Asia's first swine flu case reported in Hong Kong

• WHO confirms over 300 cases of virus around the world
• Mexicans told to stay indoors for five days

The first case of swine flu in Asia was confirmed by the Hong Kong government today as the worst-hit country, Mexico, began an unprecedented nationwide shutdown in a bid to contain the spread of the virus.

The World Health Organisation (WHO) raised its tally of confirmed human cases of the virus to more than 330.

Thirteen countries around the world have reported confirmed cases, including Denmark, which also announced its first case today.

Rory Carroll in Mexico City Link to this audio

The Hong Kong government's chief executive, Donald Tsang, told reporters a Mexican citizen who had flown to the territory with a stopover in Shanghai had developed a fever after arriving yesterday. The patient has been isolated in a hospital and is in a stable condition.

Tests by Hong Kong's department of health and the University of Hong Kong confirmed the diagnosis, Tsang added.

Mexico has confirmed 156 cases and nine deaths, although authorities suspect the actual death toll is closer to 180. The US has 109 cases and one death, a 23-month-old boy from Mexico who died in Texas.

There are confirmed cases in Canada, Spain, Britain, New Zealand, Germany, Israel, Austria, the Netherlands and Switzerland.

However, the WHO figure of 331 confirmed cases, up from 257 yesterday, does not include all the most recent figures from various governments and disease control agencies. The US says it has 132 confirmed cases; Mexico says it has 300.

The Mexican government has ordered most of the economy to be shut down and for people to stay indoors for five days.

The nation of 111 million people will grind to a halt until 5 May in an effort to stifle the spread of swine flu, which is on the brink of becoming a global pandemic.

"There is no safer place than your own home to avoid being infected with the flu virus," Felipe Calderón, Mexico's president, said in a television address.

Transport, policing, supermarkets and hospitals will continue but otherwise the country will largely come to a standstill. It is already operating at half-strength since earlier this week when schools, cinemas, restaurants, gyms and other services were closed or access to them was heavily restricted.

Celebrations for Dia del Nino, Day of the Child, have been cancelled today.

The shutdown will be painful for Mexico's economy, which is already suffering from recession and a bloody drug war. Central bank analysts suggest the economy may have shrunk by as much as 8% in the first three months of the year, compared to the same period in 2008.

Tourism, worth 8% of Mexico's GDP, has evaporated. Several countries in the region have cut or restricted flights to and from Mexico, and Cancún airport has been flooded by tourists trying to get out. The state of Quintana Roo, where Cancún is located, has yet to report cases of swine flu but several tourists were found to be infected after returning home. Archaeological sites have been shut.

In New Zealand the Roman Catholic church today instructed priests not to place communion wafers on worshippers' tongues or to allow them to share communion wine from a single chalice during mass because it could spread germs.

Maori politician Rahui Katene also urged a temporary halt to the hongi, a traditional greeting where two people press their noses and foreheads together and exchange breath, the New Zealand Herald reported.