This is the bi-annual update on Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infections reported to WHO from the Kingdom of Saudi Arabia. Between 1 August 2021 to 28 February 2022, six additional cases of MERS-CoV infections, including four associated deaths were reported to WHO from the Kingdom of Saudi Arabia. These cases were reported from Riyadh (four cases), Eastern (one case), and Taif (one case) regions. Based on the current situation and available information, WHO re-emphasizes the importance of strong surveillance by all Member States for acute respiratory infections, including MERS-CoV, and careful review of any unusual patterns.
Description of cases
Since the last Disease Outbreak News on MERS-CoV in Saudi Arabia published on 17 August 2021, the National IHR Focal Point of Saudi Arabia has reported six additional cases, including four associated deaths. The geographical distribution of these reported cases is shown in Figure 1.
Figure 1. Geographical distribution of MERS-CoV cases between 1 August 2021 to 28 February 2022 by region, Saudi Arabia (n=6)
The link below provides details of the six reported cases
Between September 2012 and 28 February 2022, a total of 2585 cases, including 891 associated deaths (case fatality rate: 35%) have been globally reported to WHO under the International Health Regulations (IHR 2005) (Figure 2). The majority of these cases have occurred in countries in the Arabian Peninsula, with one large outbreak outside this region in May 2015, when 186 laboratory-confirmed cases (185 in the Republic of Korea and one in China) and 38 deaths were reported.
Figure 2: Distribution of cases and deaths from MERS-CoV in Saudi Arabia from 2012 to 2021
 No cases of MERS-CoV have been reported between 1 January to 28 February 2022. However, one death was reported in January 2022.
Middle East respiratory syndrome (MERS) is a viral respiratory infection that is caused by a coronavirus called Middle East Respiratory Syndrome Coronavirus (MERS-CoV). Infection with MERS-CoV can cause severe disease resulting in high mortality. Approximately 35% of patients with MERS have died, but this may be an overestimate of the true mortality rate, as mild cases of MERS-CoV may be missed by existing surveillance systems and until more is known about the disease, the case fatality rates are counted only amongst the laboratory-confirmed cases.
Humans are infected with MERS-CoV from direct or indirect contact with dromedary camels who are the natural host and zoonotic source of the MERS-CoV infection. MERS-CoV has demonstrated the ability to transmit between humans. So far, the observed non-sustained human-to-human transmission has occurred among close contacts and in health care settings. Outside of the healthcare setting there has been limited human-to-human transmission.
No vaccine or specific treatment is currently available, although several MERS-CoV specific vaccines and treatments are in development. Treatment is supportive and based on the patient’s clinical condition.
Follow up of the household contacts was conducted for all six cases, and no secondary cases were identified.
The notification of the six cases does not change the overall risk assessment. WHO expects that additional cases of MERS-CoV infection will be reported from the Middle East and/or other countries where MERS-CoV is circulating in dromedary camels, and that cases will continue to be exported to other countries by individuals who were exposed to the virus through contact with dromedary camels or their products (for example, consumption of camel’s raw milk), or in a healthcare setting. WHO continues to monitor the epidemiological situation and conducts risk assessment based on the latest available information.
The number of MERS-CoV cases reported to WHO has substantially declined since the beginning of the ongoing COVID-19 pandemic (Figure 2). This is likely the result of epidemiological surveillance activities for COVID-19 being prioritized, resulting in reduced testing and detection of MERS-CoV cases. The Ministry of Health of Saudi Arabia continues to work to improve testing capacities for better detection of MERS-CoV during the ongoing COVID-19 pandemic.
Surveillance: Based on the current situation and available information, WHO re-emphasizes the importance of strong surveillance by all Member States for acute respiratory infections, including MERS-CoV, and to carefully review any unusual patterns.
Infection prevention and control in health care settings: Human-to-human transmission of MERS-CoV in healthcare settings has been associated with delays in recognizing the early symptoms of MERS-CoV infection, slow triage of suspected cases and delays in implementing infection, prevention and control (IPC) measures. IPC measures are therefore critical to prevent the possible spread of MERS-CoV between people, particularly in health care facilities.
Healthcare workers should always apply standard precautions consistently with all patients, at every interaction in healthcare settings:
Case management: Early identification, case management and isolation of cases, quarantine of contacts, together with appropriate infection prevention and control measures in health care settings and public health awareness can prevent human-to-human transmission of MERS-CoV.
MERS-CoV appears to cause more severe disease in people with underlying chronic medical conditions such as diabetes, renal failure, chronic lung disease, and immunocompromised persons. Therefore, people with these underlying medical conditions should avoid close contact with animals, particularly dromedary camels, when visiting farms, markets, or barn areas where the virus is known to be potentially circulating. Timely, effective, and safe supportive management of patients with MERS should be provided, particularly for those at risk of more severe disease.
Infection prevention and control in the community: General hygiene measures, such as regular hand washing before and after touching animals and avoiding contact with sick animals, should be adhered to. Food hygiene practices should be observed. People should avoid drinking raw camel milk or camel urine or eating meat that has not been properly cooked.
International travel and trade:
Citable reference: World Health Organization (7 April 2022). Disease Outbreak News; Middle East respiratory syndrome coronavirus (MERS-CoV) – Saudi Arabia. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/middle-east-respiratory-syndrome-coronavirus-(mers-cov)-saudi-arabia-2022