Although the flu season this year has nothing for the past year – one of the most deadly in the past decade – when it comes to influenza, vigilance is always important, experts say on infectious diseases and public health.
Local and state reports show that the flu season is under way in the bay area, with the first deaths announced this month. Now that the flu is widespread, doctors, nurses and civil servants carefully monitor several key monitoring reports to help them prepare for the season.
"The flu does not give the news as last year. But it is definitely there, "said Dr. Jeffrey Silvers, medical director of infectious diseases at Sutter Health. "We still have many people who get sick and many people die."
Many of the reports that follow experts like Silver are public and quite affordable even for the home, amateur epidemiologist. Here are three of these reports and what they say about the season so far
Influenza-like illness: The American Centers for Disease Control and Prevention collects reports from a network of hospitals, clinics, and other health care. suppliers that are designed to reflect what's happening in the rest of the country. Among their reports is the percentage of all outpatient visits that include flu-like symptoms – in particular, fever and cough or sore throat.
It is not accurate reporting of the actual number of people who have flu; this number is almost impossible to get because most people who get flu do not attend a doctor. But this gives a reasonable sense to the general picture: if people appear in the doctors' offices with fever and sore throat at this time of year, it is a pretty good bet that some of them have flu. As this number goes up, it means that more flu is circulating.
Out of the flu season, the rate of flu-like illness or ILI, visits will range between about 1% and 2%. Typically, around November, it slips with the last 2%, and then reaches peaks somewhere between 3% – a very soft year – and 8%. Last year, the GIP rate reached 7.5, which was comparable to the swine flu season 2008-2009
The January 12 rate – the latest available report – was 3.1, much lower than 5 , 9 the same time last year. But the season is far from over.
"You do not know if a low level of activity means you will have a good year or you just have not reached a high level," said Dr. Jonathan. Blum, an infectious disease specialist at Kaiser Permanente Santa Clara. Viral strains: There are hundreds of flu strains, but usually only four or five circulating in a typical flu season with one of the dominant ones. Which strains are circulating, as some cause more severe disease than others, and the efficacy of the flu vaccine varies greatly among strains.
Part of the reason last year was so bad because the dominant strain is type A, subtype H3N2, which is known to be particularly virulent and does not coincide well with the flu vaccine. This year, the dominant strain is type A, subtype H1N1. This is the so-called swine flu strain, and although it has caused a widespread disease when it first spreads in 2008 and 2009, it appears to cause relatively mild illness for most people. unless it is known that a certain strain is resistant to antiviral drugs, the treatment will be the same regardless of the type. But experts will use national and regional reports as another tool to prepare for the season. If this is a H1N1 year, they are probably dealing with a normal upsurge in the office in the winter. If it's a H3N2 year, public health officials can make plans for triathlete tents in emergency wards.
Experts on infectious diseases look after strains they have mutated, especially in ways that can make them more dangerous. For example, there are early reports of antiviral resistance in H3N2 strains in Japan.
"We want to know about unusual or new workloads in real time," said Dr. Erica Pan, an interim health official at the Alameda County Public Health Department. Diseases: Infectious disease experts across the country believe that about 80,000 people died of influenza last year. But this is an assessment, not an actual number.
No one monitors every death of the flu every year – their number is too high. Instead, various local and national agencies will monitor flu-related deaths among certain age groups and use these data as another marker for the severity of a season and to extrapolate total deaths. They require countries to report all influenza deaths among people under the age of 65. health problems that make the death of a flu challenging.
This year, the Public Health Department has stopped asking countries to report adult flu deaths. Instead, the state monitors deaths under the age of 65 by examining the death certificates in which the flu was cited as the cause of death. Indeed, the overall mortality rate for this season so far (75) is higher than last year (74), although last year was a much heavier influenza season.
In addition to informing public health officials and doctors about how the season is progressing, the number of deaths from influenza serves another purpose: they are a painful tool to remind society to treat the flu seriously. "People still do not have a healthy attitude to the flu," Pan said. "It's a real thing that kills people every year."
At the factory: So what does the average person have to do with all this information? Not very, necessarily. As infectious disease experts say, flu is only predictable for its unpredictability, and even at first glance the mild year may turn into a shit without much warning. Do not go to work or school if you have a fever, cough or sore throat. Call your doctor if you think you may have flu. And yes, there is more time to get a flu virus.
Erin Aldeade is a writer from the San Francisco Chronicle team. Email: firstname.lastname@example.org Twitter: @erinallday