Geneva - Swine flu, according to the latest data, is the main type of influenza being transmitted globally, the World Health Organization said Friday.

"Pandemic (H1N1) influenza virus continues to be the predominant circulating virus of influenza, both in the northern and southern hemisphere," the WHO reported, using the technical name for the disease.

In Japan, influenza activity was increasing past the seasonal epidemic threshold, "indicating an early beginning to the annual influenza season," the status update said.

Many countries in south and south-east Asia and South America reported increasing or sustained high levels of respiratory disease, but two, Thailand and Brunei Darussalam, noted a decline.

In Central America and the Caribbean respiratory disease levels appeared to be declining. Canada and the United States had low overall influenza activity, the WHO said, but there were regional increases in the southeastern US.

South Africa and the southern and western parts of Australia still had high overall rates of influenza, while European countries had mixed reports, with most noting low flu activity but a few sustaining a high number of cases or respiratory diseases.

According to the health agency's latest tally, there were over 254,206 confirmed cases of infection around the world, leading to at least 2,837 deaths.

The Americas remained the hardest hit region, accounting for at least 116,046 cases, with 2,234 incidents proving fatal.

The WHO says that because "countries are no longer required to test and report individual cases, the number of cases reported actually understates the real number of cases." (dpa)