The Hajj: a threat to infectious disease prevention?

August 31, 2017

1 Comment

By Jaclyn Guerrero, Epidemiologist at Metabiota, the pioneer in epidemic risk modeling

This week, millions of Muslims will make their pilgrimage to Mecca, Saudi Arabia, known as the Hajj. For observant Muslims, the Hajj is a religious duty and important act of faith. For public officials in Saudi Arabia and internationally, the Hajj poses serious challenges in the prevention and control of infectious diseases.

During the Hajj, more than two million travelers from over 183 countries throughout the world gather in Mecca. This is one of the most geographically and ethnically diverse mass gatherings in the world, and the scale, density and diversity of migration from all reaches of the planet has the potential to amplify the risk of disease transmission. For international businesses, this presents a considerable concern given the global nature of this event and its far-reaching impact.

While the risk of communicable disease outbreaks is not considered to be higher than expected for international mass gatherings of this size, the Hajj does pose unique public health concerns. Extended stays at Hajj sites, extreme heat (temperatures can exceed 120°F), and crowded living conditions increase the risk of disease transmission, especially airborne, food-borne and water-borne pathogens. For example, the probability of tuberculosis transmission is estimated to be around 10% in those with high levels of exposure; while in the past, 11% of Hajj returnees tested positive for influenza viruses in 2014 and 2015. The World Health Organization has raised concerns about the risk of cholera during the Hajj, related to the ongoing outbreaks in Yemen and some African countries that may send pilgrims to Mecca. However Saudi health officials maintain they are prepared to deal with any potential health risks.

Although the Hajj has not given rise to large scale infectious disease outbreaks, there have been numerous, minor outbreaks that have been facilitated by the extreme congestion of people and the physically strenuous conditions of this pilgrimage. One notable example is the worldwide outbreak of serogroup W-135 meningococcal disease that occurred during the 2000 Hajj, which resulted in an estimated 400 cases in Hajj pilgrims and close contacts in 16 countries.

Due to the concern for disease transmission, the Ministry of Health (MoH) of Saudi Arabia carries out enhanced surveillance and staffing of health facilities prior to and during the event. To obtain a Hajjvisa, the MoH requires all pilgrims to produce proof of vaccination for meningococcal disease as well as polio and yellow fever for those coming from at-risk locations. Additionally, Saudi Arabia provides free medical care to all pilgrims in 25 hospitals with 5000 beds. All communicable diseases of importance at mass gatherings are monitored, especially respiratory tract infections, food poisoning, diarrheal diseases, meningococcal disease, viral hemorrhagic fevers (dengue, Alkhurma, Marburg, Crimean Congo, Ebola and Lassa), yellow fever, MERS, polio and plague.

When was the last time you slept through the night? ZQuiet.com

While Saudi Arabia is prepared to identify and treat infectious diseases during this mass gathering, the risk of infectious disease outbreaks remains given the large, geographically dispersed number of pilgrims travelling to Saudi Arabia. Returning pilgrims can spread disease upon their return and thus trigger outbreaks in their home countries. It only takes one case to go unnoticed or undetected to cause an epidemic. Examples of disease outbreaks linked to returning travelers (but not the Hajj) include MERS in South Korea and the global spread of SARS.

To contain epidemic-risk, the global community must be equipped to stop the spread of disease, which cannot be solely the responsibility of Saudi Arabia. While countries assess and prepare for potential outbreaks, international corporations also have a prime opportunity to assess and manage their risk, especially companies with supply chains dependent on Saudi Arabia and the surrounding region, or those with large amounts of international travel. Should the Hajj, or another mass gathering, spark the spread of an infectious disease, companies must act swiftly to protect their employees and maintain stability within the workplace.

To effectively and efficiently manage infectious disease outbreaks, international corporations should consider the following:

Review, update and create outbreak contingency plans: Using plans that may already exist for natural catastrophic events such as floods or earthquakes, build a framework for responding to an outbreak that affects your employees, facilities, distribution supply chain or customer base. Having a plan at place before an outbreak, ensures the most rapid response.
Assess risk at each location of your company: The risk for disease spread varies greatly by region and by location. Ensure that airborne and water-borne diseases likely for a given area are covered and that plans vary by geography and demographics of each location.
Offer immunization programs: Corporations can reduce risk of vaccine preventable diseases by offering immunization programs, such as programs for seasonal flu. Several notable companies offer immunization programs and international travel immunization advice including Lowe’s Companies, United Continental Holdings, Hewlett-Packard, and American International Group.