Ebola virus disease: are you up to date?

On 17 July 2019, an outbreak of Ebola virus disease in the Democratic Republic of Congo (DRC) was declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (France 24, 2019a; [WHO], 2019a; BBC News, 2019). Four years ago, another PHEIC was declared in relation to an Ebola outbreak spread across Sierra Leone, Liberia and Guinea (WHO, 2019b). This eventually became the largest Ebola outbreak in history. There were only a handful of patients with Ebola cared for by the NHS, but the media interest was high and public anxiety widespread. The fear of infection led to much time and effort being put into developing a multi-agency framework to prevent and control any potential risk of spread.

Why the need for an article about Ebola virus disease now? During the last Ebola outbreak, a plethora of guidance, policies and protocols were developed to prepare the NHS for potential cases either travelling to, or occurring in, the UK. However, it is now 4 years since the outbreak in West Africa was declared over—how many organisations have looked at their policies and procedures since then? Would any staff in a GP practice remember where the personal protective equipment (PPE) is held and remember what to wear in what circumstance? Has anyone checked expiry dates of stock recently? Does everyone know who to call or what to do in the event of a suspected case presenting at the general practice premises? While the UK has declared that ‘this outbreak presents a negligible to very low risk to the UK public’ (PHE, 2019a), it is an opportune time to review response arrangements.

This article will provide a summary of the disease, a description of the current outbreak in the DRC, further information on risk assessment of possible cases in the UK, and links to guidance for further information.

What is Ebola virus disease?

Ebola virus disease (EVD) is classed as a ‘viral haemorrhagic fever’ (VHF)—a group of acute, severe infections often associated with haemorrhage and multi-organ failure. It is a rare disease seen in sub-Saharan Africa and has a mortality rate of between 50 and 90% (WHO, 2019c).

The Ebolavirus genus belongs to the Filoviridae family and first appeared in 1976, near the Ebola river of the DRC. There are 6 species within the genus Ebolavirus, with Zaire ebolavirus the most common.

It is believed to be a zoonotic infection, but there is still uncertainty surrounding the exact reservoir of the Ebola virus. The fruit bat remains the most likely natural reservoir (Leroy et al, 2005). The introduction of Ebola into the human population occurs after close contact with blood, secretions or other bodily fluids of infected non-human primates and other mammals. Most further transmission is then from human-to-human through contact with infected blood, secretions or other bodily fluids (Bausch et al, 2007). The disease is also transmitted sexually, even after recovery from Ebola.

During previous outbreaks, healthcare workers have been frequently infected when caring for Ebola patients. Traditional burial ceremonies, in which the body of the deceased is touched by many members of the community, can also accelerate transmission.

Symptoms

After infection, there is an incubation period of between 2 and 21 days (average of 9 days) before symptoms develop. Initially, the disease begins with a sudden onset fever, sore throat, headache and myalgia. This can progress into diarrhoea and vomiting, acute kidney injury, liver damage and a non-specific rash. Internal and/or external haemorrhage is a late symptom and ranges from mild to severe. An individual becomes infective only after they have developed symptoms. Due to the non-specific initial symptoms, Ebola is hard to identify and can mimic common diseases such as malaria or typhoid fever. This can facilitate further transmission through late identification and inadequate isolation. Equally, other differential diseases could be overlooked if clinicians are concerned about a possible diagnosis of Ebola or other VHF. It is critical to be aware of other infections more commonly seen as a result of travel in the tropics, such as malaria. The national guidance highlights the need for urgent malaria investigation as well as obtaining a full blood count, urea and electrolytes (U&Es), liver function tests (LFTs), clotting screen, C-reactive protein (CRP), glucose and blood cultures (PHE, 2015).

Treatment and prevention

The main emphasis in Ebola management should be prevention of spread through avoidance of contact with infected blood, tissues or bodily fluids. During an outbreak, the use of specialised Ebola treatment centres for isolation of any suspected Ebola patients is key to preventing transmission. Specialist PPE should be worn by all healthcare workers treating suspected Ebola patients, and staff should be trained on decontamination and caring for Ebola patients. Other public health outbreak measures like contact tracing and surveillance are integral to preventing further cases. Each country in the UK has developed their own guidance and plans for where patients with Ebola will be cared for. The Royal Free Hospital in London is the national unit for England, with specialist facilities and highly trained staff (Wilcock, 2015).

The main treatment for Ebola is supportive care with oral and intravenous fluids. There are currently no proven treatments, but potential treatments are being evaluated in a multi-drug randomised controlled trial (RCT) being conducted in the outbreak in the DRC.

An experimental vaccine was trialled in over 11 000 people during the 2015 Ebola outbreak in Guinea. The vaccine proved to be highly protective and is being used in the current DRC outbreak (WHO, 2019c). Initial data have shown the vaccine to be highly effective against disease and death. Unfortunately, the unstable political situation and fear and mistrust of the vaccine and other control measures have meant that controlling the outbreak in DRC is not straightforward.

Current outbreak in the DRC

On 28 July 2018, North Kivu Provincial Health authority reported a cluster of 26 cases of VHF. Blood samples from 4 patients tested positive for Ebola on 1 August and the DRC Ministry of Health (MoH) therefore declared an outbreak of Ebola in North Kivu in North Eastern DRC (WHO, 2019b). On 6 August 2018, gene sequencing confirmed the species to be Zaire ebolavirus. As the area borders many countries, including Uganda and Rwanda which are closest to the outbreak area, the WHO conducted a rapid risk assessment of the North Kivu outbreak. The public health risk was determined to be high at a regional level (WHO, 2019b).

In August 2018, Ebola treatment centres were set up swiftly in the region under government and WHO supervision. After years of civil war, the sudden international interest in the area was met with suspicion and rumours regarding the outbreak began to circulate. Initially, Mabalako Health Zone was the epicentre of the outbreak but the virus quickly spread to neighbouring Beni Health Zone and north into the Ituri province. The number of new cases was initially stable, averaging 30 new cases per week (WHO, 2019b).

This was the tenth Ebola outbreak in the DRC, but was the first Ebola outbreak in history to occur in an active war zone (WHO, 2019b). Since the 1990s, the region of North Kivu has experienced ongoing violence during the Second Congo War (1998–2004) and the Kivu Conflict (2004–present). The conflict has resulted in a deteriorating humanitarian crisis in the region, with 1 million of its inhabitants currently internally displaced. Several militia groups are active within the region and attacks on civilians and healthcare workers have complicated the outbreak response (France24, 2019a).

In October 2018, the situation became violent when burial teams, performing safe and dignified burials (SDBs), were attacked with stones. SDBs have been highlighted as a key intervention to reduce transmission of the virus in previous outbreaks, but have been an emotive topic, often differing greatly from culturally normal ceremonies (WHO, 2017; France24, 2019b).

Rumours and unrest intensified after an important election was postponed in December 2018 due to the ongoing outbreak in North Kivu. By February 2019, most new cases were occurring in Butembo and Katwa and violence was increasing. On 19 February 2019, a nurse was killed at the Bisongo Health Centre near Butembo (France24, 2019a) and an Ebola treatment centre was burned down 5 days later (Medecins Sans Frontieres, 2019).

April 2019 saw a dramatic increase in new cases to around 80–100 per week. On 19 April, the violence reached a peak when Dr Richard Mouzoko, a consultant epidemiologist from Cameroon working with WHO, was killed by rebels in Butembo Hospital (Stafford, 2019). A note was left by the perpetrators warning healthcare workers of future violence if they continued to support the Ebola outbreak response (France24, 2019a). Similar attacks and security incidents continued throughout May, reducing the response to limited or suspended activity on many days (WHO, 2019b).

The outbreak briefly spread to Uganda on 11 June 2019, when the Ugandan MoH confirmed 3 cases in Kasese District, on the DRC border (Jephcott, 2019). The index case was identified as a 5-year-old returning from Mabalako health zone, DRC, after attending his grandfather's burial (a confirmed Ebola case) (BBC News, 2019). The boy's mother (who has since died) and 3-year-old brother were also confirmed positive (WHO, 2019b). Control measures applied included efficient and effective tracing of contacts. Recently, Uganda passed 42 days (twice the length of the incubation period) without any new cases and has therefore been declared Ebola-free (WHO, 2019b).

Beni remained the epicentre of the outbreak and on 14 July, a case was identified in Goma, a city of 2 million inhabitants, close to the Rwandan border (CBS, 2019). The case, a pastor travelling from Butembo, died on transfer to an Ebola treatment centre (WHO, 2019b). Despite concerns of further spread, the WHO report that there has been great preparation for the first confirmed case in Goma, as it has long been anticipated. However, the likely spread of Ebola to Goma, a large city with multiple international travel connections, precipitated a meeting of WHO experts to consider the situation (WHO, 2019b). For only the fourth time in history, the WHO declared the Ebola outbreak in DRC a ‘Public Health Emergency of international interest’ on 17 July 2019 (BBC News, 2019; France 24, 2019a). At the time of declaration, there were 2512 cases of Ebola, of which 136 were healthcare workers (WHO, 2019b). A highly mobile population, unstable security situation, complex political environment and continued reluctance within the community were all highlighted as factors affecting the outbreak. WHO advised countries to keep their borders open and to continue trade with the region and encouraged neighbouring countries to continue to prepare for a potential outbreak (WHO, 2019b).

The outbreak is now the second biggest outbreak in history, after the West African outbreak of 2014. At the time of writing, the number of cases has surpassed 2852 with 1913 deaths (WHO, 2019c).

Control measures within the UK

As previously stated, there is currently a very low risk of spread to the UK (PHE, 2019a). Many of the control measures required in hospital or the community for a suspected case of Ebola will be performed by PHE. Notification of a possible case should be made as soon as possible to the local health protection team (contact details available at: https://www.gov.uk/health-protection-team). The local health protection team will advise on control measures, samples required, isolation required and facilitate access to the Imported Fever Service to discuss management of possible cases (Figure 1).

Figure 1. Imported Fever Service.

While the possibility of a traveller returning to the UK from the outbreak area within the DRC and displaying symptoms of Ebola virus disease is very unlikely, it is imperative that all healthcare staff are aware of the actions to take. Often it is managing anxiety that places the largest stress on the diagnosing clinical staff; fear of infection can be overwhelming. It is important to stress that while the virus is spread like other blood-borne viruses (through direct contact with blood and body fluids), it is not an airborne infectious disease like measles. Despite the potential for contamination of the environment through haemorrhage or vomiting, environmental contamination does not appear to play a large part in transmission of the infection (Bausch et al, 2007). However, Ftika and Maltezou (2013) report that outbreaks of Ebola ‘are notorious for their explosive course and virulence, with nosocomial settings playing an amplifying role in their evolution’. As available research in the role of the environment in the spread of Ebola is limited, it is prudent to ensure the highest standards of infection prevention and control are maintained at all times.

The first step is a risk assessment regarding the potential for a patient to have Ebola (or any other VHF). The risk assessment should take into account travel history, symptoms displayed, and any contact with known cases. There is a useful algorithm taking the assessing clinician through the risk assessment and next steps provided by PHE (Figure 2).

Figure 2. VHF risk assessment.

If Ebola (or other VHF) is suspected in a patient then isolation facilities should be utilised while the risk assessment process is ongoing. As stated, early contact with the local health protection team (available 24 hours a day, 7 days a week) will ensure that advice and support is available throughout the assessment. Local infection prevention and control teams will also provide advice and support.

In terms of PPE, the choices made depend on the level of likelihood of Ebola (or other VHF). It is important to ensure PPE is available at all times; this is something that should be checked at all healthcare locations regularly, together with staff knowledge of PPE required in any given situation. In summary, the choice of PPE depends on the nature of the disease suspected and the clinical actions to be performed. Table 1 provides a useful summary of the PPE required when suspecting a patient has Ebola (or other VHF); it is taken from the risk assessment algorithm (Figure 2) where the colours in the table match the categorisation of risk of disease.

If a diagnosis of Ebola (or other VHF) is confirmed, specialist clinical services will provide care for the patient who will be transferred safely. The health protection team will form an incident control team and provide the framework and resources for the public health response. PHE will undertake the following as outlined in the national guidance—‘Management of Hazard Group 4 viral haemorrhagic fevers and similar human infectious diseases of high consequence’ (Advisory Committee on Dangerous Pathogens, 2015):

• Formation of an incident control team
• Notification of the case by the reference laboratory to the relevant regulatory health body
• Notification of the case by PHE to the European Centre for Disease Control (ECDC) and the WHO
• Categorisation and management of contacts
• Determine media handling strategy.

Other control measures

During the 2014–2015 outbreak of Ebola, PHE established a monitoring scheme for returning humanitarian workers. All those registered on the scheme who returned from the outbreak area were contacted by PHE, given a thermometer and asked to report temperature and development of any symptoms to their PHE contact on a daily basis for 21 days post-return. This enabled early identification of possible cases. If someone did develop symptoms, then PHE would arrange for assessment and admission to a regional specialist Infectious Diseases Unit. This dramatically reduced the number of potential cases likely to appear at their local GP or A&E department. This scheme has been revived to support the humanitarian workers currently working in the outbreak response in the DRC (PHE, 2019b).

Conclusion

There is a plethora of information available providing advice and guidance about correct infection prevention and control measures when suspecting a patient has Ebola or any VHF. PHE have produced a simple one-page algorithm which summarises the actions required in the management and infection control aspects of managing a case (Figure 2) (PHE, 2015).

During the last large outbreak of Ebola in West Africa in 2014–15, it was reported that ‘Ebola virus disease is a severe infection causing significant morbidity and mortality. However, while the current outbreak is large in the context of previous Ebola outbreaks, the number of those infected in the affected countries is small in relation to the total population of those countries’ (Beckett and Monk, 2014). This is still current today—the risk to the UK in general is considered to be very low; the risk to an individual practice of a symptomatic patient appearing at a community healthcare premise is even lower still. However, complacency is not an option given the serious consequences of this disease. Preparations and readiness for a case of Ebola will also ensure that the community healthcare premises is prepared for all potential infectious threats which may occur.

Further information

• Ebola – overview, history, origins and transmission: https://www.gov.uk/government/publications/ebola-origins-reservoirs-transmission-and-guidelines/ebola-overview-history-origins-and-transmission
• Viral haemorrhagic fever – ACDP algorithm and guidance on management of patients: https://www.gov.uk/government/publications/viral-haemorrhagic-fever-algorithm-and-guidance-on-management-of-patients
• Ebola virus disease – BMJ resources: https://www.bmj.com/ebola
• Imported fever service – enquiries process: https://www.gov.uk/government/publications/imported-fever-service-referrals-process

For those interested in learning more about Ebola there are free online courses available

• WHO online learning resources for Ebola virus disease: https://www.who.int/knowledge-transfer/online-learning-resources-for-ebola/en/
• Ebola – Essential Knowledge for Health Professionals: https://www.coursera.org/learn/ebola-essentials-for-health-professionals
• Ebola in Context: Understanding Transmission, Response and Control https://www.futurelearn.com/courses/ebola-in-context

KEY POINTS

• Ebola virus disease (EVD) is classed as a ‘viral haemorrhagic fever’, a group of acute, severe infections often associated with haemorrhage and multi-organ failure
• EVD is a rare disease seen in sub-Saharan Africa and has a mortality rate of between 50 and 90%
• In July 2019, an outbreak of Ebola in the Democratic Republic of Congo was declared a Public Health Emergency of International Concern by the World Health Organization
• The risk to the UK in general is considered to be very low; the risk to an individual practice of a symptomatic patient appearing at a community healthcare premise is even lower still. However, complacency is not an option given the serious consequences of this disease. Practice nurses must be aware of symptoms and procedures for the management of potential cases

CPD reflective practice

• In your clinical area of practice, do you know where to find your local guidance for dealing with a patient suspected of having Ebola or another viral haemorrhagic fever?
• Have you considered having a trial run, perhaps via an exercise, to test if the guidance is practical and achievable?
• Having read this article, do you think you would be able to complete a risk assessment for a returning traveller?
• Do you consider travel history in all patients you see with a fever?