In the U.S., the CDC's count rises to more than 100 confirmed infections. Worldwide, WHO reports the number of lab-confirmed cases worldwide rose to 236 in 11 countries, with Switzerland, the Netherlands and Peru the latest to announce cases.
Robert Gibbs, White House press secretary, says a staffer on Obama's recent trip to Mexico apparently carried the virus home. Gibbs said that person never came within 6 feet of the president.
The World Bank in Washington, D.C., says a staff member who traveled to Mexico on business April 14-18 has been "preliminarily diagnosed" with swine flu.
Mexico government orders all nonessential businesses to close. According to Mexico's health ministry, there are a dozen confirmed deaths from swine flu in Mexico, but upwards of 170 deaths there are suspected of having been caused by the virus.
WHO's decision to raise the alert level helps mobilize pharmaceutical companies and governments to start manufacturing adequate antiviral drugs and speed up the creation of a vaccine.
Health officials confirm the death of a 22-month-old boy in Texas -- the first swine flu death in the U.S. The boy was from Mexico and had traveled with his family to visit relatives in Brownsville, Texas, on April 4. He developed a fever on April 8, followed by other flulike symptoms.
Homeland Security Secretary Janet Napolitano resists the notion that it's necessary to close the U.S.-Mexico border when pressed by Sen. John McCain. "What we have been told by the experts is that any kind of universal closing of a port would have no impact or very, very little impact at all on the spread of this virus," Napolitano says. "This virus is already in the United States, so any kind of containment theory that you're going to keep it out of the United States is -- is really moot at this time."
Gallup poll shows 78 percent of Americans are not worried about swine flu and only 1 to 3 percent are changing their daily lives because of it.
WHO has confirmed more than 100 cases in at least nine countries. In the U.S., the virus in in at least ten U.S. states, infecting nearly 100 people. WHO confirms eight deaths -- sevent in Mexico and one in the U.S.
With the majority of U.S. cases in New York, New York City health officials say they have stopped trying to test everyone who gets sick, just focusing on those with the most severe cases, meaning that the "confirmed" number of illnesses will fall further and further behind the actual number of people who are sick.
Texas Gov. Rick Perry makes an official disaster declaration, allowing access to further state emergency resources. Fort Worth closes all schools until May 8. State officials postpone all public high school athletic and academic competitions until May 11.
Federal health officials say 25 percent of the U.S. stockpile of antiviral drugs like Tamiflu & Relenza are being shipped to states.
China's Commerce Ministry says the government is providing $5 million in humanitarian assistance to Mexico, for masks, gloves, disinfectants, infrared thermal scanners and other equipment.
Egypt begins slaughtering the country's roughly 300,000 pigs as a precaution.