The toll from swine flu in the US reached five on Friday, with nearly 5,000 confirmed cases.
Texas state health officials late on Friday announced that a man who died last week in South Texas has been confirmed by laboratory tests to be infected with the A (H1N1) flu virus. The victim was described as in his 30s and suffering underlying health problems that increased his vulnerability to flu complications.
Phoenix, Arizona officials Thursday revealed that a woman in her late 40s with lung disease had died last week from complications of the same virus.
New York Mayor Michael Bloomberg said Friday that one person was hospitalized with severe symptoms of what appeared related to the A (H1N1) influenza virus while three schools in the city have been closed after many students were found sick. Three additional schools were ordered closed later Friday.
The US Centres for Disease Control and Prevention (CDC) said Friday that there have been 4,714 confirmed or probable cases in the United States.
Bloomberg said in a news conference after visiting a closed school in Queens that the sick students showed symptoms that are no more serious that seasonal flu, which strikes people in winter. More than 2,000 New Yorkers died each year from seasonal flu.
"If you're sick, stay home. Parents should keep their children at home if they are feverish, and if you have difficulty breathing, go to the hospital," Bloomberg said, repeating a message that offered already weeks ago, when New York was hit with the first confirmed US case of so-called swine flu.
New York City had the largest cluster of flu cases in the US in early May, with most of the confirmed cases concentrated at the Saint Francis preparatory school. That school and one nearby were closed for a week.
Authorities said the new cases were not connected to the earlier school closures, where health authorities confirmed close to 50 flu cases in late April.
"While the symptoms of H1N1 flu seem to resemble those of seasonal flu, the H1N1 virus appears to spread rapidly," Bloomberg said. "So we're closing these schools in order to slow transmission."
With the new closures, thousands of students had to stay home while their classrooms were being sanitized.
Bloomberg, meanwhile, was losing his city health Commissioner, Thomas Frieden, who was nominated Friday by US President Barack Obama to become the head of the CDC, based in Atlanta, Georgia.
Frieden, 48, has been health commissioner for New York City for seven years, drawing praise for handling the swine flu outbreak in the city of more than 8 million people. Frieden is expected to take the helm next month at the CDC.
Last week, a man with heart problems died from H1N1 flu complications in Seattle, Washington. The two other human deaths in the United States occurred in Texas, which like Arizona borders Mexico, where the outbreak first spread widely.