Friday, May 2, 2014

MERS-CoV and the Hajj: Maintaining Public Health Security after Dense Population Events

Update: First U.S. Case hospitalized in Indiana

The thing that almost makes it easier about Hajj is that you know when people are going and when they are coming back. But if you have migrant workers coming and going the whole time, then it requires constant vigilance,"

One of the common denominators of controlling the spread of disease during highly pathogenic outbreaks such as smallpox, Ebola, H5N1, SARS-CoV and more recently MERS-CoV is the application of isolation and quarantine. In some instances such as the 1972 outbreak of smallpox in Yugoslavia, it is necessary to ban public gatherings. In modern democratic society, banning public events and issuing quarantine orders is often considered in conflict with civil rights. How does a country like Saudi Arabia handle disease containment particularly during the Hajj? The Hajj pilgrimage to Mecca, Saudi Arabia, is among the largest mass gatherings in the world. In 2013, the Saudi regime and other international health institutes such as the World Health Organization based in Geneve and the Centers for Disease Control and Prevention in Atlanta issued health advice to those travelling to attend the Hajj. Saudi Arabia's approach was sound. "Because they bring large numbers of people from all around the world, mass gatherings such as Hajj and Umrah can increase the risk for infectious diseases. Outbreaks of meningococcal disease used to be a problem so the Saudi Ministry of Health required all pilgrims to receive the meningococcal vaccine and neither Hajj or Umrah visas can be issued without proof of vaccination." See: 

In a study undertaken by Ziad Memish of Riyadh University and colleagues, it appears MERS-CoV emerged between July 2007 and June 2012, with perhaps as many as 7 separate zoonotic transmissions. Among animal reservoirs, CoV has a large genetic diversity yet the samples from patients suggest a similar genome, and therefore common source, though the data are limited. It has been determined through molecular clock analysis, that viruses from the EMC/2012 and England/Qatar/2012 date to early 2011 suggesting that these cases are descended from a single zoonotic event. It would appear that MERS-CoV has been circulating in the human population for greater than one year without detection and suggests independent transmission from an unknown source (11)(12). See: 

While it is important to note the case differences between SARS-CoV and MERS-CoV as an emerging zoonosis, a recent spike in cases has alarmed some within the epidemiology community. Eurosurveillance (a European peer-reviewed scientific journal devoted to the epidemiology, surveillance, prevention and control of communicable diseases, with a focus on such topics that are of relevance to Europe), notes on their site, "As of 23 April 2014, 345 people have been reported infected, and of those 107 have died(2). Most cases occurred in Saudi Arabia (SA) and to a lesser extent in the United Arab Emirates(UAE), still further 11 countries in Europe, Asia and North Africa have reported cases linked to the Arabian peninsula. Few clusters and cases were noted in the second half of 2012, and the epidemic has been stable at low levels in 2013 with about 15 cases notified monthly (Figure). This has changed dramatically over the past weeks when we faced an unprecedented increase in cases and community transmission as well as transmission in hospital settings. April 2014 reported cases were higher than the past two years combined. See: 

Protocols developed by China to prevent the spread of SARS-CoV offer in depth knowledge for containing outbreaks of emerging disease. In a CNN report on MERS today, in an interview with Professor Malik Peiris, Director of Hong Kong University School of Public health, notes "SARS not only took everyone by surprise, it marked the re-emergence of infectious diseases as a major concern. He says that in the wake of SARS, not only were resources--like isolation wards in hospitals--reallocated to combat infectious diseases like SARS, but as a result Hong Kong has now become a center for infectious disease epidemiology and virology. "The HKU group have contributed very signficantly to that event and to understanding what's going on there. We have been working on MERS since almost the time it emerged. We have a greater awareness of the emergence of coronaviruses--not only in Hong Kong but internationally." See:
The Hajj in October of 2014 will likely require greater efforts to include provisions for MERS-CoV again. Since concerns were raised over in 2013, the Saudi regime has taken a number of steps to ensure that travelers to and from the Hajj do not come into contact with MERS. Allison McGeer, MD, a microbiologist and infectious diseases consultant at Mt. Sinai Hospital in Toronto, who led efforts to stop the SARS (Severe Acute Respiratory Syndrome) coronavirus outbreak in Toronto in 2003, compared the Jeddah outbreak with the outbreak in Al-Ahsa (also written Al-Hasa) in eastern Saudi Arabia a year ago. That one involved 23 confirmed and 11 probable cases in several hospitals, according to a June 2013 report in the New England Journal of Medicine (NEJM)."The Kingdom of Saudi Arabia has perfectly good infection control practices, they know how to do that well, they did a great  with Al-Hasa last year, yet this outbreak appears to be substantially larger than Al-Hasa was," she said.
"So how this virus got past what I think generally are competent infection control people and caused a larger outbreak than was seen last year, I think really raises an issue about whether the virus has changed," McGeer added." See:
Prior to the 2013 Hajj WHO provided support at the invitation of Saudi Arabia, "to participate in a technical mission to observe, guide and advise on appropriate public health preparedness measures for prevention of any outbreak during the coming hajj 1434H/2013." On WHO's site they note: "It is expected that WHO's collaboration this year with the Ministry of Health of Saudi Arabia will help in early detection of any cluster amongst the pilgrims, initiate rapid control measures for preventing spread that will effectively stop any international spread of MERS-CoV when the pilgrims start returning to their own countries after the hajj. The team from WHO, led by a senior communicable disease expert, will be based in Mina and Arafat during the period of the hajj and will visit field hospitals in selected points of entry for pilgrims to have a first-hand idea on curative, preventive and promotive health services provided by the Kingdom to the pilgrims. The team will review, and where applicable will advise on improving the public health surveillance systems for early detection of, and response to, any infectious disease outbreaks amongst the pilgrims and will also advice Saudi Arabia on appropriate dissemination of risk communication messages to the pilgrims in a mass gatherings event such as the hajj. Hajj and umrah are the two of the largest and most crowded mass gathering events which is organized by the Kingdom annually. The hajj takes place every year during the twelve months of the Islamic calendar in Saudi Arabia and are attended by over 3 million people from more than 180 countries every year. [ ] Since 2010, WHO is collaborating with the Ministry of Health in the Kingdom advising on implementing appropriate public health measures for prevention and control of epidemic prone infection disease amongst the hajj pilgrims as well as identifying important lessons for effective surveillance and public health response to epidemic prone infectious diseases in mass gathering situations. As a result of this collaboration the annual hajj has remained free from any public health event of potential concern for the last 3 years. "

Clearly, Saudi Arabia has extensive expertise in disease control and surveillance and one is tempted to say that their approach is almost a case study in containment done right for dense population events. As of May 2, 2014, Saudi Arabia's Health Minister has appointed a ten member council  of infectious disease medical advisers.

Note: I will be following up with an article on Novovax vaccine candidate for MERS on my Bio-Industry Analyst blog:
For further interest see: The Lancet. see:
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