The growing evidence that the emerging Zika virus is linked with a rare developmental disorder is disturbing. In Brazil, the worst-hit country of the climbing epidemic, almost 4,000 babies have been born with abnormally small heads since investigations began in October, the Associated Press reports. That’s almost a 2,500 percent increase on the figure for all of 2014, which was 150 babies.
Called microcephaly, the shrunken head is often a result of the brain being underdeveloped and smaller than normal. Symptoms range from mild vision problems and hearing loss to severe intellectual disability and, dependent on severity, the condition can be fatal. Women with affected fetuses will sometimes miscarry. A range of causes have been attributed to the birth defect, and while these have included viruses such as the one that causes rubella, Zika is a novel possibility.
Although the link has not been definitively proven, in the absence of other suggestions, the shocking increase in cases in Brazil during this outbreak, combined with positive virus diagnoses in some cases, is strongly suggestive of a role. While most infected individuals don’t even fall ill, the absence of a vaccine or treatment means that the current epidemic is particularly worrying for pregnant women. That’s why the Centers for Disease Control and Prevention has issued travel warnings, advising pregnant women not to travel to countries in Latin America and the Caribbean where cases have been documented.
But some nations have gone further than that, even recommending that women avoid getting pregnant at all – certainly not a long-term solution. Although Brazil has invested in vaccine development, in the meantime people should focus on simple prevention strategies. The disease is mosquito-borne, transmitted by the same insect that spreads dengue and chikungunya, Aedes aegypti. Unfortunately, this mosquito bites mostly during the day, so bed nets offer limited protection, but people can reduce the likelihood of being bitten by using repellants and removing stagnant pools of water that serve as breeding grounds.
A different strategy that could possibly offer help sooner is the use of genetically modified mosquitoes, which in trial areas has already seen a dramatic reduction in numbers of the insects. In the Brazilian city of Piracicaba, for instance, an 82 percent drop in mosquito larvae was observed in just nine months. These engineered insects contain a stable gene that causes offspring to die before reaching reproductive age, an environmentally friendly alternative to pesticides.
While Brazil may have been hard hit by Zika, other countries are also feeling the strain. Colombia, for example, has seen more than 13,500 people infected – a number that’s expected to leap up to a staggering 700,000 – following last year’s trend of chikungunya. Strangely, so far no cases of microcephaly have been documented in this country, despite the fact that 560 pregnant women have been infected so far. Still, the fear was enough for the country to advise that women wanting to become pregnant to delay doing so for up to eight months.