Middle East respiratory syndrome coronavirus (MERS-CoV), which was first identified in 2012, is considered an emerging zoonotic virus with epidemic and pandemic potential, for which dromedary camels have been identified to serve as the animal reservoir. The emergence of a new virus means that we have a limited understanding of transmission patterns, severity, clinical features and risk factors for infection. To address these unknowns, WHO has provided several MERS-CoV investigation protocols. Data collected using these investigations will be critical to refine recommendations for case definitions and surveillance, characterize key epidemiological features of MERS-CoV, help understand the geographical extent of MERS-CoV circulation in humans and camels, its severity, the spectrum of human disease and its impact on the community. Furthermore, the findings of these studies will inform guidance for application of countermeasures such as case isolation and contact tracing. These protocols are designed to rapidly and systematically collect and share data in a format that facilitates comparison across different settings globally.

What to expect. The WHO MERS-CoV investigation protocols were published in 2024 as part of WHO’s Investigations and Studies (Unity Studies), applying a standardized format and including implementation tips and figures to clearly depict recommended procedures. Provision of background on the topic of the study is followed by study objectives and detailed methods on recruitment, follow-up and data collection, and laboratory testing. Also included is information on ethical considerations, guidance for statistical analysis, and considerations for the interpretation of study findings. Finally, annexes within each protocol include further background information on laboratory testing as well as a set of detailed standardized questionnaires that can be adapted to local contexts. Unity Studies empower countries, regardless of resource settings, to conduct local, country-owned investigations, thereby enhancing global preparedness and response strategies. Through these efforts, countries can better prepare for and respond to MERS-CoV and other emerging infectious diseases, fostering a globally coordinated and equitable research approach.

The primary objectives are:

1. Detect and identify early cases of MERS-CoV infection, clusters and any evidence of sustained human-to-human
2. Determine risk factors and the geographic risk area for infection with the virus.

Additional clinical and epidemiological investigations (see Figure 1) are needed to:

1. Determine key clinical characteristics of the illness, such as incubation period, spectrum of disease and the clinical course of the illness.
2. Determine key epidemiological characteristics of MERS-CoV infection, such as exposures that result in infection, risk factors, secondary attack rates and investigate modes of transmission.

Figure 1 (Download PDF)

1. Translated versions of all protocols into Arabic language (coming soon)
2. Translated versions of protocols into French language (coming soon):
   • How to sample surfaces in health-care settings for Middle East respiratory syndrome coronavirus.
   • How to conduct surveillance and investigations of human infection with Middle East respiratory syndrome coronavirus using WHO’s Investigations and Studies (Unity Studies 2.0) protocols
3. MERS Outbreak Toolbox

• Unity Influenza
• Unity Respiratory
• Unity COVID-19