Guidance

Algorithm for the investigation and management of possible cases of MERS-CoV

Updated 14 June 2024

Possible case definitions

There are 3 possible case definitions.

Definition 1

Any person with severe acute respiratory infection who shows all 3 of the following symptoms – they:

• require admission to hospital with symptoms of fever (greater than or equal to 38°C) or history of fever, and/or cough
• have evidence of pulmonary parenchymal disease (for example, clinical or radiological evidence of pneumonia or acute respiratory distress syndrome (ARDS))
• have no other aetiology that fully explains the clinical presentation (clinicians should also be alert to the possibility of atypical presentations in patients who are immunocompromised)

Plus at least one of the following in the 14 days before the onset of symptoms:

• a history of travel to, or residence in, an area where infection with Middle East respiratory syndrome coronavirus (MERS-CoV) could have been acquired ^{[footnote 1]}
• close contact with a confirmed case of MERS-CoV infection (close contact is defined below)
• the person has been in a healthcare setting in a country in list A ^{[footnote 1]}
• the person is a healthcare worker caring for patients with severe acute respiratory infection, regardless of travel or personal protective equipment (PPE) use

Or if either of the following apply – the person:

• is part of a cluster of 2 or more epidemiologically linked cases within a 2-week period requiring ICU admission, regardless of history of travel
• develops an unusual or unexpected clinical course, especially sudden deterioration despite appropriate treatment, with unknown place of residence or history of travel

Note: Gastrointestinal symptoms may also be present. Clinicians should also be alert to the possibility of co-infections with MERS-CoV. Clinicians should additionally be alert to the possibility of atypical presentations in patients who are immunocompromised; atypical presentations may include absence of fever.

Definition 2

Acute influenza-like illness (ILI) symptoms plus either of the following in the 14 days prior to onset:

(A) In countries in list A ^{[footnote 1]}: any contact with camels, camel environments or consumption of camel products (for example, raw camel milk, camel urine) or attendance to a hospital or contact with people who have attended a hospital

Or:

(B) In countries in list B ^{[footnote 2]}: occupational exposure to camels (for example, in animal husbandry or abattoirs) or consumption of camel products (for example, raw camel milk, camel urine)

(ILI is defined as sudden onset of respiratory infection with measured fever of greater than or equal to 38°C and cough.)

Definition 3

Acute respiratory illness (ARI) plus contact with a confirmed case of MERS-CoV in the 14 days prior to onset.

(ARI is defined as sudden onset of respiratory infection with at least one of: shortness of breath, cough or sore throat.)

Meets case definition

If the case meets the possible case definition, steps must be taken by the local clinician or microbiologist and by the UK Health Security Agency (UKHSA) Health Protection as follows:

Local clinician or microbiologist

Ensure appropriate samples are taken and contact the nearest MERS-CoV primary testing laboratory (UKHSA Public Health Laboratory Manchester or Birmingham, or hospital laboratory with validated MERS-CoV assay).

Ensure full PPE is worn (correctly fitted respirator (FFP3), gown, gloves and eye protection) and that the patient is managed as per MERS-CoV infection control advice (details on infection prevention and control (IPC) precautions below).

Notify the local UKHSA health protection team (HPT).

Consider testing for Legionnaire’s disease.

UKHSA health protection

Inform the UKHSA TARZET Acute Respiratory Team at acute.respiratory@ukhsa.gov.uk and enter case details on HPZone (Infection and unlisted managed context: MERS-CoV).

Collect possible case data set (Form 1) and email TARZET Acute Respiratory Team at acute.respiratory@ukhsa.gov.uk, during working hours, Monday to Friday, or contact the CEI out-of-hours duty consultant at any time outside of working hours.

If a cluster is suspected, establish whether there is an epidemiological link between cases.

Pathway 1. Presumptive positive

If the testing laboratory result is positive for MERS-CoV – presumptive positive – (see laboratory guidance), then follow these steps (note that a presumptive positive case will trigger an incident management team (IMT)):

1. MERS-CoV testing laboratory

Inform the local HPT, the referring laboratory and UKHSA reference laboratory and send residual material urgently to UKHSA reference laboratory (RVU) for confirmatory testing (see laboratory guidance).

2. Clinician or microbiologist

Ensure full PPE is worn (see infection control advice).

3. UKHSA HPT

Contact the TARZET Acute Respiratory Team immediately at acute.respiratory@ukhsa.gov.uk during working hours, Monday to Friday, or contact the CEI out-of-hours duty consultant at any time outside of working hours.

Start to identify and collate list of close contacts (close contact is defined below) and email to UKHSA Colindale.

Following the above actions, refer to reference laboratory results below for further actions.

Pathway 2. Negative result for MERS-CoV

If the testing laboratory result is negative for MERS-CoV or if the reference laboratory result is negative for MERS-CoV (see laboratory guidance), then discard as MERS-CoV.

Reference laboratory results

If the reference laboratory result is positive for MERS-CoV – it is a confirmed case – move on to the confirmed case actions, below.

Confirmed case actions

If a confirmed case, take the following actions:

1. Clinician or microbiologist

Collect appropriate baseline samples and send to UKHSA reference laboratory (RVU) (see laboratory guidance)

2. UKHSA HPT

Complete confirmed case initial form (Form 1a) and email tothe TARZET Acute Respiratory Team acute.respiratory@ukhsa.gov.uk during working hours, Monday to Friday, or contact the CEI out-of-hours duty consultant at any time outside of working hours.

In addition, follow the UKHSA MERS-CoV close contact algorithm.

Follow-up

1. Clinician or microbiologist

Ensure appropriate sequential follow-up samples are taken after discussion with the UKHSA Colindale incident management team (laboratory guidance).

2. UKHSA HPT

Complete confirmed case follow-up Form 1b 14 to 21 days after Form 1a has been completed and email to TARZET Acute Respiratory Team acute.respiratory@ukhsa.gov.uk.

Important notes

Close contact

Close contact is defined as either:

• prolonged face-to-face contact (more than 15 minutes) with a symptomatic confirmed case in a household or other closed setting

Or:

• health or social care worker who provided direct clinical or personal care or examination of a symptomatic confirmed case, or was within close vicinity of an aerosol generating procedure, or had direct contacts with body fluids from a symptomatic case and was not wearing full PPE at the time (infection control advice)

All persons meeting the close contact definition should be notified to the local HPT regardless of decision to test or test results.

The HPT is then to discuss with the national incident management team.

IPC precautions

It is recommended that patient assessment and collection of clinical specimens for MERS-CoV testing is undertaken in settings where appropriate IPC measures can be implemented. This may not be feasible in primary care settings, in which case an appropriate local secondary care service should be contacted to discuss if patient referral is appropriate and to ensure IPC measures can be implemented.

Co-infection

MERS-CoV co-infection with other respiratory pathogens has been reported previously. Therefore any patient meeting the possible case definition should be tested for MERS-CoV infection regardless of other infections being identified.

Occupational exposure in cases from countries in list B

No human cases have been reported by the World Health Organization (WHO) from the countries named in list B ^{[footnote 2]}. However, peer reviewed studies have identified evidence of MERS-CoV infection in individuals with close occupational exposure to camels (including but not limited to animal husbandry, abattoirs) from these countries. This is a precautionary measure to maximise preparedness.

Notes

Note that UKHSA periodically assesses the type and strength of international evidence of MERS-CoV in humans and animals, to maintain list A and B.

1. List A: Bahrain, Jordan, Iraq, Iran, Kingdom of Saudi Arabia, Kuwait, Oman, Qatar, United Arab Emirates, Yemen – see map and risk assessment. ↩ ↩² ↩³

2. List B: Kenya. ↩ ↩²