Infectious Diseases and Mass Gatherings

Abstract

In the context of Hajj, one of the largest religious MGs at Mecca, Saudi Arabia, respiratory tract infections are the leading cause of infectious diseases in pilgrims with a prevalence of 50-93%. The most commonly acquired respiratory viruses were human rhinovirus, followed by human coronaviruses and influenza A virus, in decreasing order. Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae were the predominant bacteria. The prevalence of Hajj-related diarrhea ranged from 1.1 to 23.3% and etiologies included Salmonella spp., and Escherichia coli, with evidence of acquisition of antimicrobial-resistant bacteria. In other MGs such as Muslim, Christian, and Hindu religious events, sports events, and large-scale open-air festivals, outbreaks have been reported less frequently. The most common outbreaks at these events involved diseases preventable by vaccination, notably measles and influenza. Gastrointestinal infections caused by a variety of pathogens were also recorded. Because social distancing and contact avoidance are difficult measures to implement in the context of many MGs, individual preventive measures including vaccination, use of face mask, disposable handkerchief and hand hygiene may be recommended. Nevertheless, the effectiveness of these measures has been poorly investigated in the context of MGs.

Respiratory and gastrointestinal infections at the 2017 Grand Magal de Touba, Senegal: A prospective cohort survey

“…This result is in line with studies conducted at the Hajj, where 50-93% pilgrims presented respiratory symptoms [24]. The use of face masks was rare, while 2/3 of pilgrims declared using hand sanitizer.…”

Environmental investigation of respiratory pathogens during the Hajj 2016 and 2018

“…Memish et al hypothesized that, in the absence of good hand hygiene, there is a possibility that pilgrims could pick up environmental pathogens on their hands from contaminated surfaces and self-inoculate or further transmit these pathogens [23]. Respiratory tract infections during Hajj continue to exert a heavy burden on pilgrims [4]. Besides early identification of pathogenic bacterial or viral clusters for faster mitigation of outbreaks and better understanding of disease etiology, we believe that further larger-scale studies are needed to better evaluate the possible role of environmental respiratory pathogens in causing respiratory infections among Hajj pilgrims.…”

“…The pathogens tested were based on their frequency in respiratory samples obtained from Hajj pilgrims [4,7,15].…”

“…Acute upper respiratory tract infection is the most common clinical presentation. The overall prevalence of RTIs, when evaluated among cohorts of pilgrims from different origins, varied from 50 to 93% [4].…”

“…The [4]. The most common viral pathogens are human rhinovirus (HRV), non-MERS coronaviruses (HCoVs) and influenza viruses [4][5][6]. Many pilgrims are elderly people with co-morbidities that could increase the risk of RTIs [3,7].…”