2:00 p.m. (AP) - A U.S. travel alert has been issued for four more destinations because of the Zika virus.
Health officials on Monday added American Samoa, Costa Rica, Curacao and Nicaragua to the list of places with outbreaks where travelers should take precautions against the mosquito-borne virus.
Because of mounting evidence linking Zika infections to a birth defect, the government recommends that pregnant women consider postponing trips to places on the list.
1:45 p.m. (AP) - U.S. House members are asking government health officials for more information on the Zika virus.
The requests from top Republicans and Democrats on the House Energy and Commerce Committee follow the World Health Organization's declaration of mosquito-borne Zika as a global health emergency. The virus has been linked to birth defects.
The committee members asked officials from the Department of Health and Human Services, the Centers for Disease Control and Prevention and the National Institutes of Health for briefings on the disease. In letters, they asked for information on research, testing and available dollars to ensure the U.S. is prepared.
In a letter to the CDC, they asked if a travel warning could have been issued sooner.
1:27 p.m. (AP) - In Rio de Janeiro, a union made up of workers handling the Zika virus response on the ground is threatening to go on strike just as Brazil gears up to fight the Aedes aegypti mosquito that transmits the disease.
The union is demanding better working conditions, as well as uniforms, sunscreen and bug repellent for city workers going door-to-door in hopes of wiping out the mosquito.
Sandro Cezar is the secretary general at the city's SINTSAUDE union. He said Monday that the union's 7,000 workers will go on stage if Brazil's health ministry doesn't meet their demands by Thursday.
Cezar also warns that more than 220,000 other health workers could later join them in a nationwide stoppage.
11:37 a.m. (AP) - The World Health Organization has announced that the explosive spread of the Zika virus in the Americas is an "extraordinary event" that merits being declared an international emergency.
The agency convened an emergency meeting of independent experts on Monday to assess the outbreak after noting a suspicious link between Zika's arrival in Brazil last year and a surge in the number of babies born with abnormally small heads.
Although WHO Director-General Dr. Margaret Chan said there was no definitive proof that the Zika virus, spread by mosquitoes, is responsible for the birth defects, she acknowledged on Thursday that "the level of alarm is extremely high."
The last such public health emergency was declared for the devastating 2014 Ebola outbreak in West Africa, which killed more than 11,000 people.
WHO estimates there could be up to 4 million cases of Zika in the Americas in the next year.