Social distancing and a little prudence in sneezing and coughing in public will help Filipinos avoid the deadly swine influenza virus, Health Secretary Francisco Duque said Thursday.

When sneezing or coughing, Duque said it is important for people to cover their mouths with handkerchiefs, tissue paper or their shirt to prevent transmitting the virus to other people.

He also urged the public not to get too close to people when talking. Touching, kissing and hugging in public was also discouraged.

 “Sing 'Happy Birthday' to make sure that you have thoroughly washed your hands,” he said.

Duque, meanwhile, urged people to drop the "swine" flu tag and instead call the illness "Mexican" flu. He said the swine flu tag has affected the sales of pork in the country.

More than 150 people are believed to have died from swine flu in Mexico though the number confirmed by strict laboratory tests is just seven. More than 1,600 people have been infected in Mexico and the World Health Organization has stepped up pandemic warnings in recent days.

The WHO on Wednesday raised its flu alert to phase five out of six, WHO chief Margaret Chan said, signalling that a pandemic was "imminent" following the swine flu outbreak.

Phase five, one step short of a full pandemic or phase six, is characterised as a "strong signal that a pandemic is imminent and that the time to finalise... the planned mitigation measures is short," according to the WHO's global emergency planning.

Duque earlier assured the public that the deadly swine flu has not reached the Philippines.

Eric Tayag, the head of the DOH National Epidemiology Center, said the government has intensified the monitoring of arrivals at airports and urged people to limit physical contact in public.

The DOH said there was no ban on arrivals from Mexico or other parts of North America but asked Filipinos to "reconsider their plans" to travel to Mexico.

Health officials said 11 thermal scanners operating at the country's international airports -- first set up during the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak in Hong Kong -- would detect any fever among new arrivals and that four extra scanners had been ordered.

District health officials have also been asked to be vigilant for outbreaks of flu or "atypical pneumonia" that might be a sign of swine flu.

Duque said the Philippines was merely "tweaking and improving the systems" already in place for preventing the spread of SARS and bird flu.

He said the disease cannot be transmitted by eating properly cooked pork, but as a precaution the government temporarily banned pork products from the United States and Mexico.