A call for IPC Epistemic Responsibility – Part 1

In this two part blog, Dr Evonne T Curran, a retired infection prevention control (IPC) nurse, draws on historical examples to highlight the need for IPC professionals to question what they think they know – just because you’ve always been taught that something is right doesn’t mean it is. Evidence from the ongoing covid pandemic suggests this isn’t the case in the UK at the moment.

“Most importantly, an improvement in infection-control requires questioning basic beliefs” Boyce et al (2002)

The Infection Prevention and Control (IPC) pre-pandemic mode of respiratory transmission was shown to “defy physics”. Consequently, the IPC leadership at both professional and national level should have immediately corrected these definitions and then searched for possible errors in other modes of transmission. The weight attributed to individual modes of transmission as stated in IPC documents should also have merited immediate scrutiny. For example, is there evidence to support hand hygiene being the single most important mode of transmission? Had they undertaken these exercises, the IPC leadership would have demonstrated “epistemic responsibility”, i.e., a re-examining of the evidence used and omitted to confirm the truth behind their assertions. In this blog, I am going to show that the need for epistemic responsibility in IPC is now paramount. Only with an accurate understanding of all transmission modes can there be evidenced prevention recommendations.

The entire IPC focus changed with the launch of the World Health Organization (WHO) 2009, hand hygiene guideline. Three years prior to this WHO publication, Pittet et al (2006)  published on behalf of the WHO Global Patient Safety Challenge World Alliance on the model for hand transmission during patient care. [The Hand Hygiene Guideline 2009 being their first challenge.] Pittet et al (2006) asserted (perhaps for the first time) that “hand hygiene is considered the most important measure for preventing HCAI and the spread of antimicrobial resistant pathogens”. This is a connoisseurship statement, i.e., an influential opinion, not backed up by evidence. However, Pittet et al (2006) did support their statement with a citation from a hand hygiene guideline by Boyce et al (2002). For the Pittet et al (2006) claim to be evidenced within the citation, there should have been an evaluation and comparison of all the ways pathogens are known to transmit in healthcare – this was not presented. Indeed Boyce et al (2002) state something less affirming than Pittet et al 2006 “as a result of the seminal studies by Semmelweis and Holmes, handwashing gradually became accepted as one of the most important measures for preventing transmission of pathogens in healthcare facilities.”

However, this historical perspective is neither complete nor accurate. Holmes (1843) undertook what might be considered today a narrative review of all available data (including anecdotes) on erysipelas and puerperal fever. He identified that some HCWs became carriers and dispersers of this then unidentified infectious agent (Streptococcus pyogenes). Holmes (1843) made eight recommendations; the first being that doctors who attend women in labour should never “take any active part in the post-mortem examinations of puerperal fever [or erysipelas] cases”. Indeed, hand hygiene was not specifically mentioned in his recommendations. However, he did state that if a doctor was present at a post-mortem or a case of erysipelas, or puerperal fever then the doctor “should use thorough ablution, change every article of dress and allow twenty-four hours or more to elapse before attending any midwifery case” Holmes (1843). Boyce et al (2002) did not cite Holmes’ directly; they cited a chapter within a book written by another.

Holmes (1843) published his opus 4-years before Semmelweis took up post in Vienna. Had Semmelweis adhered to Holmes’ (1843) recommendations he would have stopped visits to the PM room by his students and ended an outbreak that had continued for years. Instead, Semmelweis introduced disinfectant hand washing (in addition to soap and water hand washing) on entry to the labour suite (Semmelweis 1861 p92). The disinfectant procedure was long and noted to irritate and burn the doctors’ skin – which could only make it intolerable in the long term. However, this was not Semmelweis’ only intervention. As his theory developed from smaller outbreaks, Semmelweis introduced the isolation of cases already infected and hand disinfection after contact with infected cases (in addition to that done on entry to the ward) (Semmelweis 1863 p93). Additionally, he recommended the disinfection of all instruments and items in contact with a patient’s genitals (Semmelweis 1861 p165). However successful the hand disinfection regimen was in reducing cases – it was (understandably) poorly tolerated.

Eventually, (Semmelweis 1961 p163) concluded that the number 1 prevention measure to reduce women being infected was to prevent the doctors becoming contaminated. Semmelweis affirmed “it is safer to avoid contamination than to clean what has already been contaminated”. This is what Holmes (1843) had already concluded 4 years before Semmelweis’ appointment, i.e., doctors attending post-mortems should not attend women in labour. It has since been shown that some outbreaks are traced back to individual carriers and dispersers of organisms including Streptococcus pyogenes (cloud healthcare workers). Thus, as concluded by Holmes (1843), the cause of puerperal fever and erysipelas (Streptococcus pyogenes) is transmitted by contact and disseminated through the air.

Part 2 of this blog will be published next Tuesday (8th July).

Reference

Semmelweis I. (1861) The etiology, concept and prophylaxis of childbed fever. Translated by Codell Carter K. 1983. Wisconsin Publications.