Even as New York City health officials said the death of a 16-month-old toddler who had flu like symptoms did not have swine flu, the number of schools closed in the city because of the virus rose again.
As of this evening, there were 25 schools closed in the city, an increase of nine over Monday's count, and another school in New Jersey was shut down because of tensions about the new virus.
Jonathan Zamora, of Corona, Queens, was admitted to Elmhurst Hospital Center Monday night around 9:30 with a high fever and "severe flulike symptoms," according to a Tuesday morning announcement by New York City Mayor Michael Bloomberg.
Officials at Elmhurst Hospital Center told The Associated Press that the boy died an hour after being admitted, but tonight officials said the boy appears not to have had H1N1 swine flu infection.
New York City has conducted tests that did not indicate that H1N1 swine flu was the cause of death, but a tissue sample has been sent to the U.S. Centers for Disease Control to confirm their results.
Bloomberg also said today that the flu is spreading at the Rikers Island prison complex, including four confirmed and four more probable cases. The jail can't be closed, but authorities are taking steps to contain the outbreak, he said.
The new tensions about the outbreak come just two days after the city's first confirmed death of a patient with swine flu. Meanwhile, amid a new cluster of school closings and revived discussions about whether the World Health Organization should raise the pandemic alert to the highest level, there is a new level of concern about the still mysterious swine flu virus.
On Monday, New York City officials closed 16 schools after 103 students in four schools came down with influenza-like symptoms in the past week. Late Sunday, 55-year-old assistant principal Mitchell Wiener died from complications of the swine flu he likely contracted in an outbreak at his school.
Wiener's untimely death was the sixth in the United States that has been linked to swine flu.
But while the American deaths and the outbreak's rapid spread across the country has raised fears, health officials said it's still not clear how bad swine flu really is.
"The illness severity that we're seeing is still similar to what we've seen with seasonal influenza," Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases, said Monday at a press conference. "I think our best estimate right now is that fatality is likely a little bit higher than seasonal influenza, but not much higher."
Despite that, the new virus may be contributing to higher than normal levels of flu infections in general for this time of year -- as well as more school-based outbreaks, which Schuchat said are unusual for spring time.
"About half of what we're seeing lately is the novel H1N1 strain," she said.
Mysteries surrounding the illness remain. Schuchat said that even with the climbing reports of cases, the overall numbers are not yet high enough to make solid conclusions about how severe this illness will be in terms of sickness and death.
"Things could change quickly, and we do continue our efforts to prepare for fall, where history tells us we could have another outbreak," she said. "I think it's important to dispel the idea that we're out of the woods or that this was a problem that really didn't merit response," she said.
Worldwide, health officials are identifying more cases. According to WHO statistics released Tuesday morning, 9,830 cases of swine flu have now been identified in 40 countries, and 79 of those infected have died.
Yet prominent infectious disease experts say that even if the WHO does raise the pandemic alert to 6 -- the highest level -- the formal classification is not likely to sway future public health response.
Experts Debate What a Swine Flu Pandemic Threat Level Means
"Pandemic level is another disservice; it reflects only the degree of spread of a bug and nothing else," Dr. Frank James of the School of Public Health and Community Medicine at the University of Washington, Seattle told ABC News. "If a team of experts went out looking for the bug widely they could find it now in enough areas to qualify this as a Level 6."
Dr. William Schaffner, chairman of the Department of Preventive Medicine at Vanderbilt Medical School, also wondered what a "Level 6" definition would mean for people affected.
"I continue to wonder whether this is useful, given the general level of severity of the illness," he said. "Recall that these levels relate only to geographic distribution of the illness, not severity."
To further complicate the matter, severity of the flu is not the only important signal to those fighting infectious disease. If it is too lethal, the flu might defeat itself by killing its victims before there's time for the virus to spread.
"One of the better determinants is the incubation period," said Robert I. Fields, chair of the department of health policy and public health at the University of the Sciences in Philadelphia.
Fields said a long incubation period with mild to no symptoms would allow the virus to spread quickly and widely before people quarantine themselves. Couple a long incubation period with a particularly deadly strain, and doctors have their "worst nightmare" of a flu virus, Fields said.
When to See the Doctor for the Flu
While experts search for signs of how deadly the swine flu may become on a global scale, family physicians and emergency medical doctors say patients at home are in the same quandary: how to tell if this flu will pass as usual or turn serious and deadly.
"People who are walking around with a normal-grade fever shouldn't be going to the emergency room for treatment, even though they are," said Dr. Andrew Sama, a member of the American College of Emergency Physician's Board of Directors.
Sama said the majority of flu cases can be treated at home or with a phone consultation, or a visit to the family doctor.
In the most severe cases, Sama said patients will be shuttled off to the intensive care unit to protect from respiratory failure. He said most people survive, "But generally speaking not everyone who is on a respiratory ICU treatment can be saved."
"Generally speaking only people who are really ill from the flu -- non-stop vomiting, extremely high fever, inability to eat and drink, excessive weakness, chest pain, severe cough, lethargy, trouble breathing -- should come in," he said.
However Sama and Dr. Lori Heim, the president-elect of the American Academy of Family Physicians, said three specific groups of people should go to the doctor with much less severe symptoms: children under age 4 with a high fever, people with compromised immune systems and the elderly.
"If you're one of the lucky people in the country who has a regular physician, calling them would be my first choice," Heim said. "But if you can't breathe, don't wait for a phone call back."