Zika Virus: Emerging Threat to Human Civilization

Zika virus (ZIKV) is a mosquito-borne virus classified within the Flaviviridae family, alongside notable members such as Japanese encephalitis (JEV), West Nile (WNV), dengue (DENV), and yellow fever (YFV) viruses. The Zika virus was initially isolated in 1947 from a rhesus macaque monkey in the Zika Forest, located on the Entebbe Peninsula, Uganda. Subsequently, it was isolated from Aedes africanus mosquitoes. Mosquitoes are the primary mode of viral transmission across various geographical regions. Originating in the Ugandan forest, the virus has spread to the Pacific Islands, Latin America, North America, and now Southeast Asia.

Zika virus (ZIKV) primarily transmits to humans through the bite of infected mosquitoes. Additionally, it can cross the placental barrier, affecting the fetus during pregnancy, and spread through sexual contact, breastfeeding, or blood transfusion.

The Zika virus primarily circulates through two transmission cycles: the sylvatic cycle, occurring in forested areas where the virus is maintained between non-human primates and arboreal mosquitoes and the urban cycle, prevalent in urban settings where the virus circulates between humans and urban mosquitoes.

Recent concern has focused on managing urban mosquitoes, specifically two species: Aedes aegypti, identified by white bands on its legs, and Aedes albopictus, known for a single long dorsal stripe and white leg bands. These mosquitoes are active during daylight hours.

Zika virus can spread through sexual contact, blood transfusion, and breastfeeding. It can also be transmitted from a pregnant woman to her fetus. The virus has been found in urine, saliva, and nasopharyngeal swabs. Direct transmission through skin or mucous membranes is uncommon due to low viral levels in the blood.
Zika virus (ZIKV) symptoms range from mild to severe. Mild cases typically resolve within 4–10 days after an incubation period. Symptoms include flu-like syndromes such as low-grade fever, rash, arthritis, conjunctivitis, headache, myalgia, edema, and vomiting. Severe cases may lead to Guillain-Barre syndrome in adults, characterized by autoimmune attacks on the peripheral nervous system causing tingling, muscle weakness, and paralysis. In infants born to infected women, ZIKV can cause microcephaly, a condition where the brain does not develop properly, resulting in a smaller-than-normal head.

Currently, there are no specific medications available for preventing or treating Zika virus (ZIKV) infection. Developing a safe and effective vaccine is crucial to stop the spread of the virus. Progress in Zika vaccine development is ongoing, using various technologies such as DNA vaccines, subunit vaccines, live-attenuated vaccines, virus-vector-based vaccines, inactivated vaccines, virus-like particles (VLPs), and mRNA-based vaccines.
Before a safe and effective vaccine becomes available, the primary strategy to prevent Zika virus infection is vector control, which focuses on reducing mosquito populations, eliminating breeding sites, and avoiding mosquito bites. These measures are also effective in preventing Dengue and Chikungunya infections.