A dramatic rise in the number of Brazilian babies being born with a serious brain condition has been linked to a mosquito-borne virus, Zika.
Last year, according to Brazil’s Ministry of Health, the country witnessed 2,782 cases of microcephaly – a rare condition which results in children being born with an abnormally small head – compared to just less than 150 cases in 2014.
The state of Pernambuco in northeast Brazil has been hit the hardest, with some 900 reported cases.
There is no treatment for the condition and children born with it are prone to serious complications, including developmental delay, difficulties with balance and co-ordination, and seizures.
A state of emergency has been declared in at least six of the country’s states, and the Brazilian government is encouraging women to try to postpone their pregnancies.
Brazilian researchers have attributed the rise in the number of microcephaly cases to Zika, a virus transmitted by Aedes aegypti mosquitoes.
There is no cure for the virus, but symptoms are usually mild and last only a few days.
It is estimated that since May 2015, between half a million and 1.5 million people in Brazil have been infected by the Zika virus.
The Brazilian Ministry of Health announced in November 2015 that a link between the Zika virus and the brain condition was established after an autopsy revealed the presence of the virus in the placenta of a baby born with microcephaly.
According to CNN, most mothers who gave birth to babies with the disorder reported previously experiencing symptoms associated with the virus, including joint pain, fever, and a rash.
A 27-year-old mother from Recife, in the state of Pernambuco, told the New York Times that a few she had suffered Zika-like symptoms a few months before giving birth to a baby daughter with microcephaly.
The mother-of-three said she “cried for a month” after learning during an ultrasound that her daughter had the condition.
“Now I just pray that my daughter can endure life with this misfortune,” she added.
Despite the supposed connection between Zika and microcephaly, the New York Times reports that some virologists have warned that more tests must be carried out in order to prove the relationship between the two.
The European Centre for Disease and Control (ECDC), for example, says “there is currently only ecological evidence of an association between the two events, while a possible causative association cannot be ruled out; further investigations and studies are needed to understand the association and the possible role of other factors”.
First observed in humans in 1954 in Nigeria, Zika is one of several disease transmitted by Aedes aegypti mosquitoes. Other viruses include dengue fever, yellow fever, and chikungunya.
In 2007, the South Pacific’s first outbreak was on Yap Island in the Federated States of Micronesia, according to the World Health Organisation it affected some 180 people.
The first epidemic reported in French Polynesia occurred in 2013, spreading to other Pacific Islands, including New Caledonia and Easter Island.
By 2014, it had reached Chile, and in December 2015, the virus was reported to have spread to Panama, Brazil, Guatemala, El Salvador, Paraguay, Mexico, Colombia, and Venezuela.
In January 2016, Puerto Rico reported its first case of Zika.