Zika virus is another vector-borne disease which, like dengue, is spread by Aedes mosquitoes. A. aegypti and A. albopictus are its main vectors. It has come into international focus since the zika virus epidemic of 2015-16. The virus is named after Zika Forest in Uganda, where the virus was first identified in 1947.
This infection is asymptomatic in three out of four cases. The symptoms which are generally mild can include fever, rash, conjunctivitis, muscle and joint pain, headache and fatigue. While the incubation period of the disease is 3-14 days long, the symptoms last for 2-7 days.
Apart from the disease-carrying vectors, human-to-human transmission of zika virus is also possible: through blood transfusion, sexual transmission or maternal-fetal transmission.
Pregnant women who live in or have travelled to endemic areas should get regularly tested for the virus and seek clinical care. Regular ultrasound scans are recommended. Women who plan to get pregnant should hold it off when this virus is spreading. Effects of zika virus during pregnancy are numerous and dangerous. The fetus is at risk of microcephaly, ventriculomegaly, neuronal migration disorder, congenital contractures, stillbirth and neonatal death. Other possible effects of zika virus in children and adults are guillain-barré syndrome, neuropathy and myelitis.
Initially endemic in Africa, the first major zika virus epidemic actually hit the Pacific, in Yap Island, in 2007. Since then, the disease has been reported in Polynesia, Latin America and parts of Asia. According to WHO, today the impact of zika virus extends to 86 countries and territories. Cases have also been popping up in Indian states now and then since 2017, with 65 reported cases in Kerela last year.
The reasons behind zika virus’s rise are the same as that of other vector-borne diseases: climate conditions, rapid urbanization and increased international travel. Prevention should take centre stage in our efforts to battle the disease. Eradication of mosquito habitats like stagnant water, clothing which fully covers the body, effective insecticides, mosquito screens and keeping doors and windows closed whenever possible are some measures that should be taken. Individuals should also practice safe sex to prevent sexual transmission.
Increase in cases of microcephaly and neurological disorders associated with zika virus has led to an increase in demand for laboratory testing. Some diagnostic methods used for zika virus are Polymerase Chain Reaction (PCR) tests for detection of RNA from zika virus in human samples and ELISA tests for detection of IgM antibodies.
All of zika virus’s secrets haven’t been uncovered yet. The pregnancy complications and neurological disorders in children and adults which it causes and specific prevention strategies are open questions in the medical world. Additionally, since zika virus has been found in many species of Aedes, the true extent of its vectors is unknown. Research and clinical trials to solve these mysteries and find a cure are ongoing. Governments and healthcare institutions should make these efforts their priority. Nothing is more dangerous than a viral disease we do not understand.