Common Respiratory Illnesses including Influenza, COVID-19, and RSV

Common Respiratory Illnesses Menu Workers' Rights

Background

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Respiratory Illness Symptoms

Respiratory viruses cause illnesses that can affect both the upper (nose, sinuses, throat) and lower respiratory (bronchial tubes, lungs) system. Respiratory symptoms can range from very mild to severe and are most often caused by viruses that circulate year-round. Mild illness caused by these circulating viruses is referred to as the "common cold". Common colds rarely result in serious illness in healthy adults and resolve in one to two weeks. Cold infections are caused by more than 250 virus types belonging to at least five different families. The most common among these, the rhinoviruses, are responsible for between 10 and 40 % of "colds" per year. According to the CDC, adults have an average of one rhinovirus infection every year. Other families of viruses that cause the common cold include, but are not limited to, human coronaviruses (non-SARS), human parainfluenza viruses, human metapneumovirus (HMPV), and adenoviruses.

In some cases, colds can be complicated by secondary bacterial infections of the sinuses (sinusitis), bronchial tubes (bronchitis), and lungs (pneumonia). Most often this occurs in persons with certain underlying medical conditions or weakened immune systems.

Symptoms of other circulating viruses, such as influenza, COVID-19, and RSV, are usually more severe. Although diagnostic testing is the only way to be certain what type of virus is causing a respiratory disease, the following table provides a general overview of the common symptoms associated with each of these respiratory infections and may be helpful for distinguishing the common cold from other illnesses that typically have more serious health impacts.

Table 1. Common Respiratory Illnesses: Comparison of Symptoms
  Common Cold* Influenza COVID-19 RSV
Cough Often Often Often Often
Sneezing Often Sometimes Rarely Often
Sore throat Often Sometimes Sometimes Rarely
Headache Rarely Often Sometimes Sometimes
Body aches Sometimes Often Sometimes Rarely
Stuffy/runny nose Often Sometimes Sometimes Often
Fatigue Sometimes Often Often Rarely
Fever/Chills Rarely Often Often Often
Headache Rarely Often Sometimes Sometimes
Loss of taste or smell Rarely Rarely Sometimes Rarely
Vomiting/Diarrhea Rarely Sometimes Sometimes Sometimes
Shortness of breath Rarely Sometimes Often Sometimes

Sources Signs and Symptoms of Flu: Cold versus Flu, Similarities and Differences between Flu and COVID-19 | CDC; Respiratory Syncytial Virus Infection (RSV) | CDC;
*The information provided here about the common cold is included for the sake of comparison only.

Other differences between respiratory viruses are the incubation periods, or the number of days it takes for symptoms to appear after having acquired the infection; the contagious periods, or number of days that the disease can spread to another person; and the length of time that symptoms last.

Table 2. Average course of illness (in days) for Respiratory Viruses
  Influenza COVID-19 RSV
Incubation period 1-4 2-14 4-6
Contagious period 6-10 5-21* 3-28†

* People with moderate to severe COVID-19 are contagious for up to 21 days †Infants and children with RSV can be contagious for up to 28 days
Sources: Cold Versus Flu (CDC); About Influenza (CDC); How RSV Spreads (CDC); Long COVID Basics (CDC)

In addition, some aspects of respiratory viruses facilitate their spread from person to person. For example, COVID-19 has a longer contagious period than influenza. Although respiratory viruses spread more easily when a person has symptoms that propel infectious agents outwards (coughing and sneezing), they can also spread to others unknowingly in the absence of symptoms.

Complications

All respiratory illnesses can be complicated by additional conditions affecting the upper (nose, sinuses, throat, middle ear) and lower (bronchioles, lungs) respiratory systems. Most often, these complications are caused by secondary bacterial infections that are common to all respiratory illnesses. Secondary bacterial infections can occur in healthy adults and cause significant illness. Pneumonia, an infection of the lungs, is the most common cause of hospitalization from respiratory illnesses.

Adults most impacted by respiratory illness complications may include those who:

*Living in nursing homes or other care facilities increases transmission risk and thus risk of severe respiratory disease and complications

All respiratory infections can be complicated by pneumonia, but for adults at risk of complications, influenza, RSV and COVID-19 infections may lead to other life-threatening conditions, particularly for workers who are hospitalized. When the immune system overreacts to fighting infection, it can cause blood clots to form throughout the body, followed by excessive bleeding and sometimes death.

Respiratory Disease Transmission

Typically, respiratory viruses are transmitted via small airborne droplets or particles that are expelled from a person nearby who has an infection.

The World Health Organization (WHO) and several other international public health agencies have updated their terminology for pathogens that transmit through the air. Pathogens transmitted through the air, known as Infectious Respiratory Particles (IRP), can be released during exhalation (e.g., from coughing, sneezing, breathing, exercising, talking, and singing). When IRP are in droplets, they travel short distances and land on nearby surfaces. When these surfaces are touched by another person, followed by rubbing or touching the eyes, mouth, or nose, the infection can be transmitted. Similarly, IRP in droplets can be deposited directly on the exposed mouth, nose or eyes of another person nearby. This type of transmission is called "direct deposition" or "droplet transmission."

IRP that are not within droplets when expelled from an infected person can travel much longer distances through the air. These IRPs may travel through air currents or can remain airborne for hours and linger in rooms of built environments and be transmitted when inhaled by another.

Respiratory Viruses in the Workplace

Absent sufficient controls or practices, respiratory viruses can be transmitted in any workplace where employees are exposed to other infectious employees, customers, or people. Healthcare workers have an increased risk of infection with respiratory illnesses. Preventing workplace transmission in healthcare settings requires additional precautions. See OSHA's Healthcare: Infectious Diseases page and CDC's Infection Control: Guidelines and Guidance Library.

While there are a number of ways these viruses can spread in workplace settings, there is a heightened risk of transmission when work activities involve close (conversational distance) and/or prolonged contact with others including patients, coworkers, customers, residents, or students. Working in places where people may live or gather, called congregate settings, increases the risk or exposure to respiratory diseases. Congregate settings include:

  • Hospitals and long-term care facilities
  • Schools and childcare facilities
  • Correctional facilities
  • Homeless shelters
  • Sports and entertainment venues.

In both congregate and enclosed (e.g., vehicles and ships) workplace settings, good ventilation is an important variable in reducing the likelihood of respiratory virus transmission.

It is important for employers to take appropriate measures to prevent and control occupational exposure to respiratory illnesses in their establishments. This is particularly true when there are multiple cases of influenza or COVID-19 in the workplace or there is an indication of high rates of transmission of these illnesses in the community and employees have occupational exposure to the public or others at work. An effective way to reduce transmission of respiratory illnesses between coworkers is for employees to stay home when they are contagious with influenza, COVID-19, or RSV.

Transmission of respiratory illnesses in the community can be monitored by following local news sources, contacting your state or local health department, or by using the CDC's National Respiratory and Enteric Virus Surveillance System for online tracking of influenza, COVID-19, and RSV.