Pneumonia: It can be more deadly than you think

Published on 15 October 2021

At the start, pneumonia can feel much like a flu – with fever, dry cough, muscle aches and lethargy. But as it progresses, it can cause low oxygenation and breathing difficulties – and even lead to the need for critical care.

According to Dr Adeline Tan, Senior Consultant, Respiratory Medicine, Ng Teng Fong General Hospital (NTFGH), pneumonia is a lung infection that leads to inflammation of the alveoli (air sacs) of the lungs. “This can result in the lungs filling with inflammatory fluid or pus,” she explained.

Pneumonia can be caused by:

• Viruses, such as those that cause colds and other respiratory tract infections. This type of infection is one of the most common causes of pneumonia in adults. 

• Bacteria, such as streptococcus pneumoniae and mycoplasma pneumoniae.

• Fungal infections, especially in people with weakened immune systems, such as patients on active chemotherapy. 

• Aspiration, which is when particles (food, saliva, liquids, or vomit) are inhaled into the lungs. Aspiration pneumonia is common in those who have swallowing difficulties due to advanced dementia or stroke.

Antibiotics are very effective at treating most pneumonias, especially in people who are healthy, Dr Tan said. However, it can take a while for patients to recover completely and feel back to normal.

A matter of concern

The larger concern is that pneumonia has a far more long-lasting and negative impact on older adults, people with chronic diseases and those who have lower immunity. In fact, pneumonia is a very common reason for hospitalisation in Singapore among these high-risk groups. It is also a leading cause of death, second only after cancer.

“Age is a risk factor for pneumonia, especially when there are chronic comorbidities such as lung diseases, diabetes or heart conditions,” Dr Tan shared. People who are immunocompromised, such as those undergoing chemotherapy or who have an autoimmune disease and are on immunosuppressants are also more vulnerable.

These groups are not only more susceptible to pneumonia (and infections in general) but they are at greater risk of severe pneumonia and severe respiratory distress syndrome that require intensive care and the need for intubation (a breathing tube).

There is also a higher risk of the infection getting into the bloodstream, causing shock and a severe type of inflammation called sepsis. Those in a weakened state due to comorbidities and are in hospital for a long time can also develop what is known as hospital-acquired pneumonia.

Another significant point to note is that pneumonia is not just an acute problem. Dr Tan pointed to studies that show that pneumonia can increase both short-term and long-term mortality. “Short term mortality can directly result from pneumonia itself or indirectly from cardiovascular events,” she explained, “Causes of long-term mortality are primarily related to the underlying comorbidities and also include malignancy and cardiovascular disease.”

Preventing pneumonia

These reasons, said Dr Tan, are why it is important to manage chronic illnesses well and to avoid unhealthy habits such as smoking and alcohol intake. Smoking damages the lungs, while alcohol interferes with how the body fights infection.

Dr Tan also emphasised that vaccinations for pneumococcal and influenza – as well as COVID-19 – are very important to reduce the risk of getting these illnesses, reduce their severity and lower overall pneumonia incidence, especially for older adults and those with chronic illness. 

In consultation with Dr Adeline Tan, Senior Consultant, Respiratory Medicine, Ng Teng Fong General Hospital.