Cross-infection

Bacteria

Cross-infection, or cross contamination, occurs when one person spreads an infection to another, either directly or indirectly.

For people with cystic fibrosis, cross-infection can be very harmful and poses a particular threat. This is why people with cystic fibrosis should not meet face to face.

People with cystic fibrosis are vulnerable to different bacteria or 'bugs', which grow in their lungs. While these bugs are usually harmless to people who don't have cystic fibrosis, they can settle in the lungs (colonise) and be harmful for those who do. These bugs can be easily transmitted from one person with cystic fibrosis to another.

There is less risk of transmission of 'bugs' in an outdoor environment, but meeting indoors, travelling with other people with cystic fibrosis, or spending time with them socially has a high level of risk. The risk of cross infection increases the longer people with cystic fibrosis are in close proximity to one another.

Bugs' such as Burkholderia cepacia complex and Pseudomonas aeruginosa can be transmitted from person to person by close personal contact and activities such as meeting, sharing rooms, medical equipment, cutlery or crockery; and by kissing or coughing.

In the mid to late 1990s following research into the rise in incidences of B. cepacia, it was decided that people with B. cepacia complex should be kept apart from others with cystic fibrosis because it could be very harmful to them. Later it was found that there are several types of B. cepacia complex, some more serious than others because of the treatment-resistant nature of the bug, and so people with B. cepacia complex were further separated when attending outpatient clinics according to which strain they had.

Cystic fibrosis centres and clinics are advised to ensure segregation measures are in place.

Pseudomonas aeruginosa is a 'bug' that people with cystic fibrosis commonly acquire, most often from the environment. This can usually be eradicated or kept under control with early antibiotic treatment, after isolation of the infection. Most cystic fibrosis patients will pick up Pseudomonas from time to time. There are many different strains of Pseudomonas, and if it takes root and starts to become resistant to antibiotics, it can cause problems.

There is concern that people with cystic fibrosis are more likely to pick up Pseudomonas from each other that are harder to treat than strains contracted from the environment. This is why cystic fibrosis centres and clinics should offer separate clinics for cystic fibrosis patients according to whether or not they have Pseudomonas and to try to determine whether the strain is known to be more passable from one patient to another.

People who have had a lung transplant need to take powerful medication for the rest of their lives to dampen down their immune system and to protect the transplanted lungs from rejection. This medication, which is called immunosuppression, has the unwanted effect of increasing the risk of infection in those taking it.

It is therefore important that after having a lung transplant people avoid, where possible, any non-essential contact with anyone who has an active infection, especially winter bugs, colds and flu. Although the annual flu jab is essential to protect against severe flu it does not protect people from seasonal bugs and colds.

After a lung transplant it might also be necessary to avoid close contact with other people with cystic fibrosis if their lungs are infected with particular bacteria or fungi. This is decided on an individual basis and should be discussed with the transplant centre. Some people after lung transplant may continue to carry bacteria or fungi in their sinuses or upper airway or their newly transplanted lungs which might pose a risk to other people who have had a lung transplant. If this is the case some restrictions on contact with them might be advised. Again this is individual and should be discussed with the transplant centre.

You can find more information on the various kinds of infection in our Consensus Documents in the Publications archive.

Read Emma's story of why it's important to consider cross-infection and how it affects people with cystic fibrosis.

If you are organising or taking part in an event, please read our Cross-infection Policy (PDF 197KB).

A working group brought together by the Cystic Fibrosis Trust and including healthcare professionals and experts on microbiology and cross-infection has released new advice to help protect people with cystic fibrosis from catching infection with M. abscessus.

Read more on Interim cross-infection guidelines to prevent spread of superbug and download the draft guidelines (PDF 94.3KB).