Bracing for Impact: How Healthcare Workers Can Effectively Manage the Spread and Impact of the Flu

November, December, and January are flu season, the stretch when the flu is most prevalent and most contagious in the U.S. This annual event is all at once predictable and unknown. The flu, after all, remains a significant risk to public health, affecting millions worldwide and causing between 12,000 and 52,000 deaths in the U.S. annually. Exact statistics fluctuate based on factors including flu strain, which can vary widely from year to year, as well population immunity and the effectiveness of that season’s vaccine.

While the majority of flu patients are back on their feet within two weeks or so of contracting the virus, a sizable percentage do end up in critical care units or with prolonged recoveries. The World Health Organization estimates that 3 to 5 million cases of severe flu-related illnesses require ICU-level care each year; domestically, the Centers for Disease Control (CDC) estimates that 14,000 to 162,000 flu cases end up in critical care. And the flu’s toll extends beyond human health. In the U.S., it is estimated that $11.2 billion is spent annually on direct and indirect flu-related expenses.

Understanding influenza, then, is crucial for healthcare workers as we set out not only to care for, protect, and educate our patients, but also ourselves. By exploring current statistics, pathophysiology, transmission, treatment options, and prevention and management strategies, individual clinicians and our field as a whole can better equip ourselves and the public to help reduce the spread and impact of the flu.  

LOOKING BACK: A BRIEF HISTORY OF THE FLU

America’s first flu pandemic lasted from 1918 to 1921, killing more than five hundred Americans and an astounding 50 million people worldwide – one of the deadliest pandemics in modern history.

The first flu vaccine debuted in the 1930s, tempering outbreaks. However, in 1957, a new flu strain – H2N2 – caused yet another pandemic; 116,000 American lives were lost. In 1968, yet another strain and pandemic prompted researchers to develop and release a vaccine targeting specific flu strains. From 1968 to the 2000s, much progress was made on vaccines. Still, predominant viruses and strains continue to vary from year to year. The most recent seismic flu outbreak was the H1N1 outbreak of 2009. This graph depicts predominant viruses, severity, and incidence percentage by age group from 2010 through 2021:

INFLUENZA VIRUS OVERVIEW

Whether you’re new to the medical field or have many flu seasons under your belt, it’s worthwhile to brush up on flu basics: 

• Influenza is an acute viral upper respiratory infection resulting from a single-strand RNA virus
• Three types affect humans: A, B, and C. Flu A is the only flu virus type known to cause pandemics
• Infection can range from asymptomatic to severe or even fatal
• The flu is spread via respiratory transmission, i.e., via the respiratory tract – likely contributing to its high degree of contagiousness

In terms of clinical manifestation: The flu us known for its sudden onset, and is characterized by a wide range and combination of respiratory symptoms (cough, congestion, runny nose, sore throat), gastrointestinal symptoms (nausea, vomiting, diarrhea), and systemic symptoms (fever and chills). For the majority of patients, recovery is relatively rapid. The flu typically lasts three to seven days. 

INFLUENZA COMPLICATIONS

Why do some people with the flu bounce back after a few days of mild symptoms while others end up in the ICU? The answer comes down to flu complications. Complications of the flu can be organized into three categories:

Respiratory complications – the most common flu complications, routinely seen in ERs, ICUs, and on med-surg units during flu season:

• Primary viral – dehydration is among the most common of these complications.
• Secondary bacterial – include sinusitis, bacterial pneumonia, and otitis media, which present after the flu has begun to resolve.
• Influenza-bacterial co-infection – flu plus bacterial pneumonia, strep, or another bacterial infection simultaneously; associated with higher numbers of ICU stays and higher 28-day and in-hospital mortality, pointing to the importance of early diagnosis.
• Invasive pulmonary aspergillosis – a fungal infection in which Aspergillus fungus invades the lung tissue, occurring specifically in flu patients.

Cardiovascular complications – the flu can cause cardiovascular complications by stressing the overall body, activating endothelial cells, and/or causing microcirculatory dysfunction[1], which can result in any of the following:

• Myocarditis – inflammation of cardiac muscle causing fever, fatigue, chest pain, lethargy, and more; rare but potentially fatal.
• Acute coronary syndrome – when the flu triggers a heart attack or another coronary event in individuals with pre-existing heart disease.

Neurological and musculoskeletal complications – rarer than the complications above, but potentially serious:

• Influenza-associated encephalitis – most common in children and young adults, it’s important to recognize its symptoms: seizures, loss of consciousness, and coma.
• Guillain-Barré syndrome – a neurological condition in which the immune system attacks the peripheral nervous system; early symptoms include muscle weakness, tingling, and numbness.[1]
• Myositis – a disease that causes muscles to become, inflamed, weak, and painful; early symptoms include muscle pain that’s more extreme than standard flu-related body aches. Myositis is also marked by elevated muscle enzymes on labs. It presents most often in cases of flu B.

Susceptibility to flu-related complications depends on a number of factors including age and baseline health. Very young babies and children, the elderly, and patients with comorbidities are at the highest risk for these complications. Sleep apnea, myocardial infarction, diabetes, renal conditions, and BMI greater than 30 are other risk factors.

GENERAL FLU TREATMENT

For standard, complication-free flu in healthy, non-hospitalized individuals without co-morbidities, treatment is generally as follows, at the discretion of a primary care physician:

• Hydration – maintain adequate fluid intake to prevent dehydration.
• Fever and pain management – follow your provider’s instructions, which usually involve over-the-counter drugs such as antipyretics (e.g., acetaminophen) and analgesics (e.g., ibuprofen) that reduce fever and alleviate body aches and headache.
• Rest – more crucial to immune function and recovery than many care to admit! 

Notice that the list above does not include antibiotics. Because it’s viral – not a bacterial infection – antibiotics do not work on the flu. This is a common misconception that healthcare worker can help dispel.  

ANTI-VIRAL THERAPY

Anti-viral therapy can reduce the severity and duration of influenza, helping to prevent the risk of complications. However, it is administered selectively. Candidates for anti-virals generally include those hospitalized or at high risk of complication: young children ages two and under, elderly patients, pregnant women, individuals with chronic health conditions, as well as those who are immunocompromised.

When anti-viral therapy is a consideration, conversations should start early and proceed quickly, as timing is critical. Anti-viral treatment is most effective when started within 48 hours of symptom onset (some studies showed a 35% reduction in mortality risk when patients received Tamiflu, an anti-viral therapy). Providers may prescribe anti-virals before a flu diagnosis is confirmed.  

However, anti-viral medications can still hold benefits when started later, as is often the case for hospitalized or high-risk flu patients. Common anti-viral medications include neuraminidase inhibitors such as Oseltamivir (e.g., Tamiflu, the most common in the U.S.), Zanamivir (e.g., Relenza), and Peramivir (e.g., Rapivab), as well as polymerase inhibitors – most often, Baloxavir marboxil (e.g., Xofluza). Each of these options has its own pharmacological considerations. For example, Zanamivir is an inhaled medication, suitable for patients cannot take oral medication such as Baloxavir marboxil.

FLU TREATMENT OPTIONS FOR CRITICALLY ILL PATIENTS

Emergency rooms and critical care units fill up quickly during flu season, often with patients experiencing one or more of the following flu-related symptoms or signs of flu-related complication:

• Severe respiratory distress
• Sepsis
• Pneumonia
• Acute Respiratory Distress Syndrome (ARDS)
• Multi-organ dysfunction
• Myocarditis
• Rhabdomyolysis
• Encephalitis

Advanced support measures often include mechanical ventilation, extracorporeal membrane oxygenation (ECMO), proning, and vaso-supportive drugs. The chart below is a summary of treatment options for those patients who are critically ill:

Advanced support measures often include mechanical ventilation, extracorporeal membrane oxygenation (ECMO), proning, and vaso-supportive drugs. The chart below is a summary of treatment options for those patients who are critically ill:

FLU TREATMENT OPTIONS FOR CRITICALLY ILL PATIENTS

PREVENTION AND PRECAUTIONS

The following are CDC recommendations for preventing the flu – key to reducing public health risk all year long, and during flu season in particular. Beyond practicing these habits yourself, educate your patients, their families, and facility guests on these tips whenever you can:

• Get vaccinated – hands down the best way to reduce the risk of flu and related complications.
• Avoid close contact – stay away from sick individuals whenever possible to avoid the risk of contracting the virus; if you are sick, keep your distance from others. Remain at home whenever possible and only resume activities and close contact with others after you’re fever-free for 24 hours without medication.
• Cover your nose and mouth – use tissues or your elbow to cover coughs and sneezes; consider wearing a mask to prevent spreading or inhaling flu droplets.
• Wash your hands – frequently, with soap and water. Use an alcohol-based hand sanitizer if soap isn’t available.
• Avoid touching your face and putting hands near your mouth – key to reducing chances of infection.
• Take steps for cleaning air – allow for fresh air, use air purifiers, and/or get outdoors to reduce virus exposure risk.
• Practice good hygiene and healthy habits – get adequate sleep, stay active, manage stress, hydrate, and eat nutritional foods.
• Clean frequently-touched surfaces – ideally with high-potency cleaners.

Widening our lens a bit, here are ways that health care facilities as a whole can help limit spread throughout the facility:

• Manage visitor access and movement if needed – enact standards for limiting the number of people entering a facility or floor, and the number of areas they can access. This is huge teaching point with our patients. Fair warning that it often does not go over well for those who don’t understand what’s at stake and at play, pointing to the importance of education.
• Disclosure ­– instruct patients (as well as their family and guests) to notify personnel if they have respiratory infection symptoms, and, if so, to take preventative actions like putting on a mask upon arrival, minimizing elective visits, or opting for phone or video visits, especially during flu season. It can be helpful to hang signage explaining: What is a flu symptom? Why do we want to keep them from entering the facility?  
• Face masks – provide them and educate on how and when to wear them.
• Rapid screening – during periods of increased community influence activity, consider triage stations that facilitate flu screenings; set up systems for separating infected patients from those who are well.
• Stay-home messaging and tolerance – encourage healthcare workers to stay home when sick.
• Aerosol generating procedure precautions – designate a specific place for these procedures and mandate a wipe down of the room before and after.

If any patient has suspected or confirmed flu, don’t wait for testing to come back to enact proactive protective measures. Droplet precautions (or whatever precautions your healthcare site chooses) should be immediately initiated. Continue those precautions until the patient is 24 hours fever-free.

THE FLU VACCINE: EFFECTIVENESS AND MISCONCEPTIONS

Flu vaccines are designed to produce antibodies that protect against flu viruses. Specific flu vaccine formulations evolve as flu vaccine strands evolve. The 2024-2025 flu season vaccine is trivalent, meaning it protects against three different strains expected to prevail this season: H1N1, H3N2, and influenza B Victoria.

Flu vaccinations decrease the number of flu illnesses, the severity of flu illness and hospitalizations, and flu-related deaths. Still, pushback is not uncommon – specifically, “I got the flu vaccine, but I still got the flu.” A good teaching point would be is, “Yes, you still got the flu. However, you likely didn’t develop any secondary complications and likely had a much less severe illness than somebody without the flu vaccine.”

The CDC offers different flu vaccination guidelines for different age groups and demographics, with three vaccines typically recommended for those ages 65 and older. Generally speaking, almost everyone aged six months and older should get vaccinated yearly with some exceptions based on health factors – a great discussion to have with primary care providers. While the best time for vaccination is generally September or October, certain groups might need to consider timing adjustments.

It should go without saying that all health care workers are advised to receive the flu vaccine annually. The most recent statistics show that three out of four health care workers currently receive the flu vaccine; numbers are highest when an employer offers the vaccination onsite.

The flu is not going anywhere, and while it passes quickly enough for many, for others it can be dire – even fatal. Healthcare workers and the public alike are advised to get vaccinated annually (ideally in September or October) and in accordance with their primary care provider’s directions, wash hands thoroughly year-round, and wear masks in dense public settings and in healthcare settings during flu season.

Many more proven guidelines exist for effective treatment of flu patients – and effective ways to protect yourself while caring for them. Explore them and earn one free contact hour by listening to the full on-demand webinar.

[1] https://www.cdc.gov/flu/highrisk/heartdisease.html#:~:text=Among%20adults%20hospitalized%20with%20flu,in%20heart%20attacks%20and%20stroke.

[1] https://www.ninds.nih.gov/health-information/disorders/guillain-barre-syndrome