Everything you wanted to know about Zika virus
The World Health Organization (WHO) expects that Zika virus, a mosquito-borne disease, spreading through the Americas, to affect between 3 million and 4 million people. Let’s analyse this in brief!
Where was the first Zika virus outbreak identified?
- Zika virus is an emerging mosquito-borne virus that was first identified in Uganda in 1947 in rhesus monkeys through a monitoring network of sylvatic yellow fever.
- It was subsequently identified in humans in 1952 in Uganda and the United Republic of Tanzania.
- Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.
Trivia : Do you know why is it called Zika Virus?
It was first isolated from Rhesus monkeys in Zika forest near Lake Victoria in Uganda.
Find Out why was Ebola virus named as such?
What makes this outbreak different?
- The current outbreak, the first ever in the western hemisphere, is a big deal for a number of reasons
- We now know that it’s not adults who have the most to lose but their unborn babies
- Microcephaly is a condition where a baby is born with an abnormally small head and brain defects
- Worldwide it affects only 1 in 30,000 to one in 250,000 newborns
- In Brazil there are usually a few hundred cases annually at most, but since October 2015, there have been 3,500 new microcephaly cases
But, what is microcephaly?
- Microcephaly is a rare condition where a baby has an abnormally small head.
- This is due to abnormal brain development of the baby in the womb or during infancy.
- Babies and children with microcephaly often have challenges with their brain development as they grow older.
- Microcephaly can be caused by a variety of environmental and genetic factors such as Downs syndrome; exposure to drugs, alcohol or other toxins in the womb; and rubella infection during pregnancy.
How does the Zika virus spread?
- Zika virus is transmitted to people through the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti in tropical regions
- This is the same mosquito that transmits dengue, chikungunya and yellow fever
- Zika virus disease outbreaks were reported for the first time from the Pacific in 2007 and 2013 (Yap and French Polynesia, respectively), and in 2015 from the Americas (Brazil and Colombia) and Africa (Cape Verde)
How bad is it now?
- As of January 23, 2016, the Zika virus has spread to 21 countries and territories of the Americas
- It’s speculated that the virus must have arrived in Brazil along with the throngs that swept in during the 2014 FIFA World Cup
- Things look so grim that governments of 4 South American countries are now advising women to not get pregnant until the situation is brought under control
- The WHO has predicted that the virus is likely to spread all over North and South America, except for Chile and Canada where the Aedes aegypti mosquito is not present
- The reason that the WHO thinks these countries are so susceptible is that their populations have not been exposed to the virus before and hence have no immunity
Is there a cure?
- No, there isn’t. There exists medication for symptomatic relief but these are quite useless now that we know about the microcephaly link
- Research on the Zika virus is still quite primitive
- Given its generic symptoms in adults, it’s very easy to miss or misdiagnose
- Moreover, the virus doesn’t seem to show effects in common lab animals like mice and rats. Getting monkeys is extremely tough because of restrictions on primate research
- Vaccine development and antiviral drug discovery efforts are on but this takes time, and with the Zika virus, we’ll be starting from scratch
Does Brazil have a way out?
- Brazil needs an immediate plan of action for more than one reason
- Rio de Janeiro is frantically spraying insecticides at the parade grounds where the annual carnival celebrations will commence soon
- In August, the city is due to host the Olympics
What about India?
- India is one of the Aedes aegyptis’s many homes but the Zika virus itself has not ever been detected in our country so far
- However, in a study in the 1950s, healthy individuals from 6 Indian states showed passive immunity to the virus
- This means that though their blood contained antibodies against the virus, this was not because they were exposed to the virus
- Usually passive immunity is acquired through vaccines, from mother-to-child transmissions or breast milk
- In the case of India, where the Zika virus is not known to exist, the antibodies probably arose from exposure to similar viruses
- Nevertheless, theoretically, Zika can spread anywhere that the mosquito exists
- That means India, too. Indians are just as susceptible if they travel to high-risk countries
Is there something more that you wanted to know which we did not answer yet? Drop in with your questions.
Published with inputs from Arun | Image - Outbreaknews