Table 3. .

Hypothetical Causal Pathways Between Sink Drainage and Patient or Health Care Worker Colonization or Infection

Hypothetical Causal Pathways	Number of Studies That Mention This Causal Pathway (References)	Number of Studies That Demonstrate 1 or More Potential Steps in This Causal Pathway (References)
Direct patient use of sinks with contaminated drains	6 [20, 33, 37, 42, 53, 61]
Water from sinks with contaminated drains used in relation to patient care activity	1 [34]	1 [34]
Contamination of health care personnel hands or gowns during use of sinks with contaminated drains, and subsequent transmission to patients	24 [13, 15, 17, 18, 22, 23, 32, 33, 35–37, 39, 40, 42–44, 50, 51, 63, 66, 67, 71, 72]	5 [36, 40, 42–44]
Splash or aerosolization of bacteria from contaminated sink drains into taps	1 [66]	1 [66]
Splash, aerosolization, or leak of bacteria from contaminated sink drains onto surroundings/fomites	19 [13, 14, 17, 18, 23, 32, 37, 40, 41, 45, 51, 52, 59, 62–64, 67–69, 71, 72]	11 [13, 18, 22, 40, 41, 45, 52, 59, 63, 64, 69]
Splash or aerosolization of bacteria from contaminated sink drains directly onto patients	3 [18, 35, 39]