As more cases of swine flu are reported in various parts of the world, governments and health officials have scrambled to take precautions to prevent the outbreak from entering their borders.
The World Health Organization urged countries worldwide to look out for "unusual" outbreaks of flu following an emergency meeting. It said it will decide on Tuesday whether to raise the pandemic alert level.
The following is sample of what some countries are doing to combat the outbreak:
Cases: Six mild cases
Measures: Issued a travel health notice, saying its public health agency was "tracking clusters of severe respiratory illness with deaths in Mexico."
Measures: Banned pork imports from Mexico, and from California, Kansas and Texas in the United States.
Measures: Health officials met with representatives of the WHO to discuss preparedness against a potential flu outbreak.
Measures: Increased surveillance; testing the temperatures of travelers flying into the country.
Cases: Doctors are running tests on two men who recently returned from Mexico with light flu symptoms.
Measures: The Health Ministry has not issued special instructions to the public, nor adopted measures for monitoring those returning from Mexico.
Measures: Will convene a Cabinet meeting Monday to come up with measures to block the entry of the virus into the country.
Thermographic devices are testing the temperature of passengers arriving from Mexico at Narita International Airport, which serves the Tokyo area.
Cases: The country's health minister says 103 deaths are thought to have been caused by swine flu. An additional 1,614 cases have been reported in the country.
So far, however, only 18 cases have been confirmed by laboratory tests in Mexico and reported to the World Health Organization.
Measures: Mexico City has closed its schools and universities until further notice.
Troops passed out 4 million filter masks in the city of 20 million residents.
Officials are considering shutting down the bus and subway systems.
Citizens are asked to avoid large crowds, refrain from kissing, and stay at least two meters (six feet) from one another.
The World Bank is offering $205 million to deal with the outbreak.
Cases: Twenty-two students and three teachers, who returned from a three-week-long language trip to Mexico, remain quarantined at home while the World Health Organization checks specimens to see whether they test positive for swine flu. Ten students tested positive for influenza A -- the general category of strains that includes the H1N1 swine flu.
Measures: Officials are tracing passengers on Air New Zealand flight NZ1, the flight that the college study group took to get back home.
Asked New Zealanders who traveled to Mexico or North America in the past two weeks to get in touch with health officials if they are showing flu-like symptoms.
Measures: Banned all meat imports from Mexico and the southern United States.
Announced it will screen incoming passengers from those two countries by taking their temperatures.
Set up a government commission to plan response, and advised citizens against traveling to Mexico.
Measures: Will test airline passengers arriving from the United States.
Cases: In Spain, about 16 cases were being looked into as possible swine flu infections, the country's health minister said. Lab tests confirmed another case had tested positive.
Measures: "We do not have an emergency situation in Spain, but we are working to prevent any possible development, and we are taking action in accord with the World Health Organization" guidelines, said Health Minister Trinidad Jimenez.
Measures: Airport officials are keeping a closer eye on passengers arriving from Mexico.
The public health ministry is calling the virus "the flu that has caused an outbreak in Mexico," so that the public does not confuse "swine flu" with "bird flu." The ministry also said it did not want to adversely affect the pork industry.
UNITED ARAB EMIRATES
Measures: The ministry of health issued a circular to doctors asking them to be fully prepared to deal with any potential swine flue cases.
Cases: A British Airways crew member developed flu-like symptoms during a flight from Mexico City and was tested for swine flu, but the results came back negative.
Measures: No travel advisories or quarantines issued.
Cases: 20 confirmed. The largest number of cases was in New York, where the Centers for Disease Control and Prevention confirmed cases in eight students at a preparatory school in that city. An additional seven cases have been confirmed in California; two each in Kansas and Texas; and one in Ohio.
Measures: The government declared a public health emergency to free up federal, state and local agencies and their resources, should the need arise.
Homeland Security Secretary Janet Napolitano canceled a trip to the Czech Republic this week in order to monitor swine flu preparations and response.
No travel advisories or quarantines issued.
Airlines are following their own procedures to watch for ill passengers, the U.S. Air Transport Association said. Workers at Los Angeles International Airport are also disinfecting restrooms to try to stop the spread of the disease.