Key developments on swine flu outbreaks, according to the U.S. Centers for Disease Control and Prevention, the World Health Organization and government officials:

_Deaths: 42 in Mexico and two in the U.S., both in Texas. One of those who died in the U.S. was a toddler from Mexico.

_Confirmed cases: Nearly 1,900 worldwide in 24 countries; more than 1,100 in Mexico; more than 600 in the United States. Sweden and Poland reported their first cases Wednesday.

_U.S. health officials say it took only two weeks to identify the genetic characteristics of the strain, and they are in good position to quickly produce a vaccine.

_Canadian scientists have genetically sequenced the virus, a breakthrough they hope will help identify the origins of the virus and reveal how it spreads and mutates.

_World Health Organization calls a meeting of flu experts next week to discuss whether drug companies should switch their production from regular flu vaccine to pandemic vaccine.

_U.S. health officials say the median age for confirmed hospital cases in the United States is 15. And in Mexico, new figures show that almost half the confirmed swine flu deaths were of people 29 and younger.

_More than 140 schools totaling more than 100,000 students reopened Wednesday after closures stemming from swine flu, according to the U.S. Department of Education. About 590 schools totaling about 370,000 students remained closed, but many were set to reopen Thursday or Friday. U.S. health officials on Tuesday withdrew recommendations that schools with suspected swine flu cases close.

_Mexico allows most businesses to reopen Wednesday, with high schools and universities to reopen Thursday and primary schools to reopen next week. Mexico City says all businesses – including sports arenas, dance halls, movie theaters and all restaurants – will be allowed to operate Thursday but must screen for ill people and make surgical masks mandatory for employees and customers.

_Haiti turns away a Mexican ship carrying food aid because of swine flu fears.

_Dozens of Mexican nationals quarantined in China despite having no swine flu symptoms arrive in Mexico City on a government-chartered jet. Some complain the Chinese humiliated them and discriminated against them. China’s foreign ministry denies singling out Mexicans.

_U.S. Embassy in Beijing says two Americans quarantined in China have been allowed to leave, while two others are still being kept in isolation. China also lifts its quarantine early for a group of Canadian students.

_U.S. Navy cancels the deployment of the San Diego-based USS Dubuque and orders crew of about 370 to be treated with antiviral drugs after a crew member’s illness is confirmed as swine flu.