Symptoms
Possible symptoms of Zika fever include fever, feeling sick, a rash, muscle and joint pain, headache, and conjunctivitis. The illness is usually benign and lasts a few days to a week (2 to 7 days). An asymptomatic course is common. Guillain-Barré syndrome may rarely occur as a complication. If a pregnant woman is infected, the child may develop microcephaly and other brain damage. The children’s head circumference is much smaller than that of their peers. Microcephaly is associated with mental retardation. Zika fever was originally observed in Africa, Southeast Asia, and the Pacific Islands. In 2015, it spread to Central and South America. The virus was discovered in Uganda in 1947. The first human cases were observed in 1952.
Causes
The infectious disease is caused by Zika virus, a small, enveloped, and single-stranded RNA virus of the flavivirus family. Other members of this family also include dengue virus, West Nile virus, and yellow fever virus. Zika virus is transmitted primarily by mosquitoes of the genus when they suck blood. These include , the yellow fever mosquito and , the Asian tiger mosquito. These mosquitoes are active during the day and breed in standing water. Rarely, transmission from the infected mother to the unborn child is possible. Infected men can pass on the disease during sexual intercourse. Infections through contaminated blood have been described (e.g., blood transfusion).
Diagnosis
Diagnosis is made under medical treatment on the basis of the patient’s history, clinical symptoms, and laboratory methods (blood, urine tests). Similar symptoms are caused, for example, by dengue and chikungunya fever, which are transmitted by the same mosquitoes.
Prevention
No vaccine is yet available for prevention. In the risk areas, mosquito bites should be avoided. Mosquitoes bite mainly during the day:
- Use suitable repellents such as DEET, icaridin or EBAAP (IR3535).
- Treat clothing and equipment with permethrin.
- Wear clothing with long sleeves and long pants.
- Sleep under a mosquito net.
- Remove standing water (eg flower pots).
- Kill insects with an insecticide.
- Use the air conditioner (avoid open windows).
- Infected people should be careful not to pass on the virus.
- Use condoms during sexual intercourse.
As a precaution, pregnant women should not travel to areas where Zika fever is endemic.
Treatment
No specific medications exist yet for treatment. Adequate hydration and bed rest are recommended. Paracetamol may be taken for symptomatic therapy of fever and pain. NSAIDs and acetylsalicylic acid are not recommended (risk of bleeding if it is dengue rather than Zika).
