OVERVIEW OF COMMON COLD PART 1

Common cold is the most popular upper respiratory tract infection in the world. It is the most common respiratory condition in children below the age of 6years old. It affects both males and females equally with no gender inclinations. It is caused by about 200 different types of viruses with rhinovirus being the most common cause.

Other viruses that cause common cold are; Adenoviruses, Coronaviruses, and respiratory syncytial viruses. It occurs in overcrowded areas with poor ventilation and most usually around spring and winter seasons due to the intense dryness in the weather during these seasons. The virus presents with symptoms such as; sneezing, nose discharge, cough, and nasal congestion. Preventive measures like frequent hand washing, avoiding the overcrowded area, and living in well-ventilated places during winters will help reduce the disease occurrence.

The management of this virus is done purposely to ease the patient of pain, treat accompanying symptoms, and ensure that the patient is comfortable. Common cold normally resolves on its own within 10 days of onset.

DEFINITION

It refers to the acute Inflammation of the mucosal membrane of the nose and throat (upper respiratory tract) caused by viruses.

The Inflammation of the mucous membrane of the nose is called rhinitis. Common cold is viral rhinitis which is also called acute coryza. Common cold is an extremely infectious disease.

CAUSES

Common cold disease is caused by different types of viruses. About 200 types of viruses are known to cause common cold.

Disease advancement differs a little among the different types of viruses. Some of the main types of viruses clinically identified to cause common cold are; rhinoviruses, coronaviruses, adenoviruses, parainfluenza viruses, respiratory syncytial virus.

The most common viral cause of common cold is the rhinovirus. The rhinoviruses are responsible for about 10 %to 50% of all common cold cases that have been recorded.

The rhinovirus normally stays localized in the nasal mucous membrane hence the name rhino (meaning nose ).

ROUTES OF TRANSMISSION

This refers to the means the various viruses that cause common cold gain access to the nose, throat, or eye of an uninfected person from an infected individual. These are some of the ways the common cold viruses can be conveyed into the human body;

1. Air-borne:

After a person who is infected with common cold coughs or sneezes, tiny drops of snot(nasal mucus) are released. These droplets are carried through the air with common cold causing viruses in them. When uninfected individuals inhale the droplets the viruses enter their nose and occupy their nasal mucous membrane.

2. Contact:

Direct contact with an individual who is infected with common cold nasal secretions or infected artifacts.

PATHOPHYSIOLOGY

Upon the entry of common cold causing viruses like rhinoviruses in the nose or less commonly the conjunctiva of the eye, they attach to the mucosal membrane. In the nasal, the virus gets attached to the mucus-membrane by cellular adhesive molecules.

The nasal mucosal membrane has a temperature around 32 to 34 degree Celsius which is favorable for the rhinovirus. Hence, the rhinovirus rarely causes lower respiratory tract infections.

The mode of action of the virus is as follows;

  • Increased mucosal secretion in response to the presence of the virus.
  • Activation of immune cells; cytokines release.
  • Inflammation of nasal mucosal membrane(RHINITIS).
  • Increased mucous production due to Inflammation and continuous irritation of the membrane.
  • Sneezes due to the irritation of the nasal membrane.
  • Coughing due to building up of fluid in the nasal cavity and back of the throat. It is a means the body use to expel the fluid and foreign irritants.
  • Nasal congestion due to nasal vasodilation and fluid accumulation.

This virus has an incubation period of about 1 to 3 days. Infected persons are contagious from the first day common cold symptoms appear to about a week or even more.

The common cold viruses mostly like a dry mucous membrane which they can occupy. That is why there are peak infections in winter where the weather is cold or harmattan in West Africa.

STAGES

  • First Stage:

This is the very early stage of the disease. It is known by the actual onset of the disease when the virus gets into the nasal membrane. It lasts from the first day of viral entrance to the third day. People are very infectious at this stage. Most often they have; sore throat, mild body pains, and fatigue. People in this stage need good bed rest and adequate hydration.

  • Second Stage:

The infection at this stage is progressive and it’s an active phase. This is about day 4 to day 7 of infection. The viral infection is at its peak and inflammation has occurred. Infected individuals are contagious. Some manifestations observed are; low-grade fever, or chills, cough, blocked nose, and runny nose. Hot tea, honey or chicken soup are good remedies for people in this stage.

  • Third Stage:

In this stage, there is declination of viral action due to increased viral clearance. Most people in this stage have markedly reduced pains with less weakness. This is the end stage of the disease and takes up from about the 8th day of infection to the 10th day. People mostly are not infectious. Cough and nasal congestion might still persist in this stage.

RISK FACTORS/PREDISPOSING FACTORS

  • Age: Common cold is more common in children 6years old and below.
  • Overcrowding: crowded environments are mostly not well ventilated. This creates a perfect medium for air-borne infections.
  • Dry weather: The characteristic reduced humidity causes drying of the mucus-membrane suitable for viral colonization.
  • Toxic fumes inhalations: Inhaled fumes damage the clearance mechanism. Microbes are able to colonize in the environment.
  • Stress: The body’s defense mechanism is decreased In the stressed state giving room for infections to easily develop.

 

PRECIPITATING FACTORS

These factors speed up or increase the effect of common cold after an individual has been infected.

  • Smoking:

Smokers who develop this virus have persistent symptoms for more than four days.

  • Immune deficiency:

People who take drugs that suppress the immune system or people with chronic diseases like HIV infection have persistent common cold infections with other complications. In these patients the duration of the disease is prolonged.