Flu season’s weighty new issue

As this year’s flu season in Los Angeles claims its first victims, medical officials are increasingly focusing on obesity as a risk factor for the virus.

Three people have died in the county so far this flu season—a 48-year-old man, a 29-year-old woman and a 4-year-old boy. Both of the adults who died were obese, and all of the victims died from an influenza strain that can be prevented by the flu vaccine, public health authorities said. They urged flu shots for everyone over the age of six months to help protect them during a fast-moving flu season that is expected to accelerate through February and continue into the spring.

Unlike last year, when there were highly-publicized vaccine shortages and widespread public concern about H1N1, commonly known as the swine flu, this year’s influenza season seems to be attracting less attention so far.

But it can be just as dangerous.

And, as the cases involving this season’s first Los Angeles County victims show, obesity could play a role in how seriously the highly contagious virus plays out.

A Public Health department analysis of last year’s flu season, when the H1N1 pandemic was in full swing, shows that obesity was the No. 1 risk factor cited in those who died of the flu in Los Angeles County, followed by “underlying pulmonary, metabolic and cardiac conditions.” The vast majority of the 149 people whose deaths were officially attributed to last season’s flu—88%–had some kind of underlying medical condition, the analysis said. Overall, health officials estimate that the average flu season results in about 1,000 deaths a year in the county, although it is listed as the official cause of death in only some of them.

Last year’s flu season was unusual in that older people—those who are typically considered most likely to die from the flu—experienced fewer deaths and complications than younger people, probably because the elders are believed to carry greater immunity to H1N1. In L.A. County, last season’s flu proved most deadly to those between the ages of 50 and 64. Latinos had the highest rates of intensive care hospitalization and death, while Asians had the lowest. And young children were the most likely to be hospitalized for the disease, but the least likely to die from it.

The link between obesity and H1N1 complications is increasingly well-documented. A recently published scientific paper studied 534 California patients hospitalized for H1N1 during the 2009 flu season and found that half of them were obese—and that those who were the most obese were the most likely to die from the flu.

“I think it is just more evidence to the story that obesity is not just a social condition. It is a medical condition that has risks,” said Dr. Janice K. Louie, head of the surveillance and epidemiology section of the California Department of Public Health and the lead author of the study. She said that anyone with a high body mass index—greater than 30 and particularly greater than 40—should treat flu season very seriously. “If your BMI is 35 or higher, you really should be very aware that influenza is very severe and can kill you. And you should get your flu shot.”

The Centers for Disease Control recently added morbid obesity to its list of medical conditions that place someone at high risk of flu complications. The others include asthma, cancer, diabetes, heart disease and HIV/AIDS; the full list is here. Others at high risk include pregnant women, children under 2 and adults 65 and older.

Flu shots and nasal mist flu vaccine are widely available. People can get the inoculations through their personal doctor or local pharmacy. They also can find a vaccination clinic by checking Public Health’s immunization program website, by accessing the Find-A-Flu-Shot locator, or by calling 2-1-1.

Whatever your risk factor, public health officials say that getting a shot is the responsible thing to do both from an individual and a community health perspective. And they point out that all of the old common sense rules of the season still apply: covering coughs and sneezes, washing your hands frequently and staying home from work or school if you’re sick.

“That’s probably the best way we can stop the spread of the disease,” said Dr. Robert Kim-Farley, director of Communicable Disease Control and Prevention for Los Angeles County. It may not be easy to call in sick in this economic climate—but it’s the right thing to do. “Employers out there should recognize that this is beneficial to them,” Kim-Farley said. “It’s self-enlightened for them to have a healthy workforce.”

Posted 1/19/11