The Cold War
04/18/2018 11:05AM ● Published by Robert Frey
Understanding Influenza And How To Fight ItBy Wynce Nolley
The 2017-2018 influenza season has been one of the worst in recent memory, with some medical experts comparing it to the infamous influenza outbreak of 2009. But as the season begins to wind down, we take a look into just what made this year’s flu season so hard on patients near and far including how effective this year’s flu vaccine proved to be and what you can do to prepare yourself and your family to fight the flu in the future.
While experts didn’t classify this year’s flu season as a pandemic, it has proved to be much more severe than previously expected and has already broken several previous records.
According to the Centers for Disease Control and Prevention (CDC) and its weekly influenza report released on March 3, a total of 119 influenza-associated pediatric deaths have been reported for the 2017-2018 season. This surpasses the total of 101 flu-associated deaths in children that the CDC reported during the 2016-2017 flu season.
The same report states that the cumulative rate of laboratory-confirmed influenza-associated hospitalizations was 62.5 per 100,000 population for ages 0 - 4; 17 per 100,000 population for ages 5 - 7; 26.6 per 100,000 population for ages 18 - 49; 93.6 per 100,000 population for ages 50 - 64; and 370.6 per 100,000 of population for ages 65 and older.
These hospitalization rates are the highest they’ve been since the CDC began its current tracking system to measure them back in 2010.
Locally, the Louisiana Department of Health released its Influenza Surveillance Summary Report, which describes the results of the tracking done by the Louisiana Office of Public Health Infectious Disease Epidemiology Section.
This report relies on data supplied by sentinel surveillance sites including hospital emergency departments, laboratories and physicians’ offices to provide a better picture of how influenza has impacted patients in Louisiana.
These sentinel sites provide weekly data on Influenza Like Illness (ILI), which is defined as an illness characterized by cough and cold symptoms and a fever of 100˚ F or greater in the absence of a known cause.
During Week 9 of this year’s flu season, which was observed from Feb. 25 - March 3, the influenza rate across Louisiana was at 3.5 percent ILI per total hospital visits, which is under the 4 percent regional baseline.
This seasonal flu rate reached its peak in Louisiana at the end of 2017 during Week 52 of last year’s flu season, which was observed from Dec. 24 -30, where it reached just under 12 percent ILI per total hospital visits.
The seasonal flu rate across the United States appeared to peak during Week 5, which ended on Feb. 3, when the ILI rate was 7.7 percent. This was higher than the previous record for a non-pandemic season of 7.6 percent in 2003-2004 and equaling the rate in 2009.
And every season, the top priority for both patients who try to survive it and physicians who try to battle it is to prevent the spread of the flu, however one of the most trusted weapons in combating the illness seems to be blunting.
The most common advice that medical professionals still offer patients to avoid getting the flu is to get vaccinated for seasonal influenza, especially for children ages 6 months and under. However, these flu shots appear to be losing their potency as an effective means against the spread of seasonal influenza.
“Influenza A H3N2 viruses continue to dominate this season and these viruses are often linked to more severe illness, especially among children and people age 65 and older,” says CDC Acting Director Dr. Anne Schuchat during a press conference on influenza updates on Feb. 9. “However, we are seeing an increasing proportion of B viruses circulating, as well as a smaller increase in the proportion of H1N1 viruses. Last week, B strains made up 30 percent of the tested viruses. We actually usually see better vaccine protection against these.”
Later in the press conference, Schuchat directly addressed concerns about the effectiveness of this season’s flu vaccine against both strains of the virus: Influenza A (H1N1 & H3N2) and Influenza B (Victoria & Yamagata).
“We continue to recommend getting the flu vaccine to prevent flu,” saya Schuchat. “I know there are ongoing concerns about whether the flu vaccine is effective this year, and it’s true that flu vaccines often have lower effectiveness against H3N2 viruses. However, some protection is better than none. Plus, the vaccine’s effectiveness against other flu viruses, like B and H1N1, is better.”
During each influenza season since 2004–05, the CDC has estimated the effectiveness of seasonal influenza vaccine to prevent laboratory-confirmed influenza associated with medically-attended acute respiratory illness (ARI).
The report released alongside Schuchat’s press conference used data from 4,562 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network during Nov. 2, 2017 – Feb. 3, 2018. During this period, overall adjusted vaccine effectiveness (VE) against Influenza A and Influenza B virus infection associated with medically attended ARI was 36 percent.
Most influenza infections, roughly 69 percent, were caused by Influenza A(H3N2) viruses. VE was estimated to be 25 percent against illness caused by Influenza A(H3N2) virus, 67 percent against Influenza A(H1N1) viruses and 42 percent against Influenza B viruses.
The CDC continues to recommend influenza vaccination because the vaccine can still prevent some infections with currently circulating influenza viruses. Even with current vaccine effectiveness estimates, vaccination will still prevent influenza illness, including thousands of hospitalizations and deaths.
The American Medical Association has also released some advice on certain steps that Americans can take to prevent catching the flu in the future.
“It is very important that you seek treatment from your doctor early if you have flu-like symptoms, especially if you are at high risk for developing flu-related complications including those who have a compromised immune system, are pregnant, are younger than the age of 5, or are over the age of 65,” said Dr. David O. Barbe, President of the American Medical Association in a prepared statement. “Oftentimes, if taken early, anti-viral medications can help reduce the severity of flu symptoms and speed up your recovery time.”
The CDC also recommends taking some everyday preventive actions to stop the spread of germs that include:
• If you are sick with a flu-like illness, the CDC recommends that you stay home for at least 24
hours after your fever is gone except to get medical care or for other necessities. (Your fever
should be gone for 24 hours without the use of a fever-reducing medicine.)
• Wash your hands often with soap and water. If soap and water are not available, use an
alcohol-based hand rub.
• Avoid touching your eyes, nose and mouth as germs can spread faster this way.
• Clean and disinfect surfaces and objects that may be contaminated with germs like the flu.