Table 3 An overview of all the hemodialysis related outbreaks in hospitals with the number of cases with the respective strains

CDC [21]

Canada

Enterobacter cloacae

NA

9

Unknown

Waste handling option (WHO) port^a: Incompetent one-way valve of the drain line waste of the dialysis machine → backflow

CDC and Wang et al. [21, 22]

United States

1. Enterobacter cloacae

2. Pseudomonas aeruginosa

3. Escherichia coli

1. 14 out of 26 machines (53.8)

2. 7 out of 26 machines (26.9)

3. Unknown

N = 10

1. 6 (60.0)

2. 4 (40.0)

3. 2 (20.0)

Two were polymicrobial

Unknown

WHO port^a: Incompetent valves on waste drain lines. Cross-contamination of hemodialysis central venous catheters from the WHO port:

Reflux from the waste drain line into the WHO^a port

Bacterial growth in the nutrient-rich environment of the WHO^a port

Rao et al. [23]

United States

Phialemonium curvatum

2 out of 19 treatment stations (10.5)

2

Unknown

Malfunction and improper maintenance of WHO^a port

CDC [21]

Israel

1. Enterobacter cloacae

2. Pseudomonas aeruginosa

3. Escherichia coli

4. Stenotrophomonas maltophilia

6 out of 13 dialysis machines (46.1)

N = 8

1. 2 (25.0)

2. 3 (37.5)

3. 4 (50.0)

4. 1 (12.5)

Unknown

Backflow of the WHO^a port

Yan et al. [24]

China

Burkholderia cepacia

NA

9

Unknown

Reverse osmosis water

Souva et al. [14]

Brazil

Burkholderia cepacia

33

28

Unknown

Inadequate cleaning procedures → leaking connections of the reverse osmosis tubing

Magalhaes et al. [16]

Brazil

1. Burkholderia cepacia

2. Staphylococcus aureus

3. Streptococcus agalactiae

4. Enterobacter aerogenes

5. Pseudomonas aeruginosa

6. Acinetobacter baumanii

37

N = 14

1. 6 (42.9)

2. 4 (28.6)

3. 1 (7.1)

4. 1 (7.1)

5. 1 (7.1)

6. 1 (7.1)

Unknown

Probable colonization in the reverse osmosis membrane

Nazemi et al. [25]

Iran

1. Legionella pneumophila

2. Pseudomonas aeruginosa

3. Staphylococcus aureus

4. Escherichia coli

5. Burkholderia cepacia

6. Gram-positive cocci

24 out of 50 samples (48.0)

1. 4 (16.7)

2. 6 (25.0)

3. 3 (12.6)

4. 3 (12.5)

5. 2 (8.3)

6. 6 (25.0)

NA

NA

Most commonly during reverse osmosis, in the storage tank and dialysate effluent

Kaitwatcharachai et al. [15]

Thailand

Burkholderia cepacian

NA

9

1 (11.1)

Deionized water used to dilute the dialysate concentrate and the in-use dialysis fluid

Oie et al. [26]

Japan

1. Moraxella spp

2. Pseudomonas aeruginosa

3. Gram-negative bacteria

4. Sphingomonas paucimobilis

5. Ralstonia pickettii

6. Pseudomonas stutzeri

7. Pasteurella multocida

17 out of 40 (42.5) dialysate samples showed bacterial count exceeding the AAMI standard

1. 10 (25.0)

2. 8 (20.0)

3. 6 (15.0)

4. 5 (12.5)

5. 2 (5.0)

6. 2 (5.0)

7. 2 (5.0)

NA

Tubing within the dialysis machine may be the site of biofilm development

Arnow et al. [20]

United States

1. Enterobacter cloacae

2. Stenotrophomonas maltophilia

3. Enterococcus faecalis

4. Acinetobacter baumannii

5. Candida parapsilosis

6. Candida tropicalis

7. Pseudomonas aeruginosa

8. Alcaligenes xylosoxidans

9. Serratia marcescens

10. Acinetobacter Iwoffi

11. Enterococcus faecium

12. Klebsiella pneumoniae

13. Flavobacterium species

14. Lactobacillus species

15. Burkholderia pickettii

16. Pseudomonas stutzeri

Unknown

N = 29

1. 7 (24.1)

2. 7 (24.1)

3. 6 (20.7)

4. 5 (17.2)

5. 4 (13.8)

6. 3 (10.3)

7. 3 (10.3)

8. 3 (10.3)

9. 2 (6.9)

10. 1 (3.4)

11. 1 (3.4)

12. 1 (3.4)

12. 1 (3.4)

13. 1 (3.4)

14. 1 (3.4)

15. 1 (3.4)

1^b (3.4)

Microbial growth in the outer portion of the WHO^a port despite circulation of a disinfectant through the fluid pathway deeper in the lumen

Olver et al. [27]

United Kingdom

Enterococcus faecali

NA

2

NA

WHO^a port cannot be cleaned adequately