Flu activity continues to increase across New York State, including in the Buffalo Niagara region, where the rate of confirmed cases has more than tripled since the start of the new year.
It's difficult to say how this flu season compares with others because it still has weeks to go, but it looks to be one of the more severe years in terms of symptoms and hospitalizations.
And it has yet to peak.
Public health officials track the spread and severity of the flu season by gauging the incidence of laboratory-confirmed cases at certain hospitals and outpatient centers.
The rate in Western New York reached 65.5 positive tests for flu per 100,000 people in the population at the end of last week, compared to 18.3 on Dec. 30, according to the latest data reported by the New York State Health Department.
The biggest surge in positive flu specimens has been in central New York, which ended last week with 104.3 laboratory confirmed flu cases per 100,000, the most flu activity of any region in the state.
Although the surveillance statistics offer a look at broad flu trends, it is important to use caution in interpreting them because they are not representative samplings of the population. If more people get tested in one region compared to another, for instance, that could influence the rate, said Dr. Gale R. Burstein, commissioner of the Erie County Health Department.
Across the country, the number of people hospitalized because of the flu is on track to be among the worst in more than a decade.
For instance, flu-related hospitalizations since 2005 in the United States ranged from an estimated low of 140,000 in the 2011-2012 season to a high of 710,000 in 2014-2015. If current trends continue, officials say it's possible the number of flu hospitalizations this season may exceed 710,000.
The flu season started earlier this year than the past two seasons, saw a rapid rise in cases and has yet to reach a peak. The predominate virus strain circulating now – influenza type A (H3N2) – is also causing severe symptoms. The flu and colds are caused by different viruses. They share some similar symptoms, but the flu tends to be worse, causing serious health problems in some individuals.
Emergency rooms and outpatient centers are continuing to report increases in the number of patients coming in with influenza-like illness, as is the trend every flu season. Meanwhile, hospitals are seeing an increase in the number of patients hospitalized with confirmed cases of flu, especially people age 65 and older.
The potential for serious illness and death in at-risk individuals is why public health officials strongly advocate vaccination. In recent years, the federal Centers for Disease Control and Prevention estimate that flu-related deaths ranged from a low of 12,000 in 2011-2012 to a high of 56,000 in 2012-2013, with young children, the elderly, pregnant women, and individuals with serious underlying medical conditions most at risk.
The CDC reported last week a total so far of 53 flu-related deaths among children this season. This compares with 110 pediatric flu deaths in the entire 2016-2017 flu season, 93 in 2015-2016 and 148 in 2014-2015, according to the agency. No deaths in children have been officially reported this season in Western New York.
For the most recent week nationally, public health officials reported 16 of the pediatric deaths, of which only around 20 percent of those children had received the flu vaccine.
"This speaks to the importance of getting vaccinated," Burstein said.
Public health officials track adult flu-related deaths by looking at pneumonia and influenza listings on death certificates across the country. The number of deaths due to pneumonia and influenza increased to 9.7 percent of deaths last week from 9.1 percent the week before. That's lower than in 2012-2013, when those deaths peaked at 11.1 percent, but it's unclear where the percentage will land by the end of this flu season, according to the CDC.
Health officials say the influenza vaccine, although not 100 percent effective, is the best way to prevent the flu. By getting immunized, people also reduce the risk of spreading the flu to others, especially those at high risk of such complications as pneumonia or death. It takes about two weeks for antibodies to develop in the body that protect against flu. The vaccine may also reduce the severity of symptoms if you catch the flu despite being vaccinated, Burstein said.
One of the enduring myths about the vaccine is that it can cause influenza. This not true.
It's possible to get that impression because you can get the flu after immunization in the period before the vaccine takes effect, and because the shot is not completely effective in everyone who gets it. However, the type of flu vaccines given with a needle are grown in chicken eggs with inactivated virus, or made by methods that do not require using the virus, so they can't actually cause the illness.