The extent of the outbreak investigations should be decided by the IMT with an emphasis on active case finding and identifying any factors which have contributed towards the development of the outbreak. Investigations undertaken and subsequent findings should be documented by the IMT.
A basic epidemiological investigation characterising the outbreak in time, place and person should be undertaken. This process will help identify potential sources and mode of transmission.
Review of patient cases should consider any potential missed opportunities to isolate a patient, a delay in which may have resulted in onward transmission. In particular, consider any missed atypical presentation of COVID-19. Any learning should be widely communicated to all clinical staff in the board.
Compliance with IPC practice on the ward should be reviewed to determine any practice which may have contributed towards onward transmission. Previous hand hygiene audits and any audits of staff practice and the environment undertaken should be reviewed to establish any education gaps which are required to be addressed.
Where AGPs are undertaken on the ward, IPCTs should check to ensure staff are wearing the appropriate PPE and the correct fallow times are being observed prior to other patients using the room in which the AGP was undertaken. The IMT may choose to repeat audits as part of the outbreak investigation.
Ensure that staff on the ward are compliant with COVID-19 IPC guidance contained within the Scottish COVID-19 addendum.
Ensure that patients are wearing face masks appropriately as per the Scottish COVID-19 addendum.
When investigating an outbreak of COVID-19, ascertain from ward staff if there has been any non-compliance with visiting rules for example, visitors presenting symptomatic, declining to wear face coverings or non compliance with physical distancing. Consider what, if any, measures need to be introduced to mitigate any risks identified.
Proactive case finding should be supported through selected testing of any suspected symptomatic cases and when indicated, asymptomatic testing as determined by the IMT. The highest level of benefit in terms of reducing transmission will be from identifying those most likely to have been infected. The highest level of benefit in terms of reducing harm will be from detecting asymptomatic positive cases who may transmit the infection.
LFD testing may be undertaken to enable early detection of cases during an outbreak however, regardless of LFD result, a confirmatory follow up PCR test must also be undertaken.
Public Health Scotland now offer a sequencing service to expedite outbreak investigations and address important clinical and epidemiological questions.
This is a 2 step process involving identification of contacts and then risk assessing which contacts will require self-isolation.
Anyone who has been in the same room/area with the confirmed case in the 48 hours prior to symptom onset (or 48 hours prior to positive test if asymptomatic) until the point when the confirmed case was appropriately isolated/cohorted/discharged should be considered as a potential healthcare setting contact.
The case definitions below should be applied to determine who is a potential contact requiring self-isolation and should take account of all staff, patients and visitors. IPCTs should then consider any mitigating factors which will exclude staff being identified as a contact and avoid the need for these staff having to be excluded from work.
A contact is defined as a person who, in the period 48 hours prior to and 10 days after the confirmed case’s symptom onset, or date a positive test was taken if asymptomatic and had at least one of the exposures listed below.
Typically, any patients in the same bed bay as a confirmed case should be considered household contacts. For larger open bedded areas such as ITUs or nightingale wards the proximity contact definition may be used however, as a minimum this should include patients on either side of the confirmed case and an assessment of the whole area/ward must take account of the patient group and circumstances surrounding potential exposures such as:
Depending on the findings of the considerations above and any other potential contributing transmission risks, the IMT may decide that all the patients and staff in the large open bedded area should be considered contacts.
For cases who have been in a single side room for the exposure period, only staff, patients and visitors who have entered the room of the confirmed case should be considered potential contacts. If the confirmed case has entered the room of any other patients or shared communal spaces with others, these should also be considered as potential contacts.
IMTs must also consider any patient transfers to other areas of the hospital within the exposure period e.g radiology, shops, other wards and consider any potential contacts in these areas.
The flow chart in appendix 1 should be used to assess staff contacts in the healthcare setting and assumes that staff who have worn PPE have had training in its use and that the PPE worn at the time of contact met technical and quality standards.
It is essential that ward staff keep comprehensive lists of all visitors who have come into the ward. These lists should be provided to Test and Protect teams when an outbreak is recognised to enable contact tracing of visitor contacts. Teams should take into account the PPE worn by visitors when considering them as possible contacts requiring self-isolation. Details of visitor PPE can be found within the Scottish COVID-19 addendum .
It should be noted that whilst visitors may have worn PPE as advised by staff, they are not trained in donning and doffing and therefore there remains a higher risk of exposure.
Learning from the COVID-19 pandemic to date has highlighted the risk of COVID-19 transmission associated with closed environments that have poor ventilation. It is important to consider best practice on ventilation and FAQs developed specifically in response to the COVID-19 pandemic. The impact of the ventilation and any contribution it may have had to the onward transmission of COVID-19 should be noted for future learning and wherever possible mitigated.
The following should be considered when deciding if the ventilation may have been a contributing factor in the outbreak;
Bed spacing in the affected ward should be reviewed to ensure that it is adequate to prevent onward transmission of Healthcare Associated Infections (HAIs) and to ensure that mitigation measures implemented to support physical distancing are adequate. See section 5.12.1 of COVID-19 addendum.
Physical distancing amongst patients and staff should be reviewed by the IMT.
Non-compliance with physical distancing by staff, particularly during breaks, when car sharing and outside of work, has been regularly reported as a factor in the development of outbreaks in the healthcare setting. Review of staff meeting rooms, changing rooms, break facilities, and other non clinical meeting areas are important to detect and control transmission between staff.
Patients must be reminded of the importance of physical distancing and refraining from entering the bed space/zone of other patients.
Organisations should ensure there are engineering and administrative measures in place wherever possible to support physical distancing such as floor markings, physical barriers, staggered tea breaks and promotional signage.
IMT should consider if the COVID-19 messaging in the ward for both staff, patients and visitors is adequate. COVID-19 messaging should be in place to promote;
Every opportunity to promote this messaging should be considered.