RS11 - Common Colds

What is another term for common cold?

Infectious rhinitis

What are the most prominent complaints?

Rhinorrhea (runny nose) and nasal obstruction

How do nasal secretions change during illness?

Clear watery, then thicken and turn cloudy, greenishy

What additional symptoms may occur?

Cough and hoarseness

How long does it usually last?

Approximately 7–10 days

When do nasal and pharyngeal symptoms usually begin to subside?

Beginning on the 3rd or 4th day

How long can symptoms last?

May last up to 2 weeks, lingering cough

What causes the symptoms?

Release of cytokines and histamine

Does it usually occur with a fever?

Usually occurs without a fever, unless secondary bacterial infection

How common is the common cold?

Most frequent infectious disease in humans

When does it mostly occur?

Mostly during winter and spring, but can happen anytime

How many colds does the average adult get per year?

2–4 common colds per year (150 million missed workdays/year)

How many colds can children get per year?

As many as 8 colds per year – they have a less mature immune system and have not built up as much immunity to the many cold viruses.

How many viruses cause colds?

Hundreds of viruses cause these colds, but symptoms are similar

Are common colds self-limiting?

Generally self-limiting

What can common colds impair?

Impair normal respiratory function

What can common colds lead to?

More serious secondary bacterial infections

Who may develop severe illness like pneumonia?

People with immune suppression, asthma, respiratory conditions

What are complications of common colds?

• Bacterial sinusitis

• Bacterial otitis media

• Worsening of asthma

• Acute bronchitis (chest cold)

• Sore Throat, tonsillitis

• Pneumonia

What two major viruses are responsible for most colds?

Rhinoviruses and Coronaviruses

What family are Rhinoviruses in?

PicoRNAviridae

What type of virus are Rhinoviruses?

Non-enveloped RNA viruses

What percentage of common colds are caused by Rhinoviruses?

30–50%

What family are Coronaviruses in?

Coronaviridae

What type of virus are Coronaviruses?

Enveloped RNA viruses

What other viruses may cause colds in adults?

Influenza viruses, Parainfluenza viruses, RSV, Adenoviruses, other

What is the genome of Rhinoviruses?

ssRNA (+), non-enveloped

How many serotypes exist of rhinovirus?

More than 100 serotypes

What disease are Rhinoviruses associated with?

Common cold (Upper Respiratory Tract Infection)

What type of infection does rhinovirus cause?

Localized infection

What proportion of URTI do rhinovirus cause?

At least half of all URTI

Who can develop lower respiratory tract infection from rhinovirus?

Patients with asthma, infants, elderly and immunocompromised patients

What are the permissive cells for rhinovirus?

Respiratory epithelial cells

What temperature does rhinovirus replicate best at?

33°C (Upper respiratory tract)

Can rhinovirus replicate in the GI tract?

Cannot replicate in the gastrointestinal tract, labile to low pH

How is rhinovirus transmitted?

Respiratory secretions, droplets, fomites

How to prevent rhinovirus?

Hand hygiene, there is no vaccine available

How long do rhinoviruses remain infectious on surfaces?

Several hours

Were rhinovirus infections heavily impacted by mask mandates?

Not heavily impacted

How does rhinovirus enter the host?

Enter through nose, mouth, eyes

What does Rhinovirus produce after infection?

Produce many virions and release to other cells

What happens to ciliary action during Rhinovirus infection?

Reduces ciliary action as cells die and slough off

What results from cellular damage during Rhinovirus infection?

Damage results in release of inflammatory cytokines (increase ICAM-1)

How is Rhinovirus infection stopped?

Infection stopped by innate and adaptive immunity

Where can Rhinovirus spread?

Can spread to ears, sinuses, or lower respiratory tract

What is the infectious dose of Rhinovirus?

Infectious dose as little as 1 viral particle

How long does immunity to Rhinovirus last?

Immunity is transient, wanes within 18 months

What is the greatest contributing factor to asthma exacerbation?

Respiratory infections have been reported as the greatest contributing factor to asthma exacerbation in both children and adults

Which viral pathogen is associated with most all virus-induced asthma exacerbations?

Rhinovirus is the viral pathogen associated with most all virus-induced asthma exacerbations

What medications are used for symptomatic treatment of the common cold?

First-generation antihistamine
NSAID – non-steroidal anti-inflammatory drugs
Decongestants if needed (oral preferred to nasal)

Does symptomatic treatment make the common cold go away faster?

No

What prevention methods are recommended for common colds?

Handwashing and environmental disinfection
Avoid touching face with unwashed hands
Covering coughs and sneezes

Is the common cold a good candidate for vaccines?

No

What ocular condition is associated with Rhinovirus?

Viral conjunctivitis

How does Rhinovirus-associated viral conjunctivitis develop?

Develops through exposure to coughing or sneezing of someone with an upper respiratory infection