Bacterial contamination of mobile handwashing stations in hospital settings in the Democratic Republic of the Congo

Background: As part of the containment of the COVID-19 pandemic, mobile handwashing stations (mHWS) were deployed in healthcare facilities in low-resource settings. We assessed mHWS in hospitals in the Democratic Republic of the Congo for contamination with Gram-negative bacteria.

Methods: Water and soap samples of in-use mHWS in hospitals in Kinshasa and Lubumbashi were quantitatively cultured for Gram-negative bacteria which were tested for antibiotic susceptibility. Meropenem resistant isolates were assessed for carbapenemase enzymes using inhibitor-based disk and immunochromatographic tests. Mobile handwashing stations that grew Gram-negative bacteria at counts > 10,000 colony forming units/ml from water or soap were defined as highly contaminated.

Results: In 26 hospitals, 281 mHWS were sampled; 92.5% had the "bucket with hand-operated tap" design, 50.5% had soap available. Overall, 70.5% of mHWS grew Gram-negative bacteria; 35.2% (in 21/26 hospitals) were highly contaminated. Isolates from water samples (n = 420) comprised 50.3% Enterobacterales (Klebsiella spp., Citrobacter freundii, Enterobacter cloacae), 14.8% Pseudomonas aeruginosa and 35.0% other non-fermentative Gram-negative bacteria (NFGNB, including Chromobacterium violaceum and Acinetobacter baumannii). Isolates from soap samples (n = 56) comprised Enterobacterales (67.9%, including Pluralibacter gergoviae (n = 13)); P. aeruginosa (n = 12) and other NFGNB (n = 6). Nearly one-third (31.2%, 73/234) of Enterobacterales (water and soap isolates combined) were multi-drug resistant; 13 isolates (5.5%) were meropenem-resistant including 10 New Delhi metallo-beta-lactamase (NDM) producers. Among P. aeruginosa and the other NFGNB, 7/198 (3.5%) isolates were meropenem resistant, 2 were NDM producers. Bacteria listed as critical or high priority on the World Health Organization Bacterial Priority Pathogens List accounted for 20.3% of isolates and were present in 12.0% of all mHWS across 13/26 hospitals. Half (50.5%) of highly contaminated mHWS were used by healthcare workers and patients as well as by caretakers and visitors.

Conclusions: More than one third of in-use mobile handwash stations in healthcare facilities in a low resource setting were highly contaminated with clinically relevant bacteria, part of which were multidrug resistant. The findings urge a rethink of the place of mobile handwash stations in healthcare facilities and to consider measures to prevent their contamination.