Respiratory tract infections

What are respiratory tract infections?

A distinction is made between infections in the upper respiratory and lower respiratory tracts.

• Upper respiratory tract infection
  This can be infections in the nose or throat (a cold), the sinuses (acute sinusitis), mucosal infections and infections of the lymphoid tissues in the nose and throat (acute pharyngitis) or in the tonsils (acute tonsillitis).
• Lower respiratory tract infection
  This can be pneumonia, the inflammation of the lower respiratory tract (the alveoli), acute bronchitis (inflammation of the central airways: the windpipe and bronchi). An acute bronchiolitis is an acute inflammation of the lower airways (the bronchioles: the tiny branches off the windpipe).

What are the complaints associated with a respiratory infection?

• Upper respiratory tract infection
  Cold symptoms include runny nose, nasal congestion, sneezing, sore throat and/or coughing. People with a cold often feel weak and tired. There can be a slight fever.
  
  Complaints associated with a sinus infection are pain in the face and a pus-like discharge from the eyes. Other common symptoms are fever, headache, an impaired sense of smell, nasal congestion and bad breath.
  
  
• The symptoms of acute pharyngitis are a sore throat (affecting the back of the throat in particular), scratchiness in the throat, an urge to clear the throat, a dry, irritating cough and later hoarseness.
  
  The symptoms of acute tonsillitis are sore throat and pain upon swallowing. The pain is mainly located at the level of the tonsils and soft palate. There may be fever and pain in the ears.
  
  
• Lower respiratory tract infection
  The symptoms of pneumonia are fever, tightness of the chest and coughing. The fever is often accompanied by cold chills, slime is coughed up and breathing can be painful. There may also be non-specific complaints such as malaise, aching muscles and headache.
  
  Acute bronchitis causes coughing, with or without the production of pus-like mucus.
  Acute bronchiolitis results in wheezing and tightness of the chest. There will not usually be a high temperature.
  
  

In people who are particularly susceptible, such as elderly people, people with dementia, sensory disorders or polypharmacy, respiratory tract infections are associated with an increased risk of delirium: impaired consciousness involving disorientation, delusions and hallucinations, usually with, but sometimes without, agitation. ²⁴⁹

People with intellectual disabilities sometimes find it impossible to communicate symptoms like pain and malaise. The people around them may then notice only a change in behaviour or delirium.

How common are respiratory tract infections in the general population?

• Upper respiratory tract infection
  The incidence rate for colds (including pharyngitis) in general practice is 6.6%. This is an underestimate of actual incidence because not everyone with a cold sees the GP. ²⁵⁰
  The incidence rate for acute sinusitis is 2.5% ²⁵⁰ and the prevalence rate is 2.7%. ²⁵¹
• The incidence rate for acute tonsillitis is 1.6% ²⁵⁰ and the prevalence rate is 1.2%. ²⁵¹
  
• Lower respiratory tract infection
  The incidence rate for pneumonia is 0.84% ²⁵²  and the prevalence rate is 0.75%. ²⁵¹
  The average prevalence rate for pneumonia is approximately 0.6% but this rate is significantly higher in younger children and older people. ⁵³⁵
  
  The incidence rate for acute bronchitis/bronchiolitis is 3.4% ²⁵² and the prevalence rate is 2.7%. ²⁵¹

How common are respiratory tract infections in people with intellectual disabilities?

No statistics are available from larger surveys. A survey of 63 adults with intellectual disabilities found that 35% had had a respiratory infection in the previous 6 months (12 people with pneumonia, 7 with sinusitis, 1 with bronchitis and 1 with an upper respiratory infection). The authors attributed this to, among other things, pathogenic micro-organisms present in the mouths of these people and poor oral hygiene. ²⁵³

Another reason for many respiratory tract infections is the high risk of aspiration due to poor swallowing. A study of adults with very severe intellectual disabilities found a correlation between respiratory distress, chronic lung disease and levels of aspiration. ²⁵⁴

Pneumonia, bronchopneumonia and other respiratory tract infections are a common cause of death in people with severe or very severe intellectual disabilities. People with intellectual disabilities are more likely to suffer from respiratory tract infections (whether or not caused by aspiration) than the general population. ^{255   536}

In addition, there are syndromes that are associated with higher rates of respiratory tract infections. There are indications, for example, that Down syndrome is associated with IgG anomalies in saliva (and therefore impaired immunity) and with recurring respiratory tract infections. ²⁵⁶ Children with Down syndrome are at an increased risk of RSV (respiratory syncytial virus) bronchiolitis. ²⁵⁷

Furthermore, pneumonia is now (given the increase in life expectancy) the major cause of death in people with Down syndrome. ⁵³⁷