On November 28th CNN reported that the New England Patriots were sacked by a bug with flu like symptoms. Although I have no direct knowledge of whats going on in the Patriots locker room the Boston Herald reported on December 2nd that only two of the 10 players that were symptomatic missed the game. So the question becomes did the players have the flu or were they experiencing flu like symptoms.
Because symptoms of an upper respiratory infection (URI) are similar to the flu I thought this might be the perfect opportunity to address what exactly is influenza, what are flu like symptoms, what is the efficacy of a flu shot and what are the myths associated with the flu.
Influenza ( flu) is a potentially deadly viral infection that attacks the upper respiratory system. The flu pandemic of 1918 was first observed in Europe, the United States and Asia. It quickly spread throughout the world killing an estimated 20 to 50 million people, about one-third of the planets population. Today, it is believed to effect 5 to 15% of the population in the northern hemisphere causing significant morbidity, mortality and economic drain. In the United States alone influenza is responsible for 10,000 to 40,000 deaths and 200,000 hospital visits per year at an economic cost in excess of $12 billion dollars.
Flu like symptoms are similar to the common cold (URI) which would be runny nose, sore throat and sneezing. The differences in flu like symptoms and the real flu are: the common cold develops slowly over a period of time where-as influenza comes on suddenly and with greater impact. You feel much worse with the flu. There are all the symptoms of the common cold with the additions of a fever over 100.4 F, chills and sweats, achey muscles, head ache and fatigue lasting 1 to 2 weeks. The incubation period for the influenza virus is about 2 days. It is believed to be transmissible from about 24 hours prior to symptoms to 3 – 5 days after the onset of symptoms.
One myth is the “stomach flu”. There is no such thing. Influenza is respiratory in nature. Gastrointestinal symptoms like vomiting and diarrhea are probably the result of gastroenteritis and not influenza and should be treated differently.
There are 4 different strains of influenza: A,B,C and D. Influenza A and B are the strains you hear about the most because they cause epidemic seasonal infections. Influenza A has a greater potential to cause pandemic infections because it is found in animals as well as humans. It is estimated that Influenza A accounts for about 75% of confirmed seasonal influenza infections and influenza B accounts for the remaining 25%. There are also subtypes to some of the strains which are beyond the scope of this blog.
Influenza B is mainly found in humans while influenza C is found in humans, dogs and pigs. You may have heard of the swine flu pandemic of 2009.
Influenza D is mainly found in cattle. The CDC reports that influenza D is not known to infect humans.
Influenza A and B can be spread up to 6 feet away by coughing or sneezing. They are also commonly spread by touching a surface that has the virus on it and then touching your nose or mouth.
The best way to treat influenza is to prevent it. Keep your distance from people who are symptomatic. Wash your hands repeatedly throughout the day and keep them away from your face.
Because influenza is a virus there is no treatment to kill it. Treatment focuses on prevention and relieving of symptoms. First and foremost is a flu shot. There are some misconceptions about the flu vaccine. When I was the head athletic trainer for the Los Angeles Lakers we offered flu shots to all personnel that would be in contact with our players from coaches and staff down to team attendants. During my tenure we had one coach that had a firm belief that flu shots did not work and were bad for you. After one game I announced in the locker room that we were giving flu shots to those who signed up for them. This coach was outraged and told the team in front of me and our team physicians that we did not know what we were doing and that the flu shot was going to give them the flu. I was livid and marched into his office to educate him on how the vaccine is created. The flu vaccine is made from dead viruses and cannot give you the flu. In about 1 to 2% of people that get a flu shot, there can be an immune response with a few mild symptoms of achy muscles or low grade fever that may last for 1 to 2 days but the side effects are inconsequential compared to being infected with influenza.
Flu vaccines first arrived in the United States in 1945. They are developed months before the flu season. They are offered by injection or for those that don’t like needles, a nasal spray. Pregnant women should request the shot, not the nasal spray. The brainiacs that study infectious diseases follow the different strains of influenza circulating throughout the globe and predict which strains will be most common. There are possibilities that some viruses will mutate along the way rendering the vaccine less effective but should still offer some protection. The vaccines are developed to protect against either 3 virus strains (trivalent) or 4 virus strains (quadrivalent). Trivalent vaccines protect against two strains of the A virus and 1 strain of the B virus while quadrivalent vaccines protects against the same 3 plus another B strain. Influenza C is not included in the vaccine. Choosing one vaccine over the other has been a complicated and a controversial subject. The CDC has recently stated there will be no trivalent vaccines offered during the 2019-20 flu season.
The influenza vaccine is an important preventive tool for everyone but especially for the elderly and individuals with chronic health conditions like: heart disease, chronic lung disease and diabetes. There is high dose shot available for people 65 years or older. It also helps protect women during and after pregnancy and can be life saving for children.
In the event one contracts influenza A or B there are antiviral medications that can lessen the severity if taken within the first 48 hours. Zanamivir (Relenza), Osteltamivir (Tamiflu) and Peramivir (Rapivab) all work by inhibiting the virus to release itself from a host cell while Baloxavir marboxil prevents the virus from replicating itself. None of the antivirals are effective for influenza C.