UPSC Express

About Zika virus

• Zika belongs to a group of viruses called the flaviviruses, which includes dengue, West Nile and yellow fever.
• Zika virus infect and replicate inside the cells of several species, including humans, monkeys, and mosquitoes.

History of Zika

• Zika was first isolated from a monkey in the Zika forest of Uganda in 1947.
• The first human case was reported in 1954.
• In 2007, the first documented outbreak of Zika took place, on Yap Island in Micronesia.
• In 2013 and 2014, another Zika outbreak occurred, in French Polynesia and the surrounding islands.
• Brazil reported a major outbreak of the disease in 2015 where more than 4000 cases were detected.
• Currently there is no vaccine to prevent infection.

Transmission

• The primary mode of Zika transmission is through mosquitoes in the genus Aedes which bite during the day.
• When a mosquito sucks blood from a person infected with Zika, the virus can infect the cells of the mosquito.
• Mosquito’s infection develops in a period of about 1 and ½ weeks.
• When it bites another human, the viral particles can be transmitted to the human, who may contract Zika.
• Other modes of transmission include
  • Pregnant woman who contracts Zika transmitting the virus to her growing fetus.
  • Sexual contact or through blood transfusions from a Zika-infected donor.

Symptoms

• Typical symptoms may include rash, fever, conjunctivitis (irritation of the eyes), and joint pain.
• Pregnant women and their unborn fetuses are at higher risk for harmful effects from Zika.
• There is a link between Zika infection during pregnancy and a condition called microcephaly in newborns.
• Microcephaly may involve neurological problems or developmental delays.
• In some rare cases, it may be linked with Guillain-Barré syndrome.
• Guillain-Barré syndrome is an autoimmune condition that causes paralysis, which is usually temporary.

Zika in India

• In India, the Zika virus was first found in Pune 65 years ago.
• In 2017 three cases infected with mosquito-borne Zika virus were detected in Ahmedabad.
• India has not witnessed a major outbreak.
• However India provides fertile climate for the aedes egypti mosquito to grow and multiply.
• Thus there is the potential of an outbreak situation in the country.