What is Zika virus and how is it transmitted?
Zika virus is an infectious disease caused by a virus that is primarily transmitted through several key methods.
Transmission Through Mosquito Bites
The most common method of Zika virus transmission is through the bite of infected mosquitoes, specifically the Aedes aegypti and Aedes albopictus species. These mosquitoes are also responsible for spreading other diseases like dengue and chikungunya. They lay eggs in standing water and can bite both during the day and night235.
Transmission from Mother to Child
Zika virus can be passed from a pregnant person to their fetus, which can lead to serious congenital conditions such as microcephaly (improper brain development) and other birth defects. This transmission can occur at any stage of pregnancy, even if the mother does not exhibit symptoms235.
Transmission Through Sex
Zika virus can also be spread through sexual contact, including vaginal, anal, and oral sex, as well as through the sharing of sex toys. The virus can be present in semen longer than in other body fluids, and transmission can occur before symptoms appear, during the symptomatic period, and after symptoms have resolved234.
Less Common Modes of Transmission
- Through Infected Blood and Tissues: There have been rare reports of Zika virus transmission through blood transfusions and the use of infected tissues. For example, Brazil has reported transmission through platelet transfusions245.
- Laboratory Exposures: There have been a few cases of laboratory-acquired Zika virus infections, although these are rare and not well-documented24.
Key Points
- Most people infected with Zika virus have mild or no symptoms.
- The virus can be diagnosed through a blood test.
- There is currently no vaccine or antiviral treatment for Zika; treatment focuses on managing symptoms4.
Prevention measures include avoiding mosquito bites using repellents, bed nets, and other protective measures, especially for pregnant women or those planning to become pregnant. Using condoms correctly can reduce the risk of sexual transmission25.