Colombia declared Monday its Zika epidemic is over, but warned that the mosquito-borne virus, which is blamed for causing brain damage in babies, would continue circulating on a smaller scale.

Colombia has been the second hardest-hit country by the disease after Brazil, with nearly 100,000 cases and at least 21 babies born with microcephaly, or abnormally small heads.

But 10 months into the outbreak, the health ministry said the number of reported cases had dropped to between 600 and 700 a week.

"Colombia is the first country in the Americas to declare the end of the epidemic," Deputy Health Minister Fernando Ruiz told a news conference.

The virus "now enters an endemic phase, in which a very small number of cases will undoubtedly remain in the future," he said.

"It's a virus that's here to stay."

Officials had initially predicted Colombia would register 450,000 to 600,000 cases of Zika before the epidemic was over.

The number of babies affected could continue to rise, however.

Doctors are still analyzing the cases of 160 babies born with birth defects to mothers who were infected with Zika during pregnancy, to diagnose their condition and determine whether the virus was the cause.

And new cases may be found in the coming months in babies conceived during the epidemic.

The total number of microcephaly cases could reach 100 to 300, Ruiz predicted.

Zika, which was discovered in Uganda in 1947, took the world by surprise when it emerged in the Americas last year with devastating effects.

Since then, health authorities in the region have sounded the alarm over a surge in babies born with microcephaly and other deformities apparently linked to the flu-like virus.

The virus is also suspected of causing nervous disorders, including Guillain-Barre Syndrome, which leads the immune system to attack the nerves and may lead to paralysis.

Colombian officials have registered 350 cases of Guillain-Barre.

Zika is mainly transmitted by the Aedes aegypti mosquito, but it has also been shown to spread through sexual contact.

Brazil has been the country hardest hit by the virus, for which there is currently no vaccine or cure.

Authorities there have confirmed more than 1,000 cases of microcephaly blamed on Zika.