infection control and post-exposure prophylaxis
in review
4 min read
Updated 2026-09-29
infection control and post-exposure prophylaxis
Routine practices for everyone; add airborne (N95 + negative-pressure room: TB, measles, varicella/disseminated zoster), droplet (meningococcus, invasive GAS, pertussis, mumps), or contact precautions (C. difficile, MRSA/VRE/CPE, norovirus, scabies) by syndrome before the diagnosis is confirmed. Rabies PEP (unimmunised): wound care + RabIg 20 IU/kg infiltrated at the wound + vaccine days 0, 3, 7, 14 — any direct bat contact counts. Tetanus: vaccine by wound type and history; TIg if <3 doses and not a clean minor wound. Needlestick: HIV PEP within 72 h, HBV by immune status, HCV monitoring only.
transmission-based precautions
| precaution | conditions | until |
|---|---|---|
| airborne (fit-tested N95, negative-pressure room) | pulmonary/laryngeal TB; measles; varicella and disseminated zoster (+ contact); SARS-CoV-2 and novel influenza during aerosol-generating procedures | TB: 3 negative smears or alternative diagnosis; measles: 4 days after rash onset; varicella: all lesions crusted |
| droplet (mask + eye protection within 2 m) | invasive meningococcal disease; invasive GAS; pertussis; mumps; diphtheria (pharyngeal); influenza and other respiratory viruses (droplet + contact) | meningococcus/GAS: 24 h of effective antibiotics; pertussis: 5 days of therapy; mumps: 5 days after parotitis |
| contact (gown + gloves) | C. difficile (soap and water, sporicidal cleaning); MRSA, VRE, CPE; norovirus; scabies; RSV; draining wounds | C. difficile: ≥48 h after diarrhoea resolves; norovirus: 48 h symptom-free; scabies: 24 h after treatment |
| contact + airborne + droplet | viral haemorrhagic fever, avian influenza, mpox (hospital) | per IPAC/public health |
rabies (CIG)
Exposure: bite, scratch, or saliva/neural tissue on mucosa or broken skin from a potentially rabid mammal. Any direct contact with a live bat counts, however minor.
- wash the wound thoroughly with soap and water immediately
- domestic dog, cat, or ferret that is healthy and available → observe for 10 days; defer PEP unless it becomes ill
- bats, wild carnivores (foxes, skunks, raccoons) → PEP; animal testing via public health if available
| person | PEP |
|---|---|
| unimmunised, immunocompetent | RabIg 20 IU/kg day 0 (as much as possible infiltrated into the wound, rest IM elsewhere) + vaccine days 0, 3, 7, 14 |
| unimmunised, immunocompromised | RabIg + vaccine days 0, 3, 7, 14, 28; check serology after |
| previously immunised | vaccine days 0 and 3; no RabIg |
RabIg can still be given up to day 7 after the first vaccine dose if missed on day 0. Rabies is almost uniformly fatal once symptomatic.
tetanus (wound management)
| history | clean minor wound | all other wounds |
|---|---|---|
| unknown or <3 doses | vaccine | vaccine + TIg 250 units IM |
| ≥3 doses, last <5 years | nothing | nothing |
| ≥3 doses, last 5–10 years | nothing | vaccine |
| ≥3 doses, last >10 years | vaccine | vaccine |
- use Tdap if no adult pertussis dose, otherwise Td
- humoral immune deficiency with a non-minor wound → vaccine + TIg regardless of timing
other exposures
| exposure | PEP |
|---|---|
| measles (susceptible contact) | MMR within 72 h; immunoglobulin within 6 days if MMR contraindicated (pregnancy, immunocompromise, infants) |
| varicella (susceptible contact) | varicella vaccine within 3–5 days; VarIg within 10 days if high risk (pregnancy, immunocompromise) |
| meningococcal close contact | ciprofloxacin, rifampin, or ceftriaxone — see bacterial meningitis |
| pertussis (household/high-risk) | azithromycin |
| animal bite (bacterial) | amoxicillin-clavulanate — see skin and soft tissue infections |
bloodborne pathogen exposure (needlestick, mucosal splash)
- immediately wash with soap and water (flush mucosa); do not squeeze or use bleach
- test source (with consent) for HIV, HBsAg, HCV antibody/RNA; baseline testing of the exposed person
| pathogen | percutaneous transmission risk | management |
|---|---|---|
| HIV | ~0.3% (lower if source suppressed) | PEP ≤72 h (ideally within 2 h): dolutegravir + TDF/FTC or bictegravir/TAF/FTC × 28 days; none if source has sustained undetectable viral load — see HIV: diagnosis, ART, and prevention |
| HBV | up to ~30% (HBeAg-positive source, non-immune recipient) | anti-HBs ≥10 IU/L ever → nothing; unvaccinated → HBIg 0.06 mL/kg (≤48 h, up to 7 days) + vaccine series; unknown response → test anti-HBs now; two-series non-responder → HBIg ×2 one month apart |
| HCV | ~0.2–2% | no PEP; HCV RNA at 3–6 weeks and antibody later; treat early infection with DAAs |
traps
- waiting for TB confirmation before airborne precautions
- alcohol hand rub for C. difficile or norovirus
- no rabies PEP after a bat in the house with direct contact — or giving it to everyone who saw a bat without contact
- forgetting RabIg (or giving it to a previously immunised person)
- TIg for a clean minor wound
- HBIg for a documented vaccine responder