Zika virus is a mosquito-borne virus that can cause mild or asymptomatic infections in humans, but also serious complications such as microcephaly and Guillain-Barré syndrome. In this article, we will explain what Zika virus is, how it is transmitted, what are its symptoms and effects, and how it can be prevented and treated.
What is Zika virus?
- Zika virus belongs to the family Flaviviridae and the genus Flavivirus, which includes other viruses such as dengue, yellow fever, Japanese encephalitis, and West Nile virus.
- Zika virus was first identified in 1947 in the Ziika Forest of Uganda, where it was isolated from a monkey. Since then, it has been detected in various African and Asian countries, but mostly in low levels of transmission.
- In 2007, Zika virus emerged in the Pacific islands, causing outbreaks in several countries such as Micronesia, French Polynesia, and the Cook Islands. In 2015, Zika virus reached the Americas, where it spread rapidly and caused a large epidemic in Brazil and other countries .
- In 2016, the World Health Organization (WHO) declared Zika virus and its associated congenital malformations a Public Health Emergency of International Concern (PHEIC), and confirmed the causal link between Zika virus infection and microcephaly. The PHEIC was lifted in November 2016, but Zika virus transmission continues to occur in some regions.
- As of November 2023, 89 countries and territories have reported evidence of mosquito-transmitted Zika virus infection, and some cases of local transmission have been reported in Europe and India.
How is Zika virus transmitted?
- Zika virus is primarily transmitted by the bite of infected Aedes mosquitoes, which are active during the day and can be found in tropical and subtropical regions. These mosquitoes can also transmit other diseases such as dengue, chikungunya, and yellow fever.
- Zika virus can also be transmitted from a pregnant woman to her fetus during pregnancy or at the time of delivery, resulting in congenital Zika syndrome, which includes microcephaly and other birth defects.
- Zika virus can also be transmitted through sexual contact with an infected person, as the virus can persist in semen, vaginal fluids, and other body fluids for several weeks or months after infection.
- Zika virus can also be transmitted through blood transfusion, organ transplantation, or laboratory exposure, although these modes of transmission are very rare.
What are the symptoms and effects of Zika virus infection?
- Most people infected with Zika virus do not develop any symptoms, or only have mild symptoms that last for 2 to 7 days12. These symptoms may include fever, rash, headache, joint pain, muscle pain, conjunctivitis, and malaise.
- Some people infected with Zika virus may develop complications such as Guillain-Barré syndrome, which is a rare neurological disorder that causes muscle weakness and paralysis . Other neurological disorders such as neuropathy and myelitis have also been associated with Zika virus infection.
- The most serious consequence of Zika virus infection is its effect on fetal development, as it can cause microcephaly, which is a condition where the baby’s head is smaller than normal and the brain is underdeveloped. Other congenital malformations such as eye defects, hearing loss, and limb abnormalities may also occur. These defects can lead to lifelong disabilities and impairments for the affected children.
How can Zika virus infection be prevented and treated?
- There is no specific treatment or vaccine for Zika virus infection, so the best way to prevent it is to avoid mosquito bites and sexual transmission.
- To prevent mosquito bites, people living in or traveling to areas with Zika virus transmission should use insect repellents, wear long-sleeved clothing, and sleep under mosquito nets or in screened rooms. They should also eliminate or reduce mosquito breeding sites, such as containers with stagnant water.
- To prevent sexual transmission, people who have or may have been exposed to Zika virus should use condoms or abstain from sex for at least 3 months (for men) or 2 months (for women) after infection or travel. They should also inform their partners about their Zika virus status and seek medical advice if they plan to conceive.
- To prevent congenital Zika syndrome, pregnant women should avoid traveling to areas with Zika virus transmission, or take strict precautions to prevent mosquito bites and sexual transmission if they have to travel. They should also have regular antenatal care and ultrasound examinations to monitor fetal growth and development. If Zika virus infection is suspected or confirmed during pregnancy, they should receive specialized care and support from a multidisciplinary team of health professionals.
- To treat Zika virus infection, people who develop symptoms should rest, drink plenty of fluids, and take paracetamol (acetaminophen) to relieve fever and pain . They should also seek medical attention if they experience severe or persistent symptoms, or signs of complications such as neurological or fetal problems.
Conclusion
Zika virus is a mosquito-borne virus that can cause mild or asymptomatic infections in humans, but also serious complications such as microcephaly and Guillain-Barré syndrome. Zika virus transmission can be prevented by avoiding mosquito bites and sexual transmission, and by seeking medical advice before and during pregnancy. Zika virus infection can be treated by supportive measures and specialized care, depending on the severity and the outcome of the infection.