State has first swine flu fatality

In many ways, the woman fit the demographics of the hardest-hit victims. She was relatively young, and officials said she had other medical conditions that may have made her more susceptible to complications of the virus.

The woman, whose identity was not disclosed because of patient confidentiality laws, arrived gravely ill at a Boston hospital June 5, spent time in an intensive-care unit, and died there Sunday, according to disease specialists at the Boston Public Health Commission. Separately, officials requesting anonymity identified the hospital as the Boston Medical Center and said the woman has at least one child.

The health agency's executive director said a preliminary review showed that the woman had previously sought hospital care, and city disease trackers were investigating whether the woman had underlying health problems that made her more susceptible to complications of the virus, known by the scientific name H1N1.

The city was alerted about the case yesterday morning, and by last night, facts remained sparse. City officials said there was no indication that the woman worked in a school, hospital, or doctor's office, sites where a virus could spread with ease and speed.

"This is a reminder flu can be serious," said John Auerbach, the Massachusetts public health commissioner. "We expect that there will be other people who will be seriously ill with H1N1, and, sadly, we do expect that other people will die."

Boston has recorded 441 confirmed cases of swine flu since late April, and 54 of those patients spent at least one night in a hospital. Statewide, 1,153 cases have been definitively identified through laboratory testing, resulting in 80 hospitalizations.

But that is believed to be only a small fraction of the total number of people stricken with the disease since it made its first appearance here about six weeks ago. For most people made ill by the germ, the symptoms mimic the seasonal flu: fever, cough, aches, and pains, but no serious side effects and, in many cases, no visit to the doctor.

That is why disease specialists took great pains yesterday to urge the public to be vigilant for signs of the flu while also not saying anything that would incite panic.

"It is important to remember as we grieve the loss of life today that the vast majority of people with H1N1 flu have relatively mild cases and fully recover," said Barbara Ferrer, executive director of the city health agency.

The Northeastern United States has been hit especially hard by the virus, baffling disease detectives. New York City alone had reported 16 deaths by last week.

"For reasons that are not clear, Boston is seeing a tremendous amount of H1N1 activity compared to some other parts of the country," said Dr. Anita Barry, director of the Infectious Disease Bureau at the Boston Public Health Commission. "If you compare us to anywhere other than New York City, our numbers would be quite a bit higher."

It is one of several mysteries that continue to frame investigations into swine flu, which has migrated from its birthplace in Mexico to 75 other countries around the world.

Specialists are trying to unravel why children and young adults have disproportionately borne the burden of the disease, which has largely spared the old. In Massachusetts, three of every four confirmed cases of the disease have been detected in people 25 and younger. As a result, hundreds of schools across the country have suspended classes as the virus moves with unusual alacrity.

It is typically the elderly who are the most susceptible to complications from the usual seasonal flu, which kills an estimated 36,000 Americans annually.

"The unfortunate news is that it seems to spread faster, at least in school-aged children, than we've been accustomed to seeing," said the new director of the federal Centers for Disease Control and Prevention, Dr. Thomas Frieden, who previously served as New York City's health commissioner. "The good news is that so far we've not seen lots of disease among the elderly."

The virus has proved most troublesome to people with underlying medical conditions such as asthma, diabetes, kidney disease, and serious cardiovascular complications. In fact, a review by disease specialists in New York City showed that more than 80 percent of hospitalized swine-flu patients suffered from underlying conditions that made them prime targets for the germ.

That is why the medical history of the 30-year-old Boston woman will prove central to the city's investigation. Did she have serious existing maladies, following the pattern of so many other victims? Or will her death reveal some new fact?

The answers will help physicians such as Dr. Lauren Smith, medical director of the state Department of Public Health, craft their messages for the public.

"This has gone on for a little while now, and there's vigilance fatigue that's set in," Smith said. "So we're walking a fine line, reminding people that in most cases, it's a relatively mild illness.

"But we also want to make sure," she said, "that if people with underlying illnesses develop symptoms, they should talk to their doctor."

Stephen Smith can be reached at stsmith@globe.com.