A cough that doesn’t go away may not be the flu.

A persistent cough could be due to mycoplasma pneumonia, also known as walking pneumonia.

A persistent cough which lasts for more than a week may not be just a mild infection. It could be due to an infection caused by a bacteria known as mycoplasma, one of the smallest known free-living micro-organisms.

Milder than other types of pneumonia, mycoplasma pneumonia (walking pneumonia) is quite common. Symptoms depend on the type of infection. The most common is chest cold (acute bronchitis) with symptoms such as:

• Slowly worsening cough that can last for weeks or months

• Sore throat

• Feeling tired

• Fever

• Headache

However, pneumonia (chest infection) can occur, producing symptoms such as:

• Cough that may produce mucus

• Fever and chils

• Shortnes of breath

• Chest pain

• Feeling tired

Anyone can get infected with mycoplasma bacteria. Those at risk include:

• Older adults

• People who have diseases that compromise the immune system or who are on chronic steroids, immunotherapy or chemotherapy

• People who have lung disease

• People who have sickle cell disease

• Children younger than the age of 5 

While no exact numbers are available on how many people have this type of pneumonia, it is estimated that 10 to 15 per cent of those with pneumonia have mycoplasma pneumonia.

“Mycoplasma causes a persistent cough whic​h lingers for weeks. It may be associated with fever, headache and discomfort, and the patient may ​have a scratchy, sore throat, so it is best to consult a doctor for treatment”, advised Clinical Associate Professor Ong Thun How​, Senior Consultant, Department of​ Respiratory and Criti​cal Care Medicine​, Singapore General​​ Hospital​ (SGH), a member of the ​SingHealth group​.

​Some symptoms are similar to those of other respiratory tract infections like the common cold. However, unlike the common cold, people with mycoplasma pneumonia (also known as walking pneumonia) seldom sneeze or have a runny nose, and they take a longer time to recover from the illness. “Mycoplasma infections can also be associated with a rash,” said Dr Ong.