During the 2009 Hajj beginning around November 25, some 2.5 million pilgrims are expected at holy sites in Saudi Arabia. A public health paper published Online First and in a future edition of The Lancet reports that in order to combat the threat posed by H1N1 influenza A, the Saudi Arabian Health Ministry has issued public health recommendations. It includes recommending groups at highest risk of contracting H1N1 to postpone their pilgrimage to a later year when the threat is reduced. The article is the work of Dr Ziad A Memish, Ministry of Health, Riyadh, Saudi Arabia, and colleagues.

Hajj is the yearly pilgrimage by Muslims to Saudi Arabia. It is one of the largest, most culturally and geographically diverse mass gatherings in the world. Muslims should make at least one Hajj in their lifetime. The mass gathering of pilgrims from more than 160 countries increases public health risks. These include for instance, food borne diseases, meningococcal outbreaks, heat exhaustion, unintentional injuries, and respiratory illnesses. During Hajj, crowd densities can increase to seven individuals per m². The basic reproduction number of an infection is also known as basic reproductive rate or basic reproductive ratio. It is the mean number of secondary cases a typical single infected case will cause in a population with no immunity to the disease in the absence of interventions to control the infection. The basic reproduction number for the 2009 pandemic influenza A H1N1 virus was estimated to be 1•2 to 1•7. However, the reproduction number and secondary attack rates could be greater among exposed, susceptible individuals in intensely crowded settings like Hajj.

In the midst of the 2009 pandemic influenza A H1N1 and upcoming Hajj, the Saudi Arabian Ministry of Health (MoH) convened a vigilance consultation in June, 2009. Consultants from global public health agencies met in their official capacities with their Saudi Arabian counterparts. The MoH intended to group and share public health knowledge about mass gatherings. It also reviewed the country’s preparedness plans, focusing on the prevention and control of pandemic influenza. The authors explain: “This process resulted in several practical recommendations, many to be put into practice before the start of Hajj and the rest during Hajj. These preparedness plans should ensure the optimum provision of health services for pilgrims to Saudi Arabia, and minimum disease transmission on their return home. Review of the implementation of these recommendations and their effect will not only inform future mass gatherings in Saudi Arabia, but will also strengthen preparedness efforts in other settings.”

Among the recommendations, the most essential was to encourage individuals at risk of severe disease to put off their participation in Hajj until another year. These include elderly people, pregnant women, individuals with chronic diseases, and children. The recommendations were applicable before or during Hajj. Instructions also included provision of education and personal hygiene packs to people with influenza-like illness to prevent onward transmission, and isolation facilities if there is not sustained community transmission

The authors write in conclusion: “After action reviews should be done to improve future performance on the basis of real-time experience. Noteworthy is that the recommendations generated during this meeting were based on the current status of the pandemic and therefore might need revision, dependent on the changes in virus characteristics and epidemiology of infections with the 2009 pandemic influenza A H1N1 virus.”

A related Lancet editorial says: “Because Hajj is one of the five pillars of Islam and should be done at least once in a Muslim’s lifetime, individuals will probably not want to postpone after they have spent much time saving money and planning for this purpose. Some of the other recommendations, such as isolation of pilgrims with influenza-like illness, might not only deter individuals from reporting their illness but will undoubtedly also cause them distress and difficulty reuniting with their companions. Improvement of hand hygiene for infection control might be more acceptable than some of the other recommendations because pilgrims should wash before they pray.”

The editorial says in closing: “These recommendations are a starting point, but they will need to be assessed. Some recommendations might need to be adjusted or discarded as the pandemic develops. However, pandemic influenza A H1N1 alone is understandably unlikely to dissuade many Muslims from going on Hajj.”

“Establishment of public health security in Saudi Arabia for the 2009 Hajj in response to pandemic influenza A H1N1”
Z A Memish, S J N McNabb, F Mahoney, F Alrabiah, N Marano, Q A Ahmed, J Mahjour, R A Hajjeh, P Formenty, F H Harmanci, H El Bushra, T M Uyeki, M Nunn, N Isla, M Barbeschi, and the Jeddah Hajj Consultancy Group
DOI: 10.1016/S0140-6736(09)61927-9
The Lancet

Written by Stephanie Brunner (B.A.)