Understanding the risks of respiratory infection

December 4, 2024

The arrival of fall is often seen as a breath of fresh air — a welcome respite from stifling summertime heat and humidity. For those in the medical field, particularly emergency medicine and urgent care, fall coincides with a marked rise in respiratory infections. 

Interestingly, it's not actually the drop in temperature that’s thought to cause the rise; more likely it’s the lack of humidity. Studies show that common respiratory viruses travel most readily when the air is dry, making the nose drier and more prone to respiratory infection.

This month, we thought it would be a good time to delve further into the topic of respiratory infections, including upper respiratory infections (URIs) and their more serious counterparts, lower respiratory infections (LRIs). 

What is upper respiratory infection (URI)?

A URI is a common and often contagious illness that affects the upper airways, including the nose, throat, and lungs. URI is a broad term that encompasses a range of conditions, including the common cold, sinusitis, pharyngitis, and laryngitis.

URIs usually stem from viruses but can also be triggered by bacteria or other microorganisms. They occur when a virus or bacteria enters the body through the nose or mouth and attaches to the lining of the upper airways, causing inflammation and congestion.

Causes of respiratory infections 

Upper respiratory tract infections are caused when a virus or bacteria enters your respiratory system. Such an infection can easily result from:

• Touching an infected surface (then touching your mouth, nose, or eyes)
• Shaking hands, embracing, or kissing someone who’s sick
• Inhaling airborne droplets (produced by a sneeze or cough)

Respiratory infections have also been linked to environment and lifestyle risk factors, such as air pollutants and pollens, exposure to chemicals, irritants or toxins, and poor indoor ventilation.¹

Risk for respiratory tract infections 

Certain individuals are more susceptible to respiratory infections, including:

• Older adults
• Young children
• People with a weakened immune system
• Those with chronic conditions like COPD, heart disease, diabetes, or lung disease
• Smokers and those who are exposed to secondhand smoke

Assessing and treating URI symptoms

An upper respiratory infection can usually be diagnosed during a physical exam. In some cases, a health care provider may perform a rapid test for strep throat or viral infection panel to determine the underlying cause of the respiratory infection. 

Treatment for a URI typically focuses on relieving symptoms and supporting the body's immune system. In most cases, URI symptoms resolve on their own within 7 – 10 days, but antibiotics may be prescribed in the case of bacterial infection.

More than URIs—when respiratory infection gets serious

Some viruses like influenza (Flu), Coronavirus (COVID-19), or streptococcus (Strep) will actually create more serious symptoms of respiratory infection known as lower respiratory infection (LRI). LRIs are systemic and affect more than one system in the body, including the lungs and airways. As a general rule, LRIs last longer and are more serious than upper respiratory infections. 

LRIs can be more serious and potentially life-threatening, especially in vulnerable populations like the elderly, young children, and those with a compromised immune system. While URIs can cause temporary discomfort and inconvenience, LRIs can lead to serious conditions like:

• Pneumonia — an infection that affects one or both lungs, causing the air sacs (alveoli) to fill with fluid or pus. Pneumonia symptoms can range from mild to serious and may include a cough with or without mucus (a slimy substance), fever, chills, and trouble breathing. Various organisms, including bacteria, viruses, and fungi can cause pneumonia. 
• Bronchitis — an infection that affects larger airways (trachea and bronchial tubes) that carry air to and from the lungs causing coughing, wheezing, and shortness of breath. Bronchitis can be acute or chronic, with symptoms ranging from mild to severe, and is often due to a viral or bacterial infection.
• Bronchiolitis — a viral infection of the smaller airways (bronchioles) that branch off from the bronchi causing symptoms similar to a common cold (runny nose, cough, wheezing). Bronchiolitis is more common in children under 2 years of age. It can be mild and treated at home; but it can also be serious, especially in babies and young children.

What’s more, the same virus that gives one person a mere common cold (URI) may lead to a more serious condition (LRI) for another. A prime example of this is respiratory syncytial virus (RSV). 

Respiratory Synctial Virus (RSV)

RSV is a common and highly contagious virus spread through close contact with an infected person, touching contaminated surfaces, and through the air. It can affect both the upper and lower respiratory tracts, but it primarily affects the lower respiratory tract.

In older children and adults, RSV may cause only upper respiratory tract (URI) symptoms, like those experienced with a common cold or sinus infection.

On the other hand, in the case of young children… RSV typically causes a lower respiratory infection that could lead to conditions like bronchiolitis or pneumonia. In fact, according to the Centers for Disease Control (CDC), RSV is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age.²

More serious RSV symptoms may include:

• Wheezing 
• Coughing
• Shortness of breath
• Rapid breathing
• Apnea/shallow breathing (in infants)

While RSV can affect anyone, premature babies, young infants, and older adults, with heart or lung disease or a weakened immune system are at higher risk of severe RVS infection. 

Vaccinations for protection 

With the impending triple threat (“tripledemic”) of flu, COVID-19, and RSV, staying on top of vaccine protocol is critical. The CDC recommends that everyone over 6 months of age receive an annual flu vaccine and continue to follow evolving guidelines on COVID vaccines (particularly in light of new variants, like many Omicron subvariants). Additionally, a single-dose, FDA-approved RSV vaccine has been made available to adults 60 years of age and older. Talk to your doctor about which vaccines may be right for you.

When to seek medical attention for a respiratory infection

For all these reasons… being aware of the seriousness of respiratory infection is important. While URIs can often be resolved at home with a little time, patience, and self-care, seeking medical help when you’re in doubt (or in distress) is always advised. For example, many people aren’t sure about the difference between a low-grade fever and a high-grade fever (and when to simply monitor symptoms or when to head to the doctor).³

Take advantage of timely care, close to home

Better than urgent care, and more affordable than the ER, GuideWell Emergency Doctors is where those of all ages (including pediatric patients) can seek prompt diagnosis and treatment for concerning symptoms of respiratory virus. Here, you’ll find Board-Certified Emergency Medicine Doctors along with diagnostic imaging and point-of-testing/rapid labs you won’t find at typical urgent care centers. 

¹WebMD (2023). Respiratory Infections: Symptoms, Causes, and Treatment. https://www.webmd.com/lung/copd/keep-getting-infections

²Centers for Disease Control and Prevention (CDC) (2020). Respiratory Syncytial Virus (RSV). https://www.cdc.gov/rsv/index.html

³Heathline (2023). Symptoms of Fever in Babies, Children, and Adults, and When to Seek Help. https://www.healthline.com/health/fever-symptoms#seek-help