood transfusion.
A92.8 – Other specified mosquito-borne viral fevers
3928002 – Zika virus disease
Differential Diagnosis & Pitfalls
- Related flaviviruses (dengue fever, yellow fever, West Nile virus, tick-borne encephalitis, Japanese encephalitis virus)
- Viral exanthem
- Drug exanthem
- Rubeola (measles)
- Kawasaki disease (occurs primarily in children younger than 6 years)
- HIV primary infection
- O'nyong nyong