Infection prevention, isolation and outbreak management — formative SAQs

SAQ 1 (10 marks)

Over a 36-hour period, three children and a nurse on a six-bed paediatric surgical bay develop abrupt-onset vomiting and watery diarrhoea; two of the children have required admission for intravenous rehydration. The ward has a central line-dependent oncology patient and an infant in the next bay. It is midwinter. The IPC team has been notified. [4]

Question: Outline your stepwise management of this suspected outbreak, including the case definition, containment measures, environmental controls, staff and visitor management, and the principles that guide standing the response down. (10 marks) [1]

Model answer

Recognition and immediate containment (2 marks). This is a cluster above baseline, consistent with a gastroenteritis outbreak — norovirus is the leading consideration given the explosive vomiting-and-diarrhoea tempo and rapid propagation. Act on suspicion: do not wait for laboratory confirmation. Close the affected bay to new admissions, isolate and cohort the symptomatic cases, and stop movement of patients, staff and shared equipment between bays. [4]

Case definition (1 mark). Set a clear case definition — for example, two or more episodes of vomiting or diarrhoea within 24 hours in a patient or staff member on the unit, with onset within the outbreak window — and apply it retrospectively and prospectively to identify every case. [4]

Hand hygiene and PPE (2 marks). Reinforce hand hygiene at the WHO 5 Moments, but switch the affected area from alcohol-based rub to soap-and-water hand washing, because norovirus is relatively resistant to alcohol. Use gloves and gowns (contact precautions) for all contact with symptomatic patients and their environment, with careful attention to donning and especially doffing. [1]

Environmental and equipment controls (2 marks). Clean the environment and shared equipment with a bleach-based (chlorine) disinfectant at the appropriate concentration, because quaternary ammonium compounds are less effective against norovirus. Dedicate equipment to the cohort, remove and clean toy pools, and increase the frequency of cleaning of high-touch surfaces and toilets. [4]

Staff, visitor and family management (1 mark). Exclude symptomatic staff until 48 hours after symptom resolution, restrict visitors and screen them for symptoms on entry, and communicate clearly with families — honestly and without stigma — about why the bay is closed. Protect the oncology patient and the infant in the adjacent bay with strict separation. [4]

Standing down and learning (2 marks). Stand controls down only after the defined period (commonly 48–72 hours) without new cases. Document the outbreak, feed it back into surveillance, and hold a debrief that drives improvement — because the outbreak that is not learned from is the outbreak that recurs. [1]

SAQ 2 (10 marks)

A 28-week-gestation neonate, now 4 weeks old and receiving parenteral nutrition through a percutaneously inserted central venous catheter, develops new fever, apnoeic spells and an increased requirement for respiratory support. The entry site looks mildly inflamed. The unit's CLABSI rate has crept up over the last quarter. [10]

Question: (a) What is the likely diagnosis and how will you confirm and manage it acutely? (b) Outline the central-line bundle and the system measures that prevent CLABSI in the NICU. (10 marks) [5]

Model answer

(a) Diagnosis and acute management (5 marks). The likely diagnosis is a central-line-associated bloodstream infection (CLABSI) — new fever, apnoea and respiratory deterioration in a line-dependent premature neonate receiving parenteral nutrition, with entry-site inflammation. This is the single largest preventable HAI burden in the NICU, and line days, low gestational age and parenteral nutrition are the strongest predictors. Take blood cultures before antibiotics — a peripheral culture and a culture drawn through the line — start empirical broad-spectrum therapy, provide respiratory and circulatory support, and decide with the team on source control: an infected line often must be removed or exchanged. Do not delay resuscitation or cultures while awaiting confirmation. [10]

(b) The CLABSI bundle and system prevention (5 marks). CLABSI is prevented by a reliable bundle, not by antibiotics. At insertion: hand hygiene, a maximal sterile barrier, chlorhexidine skin preparation, and optimal site selection. During maintenance: a daily review of line necessity with prompt removal when the line is no longer essential, scrub-the-hub access care, sterile dressing management, and minimal line handling. System measures include unit-wide hand-hygiene compliance with audit and feedback, surveillance of device-associated infection rates against baseline, and a just culture that supports staff speaking up. Link the bundle to antimicrobial stewardship because line infections and antibiotic pressure reinforce each other, and feed each case into quality-improvement work to prevent the next one. [5] [8]