Travel alert after fears of Zika virus link to birth defects

Pregnant women are being advised to consider postponing travel to areas affected by Zika amid global concern at the spread of the mosquito-borne virus in Latin America.

With a rapidly evolving epidemic in Brazil, Mexico and eight other states, international health authorities have urged travellers to take precautions in view of possible – though unconfirmed – links between the virus and neurological defects in babies. A further 10 states in central and South America have reported sporadic transmission of the virus.

In an updated risk-assessment at the weekend, the European Centre for Disease Surveillance and Control (ECDC) advised pregnant women and women who are trying to become pregnant, and who plan to travel to affected areas, to discuss it with healthcare providers and consider postponing their trip.

Travellers with immune disorders or severe chronic illness are also advised to consult a doctor before travelling and everyone going to affected areas should take steps to prevent mosquito bites.

The advice has been endorsed in Ireland by the Health Protection Surveillance Centre, a division of the Health Service Executive, while the Department of Foreign Affairs has issued travel advice to reflect the recommendations. The Tropical Medical Bureau, which has 20 clinics in the Republic, said it had received a small number of queries from intending travellers about the virus.

Zika was first identified in rhesus monkeys in Uganda in 1947 and was reported in humans in 1952. Unlike its cousin dengue, which can cause high fever and joint pain, Zika produces symptoms, including mild fever and rash, that are often so light that people don't know they have the disease. Only one in five of those who get infected feel sick, and the symptoms last for just two to seven days.

But the spread of the virus in Brazil has coincided with a surge in birth defects. Brazil’s health ministry said last week that 3,893 cases of microcephaly, a rare congenital condition in which babies are born with an abnormally small head, have been associated with Zika. Infants probably contracted the virus from their mothers who were infected while pregnant, the ministry said. The condition leads to irreversible neurological damage that affects movement and vision.

In Colombia, which has recorded the second-highest number of Zika cases after Brazil, the health ministry has told medics to treat pregnant women who are infected with the virus as high-risk pregnancies.

The World Health Organisation said agencies investigating the Zika outbreaks were finding "an increasing body of evidence" about the link between the virus and microcephaly. "However, more investigation is needed before we understand the relationship between microcephaly in babies and the Zika virus. Other potential causes are also being investigated," the organisation said on its website.

Dr Graham Fry, medical director at the Tropical Medical Bureau, said that in 2015 there were a "colossal" 40,000 cases of Zika in French Polynesia and, of these cases, there were no reports of microcephaly. "Did it happen? Possibly. But no one picked up that it was a specific issue linked with the Zika virus," he said. "Until there is a lot more research, they're not going to know for certain that Zika is definitely linked with microcephaly, but . . . out of an abundance of caution they are advising people to be careful."

“If you’re pregnant or planning to become pregnant, if you can avoid travel to the current at-risk countries that would be the wisest precaution,” he said.

Some experts have suggested that the virus may have arrived in Brazil during the 2014 World Cup, carried by visitors from French Polynesia.

According to the ECDC, there has been increasing or widespread transmission of Zika in El Salvador, Venezuela, Colombia, Brazil, Suriname, French Guiana, Honduras, Mexico, Panama and Martinique. Sporadic transmission has been reported in Bolivia, Guyana, Ecuador, Guadeloupe, Guatemala, Paraguay, Puerto Rico, Barbados, Saint Martin and Haiti.