People struck down by a winter vomiting bug are being warned to keep away from hospitals.
Health bosses are also reminding Leeds residents to only visit accident and emergency if they are seriously ill as NHS services come under pressure.
Cases of the winter sickness bug norovirus have increased, prompting the advice that those affected should dial 111 for medical help.
Matt Storey, urgent care programme manager for the three Leeds Clinical Commissioning Groups, said: “The challenge to reduce the spread of norovirus in the community is a tough one because it is highly infectious and passes easily from person to person, particularly in the winter months when people are likely to spend longer together indoors.
“Essentially, good hygiene is the key to reducing the spread of norovirus as well as other bugs like coughs and colds. The most important thing people can do is wash their hands thoroughly after going to the toilet and before preparing food.”
He said anyone affected should stay off work or school for at least 48 hours after symptoms stop, as before this, they are still contagious.
Meanwhile doctors at Leeds Teaching Hospitals say there has been a rise in people going to A&E and being taken into hospital, while numbers of those being discharged have fallen because of the festive period.
Chief operating officer Mark Smith said: “If you’re unsure about what is the best service for you, call the NHS 111 service, and they will advise you on the best care pathway for you.”
Andrew Davies, consultant in Accident and Emergency Medicine, added: “A&E should be for those with the most serious injuries or illness.
“At this time of year seasonal illnesses are on the rise and it is also very important to avoid coming to A&E with conditions such as colds, flu and diarrhoea, you are likely to pass on the infection and are potentially risking the lives of people much more vulnerable to these conditions, so we ask that you stay away unless it is urgent.”