Pneumonia that is acquired by adults in the community continues to be a common and potentially serious condition, doctors have warned.

According to Dr Ruth Cusack and respiratory medicine consultant, Dr Terry O'Connor, of Mercy University Hospital in Cork, community-acquired pneumonia (CAP) has high morbidity and mortality rates.

The doctors pointed out that CAP tends to be seasonal, with most cases occurring in the winter.

Up to four in 10 people affected require hospitalisation and death rates from CAP tend to be highest among this group.

"Over half of deaths occur in elderly patients and given the ageing population of our society, it is expected that the economic and social burden of this disease will increase," the doctors explained.

They noted that the risk of developing CAP is higher among certain people, including those who smoke, those who are malnourished and those with conditions such as cystic fibrosis.

The doctors pointed out that there are more than 100 organisms that can cause CAP, including bacteria, viruses, fungi and parasites and the most common symptoms include cough, fever, chest pain and a shortness of breath.

"Typically patients begin to show signs of resolution after three to five days of treatment, however many factors can slow resolution, including the severity of the pneumonia and older age," they explained.

They said that all patients affected by CAP should be reviewed after six weeks, either by their GP or in a hospital clinic.

"Smoking cessation should be encouraged in all patients who are current smokers," the doctors added.

They made their comments in the journal, Hospital Doctor of Ireland.