Table 1.

Hajj and large-scale open-air festivals—key points

Hajj—key points

• Event: annual Muslim pilgrimage

• Place: Mecca, Saudia Arabia

• Population size: 2 million from 185 countries (high proportion of elderly pilgrims with co-morbidities)

• Prevalence of respiratory symptoms in overall population of pilgrims: 50–93%

• Pneumonia among the leading cause of admission in Saudi hospitals during the Hajj

• Acquisition of respiratory pathogens: 13.5–34.1% rhinovirus, 12.4–14.6% non-MERS coronavirus, 1.9–7.8% influenza A virus, 7.1–36.6% Streptococcus pneumoniae, 11.4% Haemophilus influenzae, 7.5% Staphylococcus aureus

• No case of MERS-CoV, Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae observed in pilgrims in recent years

• Antibiotic consumption in overall population of pilgrims: 45–61.8%

• Prevalence of diarrhea: 1.1–23.3%

• Hajj-associated diarrhea mostly due to bacteria including: Salmonella spp. and Escherichia coli.

• Evidence for acquisition of antimicrobial-resistant bacteria

Large-scale open-air festivals—key points

• Events: music festivals and other cultural festivals in various places in the world.

• Population size: variable but usually less than 400,000 participants (mostly young participants)

• Outbreaks of respiratory tract infections and gastrointestinal infections are regularly reported including notably measles and mumps, influenza, diarrhea due to bacterial and viral infections.