London, Mar 22 (IANS): Older adults diagnosed with respiratory infections such as flu or pneumonia, are six times more likely to suffer from heart attack or stroke in the days after infection, a study warned.

The study found that several different organisms that cause respiratory infections, including the influenza virus and S.pneumoniae -- most common pneumonia causing bacteria -- are responsible for causing inflammation in the heart.

This further leads to the development of blood clots in the heart muscle that heightens the risk of heart attack and stroke.

The paper published in the European Respiratory Journal, noted that having flu or pneumonia increases the risk of having a heart attack for up to a week after infection, and the risk of having a stroke is increased for one month.

"Heart disease, strokes and lower respiratory infections have been the three leading causes of death globally for over 15 years, and are important public health problems that affect large numbers of people worldwide," said Charlotte Warren-Gash, associate professor at the London School of Hygiene and Tropical Medicine.

While the risk of heart attacks and strokes in young, healthy people, after a respiratory infection is low, the effect was found to be greater in people aged less than 65 years compared to those aged 65 and above, as well as people with pre-existing heart diseases, the researchers said.

"As people age, having more than one medical condition becomes more common, so it is even more important to understand the links between different diseases. If we can understand who is at risk of these cardiovascular complications after respiratory infections, we can potentially intervene to prevent them, with methods such as vaccines," Warren-Gash added.

The team investigated the rate of heart attacks and strokes, in 1,989 adults, in the periods of time immediately after a respiratory infection, and then compared this to the rate of cardiovascular events in other periods of time.

Vaccination could help protect against heart attacks and strokes after respiratory infection.