is an infection within one or both lungs. It is a condition that can affect children of any age, although it is more common in children younger than five years old than in older children and adolescents.
This illness can be serious -- even life-threatening. The World Health Organization (WHO) estimates there are more than 150 million cases of pneumonia each year in children younger than five years old. As many as 20 million cases are severe enough to require hospitalization.
In developing countries, pneumonia is the number-one killer of children. In developed countries, the rate of death from pneumonia in children is a lot lower (about 1 in every 1,000 cases).
What Causes Childhood Pneumonia?
The two most common causes of pneumonia
in children are bacteria and viruses. Viruses are the most common cause in children under five years old. Up to 35 percent of all cases in children are thought to be from viruses.
- Respiratory syncytial virus (RSV)
- Influenza viruses
- Parainfluenza viruses (which cause croup)
- Human metapneumovirus.
Although bacteria cause fewer lung infections in children, they often cause more serious cases of pneumonia infections. Streptococcus pneumoniae, also known as pneumococcus, is the most common type of bacteria to cause pneumonia in children. While less common, methicillin-resistant Staphylococcus aureus (MRSA) is starting to become a more important and concerning cause of pneumonia in children.
Other bacterial causes of pneumonia in children include:
- Mycoplasma pneumoniae (see Walking Pneumonia)
- Chlamydophila pneumoniae (more common in children less than four months of age or over the age of five)
- Bordetella pertussis (the bacteria that cause whooping cough).
Children can get pneumonia at any time of the year. However, both viral and bacterial forms are more common during the colder months.