Risk statement
-- The scope of this Rapid Risk Assessment is to reassess the epidemiological situation of Middle East respiratory syndrome coronavirus (MERS-CoV) following the recent exportation (in December 2025) of cases from the Arabian Peninsula to France and three healthcare-associated clusters reported by the Kingdom of Saudi Arabia (KSA) in 2024–2025.
-- These events, together with the continued occurrence of sporadic cases in Arabian Peninsula countries, highlight the ongoing risk of international spread to non-endemic countries and reflect the persistent circulation of MERS-CoV in the Middle East.
-- Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus transmitted to humans through direct or indirect contact with infected dromedary camels, which are the natural host of the virus.
-- First identified in humans in 2012 in the Kingdom of Saudi Arabia (KSA) and Jordan, MERS-CoV causes a viral respiratory infection that occurs throughout the year, with cases reported sporadically and in clusters.
-- Clinical presentation ranges from asymptomatic or mild respiratory illness to severe acute respiratory disease, pneumonia, and death.
-- The case fatality rate among cases reported to WHO is 37%.
-- Since MERS-CoV emergence in 2012, until 23 January 2026, under the International Health Regulations (IHR, 2005), 27 countries have reported human cases of MERS-CoV to the WHO:
- Algeria,
- Austria,
- Bahrain,
- China,
- Egypt,
- France,
- Germany,
- Greece,
- the Islamic Republic of Iran,
- Italy,
- Jordan,
- Kuwait,
- Lebanon,
- Malaysia,
- the Netherlands,
- Oman,
- the Philippines,
- Qatar,
- the Republic of Korea,
- the Kingdom of Saudi Arabia (KSA),
- Thailand,
- Tunisia,
- Türkiye,
- the United Arab Emirates (UAE),
- the United Kingdom,
- the United States of America, and
- Yemen.
-- However, of the 2635 MERS cases documented globally since 2012, 2418 (92%) were reported from the WHO Eastern Mediterranean Region (EMR).
-- The majority (84%) of reported cases were notified by KSA (2224/2635) followed by other Arabian Peninsula countries: the UAE (94), Jordan (28), Qatar (28), Oman (26), Iran (6), Kuwait (4), Tunisia (3), Lebanon (2), Bahrain (1), Egypt (1) and Yemen (1).
-- Exposure was commonly linked to direct or indirect contact with infected dromedary camels or transmission from infected individuals in healthcare settings or households.
-- Most cases reported outside the Arabian Peninsula countries involved people likely infected there prior to travelling elsewhere.
-- Following the first human infection with MERS-CoV in 2012, the Director‐General convened an Emergency Committee under the International Health Regulations (IHR 2005) in 2013 to assess whether the outbreaks of MERS constituted a Public Health Emergency of International Concern (PHEIC) and to provide guidance on the public health measures that should be taken.{i}
-- The Committee has met on 10 occasions and, on each occasion, concluded that the outbreaks do not meet the criteria of a PHEIC.
-- The overall risk of MERS-CoV in 2023 was assessed as moderate both at the regional and global levels.
-- A new assessment currently confirms that this risk level remains unchanged, moderate both at the regional and global levels, taking into account the following considerations:
- 1. Continued reports of sporadic cases in endemic countries in the Arabian Peninsula and the occasional occurrence of traveller cases and healthcare-associated transmission, including two cases reported from France in December 2025 and three clusters reported in the Kingdom of Saudi Arabia during 2024–2025.
- 2. Since the last RRA in 2023, cases reported to WHO have not resulted in sustained onward human-tohuman transmission, as most identified close contacts tested negative and no additional household clusters have been identified. The three healthcare-related clusters remained limited, with infection only confirmed in direct contacts with the index case.
- 3. The observed decline in reported MERS cases since 2020, in particular during the COVID-19 pandemic emergency phase, is thought to be a result of pandemic-related Infection Prevention & Control measures that also limited human-to-human transmission of MERS-CoV, as well as behavioural changes during the pandemic. Any role of potential cross-reactive immunity from SARS-CoV-2 infection and/ or vaccination remains in need of further investigation. Other hypotheses—such as reduced surveillance, viral attenuation, or decreased circulation in camel populations—are not supported by current evidence.
- 4. Significant disparities persist globally in countries' capacities to detect and respond effectively to the disease, particularly in regions where the virus has not been previously documented. Within the EMR, six fragile, conflict-affected, and vulnerable countries are considered at greater risk.
- 5. Global inequalities remain in the adequacy of preparedness, infection prevention and control capacities, and response measures, particularly in the context of a cross-border outbreak or a traveller case.
- 6. MERS-CoV continues to circulate in dromedary camel populations without causing overt clinical signs, constituting a constant source of human exposure and a risk of zoonotic spillover, which may result in occasional onward human-to-human transmission. The recent detection of Clade B viruses in camels of African origin further highlights the risk of MERS-CoV spread from the Arabian Peninsula via camel movements and poses an additional risk to other regions, particularly given the documented increased replication competence and more efficient viral entry of Clade B compared with Clade C.
- 7. Preliminary data from in vitro growth kinetics and partial sequencing indicate no major attenuation in circulating Clade B strains.
- 8. The potential public health impact of MERS-CoV should not be underestimated given the severity of disease and its high reported case fatality rate (CFR), even though sustained global spread is currently considered unlikely.
- 9. MERS-CoV can cause severe disease resulting in high mortality. The current CFR of 37% is based on laboratory-confirmed cases only and may therefore overestimate of the true mortality rate.
- 10. Existing regional and global surveillance systems may fail to detect asymptomatic and mild cases of MERS, leading to underreporting.
- 11. Limited and non-sustained human-to-human transmission has been documented, mainly in healthcare and household settings. However, due to limited research, data gaps remain in understanding transmission dynamics, including the role of environmental contaminations, asymptomatic cases and specific exposure risk in healthcare settings. Further research is needed to better understand zoonotic transmission associated with dromedary camel products and excreta.
- 12. Due to the similarity of symptoms with other respiratory diseases that are widely circulating, like influenza or COVID-19, detection and diagnosis of MERS cases may be delayed, especially in unaffected countries, creating opportunity for local onward transmission.
- 13. Should MERS-CoV result in a healthcare-associated outbreak in a previously unaffected country, as occurred in the Republic of Korea in May 2015, during which 186 laboratory-confirmed cases (185 in the Republic of Korea and 1 in China) and 38 deaths were reported, the public health consequences for that country could be substantial.
- 14. The recent exportation of cases from the Arabian Peninsula to France demonstrates the ongoing risk of international spread.
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{1} Confidence refers to the level of confidence in the data/information or the quality of the evidence available at the time the RRA is conducted. Poor quality information may increase the overall perceived risk due to the incertitude in the assessment
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