An obscure mosquito-borne virus, Zika, is on the prowl and has already caused an alarming situation in the scientific research world. It stems from a huge surge in babies being born with microcephaly, a rare, incurable condition in which their heads are abnormally small. The disease is hugely active in North-eastern Brazil, with officials reporting at least 2,782 cases in 2015, as against 147 in 2014 and 167 in 2013. At least 40 infants have died so far.
What do we understand with the Zika Virus?
The Zika virus is a mosquito-transmitted infection related to dengue
, yellow fever and West Nile virus. Although it was discovered in the Zika forest in Uganda in 1947 and is common in Africa and Asia, it did not begin spreading widely in the Western Hemisphere until last May, when an outbreak occurred in Brazil.
How the Zika virus spreads?
Zika is spread by mosquitoes of the Aedes genus, which can breed in a pool of water as small as a bottle cap and usually bite during the day. The aggressive yellow fever mosquito, Aedes aegypti, has spread most Zika cases, but that mosquito is common in the United States only in Florida, along the Gulf Coast, and in Hawaii.
The Asian tiger mosquito, Aedes
albopictus, is also known to transmit the virus, but it is not clear how efficiently.
Although the virus is normally spread by mosquitoes, there has been one report of possible spread through blood transfusion
and one of possible spread through sex. The virus was found on one occasion in semen
What are the symptoms of Zika fever?
The most common symptoms are fever, rash, joint pain
, or conjunctivitis
(red eyes). Other symptoms include experiencing muscle pain
, headache, pain behind the eyes, and vomiting. The virus causes a painful but temporary rash in adults. The illness is usually mild with symptoms lasting for several days to a week but 1 in 5 people infected with the Zika virus become sick.
How the Zika virus causes brain damage in infants?
The possibility that the Zika virus causes microcephaly
- unusually small heads and damaged brains
- emerged only in October, when doctors in northern Brazil noticed a surge in babies with the condition.
It may be that other factors, such as simultaneous infection with other viruses, are contributing to the rise researchers may even find that Zika virus is not the main cause, although right now circumstantial evidence suggests that it is.
It is not known how common microcephaly has become in Brazil’s outbreak. About three million babies are born in Brazil each year. Normally, about 150 cases of microcephaly are reported, and Brazil says it is investigating nearly 4,000 cases. Yet reported cases usually increase when people are alerted to a potential health crisis.
What is microcephaly?
Babies with microcephaly have unusually small heads. In roughly 15 percent of cases, a small head is just a small head, and there is no effect on the infant. But in the remainder of cases, the infant’s brain may not have developed properly during pregnancy
or may have stopped growing in the first years of life. These children may experience a range of problems, like developmental delays
, intellectual deficits or hearing loss
. There is no treatment for an unusually small head.
Why is this outbreak upsetting?
The Zika virus was considered benign until recently when scientists, for the first time in November 2015, linked it to a surge in babies born with microcephaly. According to Brazilian authorities, by the end of the year, Zika could infect over 1.5 million people. Further, the disease is spreading fast and experts believe it could spread to other countries in the Southern hemisphere.
Outbreaks have also occurred in parts of Africa, Southeast Asia and the Pacific Islands. Because the Aedes species mosquitoes that spread Zika virus are found throughout the world, it is likely that outbreaks will spread to new countries.
The Centres for Disease Control and Prevention (CDC) in the United States, and the Canadian government have issued travel advisories, warning tourists to protect themselves from mosquito bites. Further, the Brazilian government is advising women to delay pregnancies till the outbreak is under control.
Is the Zika virus threat to India?
Yes, it can be a potential threat to the lives of many people because India offers a similar environment for breeding of the virus. Infection of the Zika virus happens when the Aedes mosquito bites a person. Aedes mosquito also transmits the Dengue virus
and is found widely in India. Presently, only 20% of people infected with the virus are showing symptoms. A major concern of the health officials is if an Aedes mosquito bites an infected person who has come to India, in no time Zika virus would spread widely in India too. This is why the Indian Medical Association has issued advisory asking pregnant Indian women
to avoid visiting Latin America. Here is some invaluable information on Zika virus:
- The virus borne disease is transmitted by Aedes mosquito which acts as the vector. The same breed of mosquitoes is responsible for spreading dengue. The disease is spread when an Aedes mosquito bites an infected person and bites others.
- The virus is similar to that of chikungunia and dengue and has similar symptoms like body ache and fever or often without symptoms, making it difficult for pregnant women to know whether they have been infected. But more importantly, there is a casual connection established between microcephaly, a neurological birth disorder which can have fatal consequences or development anomalies.
- There is no available treatment or vaccine available to counter the virus. Prevention measures include not visiting Zika affected areas, avoiding mosquito bites. Once infected the damage could be minimized by ensuring that the disease is not spread.
- At present, most countries in the central and South America are infected which includes Barbados, Bolivia, Brazil, Cape Verde, Colombia, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, Samoa, the U.S. Virgin Islands and Venezuela.
- Since the Olympic Games are scheduled to be held in Brazil in August 2016, it has become a major concern for the president of the International Olympic Committee, who is in regular contact with the Brazilian authorities and WHO.