On Friday, the World Health Organization reported that Zika remains a global emergency. The WHO's Zika committee also reported that doctors had found no evidence of a significant spread of the virus during the Olympic Games in Rio de Janeiro last month, boding well for a "low risk assessment" ahead of September's Paralympics.

"Certainly we feel fairly confident that the risk assessment that there would be no significant increased transmission due to the Olympics is very much on track," Peter Salama, the executive director of the WHO's Health Emergencies Program, said after the meeting. He added that the UN agency had received no reports of symptoms in people returning from the games - although the virus often proves asymptomatic.

Researchers link Zika to the potentially fatal Guillain-Barre syndrome, which can lead to weakness and paralysis. Zika can prove especially dangerous for pregnant women and their fetuses.

WHO officials said studies would continue to figure out why certain regions of Brazil have reported an increase in babies born with microcephaly, a developmental disorder that causes smaller-than-average heads. Dr. David Heymann, the committee's chair, said considerable gaps remained in understanding Zika and the complications it causes.

'Not surprising'

Seventy-two countries and territories have reported infections, with Singapore reporting an outbreak earlier this week. Health authorities in the state of Florida say they have found the first mosquitoes known to carry the virus on the US mainland in the tourist hot spot of Miami Beach, where doctors had previously reported cases of locally transmitted Zika, which also spreads through sexual contact.

"This is disappointing but not surprising," state Agriculture Commissioner Adam Putnam said in a statement Thursday. "Florida is among the best in the nation when it comes to mosquito surveillance and control, and this detection enables us to continue to effectively target our resources," he added.

Officials detected Zika in Miami Beach in July and reported the first locally transmitted cases in mid-August. Officials have also found Zika in two other counties in Florida.

Authorities have issued an advisory for pregnant women, warning against travel to parts of Florida designated as active transmission zones. Forty-nine people have contracted Zika in the state, according to Florida's Health Department, which reports another 656 cases brought in by people who had traveled abroad - mainly in areas of Latin America. That includes a total of 80 pregnant women infected so far.

The US Food and Drug Administration has instructed blood banks to screen for Zika. The United States had previously declared a health emergency over Zika in the territory of Puerto Rico.

mkg/ (Reuters, AFP, dpa, AP)