Summary of WHO infection prevention and control guideline for Ebola and Marburg disease: a call for evidence based practice

WHO guideline development

The new guideline follows the Grading of Recommendations Assessment, Development and Evaluation5 and Evidence to Decision processes as described in the WHO handbook for guideline development,67 and reflects the knowledge and experience garnered from multiple outbreaks of Ebola and Marburg disease since 2014. A group of experts in IPC for filoviruses and a patient representative developed the new guideline, supported by the WHO secretariat. The updated guideline includes 11 new recommendations, 10 new good practice statements, and nine recommendations from previous guidelines.

The guideline development group prioritised 13 key questions78 and five background questions, and WHO commissioned systematic reviews to inform the formulation of the recommendations. A rapid scoping review on the modes of transmission of Ebolavirus and Marburgvirus was also conducted. Finally, a mixed methods study was undertaken to examine health and care workers’ evaluation of outcomes and to understand their perspectives on contextual factors related to IPC measures.9 The guideline development group also carefully considered the balance between desirable and undesirable effects of interventions, the certainty of evidence, the evaluation of outcomes, resource use, the acceptability and feasibility of interventions to affected populations, and the impact of interventions on equity. Although the recommendations pertain to all healthcare settings, some are also relevant to community settings—for example, when interacting in homes of individuals suspected or confirmed to have had Ebola or Marburg disease.

Evidence base for recommendations

The systematic reviews identified only a limited number of studies directly dealing with the questions identified by the guideline development group. Consequently, the certainty of evidence underpinning the new recommendations is generally very low (indirect evidence was often used), and most recommendations are conditional. Where appropriate, recommendations are complemented by good practice statements to help consolidate practices considered acceptable.78

The guideline should be viewed in full to understand the many nuances and contexts that have been considered, to ensure optimal implementation in different settings. For example, the recommendation that health and care workers who have been exposed to Ebolavirus or Marburgvirus should be excluded from work includes a consideration of safe staffing levels and ongoing operations. Although the reader is referred to the full guideline, key points are summarised below and in the infographic (see fig 1).

Highlights from the guideline

During an infectious disease outbreak, the focus is often on availability and use of PPE. Although important, PPE is at the bottom of the hierarchy of controls.10 Furthermore, excessive use of PPE is associated with adverse effects for health and care workers—notably loss of dexterity and skin irritation11—and negative impacts on the environment.1213 The hierarchy of controls instead emphasises engineering and administrative controls to create a barrier between the source of the hazard (the infected patient) and the health and care worker.10 For this reason, the new guideline deals with PPE that should be worn for specific activities or risk (such as screening, triage, direct or indirect patient care, cleaning or other hygiene activities, and safe and dignified burial) and also considers workers’ ability to maintain a distance of at least 1 m from patients during the activity. The guideline also includes new recommendations on the IPC ring approach (rapidly mobilising teams to enhance IPC activities in geographical “at risk” areas around infected individuals), screening and early recognition and isolation, triage, patient placement in single rooms while promoting patient wellbeing and safe interactions with family members and visitors, and management of potential exposure of health and care workers. Concepts such as the importance of hand hygiene using alcohol based hand rub or soap and water is re-emphasised.

For many years, WHO guidance on the management of filoviruses has advised against spraying disinfectants such as chlorine, including for disinfecting the deceased.12 Spraying chlorine in the presence of patients, visitors, and health and care workers has been shown to cause adverse ocular, respiratory, and skin reactions.14 Nevertheless, spraying chlorine or other disinfectants is still common. The new guideline includes a strong recommendation against such spraying of health and care workers. For the environment, the focus is on cleaning followed by disinfection, with wiping surfaces preferable to spraying.

Although contact precautions call for using a single pair of gloves and changing gloves between patients, some facilities caring for patients with Ebola and Marburg disease practise double gloving with varying approaches to glove disinfection, and the changing of gloves between patients. The new guideline provides specific details of when to use single or double gloves (including heavy duty gloves) on the basis of activity risk, methods for glove disinfection, and changing of gloves between patients.

A call for evidence

Although the new guideline represents an advance, it also highlights the need for more evidence to inform effective IPC measures during outbreaks of filoviruses. Adopting a transmission based precautions approach instead of pathogen based recommendations was discussed during development of the guideline. Ultimately, some pathogen based recommendations rather than an immediate shift to transmission based precautions were endorsed as the latter would represent a major change to current practice and hence would require a strong rationale and evidence base. For example, transmission based precautions15 do not include covering the head and neck or wearing heavy duty footwear or double gloves with glove disinfection and reuse, but all are widely practised in the management of filoviruses. Such practices, whether indicated or not, have become ingrained in responses to outbreaks of filoviruses and may not be easily modified unless strong evidence supports a change.

WHO calls for greater investment and engagement in research that will provide a stronger evidence base for IPC for Ebola and Marburg disease, and thus help direct future guidelines away from deep seated practices towards stronger evidence based practices.