If a person is suffering from co-morbities, this can lead to a patient’s immune system being reduced; this often means that they are more at risk of developing an infection. Patients who are immunosuppressed when they are having chemotherapy are also at risk as they have a reduced white cell count. The very old or young are at risk as again the immune system may not be working as well as it should be.

If somebody has not had immunisations, this can leave them open to certain infections, for example measles and mumps. Poor personal hygiene can mean that infections can often find a source of entry. Contamination via dirty surfaces or dirty linen can be avoided if cleaning and disposal of equipment is dealt with correctly. This is very important in environments where lots of people are living and sharing communal areas like bathrooms and kitchens