Flu

Symptoms

What are the symptoms of influenza?

Flu has a few cardinal symptoms–cough, fever, fatigue, and body aches. These often develop rapidly, without warning. Some people have a variety of associated symptoms, such as sore throat, runny nose, vomiting, and diarrhea, but those are more common with other, non-flu viruses. In the absence of cough, fever, and body aches, mild symptoms of an upper respiratory tract infection (like runny nose and sore throat) are indicative of a cold and not the flu.

What time of year or season is influenza most commonly spread?

Flu is most predominant in fall and winter. The period between October and March is generally considered to be “flu season.” Peak months are typically December, January, and February, though in some years there are still many cases of flu as late as May.

Flu

How is influenza diagnosed?

Flu is most often a “clinical diagnosis,” meaning that it’s based on the presence of symptoms, and special testing is not required. In fact, most people who have the flu know it’s the flu, and don’t need confirmation from a healthcare provider. Symptoms are usually so severe that it feels unlike a regular cold.

Sometimes, a test is performed to try to determine whether a person’s infection is from the flu, or if it’s more likely the result of a non-influenza virus. There are a few different types of flu tests available that analyze respiratory secretions to determine the presence of flu. Rapid flu tests typically provide results within 10-15 minutes. They detect the flu in roughly 50-80% of cases.

Does someone with possible influenza need to be examined in a doctor’s office?

No. In fact, it’s better to stay at home and rest. That said, the flu can cause serious complications, and if symptoms occur that suggest that things are getting complicated, it’s important to check in with a healthcare provider right away.

Symptoms suggestive of an emergency include severe shortness of breath, chest pain, and confusion. For milder symptoms or uncertainty about the necessity for an office visit, virtual care is a great first step!

There have been a lot of stories in the media about people being hospitalized or dying from the flu, can you put that in context? Are there populations that are particularly high-risk?

There are certain groups of individuals who are particularly vulnerable to complications of the flu because their immune response tends to be less robust than that of an average, healthy person. High-risk individuals include pregnant women; people 65 years of age and older; children under age 5; and people with asthma, heart disease, and other chronic illnesses.

In these patient populations, the flu can trigger a variety of serious conditions, such as inflammation of the heart, brain, muscle, and kidneys. In cases of extreme, widespread inflammation, sepsis can result–a life-threatening condition in which the entire body is overwhelmed by infection.

Treatment

How is influenza treated?

Flu is usually treated with “supportive care”–that is, a regimen of interventions that support the body while it does what it needs to do to fight infection. Rest, hydration, and over-the-counter (“OTC”) medicines are helpful supportive care measures. OTC medicines can be chosen based on predominant symptoms.

A non-steroidal anti-inflammatory (“NSAID”) medicine like ibuprofen or naproxen is generally a good choice to alleviate fever and body aches. Acetaminophen can be alternated with a NSAID to keep fever down and aches at bay. For cough, an expectorant like guaifenesin can help to loosen mucus. Combination products marketed for “cold and flu” contain a few different medicines. They can be helpful temporarily, but most contain certain ingredients that shouldn’t be used for more than a few days in a row. For instance, decongestants like phenylephrine and pseudoephedrine can cause rebound congestion– that is, worsening congestion after discontinuation of use.

There are a few antiviral medications–such as Tamiflu–that can be prescribed by a healthcare provider in the setting of symptoms highly suggestive of the flu. Tamiflu must be started within 48 hours of the onset of symptoms.

How do you decide if someone with influenza needs tamiflu?

Tamiflu is an antiviral medicine that works by reducing replication of the flu virus in the body. Tamiflu is made using a compound called shikimic acid, which prior to the last decade was derived almost entirely from the star anise fruit. On average, Tamiflu leads to a 21% faster rate of resolution of flu symptoms. It has also been shown to lower the risk of flu complications, including hospitalization due to the flu.

Tamiflu can be considered for most people who have had flu symptoms for two days or less. It’s especially impactful for individuals at risk of complications from the flu, including those who are immunosuppressed, pregnant, obese, young (<2 years old), or older (>65 years old), as well as those who have chronic illnesses, particularly asthma.

Tamiflu can also be used as prevention. It is appropriate for unvaccinated individuals who have recently (within 48 hours) been in close contact with someone diagnosed with the flu. The CDC recommends that people with this sort of flu exposure receive a flu shot right away and take a five-day course of Tamiflu.

It’s important to note that Tamiflu does have side effects–most commonly nausea and vomiting, and occasionally psychiatric disturbances–so it’s always a better plan to get a flu shot at the beginning of flu season than to rely on Tamiflu after the fact. Furthermore, some flu seasons result in a shortage of Tamiflu and when that happens, it’s reserved to treat people who are at high risk of flu complications.

Are there reliable other ways to treat influenza?

Although the evidence is not straightforward, there are a few herbal and homeopathic treatment options available over-the-counter.

Elderberry is one. Commonly administered as a syrup (though also available in a variety of other forms, including lozenges and even gummies), elderberry has been shown in some studies to shorten the severity and duration of flu symptoms.

Another non-pharmaceutical treatment option is Oscillococcinum–a homeopathic preparation that some people find effective for symptoms of the flu and other respiratory viruses. Evidence is mixed.

Flu Shot

Who should get flu shots?

Everyone! Every year! The only people who are not eligible for a flu shot are babies under six months of age, and individuals with severe, life-threatening allergies to the flu vaccine. The more people who do get the vaccine, the more likely those who can’t get it will be protected by herd immunity–that is, conferred benefit from decreased circulation of the vaccine among a largely vaccinated community.

There are special flu shots manufactured for children, flu shots specifically for pregnant women, flu shots for older individuals, and for those who are allergic to eggs. There’s even a nasal spray for people who are afraid of needles. There is virtually NO reason to not get a flu shot.

How effective is the flu shot?

The flu vaccine reduces the risk of contracting the flu by 40-60%.

What are the risks of getting a flu shot?

People sometimes feel under the weather after getting a flu shot, but it’s important to note that the flu shot cannot cause the flu. The most common side effects from the vaccine are pain and swelling at the site of the injection. The vaccine is injected into muscle, so the discomfort is akin to soreness after a particularly strenuous workout.

Are there other long-term risks to flu and other vaccines?

Unfortunately, misconceptions swirl around the flu shot and other vaccines. Largely based on a debunked study conducted in the late 90s, a former doctor in the UK–Andrew Wakefield–claimed to demonstrate a link between autism and the MMR vaccine.

This proposed link has been disproven many times by multiple, large-scale, properly conducted scientific studies. Wakefield has been discredited and the study has been removed from publication in the medical literature. And yet, false claims about autism and vaccines still abound in popular media.

It’s understandable that this scary story has deterred many well-meaning parents from obtaining vaccines for their children. But vaccines are safe and arguably the most important accomplishment of modern medicine. Illnesses that once annihilated entire families are almost nonexistent due to the protective benefits of immunization.

When is the best time to get a flu shot?

October is the best month to get a flu shot, to ensure protection in time for the flu season. Keep in mind that it takes about two weeks for the vaccine to start working.

Vaccine protection lasts through one flu season but not beyond that, so it’s important to obtain an updated flu shot every year. If October has passed and you haven’t yet gotten vaccinated, it’s not too late! The flu shot is available throughout flu season.

Additional Preventive Measures

What is the best way for close contacts of someone with influenza to prevent infection?

Aside from vaccination, frequent handwashing is the most reliable way to prevent the transmission of flu. The flu virus can survive on surfaces for many hours. Unknowingly touching the virus and then touching one’s eyes, nose, or mouth allows for introduction and replication of the virus. We touch our faces many times a day, without realizing it.

Related Links

A rich and comprehensive flu guide (CDC)

A list of myths and facts about the flu (National Foundation for Infectious Diseases)

A compilation of key facts about the flu (WHO)

A flu guide for parents (CDC)

Is it a cold or the flu? (AAFP)

A scientific look at natural products for the flu and colds (NIH)