What is pneumonia? The common infection that caused Sam Neill's death

From surviving rampaging dinosaurs to confronting supernatural horrors on screen, Sam Neill built a career portraying characters who faced extraordinary dangers.

The 78-year-old's long-time representative Philip Grenz revealed on Thursday that after previously overcoming a rare blood cancer, Neill died from the lung infection pneumonia.

Although pneumonia is often treatable, it can quickly become life-threatening, particularly for older adults and people with underlying health conditions. Here's what you need to know about the infection.

What is pneumonia?

Pneumonia is an infection of the lungs that can cause mild to life-threatening illness in people of all ages.

These air sacs can fill with fluid or pus, making breathing painful and limiting the amount of oxygen the body can take in.

Common symptoms include a cough, fever, chills, shortness of breath, chest pain when breathing or coughing, and fatigue.

Symptoms can develop suddenly or gradually and vary depending on the cause of the infection and a person's age and overall health.

How do people get it?

Pneumonia is most commonly caused by viruses or bacteria, but it can also be caused by fungi.

New Zealand actor Sam Neill died from pneumonia, his long-time agent Philip Grenz has confirmed.

The germs that cause pneumonia can spread through respiratory droplets when an infected person coughs or sneezes.

They can also spread through the bloodstream or develop after a cold or flu, when an infection moves deeper into the lungs.

According to the Lung Foundation Australia, more than half of all pneumonia cases are caused by viruses like influenza and respiratory syncytial virus (RSV). COVID-19 can also lead to pneumonia.

Less commonly, pneumonia can be caused by inhaling fungal spores, particularly in people with weakened immune systems.

Why can it become deadly?

Pneumonia becomes dangerous when the infection makes it difficult for the lungs to supply enough oxygen to the body.

As the air sacs fill with fluid or pus, oxygen has a harder time passing into the bloodstream. In severe cases, pneumonia can lead to respiratory failure, sepsis or damage to other organs.

According to the WHO, it is the leading infectious cause of death in children worldwide. Pneumonia and other lower respiratory tract diseases rank as the fourth leading cause of death globally.

Who is most at risk?

Although pneumonia can affect people of any age, some groups are more likely to become seriously ill.

adults aged 65 and older

babies and young children

Aboriginal and Torres Strait Islander people with medical conditions, and who live in remote communities

people with lung conditions such as asthma, emphysema, cystic fibrosis

people with chronic diseases such as heart, kidney or liver disease and diabetes

people with weakened immune systems, including organ transplant recipients and some people receiving cancer treatment

smokers

Can it be prevented?

While not all cases of pneumonia can be prevented, the WHO says there are several ways to reduce the risk:

Get vaccinated: Vaccines against pneumococcal disease, influenza, COVID-19, measles, whooping cough (pertussis) and Hib can help prevent infections that may lead to pneumonia.

Practise good hygiene: Wash your hands regularly and cover coughs and sneezes to help stop germs spreading.

Don't smoke: Smoking damages the lungs and increases the risk of respiratory infections.

Maintain a healthy lifestyle: Eating a balanced diet, getting enough sleep and exercising regularly can help support the immune system.

In New Zealand, the pneumococcal vaccine is offered to babies for free when they are 6 weeks, 5 months and 12 months old and funded for children under 5 and adults with some medical conditions.

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