MERS-CoV: diagnosis and management of cases and contacts

Question

Accepted Answer

This guidance supersedes guidance previously found in ‘MERS-CoV: public health investigation and management of possible cases’ and ‘MERS-CoV: public health investigation and management of close contacts of confirmed cases’.

When to suspect Middle East respiratory syndrome

Who is this guidance for

This guidance is for healthcare professionals and health protection teams (HPTs) on the identification and management of cases of Middle East respiratory syndrome (MERS), which is caused by Middle East respiratory coronavirus (MERS-CoV).

More information about MERS-CoV can be found online.

Clinical assessment

Consider MERS-CoV if a patient meets one of the 2 possible case definitions below:

Group 1: High symptom severity, wider epidemiological link

Any person with severe acute respiratory infection who requires admission to hospital and has evidence of pulmonary parenchymal disease (for example, clinical or radiological evidence of pneumonia or acute respiratory distress syndrome (ARDS)) (see note 1)

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

contact with a confirmed case of MERS-CoV infection (see contact tracing matrix, below for examples of contact)
a history of travel to, or residence in, a country in list A (box 1)
an unusual or unexpected clinical course, especially sudden deterioration despite appropriate treatment, with unknown place of residence or history of travel

Group 2: Low symptom severity, narrower epidemiological link

Any person presenting with an acute respiratory infection of any degree of severity (symptoms may include fever, cough or shortness of breath) (see note 1) and one of the following in the 14 days prior to onset:

contact with a confirmed case of MERS-CoV (see contact tracing matrix for examples of contact)
contact with camels or camel environments, or consumption of or contact with camel products (for example, raw camel milk or camel urine) in country list A (box 1)
attendance at a hospital in country list A or contact with people who have attended a hospital in country list A (box 1)
occupational exposure to camels (for example, in animal husbandry or abattoirs) or consumption of or exposure to camel products (for example, raw camel milk or camel urine) in country list B (box 1)

Note 1: gastrointestinal symptoms may also be present and there is a possibility of atypical presentation, such as absence of fever, particularly in patients who are immunocompromised as per the Green Book.

Any individual who has not had a relevant exposure, as detailed in the 2 groups within the last 14 days before onset of illness is not considered to be at risk of MERS-CoV.

Box 1

List A: Bahrain, Jordan, Iran, Iraq, Kingdom of Saudi Arabia, Kuwait, Oman, Qatar, United Arab Emirates, Yemen.

List B: Kenya, Nigeria, Morocco.

The UK Health Security Agency (UKHSA) periodically assesses the international evidence of MERS-CoV in humans and animals to maintain lists A and B, and a list of countries with any known occurrence of high consequence infectious disease (HCID) is also maintained by UKHSA.

List B includes countries with evidence of MERS-CoV seropositivity in occupationally exposed camel workers, not the general population. MERS-CoV is endemic in dromedary camels in several African countries, therefore occupational exposure is high risk.

Actions for a case of MERS-CoV

For all suspected MERS-CoV cases

Clinical assessment and risk stratification should be conducted for all individuals meeting the case definitions above, as well as for symptomatic contacts of probable and confirmed cases as described in the section for health protection teams (HPTs) below.

All patients under assessment for suspected MERS should immediately be isolated in a single side room, ideally at negative pressure. Additional IPC measures and personal protectional equipment (PPE) should be implemented as per local trust policy, including appropriate handling of waste, linen and specimens. Further guidance can be found in the NHS National infection prevention control manual for England and the Addendum on HCID PPE.

Individuals not requiring hospital admission should be provided with advice on self-isolation pending their test result.

MERS is a high consequence infectious disease (HCID) and suspected cases should be discussed with local infection services before testing.

MERS is a notifiable disease and the local health protection team (HPT) should be urgently notified of any possible cases being tested. The local HPT can contact the Acute Respiratory Infections team (ARI) at acute.respiratory@ukhsa.gov.uk in hours for advice, or the Epidemic and Emerging Infections (EEI) on-call consultant out of hours, via the UKHSA switchboard on 020 7654 8000.

Testing for MERS-CoV

Instructions for the minimum diagnostic sample set and referral of samples to laboratories for testing is available in MERS-CoV: diagnostic testing guidance guidance and in the laboratory testing flowchart for MERS-CoV. 

Case definitions for use by HPTs

Who is this guidance for

This guidance is for health protection professionals to guide public health actions for cases of MERS and their contacts, as per the contact tracing matrix below.

Possible case: any individual who falls into one of the 2 groups of suspect MERS cases and and for whom polymerase chain reaction (PCR) testing is pending.

Probable case (box 2): any individual in whom MERS-CoV has been detected by PCR at an NHS laboratory with validated MERS-CoV testing or a UKHSA and Collaborating NHS Clinical Network Laboratory (CNL) and is pending confirmatory testing in the reference laboratory UKHSA Respiratory Virus Unit.

Confirmed case: any individual in whom MERS-CoV has been confirmed by PCR by the reference laboratory UKHSA Respiratory Virus Unit (RVU).

Discarded case: any individual who falls into one of the 2 groups of suspect MERS cases who has tested negative for MERS-CoV at an NHS laboratory with validated MERS-CoV testing or a CNL and in whom there is no ongoing clinical suspicion of MERS-CoV.

Box 2

Probable cases should be managed in the same way as confirmed cases.

A probable case that goes on to test negative at UKHSA RVU should be discussed and re-tested before being considered a discarded case.

Instructions for the minimum diagnostic sample set and referral of samples to laboratories for testing is available in MERS-CoV: diagnostic testing and in the diagnostic testing flowchart for MERS-CoV.

Actions for possible MERS cases

This section is for clinical and public health professionals to guide the investigation and management of possible MERS cases. Further information on clinical presentation can be found in the Clinical assessment section. For case status definitions, see Case definition status for use by HPTs below.

Testing pathway

Follow the guidance in MERS-CoV: diagnostic testing.

Samples should not be sent to the UKHSA reference laboratory Respiratory Virus Unit (RVU) for primary testing.

Reporting and public health actions

HPTs should complete the abridged MDS form (minimum dataset form) and inform the following that testing will be carried out:

the UKHSA Acute Respiratory Infections team via acute.respiratory@ukhsa.gov.uk (in hours), or the Epidemic and Emerging Infections (EEI) consultant on-call (out-of-hours) by phone

HPTs should advise isolation until test results available. Self-isolation at home pending test results may be appropriate if the patient is considered well enough for discharge following clinical assessment, taking in to account local risk-stratification including that they:

can travel home by private vehicle, driven by the patient or a household member (the patient should sit in the back seat on the opposite side and wear a fluid resistant surgical mask, the windows should be kept open and there should be no other passengers); they should not travel by taxi or by public transport
can understand and comply with the self-isolation advice below
do not share a household with any individuals who are above the age of 65 years, immunosuppressed or have underlying conditions including diabetes, hypertension, chronic cardiac and renal disease

Self-isolation advice

Patients self-isolating at home pending their test result should be given the following advice:

avoid contact with other household members
do not share personal items such as towels, bed linen, toothbrushes or eating and drinking utensils such as cutlery or cups
risk assess if non-essential medical or dental treatment should be postponed (considering the risk of exposure, the risk of delaying the treatment and the potential risk to healthcare providers)
for essential treatment, the healthcare provider must be informed before the procedure or attendance at the healthcare facility
advise not to travel

For further guidance on self-isolating at home, see MERS-CoV: self-isolating awaiting MERS-CoV test result.

Actions for probable and confirmed MERS cases

Samples which test positive in a local NHS laboratory or UKHSA and collaborating NHS CNL should be forwarded urgently (same day) to RVU for confirmation as per the testing flowchart and testing guidance.

Cases are considered probable until confirmed as positive by RVU. Probable cases should be managed clinically in the same way as confirmed cases pending RVU confirmation.

All further samples from confirmed cases should be sent directly to UKHSA RVU and should include repeat respiratory tract sampling (upper and/or lower depending on clinical status), serological samples, and other samples depending on clinical status.

Reporting and public health actions for positive results

The consultant microbiologist or virologist or treating clinician should immediately report positive results from a local accredited laboratory or UKHSA CNL to the HPT (by phone).

The HPT should inform the UKHSA Acute Respiratory Infections Team at:

in hours: acute.respiratory@ukhsa.gov.uk
out of hours: the EEI duty consultant via the UKHSA switchboard on 020 7654 8000

For all positive MERS-CoV results, the following reporting and escalation actions should be undertaken immediately:

the HPT should complete the MDS form and email this to the Acute Respiratory Infections Team at acute.respiratory@ukhsa.gov.uk during working hours, Monday to Friday, or the EEI duty consultant out of hours via the UKHSA switchboard on 020 7654 8000
the acute respiratory infections team (in hours) or EEI consultant on-call (out of hours) should inform the National Response Centre (NRC) on-call (0300 303 3493) of any positive results for MERS-CoV. The NRC on-call should then notify the NHS England National EPRR Duty Officer, in line with alerting protocols
the NHS England National EPRR Duty Officer will liaise with the HCID clinical lead and coordinate activation of the HCID Network (airborne) to discuss appropriate placement and initial clinical management, as appropriate
in parallel, the relevant NHS Trust should follow standard alert and escalation (on-call mechanisms) via their commissioner
the expectation is that all positive MERS-CoV cases would be managed in a hospital setting via HCID pathways
patients who are in the community at the time of a positive test result becoming available should be advised to self-isolate, pending transfer to an HCID centre, co-ordinated through EPRR mechanisms outlined above

Reporting and public health actions for confirmed results

RVU should report all confirmed positive results by telephone to the:

laboratory that produced the initial positive result 
clinical laboratory that referred the sample initially 
relevant CNL microbiologist or virologist
local HPT 
the UKHSA Acute Respiratory Infections Team or EEI consultant on-call (out of hours) via the UKHSA switchboard on 020 7654 8000
the UKHSA Acute Respiratory Infections team (in hours) or EEI consultant on-call (out of hours) should report all confirmed cases to the World Health Organization within 24 hours of confirmation via the national focal point at IHRNFP@ukhsa.gov.uk

De-isolation and discharge of MERS cases 

This guidance has been produced by the UK Health Security Agency (UKHSA) to support NHS trusts in managing the de-isolation of patients with MERS-CoV infection. Arrangements for individual patients should be considered on a case-by-case basis and must be made in conjunction with the managing clinical team and the HCID network.

De-isolation of a MERS-CoV confirmed case is based on the clinical presentation and the correct interpretation of the laboratory findings. De-isolation can be considered if the patient is judged to be clinically well enough for safe discharge by the clinical team managing the patient and the following conditions are met:

the patient is at least 10 days post onset of symptoms (if symptomatic)
their symptoms have resolved (if symptomatic)
they have tested negative for MERS-CoV by PCR on 2 respiratory samples taken 24 hours apart from a site that was previously positive

If it is not possible to obtain a sample from a site that was previously positive (for example, because the patient has been extubated), or the patient remains symptomatic or PCR positive beyond 14 days, the need for repeat sampling and continued isolation should be discussed by the incident management team, to include the clinical team, the HCID network, the relevant HPT lead, the duty senior in the Acute Respiratory team at UKHSA and a virologist from RVU.

Management of contacts of probable and confirmed MERS cases in UK settings

This guidance should be used for exposures to probable (sample positive at local NHS laboratory or CNL) or confirmed (sample positive at RVU) cases of MERS.

It is a public health responsibility:

to identify, assess, and categorise contacts of a symptomatic case of MERS
to appropriately monitor contacts 
to arrange clinical assessment and testing for contacts who develop symptoms within 14 days of the last possible exposure

Health protection teams (HPTs) should conduct interviews with probable and confirmed confirmed MERS cases, or their next of kin if they are too unwell, to identify contacts during their symptomatic period. Any individual who has not had contact with a case in the last 14 days is not considered a contact.

Contact management and the requirement for isolation or MERS-CoV testing will depend on the level of risk of contact, which is described in the contact tracing matrix.

Active follow-up (for high exposure (category 3) contacts)

For active follow-up, the health protection team (HPT) should have contact with the exposed person daily (by text, telephone, or email) for the 14 days following their last exposure to check if they have developed any symptoms compatible with MERS-CoV as described in the case definitions. HPTs should immediately refer any individual who develops symptoms for clinical assessment as a possible case as per NHS Integrated Care Board guidance.

Passive follow-up (for medium (category 2) and low (category 1) contacts)

For passive follow-up, the health protection team (HPT) should provide the exposed person with information on MERS-CoV, the emergency contact instructions for the local HPT, and instruct the individual to contact the HPT if they develop any of the clinical symptoms described in the case definitions in the 14 days following their last exposure.

HPTs should immediately refer any individual who develops symptoms compatible with MERS-CoV as described in the case definitions for clinical assessment as a possible case.

For NHS healthcare staff, their local occupational health department may conduct follow-up.

Classification of contacts, follow up advice and public health recommendations for contacts of MERS cases

The classification of contacts, follow up advice and public health recommendations are outlined in the contact tracing matrix, below.

Advise contacts to:

follow instructions in the contact information sheet with regards to the requirements for self-isolation, self-monitoring of temperature and symptoms
if symptomatic (as outlined in the contact information sheet), phone designated contact immediately (category 3 high exposure contacts only)
if any delay in contacting the UKHSA designated contact, phone NHS 111, and state that they have been exposed to MERS-CoV
if seriously ill, dial 999, again reporting contact with MERS-CoV

Information for contacts of MERS-CoV cases

Contacts who become symptomatic within 14 days of their relevant exposure should be managed as possible cases, with the appropriate clinical assessment and public health actions carried out.

Contact tracing matrix

Download the contact tracing matrix: