Failure of bland soap handwash to prevent hand transfer of patient bacteria to urethral catheters.

OBJECTIVE: The study was designed to compare the efficacies of bland soap handwash and isopropyl alcohol hand rinse in preventing transfer of aerobic gram-negative bacilli to urinary catheters via transient hand colonization acquired from direct patient contact. Glove juice recovery of gram-negative bacteria was considered transient colonization; catheter recovery was considered transfer colonization. DESIGN: The contact source for gram-negative bacteria was a single "high burden" groin skin carrier (greater than or equal to 10(4)/ml cup scrub fluid). Using a two-period cross-over design, 6 healthcare workers had 2 15-second contacts for each hand followed by either soap handwash or alcohol hand rinse (12 experiments with each treatment). Between 4 to 5 minutes after contact, each hand manipulated a catheter; the catheter was then cultured and the hand was glove juice tested. RESULTS: Soap handwash failed to prevent gram-negative bacteria transfer to the catheter in 11 of 12 (92%) experiments; alcohol hand rinse in 2 of 12 (17%) (p less than .001). Soap handwash failed to prevent transient colonization in 12 of 12 (100%) experiments; alcohol in 5 of 12 (42%) (risk ratio 2.4, 95% confidence interval 1.2-4.7). Single gram-negative bacteria species carried at source levels greater than or equal to 5.5 x 10(3)/ml (heavy contamination) established transient colonization in 23 of 30 (77%) exposures following soap handwash; single gram-negative bacteria species carried at levels less than or equal to 3.5 x 10(3)/ml established colonization in 1 of 22 (5%) similar exposures (p less than .001). CONCLUSIONS: Bland soap handwash was generally ineffective in preventing hand transfer of gram-negative bacteria to catheters following brief contact with a heavy-contamination patient source; alcohol hand rinse was generally effective.

Proteeae species bacteriuria accompanying Proteeae species groin skin carriage in geriatric outpatients.

There have been numerous reports of Proteeae species urinary tract infections among elderly individuals. To explore a possible urinary carrier source of Proteeae species in this population, the frequency of aerobic gram-negative bacillus (AGNB) bacteriuria at the greater than or equal to 10(2)/ml level was determined in 67 ambulatory elderly outpatients classified as to Proteeae group (Morganella, Proteus, Providencia) groin carriage by a set of two skin cultures obtained at least 1 week apart. None had urethral catheters, symptomatic infections, skin ulcers, or recent antibiotic therapy. We found AGNB bacteriuria in 12 of 15 carriers (80%) and in 21 of 52 noncarriers (40%) (P = 0.009). Proteeae species bacteriuria occurred in eight carriers (53.3%) and six noncarriers (11.5%) (P = 0.001). At the 10(2) to 10(4)/ml level, Proteeae species were isolated in urine specimens from seven carriers (46.7%) and four noncarriers (7.7%) (P = 0.001). There was concordance of species of skin and urine Proteeae isolates in six carriers. By contrast, non-Proteeae AGNB bacteriuria at any level was present in four Proteeae species carriers (26%) and 15 noncarriers (28.8%) (P greater than 0.05). There was a 36.7% frequency of Proteeae species bacteriuria in nursing home residents, in contrast to 8.1% among those living in private homes; this parallels the greater frequency of Proteeae species groin carriage among nursing home residents in the study population. Low-level urinary colonization with Proteeae species accompanying Proteeae species groin skin colonization in elderly individuals is a hitherto unrecognized finding. This may account for the greater frequency of Proteeae species urinary infections in this population.

Indications for alcohol or bland soap in removal of aerobic gram-negative skin bacteria: assessment by a novel method.

A patient contact model was devised for health care workers (HCWs) to define heavy hand contamination with aerobic gram-negative bacilli (AGNB) that requires alcohol for complete removal. In patients, AGNB quantitation was per ml cup scrub fluid; in HCWs per ml glove juice. Following 15-second contact, two Proteeae groin carriers yielding greater than or equal to 4 log10 AGNB (high burden) transmitted greater than or equal to 3 log10 in 67% of 24 tests of six HCWs, and less than or equal to 2 log10 in 29%. Two carriers yielding less than or equal to 3 log10 in 38%. At less than or equal to 2 log10 HCW acquisitions, soap eliminated all AGNB in three of 10; alcohol in eight of eight (p = 0.009). Contact with densely colonized patient skin may cause heavy AGNB contamination of HCWs' hands that generally necessitates alcohol for complete removal.

Proteeae groin skin carriage in ambulatory geriatric outpatients.

Aerobic gram-negative bacillus (AGNB) groin skin carriage was prospectively studied in ambulatory geriatric outpatients: 42 from three nursing homes and 44 from private homes. Initially, 12 (28.6%) Proteeae carriers were in the former group and 3 (6.8%) were in the latter (P = 0.01). At one year, 6 of 7 surviving nursing home carriers remained Proteeae carriers while none from private homes remained carriers (P = 0.007). The annual prevalence of Proteeae carriage was 14 (33.3%) in nursing homes and 4 (9.1%) in private homes (P = 0.008); of non-Proteeae AGNB carriage, the annuyal prevalence was 2 (4.8%) and 4 (11.4%), respectively. Nursing home subjects had similar initial health characteristics; however, by one year, 5 of 12 carriers in contrast to 3 of 30 noncarriers were dead of chronic disease (P = 0.03). These nursing homes included persons with chronic diseases that apparently facilitated Proteeae carriage. Urethral catheters, skin ulcers, and recent antibiotics were not factors.

Proteeae groin skin carriage among nursing home residents--resistance to antiseptics.

Proteeae carriage was evaluated in groin skin carriers following vigorous antiseptic application. Three Proteus mirabilis carriers were treated with 60% isopropyl alcohol or 4% chlorhexidine, observed to prevent skin contact, and then recultured; at four and eight hours P mirabilis numbers remained undiminished. Ten Proteeae carriers received a series of nine body baths with soap, chlorhexidine, and 0.75% povidone-iodine plus three cefazolin injections over 16 to 34 days; cumulative treatments failed to clear seven carriers. Within three months, all were again carriers. Proteeae carriers also had affinity for groin carriage of various aerobic gram-negative bacilli (AGNB) including cefazolin-resistant strains. In seven subjects, more than one AGNB species were recovered shortly after applying an antiseptic. Proteeae groin skin carriage appears to reflect a major change in the nature of resident bacteria on intact groin skin.