Friday, July 01, 2022

The Upcoming Hajj & The UKHSA MERS-CoV Risk Assessment


Seven days from now (July 7th) Saudi Arabia will host the first Hajj since COVID emerged in early 2020 - and while it will be smaller than in past years, and limited to those under the age of 65 - it will draw as many as 1 million people from countries all around the globe. 

As we've discussed often, the Hajj - like many other mass gathering events - has the potential to amplify and disperse emerging and existing infectious diseases on a global scale (see J, Epi & Global Health: Al-Tawfiq & Memish On Hajj Health Concerns).

The biggest health concerns include mosquito borne illnesses (like Dengue, Chikungunya, Zika & Yellow Fever), tuberculosis, mumps, measles, chickenpox, norovirus and respiratory viruses like seasonal influenza & Rhinovirus - and since 2013 - MERS-CoV. .

In 2015's EID Journal: ARI’s In Travelers Returning From The Middle East, researchers found respiratory infections are the most commonly reported illness among religious pilgrims. This study also found that:
`Pneumonia is the leading cause of hospitalization at Hajj, accounting for approximately 20% of diagnoses on admission.’

But this year we also have the added concern of COVID, which is often indistinguishable from flu, MERS-CoV, and other respiratory viruses without testing.  

While reports of MERS-CoV cases have plummeted since early 2020, it is not clear how much of that can be attributed to lapses in surveillance and reporting, and how much to an actual decline in cases. 

Detecting MERS-CoV cases can be challenging, even when countries are actively looking for cases. A task has which has admittedly become even more difficult due to the COVID pandemic. 

Given its high case fatality rate, and the recent trend of coronaviruses adapting to humans (SARS and SARS-CoV-2), MERS-CoV remains a credible threat.  

Here is today's updated Risk Assessment from the UKHSA.

UKHSA risk assessment of MERS-CoV

Updated 1 July 2022

Epidemiological update

As of 16 June 2022, 2,591 cases of Middle East Respiratory Syndrome (MERS-CoV) have been reported by WHO, with at least 894 related deaths. The majority of MERS-CoV cases have been reported from the Arabian Peninsula, with one large outbreak outside this region involving 186 cases in the Republic of Korea (RoK) in 2015. Cases have been exported to other countries outside of the Middle East, including cases being identified in the UK and South Korea in August and September 2018 respectively.

On 22 August 2018, Public Health England (PHE) reported a laboratory-confirmed case of MERS-CoV infection in a resident of the Middle East who had travelled from Saudi Arabia. In response to this, public health measures were implemented including identification of exposed contacts and provision of health advice. This was the third imported MERS case reported by the UK; the previous case was reported in 2013 was associated with 2 infections in close contact.

Excluding the 2015 outbreak in RoK, the majority of reported cases of MERS-CoV worldwide have been from the Kingdom of Saudi Arabia (KSA).

MERS-CoV in Saudi Arabia

In KSA, cases of MERS-CoV occur throughout the year; there is currently no evidence of sustained community transmission; human-to-human transmission is most likely to occur in healthcare facilities and household clusters. Large outbreaks linked to healthcare facilities are a feature of MERS-CoV and have occurred both within the Middle East and RoK. This underlines the significance of healthcare facilities as a risk factor for amplifying infection, but also the importance of effective and rapid implementation of infection prevention and control practices for possible cases to limit the potential for onward transmission to other patients and staff.

Outside of hospital outbreaks and smaller household clusters, reported cases are sporadic and usually occur in individuals with a history of contact with camels or camel products such as consumption of raw camel milk. The UK Health Security Agency (UKHSA, previously Public Health England) will continue to monitor the situation in KSA.

Risk assessment

The previous sporadic imported cases to the UK highlight the continued risk of imported cases to the UK, reflecting the epidemiology of MERS-CoV infection in the Middle East. It is therefore imperative that health professionals remain vigilant for clinical presentations compatible with Middle East Respiratory Syndrome. Early identification and rapid implementation of appropriate infection control measures for possible cases, and reporting of these to local health protection teams is crucial.
The risk of infection with MERS-CoV to UK residents in the UK remains very low.
The risk of infection with MERS-CoV to UK residents travelling to the Middle East is very low, but may be higher in those with exposure to specific risk factors within the region, such as camels (or camel products) or the local healthcare system.

Testing for MERS-CoV is warranted for persons who meet the possible case definition together with rapid implementation of appropriate infection control measures while awaiting results of testing.

The majority of outbreaks of MERS-CoV in the Middle East have been linked to healthcare settings. A previous WHO mission to Saudi Arabia concluded that gaps in infection control measures have most likely contributed to these outbreaks; this reinforced the importance of strict adherence to recommended infection control measures in healthcare facilities.

Where UK infection control procedures have been followed, the probability of acute respiratory infection in a healthcare worker caring for a case of MERS-CoV, or a case of severe acute respiratory infection of unknown aetiology in the intensive care unit (ICU), is due to MERS-CoV is very low, but warrants testing. Any healthcare worker who develops an acute respiratory illness and has recently been in contact with a confirmed case of MERS-CoV would be tested for the virus. The risk will be higher for healthcare workers exposed to MERS-CoV who have not adhered to UK infection control procedures, such as the use of adequate personal protective equipment (PPE).

The risk to contacts of confirmed cases of MERS-CoV infection is low, but contacts should be followed up for 14 days following last exposure and any new febrile or respiratory illness investigated urgently for MERS-CoV.

Further information and guidance on MERS-CoV is available.

Travel advice

All travellers to the Middle East are advised to avoid contact with camels as much as possible:
  • travellers should practice good general hygiene measures, such as regular handwashing with soap and water at all times, but especially before and after visiting farms, barns or market areas
  • travellers are advised to avoid raw camel milk and/or camel products from the Middle East
  • travellers are also advised to avoid consumption of any type of raw milk, raw milk products and any food that may be contaminated with animal secretions unless peeled and cleaned and/or thoroughly cooked
  • travellers should follow the advice of local health authorities; there are currently no travel restrictions in place
  • travellers developing fever and cough within 14 days of travel from the Middle East should seek medical advice and must report their travel history so that appropriate clinical assessment, infection control measures and testing can be undertaken
  • people who are acutely ill with an infectious disease are advised not to travel but to seek health advice immediately
The Hajj and Umrah

International pilgrims will be allowed to undertake the Hajj in 2022.

The last Hajj where large numbers of international pilgrims could attend was in 2019. There was no reported increase in travel-related MERS-CoV cases for this latest or previous Hajj pilgrimages. However, cases of MERS-CoV have been imported to countries outside of Saudi Arabia following return from Umrah, a separate pilgrimage which can be performed throughout the year, as illustrated by the most recent Malaysian case.

UKHSA remains vigilant and closely monitors developments in the Middle East and in the rest of the world where new cases have emerged and continues to liaise with international colleagues to assess whether our recommendations need to change.

Infographics for people travelling to the Middle East or returning from the Middle East are available in a range of languages.

NaTHNaC has published travel health advice for Hajj and Umrah.

Further information for health professionals on the possible MERS case definition is available.

Past studies (see A Pandemic Risk Assessment Of MERS-CoV In Saudi Arabia) have suggested the MERS virus doesn't have all that far to evolve before it could pose a genuine global threat.

And while it remains mostly a theoretical concern, several studies have suggested that there it at least some potential for seeing a MERS-CoV/SARS-CoV-2 recombinant emerge someday. 

The Recombination Potential between SARS-CoV-2 and MERS-CoV from Cross-Species Spill-over Infections

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV) coinfection: A unique case series

Good reasons why we need improve surveillance and testing of cases, and the reporting of them promptly to WHO  Otherwise, we risk being blindsided by the next global health threat.