Estimating Potential Incidence of MERS-CoV Associated with Hajj Pilgrims to Saudi Arabia, 2014

Area of Science:

• Epidemiology
• Infectious Disease Modeling
• Public Health

Background:

• A significant Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreak occurred in Saudi Arabia (KSA) from March to June 2014.
• This outbreak raised concerns about potential MERS-CoV transmission during the annual Hajj pilgrimage.
• The Hajj attracts millions of international pilgrims, creating a risk for widespread disease transmission.

Purpose of the Study:

• To forecast the potential incidence of MERS-CoV during the 2014 Hajj.
• To assess the risk of MERS-CoV cases developing among pilgrims and returning travelers.
• To inform public health preparedness and surveillance strategies for the Hajj.

Main Methods:

• Utilized data from the KSA Ministry of Health for MERS-CoV incidence.
• Employed scenario and modeling techniques to forecast potential MERS-CoV cases.
• Developed three distinct scenarios: expected, pessimistic, and a baseline for comparison.

Main Results:

• Under expected scenarios, an estimated 6.2 symptomatic pilgrims and 4.0 asymptomatic infected returning pilgrims were predicted.
• In the most pessimistic scenario, projections indicated 47.6 symptomatic cases and 29.0 asymptomatic infected returning pilgrims.
• Even under pessimistic assumptions, large-scale MERS-CoV outbreaks during the 2014 Hajj were deemed unlikely.

Conclusions:

• The risk of a major MERS-CoV outbreak during the 2014 Hajj appears low.
• Continued vigilant surveillance is crucial to detect any emergent mass infection events.
• Minimizing international introductions of MERS-CoV remains a key public health objective.