WASHINGTON -- At least 32 people have died from West Nile virus in the United States, with New York reporting its first fatality late Monday, as authorities examined the possible spread of the disease through transfusions and transplants.

Late Monday, the New York Department of Health and Mental Hygiene announced the city's first fatality of the season. A 73-year-old man from Jackson Heights in the Queens Area of the city died Sunday, the New York Authority said.

The man, who has not been named, was hospitalized August 30 suffering from encephalitis. Two other people, including an 82-year-old woman, also from Queens, have been diagnosed with the disease.

Earlier, the Centers for Disease Control and Prevention (CDC) said one of four people to receive a transplant of organs from a woman carrying the West Nile virus died last week.

All three others have developed symptoms of the virus, the CDC said.

With public alarm growing over the disease, doctors are worried because if the cases are confirmed it will show West Nile can be spread from human to human and not just by mosquitoes.

"Preliminary evidence suggests that these illnesses may be due to West Nile virus infection," said a CDC statement.

According to the National Center, on top of the confirmed deaths across the country, 638 of those infected have needed hospitalization.

The woman who provided the organs for transplant died in a car accident last month. She received several blood transfusions before dying. Either she or the infusions could have been infected.

Two transplant operations were carried out in Florida and two in the southern state of Georgia. All four patients soon fell ill with fever and other symptoms of encephalitis which attacks the central nervous system.

One person in Atlanta, Georgia who received a kidney from the woman, died Thursday from acute encephalitis, according to James Hughes, director of the CDC's National Center for Infectious Diseases.

The other Georgia recipient is slowly recovering.

In Florida, a 63-year-old man who had a heart transplant is in a critical condition at the Jackson Memorial Hospital in Miami. So far there have been no confirmed cases of West Nile in Miami-Dade County.

Samples of the blood and the transplanted organs have been sent for testing to a government laboratory at Fort Collins in Colorado.

The Food and Drug Administration has ordered blood bank organizers, such as the Red Cross, to carry out stricter checks of donors.

The virus was first isolated in the West Nile district of Uganda in 1937, and emerged in parts of Europe in recent years. It first appeared in the United States in New York in 1999 and has pushed farther west each year.

But with the cases receiving growing publicity, the authorities have insisted that there is no cause for panic. "We think the risk is very, very low," AFP quoted Hughes as saying. "We certainly wouldn't consider a moratorium on blood transfusions."

Doctors say that 80 percent of people infected do not develop any symptoms. Those most affected are elderly or have compromised immune systems and suffer a slight fever for three to six days.

In about one case in 150, the virus causes encephalitis which in its most severe form can be fatal.