Outbreaks of infection are common in acute hospital settings and can be caused by a wide variety of microorganisms.
Public Health England (PHE) defines an outbreak as: ‘an incident in which two or more people experiencing a similar illness are linked in time or place’. The term ‘outbreak’ can also be applied to a single case of a rare disease – such as botulism, diphtheria, polio, rabies or Ebola.
In the case of hospital-associated infections (HCAIs) such as urinary tract infections and surgical site infections, every hospital should have a baseline incidence level so that they can identify outbreaks when they occur.
All hospitals should have plans in place to deal with any outbreaks of infection. The primary objective of outbreak management is to protect public health and safety by identifying the likely source and mode of transmission and implementing infection prevention and control measures.
The role of the infection prevention and control team (IP&CT)
In a hospital setting, suspicion of an outbreak of infection may be raised by the infection prevention and control team (IP&CT), although they may have first been hospital staff.
It is crucial that an initial investigation is carried out within the first 24 hours in order to avoid a full-blown outbreak. The initial investigation should clarify the nature of the outbreak and determine whether an outbreak control team (OCT) will need to be convened.
The role of the outbreak control team (OCT)
The OCT is responsible for agreeing a case definition, coordinating activities, conducting an investigation and ensuring that infection control measures are promptly implemented.
The OCT will declare an outbreak to be over once there is no longer a risk to public health, the number of cases has declined or the probable source of infection has been identified and removed.
Key actions in the management of an outbreak
The key actions in the management of an outbreak are:
1. Initial investigation and risk assessment
It is essential that an initial investigation to determine the nature of the outbreak takes place within 24 hours of the alarm being raised. This involves establishing the number of cases (infected patients), what symptoms they are experiencing, and when the onset of symptoms occurred.
A risk assessment will also be carried out to determine the risk of transmission to other patients, staff, and the general public.
2. Declaration of outbreak
These initial assessments determine whether an outbreak exists and whether the OCT needs to be called in. In some cases, a press statement may also need to be made.
3. The OCT convene
The OCT will establish a case definition and kick off an investigation. They will meet within three days alongside other parties involved in the investigation and control of the outbreak, such as hospital staff, the IP&CT and any other third parties.
4. Implementation of immediate control measures
Immediate control measures such as hand hygiene, personal protective equipment (PPE), isolation of patients and enhanced environmental cleaning are promptly implemented, as necessary, to mitigate the spread of infection.
Infected patients are treated with antibiotics, antivirals, chemoprophylaxis or vaccination.
6. Ongoing monitoring and management
The OCT meet regularly to monitor the progress of the outbreak. Patients are carefully monitored to ensure prompt recognition and management of any new cases that arise.
Affected individuals, contacts and families are educated on the infection and the outbreak. And liaison with local authorities and environmental agencies take place as necessary.
7. Declaration that the outbreak is over
When there is no longer a risk to public health, the number of cases has declined or the source has been eliminated, the OCT will declare the outbreak over.
8. Final report
A final report is completed within 12 weeks of the outbreak. On occasion, the report or findings from the report will be published so that lessons learned and recommendations can be made public and inform future outbreak management.
Healthcare facilities, including hospitals, have a responsibility to ensure they protect patients, staff and the general public from the spread of infection when an outbreak occurs. This is why infection prevention and control (IPC) processes are so crucial, as well as having a clear system in place for the management of immediate control measures.