Thursday, September 18, 2014

CIDRAP Commentary: Health workers need optimal respiratory protection for Ebola




# 9090


Last night CIDRAP published what I suspect will become a highly controversial commentary, which urges a higher standard of PPE (Personal Protective Equipment) for Healthcare Workers (HCWs) dealing with suspected or confirmed Ebola cases.  


In doing so, they also revive the `airborne’ transmission debate.


As things stand now, contact (gloves, gown) and droplet protection (surgical masks, eye protection) are recommended, but not respirators (ie. PAPR, N95) for patient care not involving aerosol generating procedures (AGPs).



The commentary, by Dr Lisa Brosseau and Dr  Rachel Jones , both from School of Public Health, Division of Environmental and Occupational Health Sciences, at the University of Illinois at Chicago is both lengthy and detailed, and should be read in its entirety, but the gist can be found in the following excerpt:


COMMENTARY: Health workers need optimal respiratory protection for Ebola

Lisa M Brosseau, ScD, and Rachael Jones, PhD

Sep 17, 2014

Healthcare workers play a very important role in the successful containment of outbreaks of infectious diseases like Ebola. The correct type and level of personal protective equipment (PPE) ensures that healthcare workers remain healthy throughout an outbreak—and with the current rapidly expanding Ebola outbreak in West Africa, it's imperative to favor more conservative measures.

The precautionary principle—that any action designed to reduce risk should not await scientific certainty—compels the use of respiratory protection for a pathogen like Ebola virus that has:

  • No proven pre- or post-exposure treatment modalities
  • A high case-fatality rate
  • Unclear modes of transmission

We believe there is scientific and epidemiologic evidence that Ebola virus has the potential to be transmitted via infectious aerosol particles both near and at a distance from infected patients, which means that healthcare workers should be wearing respirators, not facemasks.1

(Continue . . . )


Two weeks ago we saw a much different recommendation appear in The Lancet, where authors Jose M Martin-Moreno, Gilberto Llinás, Juan Martínez Hernández argued against the use of respiratory protection (see Is respiratory protection appropriate in the Ebola response?) for routine (non-AGP) care.


Part and parcel to this debate is the definition of `airborne transmission’.  


For now, there is no evidence that Ebola is `airborne’ in the classical – influenza, measles, chickenpox -  highly efficient – long duration aerosolized sort of way. But short distance droplet transmission appears likely. 


Dr Ian Mackay & company delved into this debate last month in their highly recommended VDU blog : Ebola virus may be spread by droplets, but not by an airborne route: what that means

Given that after decades of research there remain many open questions in the dynamics of influenza transmission and the relative effectiveness of different types of PPEs (see Influenza Transmission, PPEs & `Super Emitters’), one shouldn’t be terribly surprised to find ambiguity and disagreement over the transmissibility of Ebola.

Caught in the middle of this controversy are healthcare workers – both in the United States and Europe where extra PPEs are available, and in Africa where basic PPEs are often in short supply – who are uncertain as to just how big a risk they are taking when treating an Ebola patient.


While it may be some time before the risks of Ebola transmission are fully understood and quantified, there is perhaps some degree of comfort to be taken from MSF’s record of protecting their volunteers treating Ebola patients in the field using basic PPEs. 


While they did report their first infection from an International volunteer yesterday (see MSF: French Volunteer Infected With Ebola, Will Be Evacuated), the circumstances behind this incident are unknown, and it comes after literally tens of thousands of HCW – Ebola patient contacts over the past few months.


(Update:  According to the APSix local staff have been infected, three of whom died, though it was not clear that they had become sick at work and may have contracted the virus from the communities where they lived.)


That said - and being a `belt and suspenders’ kind of guy - I fully understand the desire that many HCWs who will have direct contact with Ebola patients will want to have the maximum protection they can be practically afforded – even if current evidence suggests that a lesser degree of protection is probably adequate.

The bottom line is pretty simple, and has little to do with the `best evidence’. 


If you expect HCWs to step up and put themselves in harm’s way, they need to know you’ll go the extra mile to protect them. 

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