By Professor Guy Richards MBBCh PhD FCP(SA) FRCP
Professor of Critical Care University of the Witwatersrand
Director of Critical Care Charlotte Maxeke Johannesburg Academic Hospital, South Africa.
September 30th 2014
Professor Richards led the management of nosocomial Ebola outbreak in Johannesburg in 1996.
The current West African epidemic of Ebola raises many questions that have troubled me over the years. In my hospital, we currently still use N95 respirators and visors over the whole face for any viral haemorrhagic fever (VHF) that we treat. In addition to the paper about the 1996 Ebola outbreak(1), I wrote another paper on these diseases documenting our experiences with the VHFs which I couldn't get published primarily because I couldn't /wouldn't say that surgical masks /gowns/gloves were adequate . In the case study we reported in Critical Care Medicine,(1) the anaesthetic assistant that contracted Ebola wore surgical protective gear whilst assisting in the insertion of a central line, and despite questioning others extensively about any needle stick injuries or abnormal blood exposure, could not explain how she might have contracted the disease. On the other hand in the second hospital where she was subsequently admitted prior to her diagnosis, she had a major upper GIT bleed, had a gastroscopy performed and then a laparotomy in an attempt to stop the bleeding, all with normal surgical PPE and with large numbers of exposures without transmission. These included cleaners, nurses, doctors and I am sure not all wore appropriate PPE. I cannot say now how many were exposed prior to diagnosis or post however the majority would have been pre diagnosis as we limited contact once the diagnosis had been made and she had been transferred to Johannesburg Hospital. With regard to the index case, the patient from whom the nurse contracted the disease, no precautions were taken as the diagnosis was not suspected, it was thought he had bacterial sepsis or an autoimmune disease. However he neither had diarrhoea nor was he bleeding.
The use of hepa filtered hoods are not ideal as they are hot and it was difficult to perform procedures in them . In addition, in 1996 the batteries of ours tended to run out without warning and then one would suffocate unless it was pulled off immediately.
Overall it seems to me that transmission is unpredictable - someone with major exposure does not contract the disease yet another with apparent minimal exposure does. As I said before I would encourage at least N95 masks and visors with minimization of aerosols as far as possible when doing procedures. I have had a degree of antagonism directed toward me because I have not always been able to identify a lapse in infection control that has led to nosocomial spread. I cannot understand why some stakeholders feel so strongly against respirators, when it makes sense to invoke the precautionary principle.
1. Richards, G.A., Murphy, S., Jobson, R., Mer, M., Zinman, C., Taylor, R., Swanepoel, R., Duse, A., Sharp, G., and De La Rey, I.C. Unexpected Ebola virus in a tertiary setting: clinical and epidemiologic aspects. Crit. Care Med. 2000; 28: 240–244