Washington - US officials said Thursday the US swine flu confirmed-case total had risen to 109, up from 91 on Wednesday.

Dr Richard Besser, acting director of the US Centres for Disease Control and Prevention, said six people have been hospitalized since the disease outbreak began earlier this month, including the 23- month-old Mexican toddler who died Wednesday in the Houston's children's hospital.

The first suspected case in the nation's capital was reported Thursday, when the World Bank reported that one of its staffers was diagnosed with the disease after a business trip to Mexico earlier this month.

Mexico is the epicentre of the outbreak, with 159 influenza- related deaths.

The World Bank said the staff member travelled to Mexico from April 13 to 14, before news of the outbreak had emerged, and had come into the World Bank's headquarters in Washington for one day before falling ill. The person had since made a full recovery from the flu.

In broadcast remarks, Besser welcomed the decision by the World Health Organization to raise the pandemic alert for swine flu by one level to phase 5 Wednesday night in Geneva.

The declaration of phase 5 is a strong signal that a pandemic is imminent, though not inevitable. It is characterized by the human-to- human spread of the virus into at least two countries in one WHO region.

It was a "wake-up call to the rest of the global community," Besser said. "If you've not paid attention before, it's time to pull out your pandemic plans."

He said it was also time for the global community to think about helping other countries which have not been planning as intently "as we have in the US."

Besser said the flu has been confirmed in one more state, South Carolina, bringing the total of states with confirmed cases to 11.

He greeted the fact that Mexico now has a laboratory up and running that is able to identify the H1N1 virus. Until now, Mexico had been sending tissue samples to the US and Canada for diagnosis.