Table 1.

Prevalence of respiratory viruses in studies conducted among pilgrims suffering from respiratory symptoms.

Year	Study design	Study population	Type of sample	Microbiological techniques	Pathogens investigated	Prevalence (%)	Influenza vaccination (%)	Reference
1991–1992	Cross-sectional study (Saudi Arabia)	Pilgrims suffering URTIa and LRTIb and seeking care in four hospitals/medical centers (n = 761)	Throat swabs, sputum	Cell culture/cytopathic effect and staining using virus-specific monoclonal antibodies	Influenza A	4.5		[14]
					Influenza B	2.0
					Influenza overall	6.5
					Parainfluenza 1	2.0
					Parainfluenza 2	1.7
					Parainfluenza 3	2.2
					Parainfluenza overall	5.9
					Adenovirus	4.7
					Respiratory syncytial virus	2.4
					Mixed viral infections	ND
					No virus	80.6
1994	Cross-sectional study (Saudi Arabia)	Pilgrims suffering pneumoniac and seeking care in two hospitals (n = 64)	Serum, sputum broncho-alveolar lavage and naso-pharyngeal aspirate	Direct immunofluorescence staining	Influenza A	3.1		[15]
					Influenza B	1.6
					Influenza overall	4.7
					Parainfluenza 1	0
					Parainfluenza 2	1.6
					Parainfluenza 3	0
					Adenovirus	0
					Respiratory syncytial virus	0
					Mixed viral infections	0
					No virus	89.1%
2000	Cross sectional study (Saudi Arabia)	Pilgrims suffering ILId and presenting at outpatient clinics (n = 305)	Serum	ELISA	Influenza A	5.9	4.3	[16]
					Influenza B	11.5
					Influenza overall	14.8
					Mixed viral infections	ND
					No virus	82.0%
2003	Cross-sectional study (Saudi Arabia)	Pilgrims suffering URTIe and seeking care in three hospitals (n = 500)	Throat swabs	Cell culture/cytopathic effect and staining using virus-specific monoclonal antibodies	Influenza A	0.6	4.4%	[17]
					Influenza B	5.4
					Influenza overall	6.0
					Parainfluenza 1,2,3	0.8
					Adenovirus	0
					Respiratory syncytial virus	1.4
					Enterovirus	0
					Mixed viral infections	ND
					No virus	89.2%
2004	Cross-sectional study (Saudi Arabia)	Pilgrims suffering ILIf and seeking care in hospitals/medical centers (n = 360)	Throat swab	Not described	Influenza overall	12.8	2.2%	[18]
					(including 70.9% influenza B Sichuan, 1.8% influenza B Hong Kong, 14.6% influenza A untyped, 7.3% influenza A-H1N1, 5.5% influenza A-H3N2 calculated from a mixed sample of 46 positive pilgrims and 9 positives non-pilgrims)
					Mixed viral infections	ND
					No virus	84.7%
2004–2005	Cross-sectional study (Saudi Arabia)	Iranian pilgrims suffering respiratory symptomsg and presenting at to medical centers (n = 105)	Gargled pharyngeal secretions, and serum	Cell culture/cytopathic effect and staining using virus-specific monoclonal antibodies - ELISA	Influenza A (pharynx)	1.9		[19]
					Influenza B (pharynx)	11.4
					Influenza overall	13.3
					Parainfluenza (pharynx)	0
					Adenovirus (pharynx)	36.2
					Respiratory syncytial virus (pharynx)	1.9
					Influenza A-H1N1 (serology)	6.9
					Influenza A-H3N2 (serology)	6.1
					Influenza B-Hong Kong (serology)	8.5
					Influenza B-Sichuan (serology)	12.3
					Influenza overall (serology)	21.5
					Mixed viral infections	ND
					No virus (pharynx)	48.6%
					No virus (serology)	58.1%
2005	Cross-sectional study (Saudi Arabia)	Pilgrimsh suffering respiratory symptomsi attending the British Hajj Delegation clinic in Mecca, or at Mina encampment (n = 202)	Nasal swabs	Rapid diagnostic test (QuickVue) - PCR	Influenza rapid test	4.5	27.7	[20]
					Influenza A-H1N1	0.5
					Influenza A-H3N2	9.9
					Influenza B	3.5
					Influenza overall	13.9
					Respiratory syncytial virus	4.5
					Mixed viral infections	ND
					No virus	86.1
2005	Cross-sectional study (Saudi Arabia)	International pilgrims suffering respiratory symptomsf recruited at two hospitals and at two airports (n = 483)	Throat swab	Not described	Influenza overall	9.7	29.9	[21]
					(including 17.0% influenza B Sichuan, 6.4% influenza B Hong Kong, 29.8% influenza A untyped, 34.0% influenza A-H1N1, 12.8% influenza A-H3N2)
					Mixed viral infections	ND
					No virus	90.3
2005–2006	Cross-sectional study (Saudi Arabia and UK)	UK pilgrims suffering respiratory symptomsj during their stay in Saudi Arabia or upon returning to the UK (n = 555)	Nasal swabs	Rapid diagnostic test (QuickVue) - PCR	Influenza (Rapid test)	3.2		[22]
					Influenza-A (PCR)	8.2
					Influenza B (PCR)	2.3
					Influenza overall (PCR)	10.5
					Mixed viral infections	ND
					No virus	90.1%
2006	Cross-sectional study (Saudi Arabia)	British pilgrims suffering respiratory symptomsk attending the British Hajj Delegation clinic in Mecca or at Mina encampment (n = 150) and Saudi pilgrimsk attending the National Guard Health Affair clinic at Mina (n = 110)	Nasal swabs	Rapid diagnostic test (QuickVue) - PCR	Influenza rapid test	3.5	23.1	[23]
					Influenza A	8.1
					Influenza B	2.3
					Influenza overall	10.4
					Parainfluenza 1	0
					Parainfluenza 2	0
					Parainfluenza 3	0.4
					Parainfluenza overall	0.4
					Respiratory syncytial virus	0.4
					Rhinovirus	9.2
					Mixed viral infections	0.8%
					No virus	85.4%
2006	Cross-sectional airport study (Iran)	Iranian Returning pilgrims suffering ARIl (n = 255)	Nasal wash	Cell culture/cytopathic effect and staining using virus-specific monoclonal antibodies - PCR	Influenza A	5.1	85.5%	[24]
					Influenza B	5.1
					Influenza overall	10.2
					Parainfluenza 1	5.5
					Parainfluenza 2	1.6
					Parainfluenza 3	0.8
					Parainfluenza overall	7.9
					Adenovirus	5.5
					Respiratory syncytial virus	1.6
					Rhinovirus	5.9
					Enterovirus	2.0
					Mixed viral infections	0.4%
					No virus	67.5%
2009	Cross sectional airport survey (Iran)	Iranian returning pilgrims suffering respiratory symptomsm (n = 275)	Throat swabs	Cell culture/cytopathic effect - PCR	Influenza A-H1N1 (culture)	1.1	100%	[25]
					Influenza A-H3N2 (culture)	1.8
					Influenza B (culture)	6.2
					Influenza overall (culture)	9.1
					Influenza A-H1N1 (PCR)	1.8
					Influenza A-H3N2 (PCR)	2.9
					Influenza B (PCR)	7.3
					Influenza overall (PCR)	12.0
					Mixed viral infections	ND
					No virus (culture)	90.9
					No virus (PCR)	88.0
2010	Cross-sectional airport study (Saudi Arabia)	Arriving pilgrimsn suffering from URTIo (n = 713)	Throat swabs	Not described	Influenza A-H1N1	3.1	26.9	[26]
					Influenza A-H3N2	1.7
					Influenza B-Hong Kong	1.1
					Influenza B-Sichuan	2.1
					Influenza overall	8.0
					Respiratory syncytial virus	3.1
					Mixed viral infections	ND
					No virus	88.9%
2011	Cross-sectional study (Saudi Arabia)	Australian pilgrims suffering from ILIp, at Mina encampment (n = 80)	Nasal swabs	PCR	Influenza A	6.3		[27]
					Influenza B	3.8
					Influenza overall	10.1
					Parainfluenza 1	0
					Parainfluenza 2	0
					Parainfluenza 3	1.3
					Rhinovirus	48.8
					Enterovirus	2.5
					Mixed viral infections	2.5
					No virus	41.3
2013	Cross-sectional study (Saudi Arabia)	Pilgrimsq suffering from ILIr, at Mina encampment (n = 112)	Naso-pharyngeal or throat swabs	PCR	Influenza A-H1N1	0.9	31.3%	[28]
					Influenza A-H3N2	3.6
					Influenza overall	4.5
					Parainfluenza 1	0.9
					Parainfluenza 2	0
					Parainfluenza 3	1.8
					Parainfluenza overall	2.7
					Rhinovirus	26.8
					Adenovirus	2.7
					Coronavirus OC43 and 229E	2.7
					Mixed viral infections	2.7
					No virus	62.5
2013	Cross sectional study (Saudi Arabie)	Pilgrimss admitted to 15 healthcare facilities with bilateral pneumonia (n = 38)	Sputum	PCR	Influenza A	15.8		[29]
					Influenza B	0
					Parainfluenza 1	0
					Parainfluenza 2	0
					Parainfluenza 3	2.6
					Parainfluenza 4	0
					Parainfluenza overall	2.6
					Adenovirus	0
					Respiratory syncytial virus	2.6
					MERS-Cov	0
					CoV-229E	7.9
					CoV-NL63	0
					CoV-HKU1	0
					CoV-OC43	5.3
					CoV overall	13.2
					Enterovirus	0
					Metapneumovirus	0
					Rhinovirus	39.5
					Bocavirus	0
					Mixed viral infections	15.8
					No virus	56.7
2014	National survey (Austria)	Returning Austrian pilgrims seeking caret in hospitals/medical centers (n = 7)	Serum, sputum, throat swab, or bronchoalveolar lavage	PCR	MERS-CoV	0	0	[30]
					Influenza A-H1N1	0
					Influenza A-H3N2	28.6
					Influenza B	42.9
					Influenza overall	71.4
					Rhinovirus	26.6
					Mixed viral infections	0
					No virus	0

^aBased on history and physical examination.

^bEvidence of pulmonary consolidation on physical examination and radiograph.

^cAcute episode associated with respiratory symptoms and radiological evidence of airspace disease of less than 4 weeks' duration.

^dFever and at least two of the following: headaches, myalgia, cough, sore throat or coryza.

^eSore throat or fever ≥38.3 °C, and cough, headache, runny nose, sneezing, or myalgia.

^fFever of at least 38 °C, started within 72 h of presentation; along with history of cough and/or sore throat.

^gCommon cold defined by sore throat, rhinitis, fever, ILI defined by fever >38.5 °C, myalgia, rhinitis and cough, sinubronchitis defined by headaches, purulent postnasal discharge or purulent sputum, cough and fever and pneumonia defined on radiographic findings.

^hMainly Indian pilgrims.

ⁱCough, sore throat, rhinorrhea and fever.

^jCough, sore throat, rhinorrhea and fever within one week of the onset.

^kCough, sore throat, rhinorrhea and fever.

^lTwo of the following conditions: fever, cough, sore throat, congestion, and sinus pain within the past 3 weeks during the Hajj.

^mCough, sore throat and fever.

ⁿMainly from Indonesia, Turkey and Pakistan.

^oFever and/or headaches and/or myalgia and at least of the following symptoms: runny nose, sneezing, sore throat, cough with or without sputum, difficulty of breathing.

^pSubjective (or proven) fever plus one respiratory symptom (e.g. dry or productive cough, runny nose, sore throat, shortness of breath) for 3 days or less.

^qMainly from Saudi Arabia.

^rSubjective (or proven) fever and at least one respiratory symptom such as cough, sore throat and rhinorrhea.

^sMainly from Asia.

^tFever and/or respiratory symptoms.