Table 3.

Results of Case Series Studies

Study/country	Study design details	Virus	Setting	Population characteristics	Exposure	Outcomes	Comments
Assiri et al.(51)/Saudi Arabia	Case series	MERS	4 Hospitals: 3 general and 1 regional referral	23 Confirmed cases of MERS and 11 probable cases	4 MERS patients in ICU of one hospital received unspecified type nebulizer treatments while also receiving CPAP	2 Additional cases were diagnosed among patients in ICU at the same time during which no special isolation procedures were noted.	No further cases developed after implementation of infection control procedures; genome sequencing employed
Hunter et al.(52)/United Arab Emirates	Case series	MERS	3 Hospitals with health care associated MERS clusters	30 Cases of MERS transmitted in health care setting (n = 19 HCW)	Exposure to either inhaler or unspecified type of nebulizer treatment	14 HCWs who developed MERS; 2 administered metered-dose inhaler or nebulizer treatment.	13 of 14 HCWs were exposed before diagnosis of index patient; PPE use variable among 14 HCWs; genome sequencing employed
Nam et al.(49 )/South Korea	Case series	MERS	2 Hospitals	1 Index patient admitted to both hospitals and 25 secondary cases of MERS	Lidocaine inhalation using jet nebulizer before bronchoscopy on second day of Hospital B	25 Total secondary cases (14 inpatients, 9 commercial/family caregivers, 2 hospital employees); 5 patients in same ward room in which nebulizer was used developed MERS Hospital B.	Hospital B had a higher case fatality rate versus Hospital A. Hospital B ward room had lower air ventilation and higher density of patients than Hospital A; no cases among bronchoscopy HCWs (all wore surgical masks, gloves, vinyl gowns)
Park et al.(50)/South Korea	Case series	MERS	2 Hospitals	1 Index patient admitted to both hospitals and 23 secondary cases and 3 tertiary cases	Lidocaine inhalation using jet nebulizer before bronchoscopy on second day of Hospital B	13 Secondary cases at Hospital A; 10 secondary cases at Hospital B (5 patients and 3 caregivers in same room infected).	Similar attack rates between hospitals (15.8% hospital A; 14.3% hospital B, p = 0.51); incidence rate higher in hospital B than A (7.7/100 vs. 3.4/100 exposure days, IRR = 2.3, p < 0.001)a; no secondary cases among HCW
Lee et al.(21)/Hong Kong	Case seriesb	SARS	Medical ward with isolation facilities	Secondary/tertiary cases: male 66, female 72; mean age 39.3 (SD 16.8), N = 156 with SARS (138 secondary or tertiary cases)	Jet nebulizer 6 L/min; QID administered to index patient	112 SARS patients with direct exposure to index patient (69 HCW, 16 medical students all with “unremarkable medical histories”).	Nebulizer speculated as important in transmission
Varia et al.(48)/Canada	Case series	SARS	Secondary-care community hospital in Toronto	N = 128, male N = 51, female N = 77; mean age 44.8; HCWs N = 47 household/social contacts N = 38	Index patient received nebulizerc salbutamol while in the general observation area of the emergency department	128 SARS patients that resulted from exposure to index patient, including 2 nearby patients from the Emergency Room (ER) (all cared for by the same nurse).	Highest transmission rate was observed in CCU nurses (60%) owing to prolonged exposure to severely ill patients. Unclear PPE use during the period of exposure
Wong and Hui(24)/Hong Kong	Case report	SARS	General medical ward in a tertiary care hospital; moved to negative pressure isolation room on day 8 of admission; N95+disposable gloves used day 8 forward	SARS patient (N = 1), limited information about patient	Jet nebulizer at 6 L/min for bronchodilation used QID until day 8	100 SARS patients linked to index patient.	Setting not clear regarding poor PPE standards and lack of isolation before diagnosis

^aOverlapping cases with Nam et al.⁽⁴⁹⁾

^bCase definition based on CDC, fever, lung consolidation on imaging, and exposure to index or secondary case.

^cType of nebulizer not specified.

CCU, coronary care unit; IRR, incidence rate ratio; SD, standard deviation.