AKT · Infections/Sepsis, fever & healthcare-associatedlow yield

Healthcare-associated & surgical site infection

Infections acquired in healthcare (>48 h) — C. difficile, MRSA, device/line, catheter, surgical wounds

Overview

Infections acquired as a consequence of healthcare, conventionally arising >48 hours after admission or related to a device/procedure. The high-yield set: Clostridioides difficile (antibiotic-associated diarrhoea), MRSA, central-line-associated bloodstream infection, catheter-associated UTI, ventilator-associated pneumonia, and surgical site infection. Prevention (hand hygiene, antimicrobial stewardship, device care, bundles) and prompt source control are the recurring themes.

Recognise

Onset >48 h into admission or linked to a device/operation; the picture depends on the site
C. difficile: profuse watery diarrhoea after broad-spectrum antibiotics (clindamycin, cephalosporins, co-amoxiclav, quinolones); risk of pseudomembranous colitis/toxic megacolon (cross-ref gastroenterology)
Surgical site infection: erythema/discharge/dehiscence at the wound days post-op; MRSA colonisation; line infection (erythema/pus at the site, bacteraemia); CAUTI; VAP

Red flags

C. difficile with toxic megacolon / severe colitis → surgical review (cross-ref gastroenterology)
Line-associated bloodstream infection / sepsis → remove the line + antibiotics; deep/organ-space SSI → drainage

Differentials & how to tell them apart

Community-acquired infectiononset before/within 48 h, no device link

Non-infective post-op feveratelectasis (day 1–2), VTE, drug fever — the post-op fever differential

Other causes of diarrhoeabut new diarrhoea after antibiotics in hospital = C. difficile until proven otherwise

Investigations

Site-directed: stool C. difficile toxin/PCR (and stop the culprit antibiotic); wound swab/blood cultures (SSI/line/MRSA); line tip culture; urine culture (CAUTI); CXR (VAP); inflammatory markers; MRSA screening swabs on admission per policy.

Management

Site-directed treatment + source control; C. diff → stop antibiotic + oral vancomycin; prevention bundles

1Identify the healthcare-associated source by site (C. difficile diarrhoea, SSI, line, catheter, ventilator) and treat it specifically with source control (remove the line/catheter, drain the wound) + targeted antibiotics.Gate: New diarrhoea after broad-spectrum antibiotics = C. difficile → STOP the culprit antibiotic, oral vancomycin, isolate and use soap-and-water (alcohol gel doesn't kill spores); avoid antimotility agents.
2Prevention is paramount — hand hygiene, antimicrobial stewardship, device-care bundles, MRSA screening/decolonisation, aseptic surgical technique; manage severe C. difficile/colitis with gastroenterology/surgery.

C. difficile: STOP the precipitating antibiotic; oral vancomycin (first-line) / fidaxomicin — isolate, soap-and-water (not alcohol gel), avoid antimotility agents (cross-ref gastroenterology)

Source control: remove infected lines/catheters; drain/debride surgical wounds — the device or wound is the source — remove/drain it

Targeted antibiotics (MRSA → vancomycin/teicoplanin) — per local policy and cultures; antimicrobial stewardship

PREVENTION: hand hygiene, care bundles, stewardship, MRSA decolonisation, aseptic technique — the most important element — preventing HAIs

Key points

Infection >48 h into admission / device-related = healthcare-associated. C. difficile = watery diarrhoea after broad-spectrum antibiotics → STOP the antibiotic, oral vancomycin, isolate, SOAP-and-water (not gel), no loperamide. Source control for line/catheter/wound infections (remove/drain). MRSA → vancomycin. Prevention (hygiene/stewardship/bundles) is the priority.

Monitor & prognosis

Resolution, repeat cultures, C. difficile severity, device removal; infection-control surveillance.

Good with source control; C. difficile can relapse and (rarely) cause life-threatening colitis.

Source: NICE NG199 (C. difficile); antimicrobial stewardship NG15/NG63; cross-ref gastroenterology