Risk factors of #MERS Coronavirus nosocomial infection

Recently a good question was raised by @gwendolbowling about the occurrence of a nosocomial infection in an university hospital, referenced as best of the class?


My first answer was to refer to a continous quality improvement process/PDCA wheel by including on a regular basis, health process audit and ICP inspection; as explained in another blog (Comprehensive understanding of nosocomial #MERS outbreaks), to track and check any critical point which might be responsible for a cross contamination leading to nosocomial infection.


There are different types of risk factors which contribute to trigger off a nosocomial infection:

  • Architecture:residential hospital preferable for admitting/treating infectious diseases
  • Logistics and hospitalization:a step by step inspection from supply (income), management of care (indoor) to waste management (outcome).

Noso Tab

It is always a multifactorial root causes tree which explains the occurrence of nosocomial infection.

screen prevention

Replace Malaria by MERS in the figure and you understand that several screens exist to prevent infection and each time one screen is missing then there is an increase of the infection risk leading to possible nosocomial infection. In other words, a lack of ICP is responsible for nosocomial outbreak.

By conducting an health process audit focusing on ICP, close to HACCP audit for water and food safety, it is possible to identify gaps, critical points and cross contamination risks due to lack of controls or absence of preventive measures (primary,secondary or tertiary).

What do we observe for MERS as a nosocomial infection leading to outbreak? It starts with one index case, infected outside the hospital (at home or workplace) who is admitted at the emergency room. He is waiting for a long time, sharing the overcrowded location with other ill people. As he is not identified as MERS carrier, HCW do not apply on a 24/7 the ICP by wearing adequate PPE; HCW become ill but also vector for spreading MERS infection to others, mostly by close contact (MERS is not an airborne disease), leading to an intra hospital outbreak: this is the chain reaction described in Nosocomial Mers outbreak in Riyadh.


But we have to consider that there are alternative ways to contaminate an hospital building and it is of great importance to audit the logistics process: what is going in (food, medical equipment/tools, linen) and waste management coming from infected patient, classified as bio-hazard with a specific way for elimination. Here we are talking also about hygiene and sterilization inside the hospital.


Cleaning, hand sanitazing, by insisting on specs related to MERS-CoV which can contaminate from fomites, some of them staying on sponges or rags for a while.

Implementing ICP is one thing; auditing and checking on regular basis that procedures are applyed and that performances show a low rate of nosocomial infection are the key values to prevent outbreak. Training, drills and performance review are part of the ICP.

At this stage, it is easier to understand why a nosocomial outbreak can occur even in the most famous international university hospital if there is one or multiple failures in the ICP. Zero nosocomial infection remains a day to day challenge.

Reference: Prevention of hospital-acquired infections A PRACTICAL GUIDE by WHO,2002

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