Nearly 72,000 cases of Zika in Colombia since October: Authorities

Additionally, four cases of microcephaly have been associated with the virus in the country

Nearly 72,000 cases of Zika have been reported in Colombia since October, with almost 13,000 occurring in pregnant women, although the country is going through a decline in outbreaks, health authorities have said.

Additionally, four cases of microcephaly, the rare but irreversible condition in which babies are born with small heads and damaged brains, have been associated with the virus in the country, Colombia's National Health Institute (INS) reported.

Another 22 cases of potential microcephaly are under investigation, according to the INS, which estimated that some 300 instances of cranial malformation are likely in babies by September, a smaller number than initially predicted.

Earlier this month, US health authorities confirmed that Zika causes microcephaly and other severe fetal brain defects, after months of debate and uncertainty.

Since the beginning of the epidemic in October, a total of 3,292 cases have been confirmed by laboratories and 68,660 suspected cases have been documented.

In pregnant women, a total of 1,703 cases have been confirmed while another 11,099 cases have been noted by health officials.

While Colombia had originally estimated the number of Zika cases could triple through the end of June, the government emphasised that the epidemic was "dropping precipitously" for the time, and faster than predicted.

From April 10 to 16, a total of 3,322 suspected Zika cases were reported in Colombia, but none were confirmed by a laboratory, according to the latest INS bulletin.

Mosquito-borne Zika is present in 130 countries and recent studies have shown it can also be transmitted sexually between human carriers.

Since the beginning of the epidemic in October, a total of 462 cases of neurological disorders have arisen in Colombia with possible ties to Zika.

Of these, 304 are cases of Guillain-Barre, a rare condition suspected of being linked to Zika, in which the body's immune system attacks a part of the nervous system that controls muscle strength.

There are currently no vaccines or treatments for Zika.

According to the World Health Organisation, at least a dozen laboratories and government agencies around the world are working on a vaccine, but bringing it to market could take years.