MERS-CoV: diagnostic testing

Information on taking,听submitting听and processing clinical samples from听patients听suspected of having Middle East respiratory syndrome coronavirus (MERS-CoV).听

From:: UK Health Security Agency
Published: 18 May 2026

Applies to England

Aim of guidance

This guidance supersedes guidance previously found in 鈥楳iddle East Respiratory Syndrome Coronavirus (MERS-CoV)鈥�.

It is aimed at clinicians and healthcare workers, health protection teams (HPTs) and clinical diagnostic laboratories in听both听the public and private sectors.

MERS-CoV reporting and diagnostics

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic respiratory virus. It can be transmitted to humans through direct or indirect contact with infected dromedary camels or contaminated camel products. Human-to-human transmission does occur, through听close unprotected contact听with MERS-CoV听positive cases听in health care settings and听among household members.

罢丑别听听尘补颈苍迟补颈苍蝉听耻辫-迟辞-诲补迟别 MERS-CoV epidemiological case data.

The UK government is听obligated听to report any鈥�MERS-CoV鈥痯ositive cases to the World Health Organization (WHO) under the International Health Regulations (IHR) 2025 via the National鈥�IHR鈥疐ocal Point. This guidance sets out the explicit testing and reporting criteria required by the NHS and the UK Health Security Agency (UKHSA) to meet these obligations.听As a notifiable disease,听Registered Medical Practitioners听are required to听notify听all suspected cases of听MERS听urgently (within听24 hours) to a health protection team, under Health Protection (Notification) Regulations 2010 (HPNR).

Primary diagnostic testing for MERS-CoV听is available at鈥疷KHSA听and Collaborating听NHS Regional听Public Health听Laboratories (PHLs) or听may be offered by听non-鲍碍贬厂础-诲别蝉颈驳苍补迟别诲听MERS-CoV听(NHS/non-NHS)听testing laboratories with adequately verified MERS-CoV assays holding appropriate accreditation.听Confirmatory testing and characterisation听for international reporting听is听performed in the National听Reference Laboratory in the Respiratory Virus Unit听(RVU), Colindale.

MERS-CoV听viruses are genetically diverse听and continuously evolving. Genomic surveillance at the animal interface is听limited,听and human cases are rare, with limited virus genome sharing. Consequently, this听guidance takes into consideration associated uncertainties for diagnostics, including limited availability of contemporaneous virus positive materials听for up-to-date diagnostic assurance.

UKHSA guidance听is available on听when to suspect a case of MERS-CoV,听and the鈥痗lassification of contacts of MERS-CoV cases and follow-up advice.

Who to inform testing is taking place

The decision to test for MERS-CoV should be based upon the case definition and made after consultation with local NHS infection specialists and the local health protection team.

If testing is听required, the local HPT and NHS infection specialists听will provide advice on听initial听management of the case.

HPTs should inform the UKHSA Acute Respiratory Infections team when a MERS-CoV infection is suspected (via acute.respiratory@ukhsa.gov.uk),听or phone the EEI听duty consultant听on-call, if out of hours.

Testing strategy for suspected MERS-CoV

Diagnostic testing for MERS-CoV should be undertaken for individuals according to the criteria described in MERS-CoV: diagnosis and management of cases and contacts - 扒哥吃瓜.听The summary process is available as听an algorithm.

鲍碍贬厂础-诲别蝉颈驳苍补迟别诲听PHLs听辞蹿蹿别谤 MERS-CoV diagnostic testing for England. If the local NHS laboratory service offers an accredited MERS-CoV diagnostic test, samples听may be processed there.

鲍碍贬厂础-诲别蝉颈驳苍补迟别诲听PHLs听will only accept samples for testing where the patient meets the case definition or after discussion with the local clinician explaining the need for testing. If initial tests are negative for MERS-CoV and the patient develops new relevant symptoms within the 14 days following exposure,听swabbing听and testing should be repeated.

Sampling for diagnostic testing of MERS-CoV

Do not delay sampling and testing. Samples should be obtained and sent to a听MERS听testing laboratory as soon as possible after identifying the possibility of MERS-CoV infection and results should be available within 24 hours of sample receipt. In exceptional situations where out of hours testing may be necessary, discuss options with the local NHS testing laboratory or UKHSA PHL duty consultant virologist.

When taking samples ensure that you are wearing the听required PPE.听Further guidance can be found in the NHS鈥€痑nd the鈥�. All samples must be labelled with the patient鈥檚 name, date of birth, NHS number, the date and anatomical听site of the sample. Unlabelled samples听cannot be processed.

After consultation with the听HPT听and/or consultant infection specialist, the clinical team should take the following samples specifically for MERS-CoV testing:

2 upper respiratory tract samples听(box 1)听(nasopharyngeal viral swabs are preferable, but nose and throat swabs听are acceptable听where supported by local validation,听or nasopharyngeal听aspirate)
the primary testing laboratory should use one sample for testing and store the second. The stored sample should be reserved for听forwarding听to RVU if a presumptive positive is detected and confirmation is needed. Ideally, the stored sample should be collected into virus transport medium (VTM), avoiding medium听containing听an inactivating agent
if obtainable and the patient鈥檚 symptoms or clinical assessment considers it appropriate, take a lower respiratory tract sample, 2 if听feasible (box 1) (sputum, or an endotracheal tube aspirate if intubated), in addition to the upper respiratory tract samples.听Avoid听medium听containing听an inactivating agent

If the local NHS laboratory service offers an accredited MERS-CoV diagnostic test, samples may be processed there. If听primary testing听is unavailable locally, send听all samples听to听a听designated听MERS 迟别蝉迟颈苍驳听鲍碍贬厂础听PHL for testing. Do not send samples directly to RVU听Colindale听for primary testing.

Additional听samples should be collected if听other听diagnostic听testing is听required by the local听laboratory.

Box 1

A听single听negative听test听result听particularly if from听an upper respiratory tract sample,听may not exclude MERS-CoV in a patient with听clinically relevant travel history and disease. Where clinical suspicion听remains, repeat听sampling听including from听the lower respiratory tract听if possible听is recommended.听Lower respiratory tract samples obtained as soon as possible after symptom onset (less than 7 days) have the best diagnostic sensitivity. Studies have also shown shown that听swabs taken from the nasopharynx听not just the nostril听have a better diagnostic sensitivity for MERS CoV.听Not all NHS laboratories will have the capability to test lower respiratory tract samples for MERS-CoV. Clinicians should discuss options with the local NHS testing laboratory or UKHSA PHL duty consultant virologist.

As the clinical features of MERS-CoV are听similar to听those of other respiratory infections, consider testing for a wide range of respiratory pathogens,听as this听helps in听determining听a final cause for the illness, depending on the local epidemiology of circulating respiratory viruses and travel history.

What tests will be performed听

罢丑别听鲍碍贬厂础-诲别蝉颈驳苍补迟别诲听MERS听迟别蝉迟颈苍驳听PHL听will use听verified听nucleic acid amplification tests for MERS-CoV听and听hold听appropriate accreditation.

Laboratories that听test for鈥�MERS-CoV鈥痗an also perform seasonal respiratory virus screens if desired, but panels offered may vary. If a referring laboratory chooses to perform its own respiratory virus panel (in addition to requesting MERS-CoV testing), a local risk assessment should be performed听for handling a suspected CL3 organism, and appropriate health听and safety measures followed.

If听alternate diagnoses are under consideration and听any听additional听tests听are required, please discuss with the听PHL at the time of referral.听Always inform each laboratory of the risk of infection with HG3/4 pathogens, prior to sending听samples, and听ensure request forms clearly听state听the HG3/4 risk

Non inactivated samples must be handled at CL3. Aliquots of the original sample should be separated and inactivated by lysis or other validated method. Following inactivation, sample aliquots may be handled at CL2 for molecular testing.听It is important to reserve some听(non-inactivated)听material suitable for virus culture should it be听required.

Transport of samples to听UKHSA听and听Collaborating NHS听Regional Public Health听Laboratories听for MERS-CoV diagnostic testing

Details of the address of each of the听UKHSA and Collaborating NHS Regional Public Health Laboratories that offer testing for MERS-CoV听are listed听in听Table 1听and on the public health laboratories听website.

Send all samples for MERS-CoV听primary听testing to the听PHL.听Do not send any samples directly to RVU听Colindale. 罢丑别听PHL听will听send听samples to the RVU 颈蹿听谤别辩耻颈谤别诲.

MERS-CoV is an Advisory Committee on Dangerous Pathogens (ACDP) Hazard Group 3 pathogen.听Diagnostic samples should be sent by听Category B transport听(UN3373, packing instruction P650), clearly听indicating听that the samples听contain听a suspected HG3 pathogen on any referral form to ensure safe handling on receipt.

Provide the听contact听details for your clinical laboratory听for the purposes of听telephone听and hard copy reporting. This must include an out-of-hours telephone number.

Send samples by DX transfer or courier services according to urgency and timing.

The referring laboratory听is responsible for听booking and paying for the transport.

MERS-CoV test result communication

Results from the听UKHSA听and听Collaborating NHS听PHLs听should be provided within 24 hours of receipt of the sample at the testing laboratory.

PHL staff听are responsible for听informing the referring clinical centre,听HPT听and UKHSA acute respiratory infections team of the results including via urgent phone communication to the referring clinical centre.

If testing has taken place outside of a 鲍碍贬厂础-诲别蝉颈驳苍补迟别诲听service, the testing service must inform the听referring clinical centre,听and the听HPT听of the results including via urgent phone communication to the referring clinical centre.

The relevant clinical team听that听requested the tests will need to be available to receive the results,听which may be out of routine hours.

罢丑别听laboratory听testing process may generate negative, positive, or inconclusive results for the presence of MERS-CoV, as well as for the presence of other respiratory virus pathogens.听

MERS-CoV testing results - definitions and actions for听primary testing laboratories

MERS-CoV positive

If the NHS or听PHL听MERS testing laboratory听obtains a presumptive positive result for MERS-CoV regardless of any other respiratory pathogen detection rapid communication听is essential, so that public health control measures can be implemented.听Refer to the听MERS-CoV: diagnosis and management of cases and contacts.

The primary testing laboratory should听contact RVU听to arrange sending of samples for confirmatory testing听in the event of听a MERS-CoV presumptive positive result. See section on听referral of presumptive positives to RVU听for guidance on sample referral.

MERS-CoV negative

If the test results show that the sample was MERS-CoV negative, then the patient should be managed according to any other relevant test results.

If appropriate samples were obtained and an alternative diagnosis is likely, then MERS-CoV may be considered excluded. In cases where a strong clinical suspicion听of MERS-CoV remains after a single negative test result, particularly if this is from an upper respiratory tract specimen, repeat sampling and testing, especially with lower respiratory specimens, is strongly recommended. For advice and to discuss options for further testing, the UKHSA听PHL or NHS duty microbiologist or virologist should contact the RVU.

MERS-CoV testing inconclusive

Where inconclusive results are obtained, the patient should continue to be managed as a suspected MERS-CoV case, until a definitive result is obtained unless a clear alternative diagnosis has been made and dual pathology excluded.

Referral of presumptive positive MERS-CoV human samples to the Respiratory Virus Unit, Colindale听

All presumptive positive MERS-CoV positive samples must be notified to RVU by telephone and arrangements made to听send听urgently for confirmatory testing and virus characterization including whole genome sequencing.

For cases where MERS-CoV testing was inconclusive, or where negative results have been obtained, but clinical suspicion听remains,听PHL or NHS laboratories听should contact the RVU to discuss听appropriate testing听and sample referral.

To contact RVU听Colindale听within working hours (Monday to Friday, 09:00 to 17:00) telephone:

020 8327 7125
020 8327 7002
020 8327 6017

If managing听out of hours, contact the Epidemic and Emerging Infections (EEI)听duty consultant听for advice.

After discussion with RVU, samples should be sent by category听B听transport, packaged accordingly, with clear labelling to听indicate听an urgent sample with suspected Hazard Group 3 pathogen. Routine daily DX transfer can be used (package separately from other samples)听or specific courier services depending on urgency and timing.

The completed听E16 MERS-CoV referral form听must be included in the package.

All available original clinical samples collected for testing, including residual material from the tested sample and the听second reserve sample,听must be sent听to RVU听(minimum 400碌l, in VTM, not lysed or inactivated). Non-inactivated听material听is important due to suitability for virus culture.听In the event there is a lower volume, or no clinical material remains, contact RVU for further advice.

Reporting of confirmatory MERS-CoV results听by the Respiratory Virus Unit

RVU will report all results of confirmatory testing, positive and negative, by phone to the referring laboratory.

The Acute Respiratory Infections Team should be notified by phone (followed up by email) in hours. Out of hours, notify the EEI听duty consultant听by phone. The local HPT will be updated by the ARI team if results are obtained during working hours, or by the EEI consultant outside of working hours.