The World Health Organization (WHO) now claims that the Zika virus was more dangerous than was earlier assumed. "The geographic spread of the disease is greater, because the risk groups are bigger and the fact that it can be sexually transmitted as well as by being bitten by an infected mosquito", said WHO Director-General Margaret Chan in Geneva. She added that "it is alarming".

There has been no significant break-through in finding a vaccine or a way to eliminated infected mosquitoes. The WHO says that latest studies indicate that the virus is the cause for the rise of microcephaly in babies, a condition defined by unusually small heads that can result in developmental problems. It has also been associated with other neurological problems like Guillain-Barre syndrome, a rare disorder in which the body's immune system attacks part of the nervous system.

Last month, WHO declared the explosive spread of Zika in the Americas to be a global emergency. Zika outbreaks have been reported by some 50 countries. The US #link:http://www.cdc.gov/zika/geo/active-countries.html:Center for Disease Control and Prevention#, CDC, lists on its homepage where Zika outbreaks have occurred. Outside of the Americas it has spread to the Caribbean as well as Pacific Islands like Samoa.

David Heymann, who chairs the emergency expert committee that advises WHO on Zika said it was the responsibility of every country to clearly identify the areas where an outbreak has occurred. He added that "it was then the responsibility of pregnant women then to decide whether or not to travel to these regions". The WHO has not issued a general travel warning but it has advised pregnant women to avoid areas where there have been Zika outbreaks.

The Zika virus has been known for nearly 70 years. It was first identified in rhesus monkeys in Uganda.

at / sbc (dpa, ape, rtre)