Schools across Burnley and Padiham have been warned to be vigilant as the sickness bug norovirus starts to sweep the county.
A letter from Public Health England has gone out to all schools appealing for both staff and parents to help prevent and control any outbreaks of the bug that strikes its victims down with vomiting and diarrhoea.
The letter points out that a seasonal increase in the virus has already begun so it is vital to be aware of symptoms as early recognition is vital to help prevent and control outbreaks in schools.
Sometimes known as the winter vomiting bug, the virus can affect people of any age and is characterised by nausea, vomiting, watery diarrhoea, abdominal pain and in some cases loss of taste. Although having the bug can be unpleasant it is not usually dangerous and most who contract it make a full recovery within two to three days.
Public Health England points out it has seen an increasing number of norovirus outbreaks which causes considerable difficulty throughout all sections of the community.
Vital infection control measures are listed as thorough hand washing with liquid soap and water, environmental cleaning and immediate exclusion of affected children or staff.
And the guidelines are that those struck down should not return to school until they have been symptom free for 48 hours.