Influenza: What parents should know

“The Flu” or Influenza season is almost upon us. Every year, I see so many misconceptions about the illness.

So I wanted to break down the reality a little bit - to discuss what influenza can look like, how to tell if your child has it, and why we care. I’ll do a separate post later this week discussing the flu vaccine specifically.

Why I am especially concerned this year

Over the past two years, the flu season has been exceedingly mild - so much so that many of our pandemic babies have never seen it (and many may not have received the flu vaccine). But I am concerned this year will be different.

Australia and South Africa saw more significant cases of influenza this year during their winter months (our summer months). Every year, we predict the severity of our upcoming flu season based on what was seen during winter in the southern hemisphere. And while that isn’t perfect, it is the only predictor we have … for this reason, I think we should gear up for something similar here in the US.

Exposure to a germ is what gives the immune system the blueprint needed to help fight that germ more effectively in the future. So many of our youngest infants and children have naive immune systems when it comes to influenza, and that is why I think this year it is especially important to get the vaccination.

What is “the flu”?

Influenza is a viral infection that can be caused by different strains of Influenza virus. In the US, it typically circulates between October and May.

Although most people recover without incident, similar to COVID-19, certain groups are higher risk for severe illness (and even death): the elderly, those with underlying health conditions, and young children (under age 5y - and especially those under 2y).

During the 2019-2020 season, there were 188 pediatric deaths reported to the CDC (among those who were eligible for vaccines, only 34% of these had received one dose). About 50% of deaths occur in previously healthy children.

Symptoms

• Abrupt onset of fever (95% of kids will have temps >102.2)

• Respiratory symptoms (cough, congestion, sore throat, etc)

• Headaches

• Body aches

• Fatigue/malaise

• Gastrointestinal symptoms (vomiting, diarrhea, nausea)

Incubation and transmission

Symptoms typically develop within about 1-4 days after exposure.

Influenza is contagious via:

• Respiratory secretions (sneezing, coughing, talking)

• Contact with contaminated objects/surfaces

• Aerosolized particles that are released into the air during breathing

The pattern of viral shedding/infectivity depends a bit on the strain, but in general you are most contagious in the first few days of illness. Influenza B can actually be transmitted before symptom onset. Most of the time, you are no longer contagious by about day 5-10

The Pediatrician Mom Note: Children (and immune-compromised people) are known to shed virus for longer than healthy adults

How is influenza diagnosed?

In many cases we can diagnose flu clinically based on history and knowing what is going on in the community. In most cases, we diagnose it in the office using nasopharyngeal swabs (antigen tests and PCR).

Expected clinical course

The majority of children recover on their own within about a week. Antiviral therapy (see below) can shorten the duration of illness but it has its drawbacks. It is worth knowing that some symptoms (such as cough and fatigue) can linger for several weeks after illness.

Complications

Influenza can lead to hospitalization due to severe dehydration, respirator failure, or serious secondary bacterial infections. But even on an outpatient basis, secondary bacterial infections are a common complication: eg pneumonia, ear infections, abscesses in the throat. Febrile seizures can occur in 5% of kids. Rare complications can include sepsis, meningitis, myositis and myocarditis.

Treatment

Antiviral medications do exist, although only some of them are licensed for young children. As with many viruses, the most important component of treatment is primarily supportive: focusing on hydration, fever management and comfort.

What is the deal with Tamiflu?

Tamiflu (or Oseltamivir) is a “neuraminidase inhibitor” - it works by preventing the replication of the virus and can decrease severity, shorter duration of illness (by 1-2 days) and decrease complications. It can also be used for prevention if someone has been exposed and is higher risk for complications.

Dosing: Tamiflu is usually dosed twice per day for 5 days (for treatment) or once daily for 10 days (for prevention). The actual dose depends on weight in children, and it comes in both a liquid and a pill form.

Drawbacks: Tamiflu must be given within 48 hours of symptom onset in the outpatient setting, and it can be hard for some children to tolerate due to its side effects (it can cause nausea/vomiting, headaches, and neuropsychiatric symptoms eg seizures, nightmares, etc). It also doesn’t taste great.

So should you give it to your child? There is no single right answer here. For every intervention, the decision must be individualized based on risks and benefits - and the best guide for your child will be their pediatrician. Some healthcare providers seem to have a blanket “I don’t prescribe Tamiflu” mentality but I am not in this camp. Because young children are at high risk, there is a strong argument to be made for using it in many circumstances.

When can children return to school?

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Per the CDC, children can return to school when they have been fever free for 24h (without antifever medication) and they are overall feeling better, hydrated, etc.

Flu prevention

The best way to prevent the flu is by vaccination. Stay tuned for a post later this week that goes into details about the flu vaccine.

Other important prevention methods are the same as with most other viral illnesses: wash hands, wipe frequently sued surfaces such as door handles and countertops, and avoid sick people. If you are interested in learning more about evidence based ways to support immune function, check out my free download here.

When to call the pediatrician

This is not a comprehensive list. In general, always err on the side of calling your pediatrician if you have any concerns about your child.

There is a lot to be said for a parent’s gut instinct, and I promise: your pediatrician would rather you called!

If your child is under 3 months and seems sick, call your pediatrician. If they are older and are not improving within a few days, or if they seem to be getting worse, call your pediatrician.

Other concerning symptoms include:

• Any illness in infants under 3 months

• Severe pain, irritability or difficulty being consoled

• Lethargy

• Poor feeding

• Dehydration — see this post for signs to look for

• Difficulty breathing

• Ongoing fever beyond 3-5 days

• Anything else tickling your spidey sense!!

Hope this post helps you understand why pediatricians are so concerned, every year, about influenza. If you haven’t yet scheduled your child’s flu vaccine, now is the time to start thinking about it!

Some children need two flu vaccines this season. Stay tuned for tomorrow’s post to figure our if your child is in this group.