A prospective nationwide study of Clostridium difficile-associated diarrhea in Sweden. The Swedish C. difficile Study Group.

Clostridium difficile-associated diarrhea (CDAD) is regarded as an emerging nosocomial infection. All patients positive for C. difficile in Sweden were recorded during 1995, including primary care patients. Those positive for toxin in feces were defined as CDAD cases. A total of 5,133 CDAD cases were recorded (58 per 100,000 inhabitants per year), as compared with 86 cases diagnosed in 1978 and 553 in 1983. CDAD was almost twice as prevalent as all (combined) diagnosed domestic cases of reportable bacterial and protozoal diarrhea. The age-specific incidence was little affected by gender but increased > 10-fold over the age range of 60-98 years. The differences in overall CDAD incidence were sixfold between counties and threefold between major hospitals. Among hospitalized patients the incidences were highest in geriatric/rehabilitation wards, followed by infectious diseases and internal medicine wards; 28% of all cases involved no recent hospitalization and were defined as community-acquired CDAD.

Transmission of urinary bacterial strains between patients with indwelling catheters--nursing in the same room and in separate rooms compared.

Despite lack of supporting scientific data it has been suggested that patients with an indwelling urinary catheter (IUC) should be nursed in separate rooms to reduce the risk of cross-infection. We conducted a one-month case-control study of nursing home patients with an IUC and bacteriuria, 20 nursed together pairwise and 20 in separate rooms, by weekly urine cultures and typing of the bacterial isolates. The transmission rate of urinary strains between patients was three times higher within rooms (5/9 possible transmissions) than between rooms (9/53 possible transmissions, P = 0.02). The study thus supported nursing IUC patients in separate rooms.

The value and limitations of protective gloves in medical health service: Part III.

The value of protective gloves in the health care environment is well known. However, these gloves are not perfect. Some are permeable to microorganisms and various chemicals, and/or result in side effects for health care professionals. Gloves that offer the greatest protection and least side effects are highly desirable. Limitations of glove use due to side effects, and glove selection and therapeutic alternatives are described in Part III of this three-part series.

The value and limitations of protective gloves in medical health service: part II.

The value of protective gloves in the health care environment is well known. However, these gloves are not perfect. Some are permeable to microorganisms and various chemicals, and/or result in side effects for health care professionals. Gloves that offer the greatest protection and least side effects are highly desirable. Protection against microorganisms and protection against chemicals used in health care are described in Part II of this three-part series.

The value and limitations of protective gloves in medical health service: Part I.

The value of protective gloves in the health care environment is well known. However, these gloves are not perfect. Some are permeable to microorganisms and various chemicals, and/or result in side effects for health care professionals. Gloves that offer the greatest protection and least side effects are highly desirable. Field of application rules and regulations, materials and manufacturing, and test methods of protective gloves are described in Part I of this three part series.

Survival on skin and surfaces of epidemic and non-epidemic strains of enterobacteria from neonatal special care units.

It has been suggested that increased ability to survive on the hands of hospital staff contributes to transmission of certain strains of Gram-negative bacteria. We tested this hypothesis by comparing the survival on fingertips, glass slides and membrane filters of epidemic (M, major) and matched non-epidemic (S, sporadic) faecal strains of Escherichia coli (n = 13 vs. 13) and Klebsiella spp. (n = 19 vs. 19) found among 1066 neonates in 25 special care units (SCUs). The time to 50% killing at 22 degrees C in air was longer for E. coli than for Klebsiella spp. both on human skin (median 6 vs. 2 min P < 0.001) and glass surfaces (15 vs. 8 min P < 0.001). On the other hand, Klebsiella spp. were superior to E. coli in long-term survival tests on membrane filters expressed as the minimum inoculum still yielding growth after 10 days exposure at 22 degrees C in air (10(5) vs. 10(8) bacteria P < 0.001). Despite a large variation in survival times between individual strains no differences between M strains and S strains were observed in any of the three tests. This indicates that bacterial properties other than survival on surfaces contribute to the increased capacity for transmission of certain strains of enterobacteria in SCUs.

Epidemiology and attack index of gram-negative bacteria causing invasive infection in three special-care neonatal units and risk factors for infection.

Of 13 consecutive episodes of gram-negative septicemia (Escherichia coli eight, Klebsiella oxytoca four, Klebsiella pneumoniae one) among 113 infants in three special-care neonatal units studied, five episodes were epidemiologically related according to a novel fingerprinting method for enterobacteria. In ten episodes the invasive phenotype was found in the fecal flora of up to 54% of the fellow infants in the same ward and for periods of up to 70 days. Two units exchanged patients, which further promoted the transmission of invasive strains. The attack index was highest for certain E. coli strains, generally low for K. oxytoca strains, but lowest for other E. coli strains. The infants contracting septicemia had lower birth weight (p = 0.04) or were more often classified as high-risk infants than matched non-infected fecal carriers of the invasive strains (p = 0.04). In summary, gram-negative neonatal septicemia was either due to an apparently high-virulent strain capable of attacking the single full-term infant carrier or a high-colonizing phenotype of lower apparent virulence, which occasionally attacked a high-risk infant among a large number of infants colonized.

Cleaning and disinfection of reusable items in Swedish hospitals.

1. In Sweden, every ward has one or two utility rooms equipped with a washer disinfector for cleaning and disinfection of such items as instruments and wash basins, and a flusher disinfector for cleaning and disinfection of bedpans/urinals and emptying of fluids. 2. Thermal disinfection of reusable items is accomplished in a sealed chamber with an efficient, controlled process--which is a simple, inexpensive, and reliable method for high-level disinfection. 3. The use of flusher and washer disinfectors in hospital wards, surgery areas, and critical care units is recommended to minimize the use of single-use items and provide a safer environment for patients and personnel.

Association between climate and Enterobacter colonization in Swedish neonatal units.

OBJECTIVE: To study risk factors for the highly variable local colonization rates with unrelated Enterobacter species strains previously found in 22 Swedish neonatal units (0% to 32.4% of the infants). PATIENTS AND SETTING: The fecal Enterobacter species carriage rates among 953 infants in the 22 special-care neonatal units were correlated with variables related to the ward (size, crowding, staffing, work load, antibiotic usage, level of care, hygienic precautions), and the hospital (temperature of water supplied, geographical location). RESULTS: The average Enterobacter species carriage rate was highest at seven days of age (17% of the infants) and then declined to 3%. Only location of the hospital in an area with warmer climate according to horticultural zone showed an association with Enterobacter species carriage in multivariate analysis (P = 0.005). CONCLUSION: Although Enterobacter species mainly cause nosocomially acquired infections, the occurrence of the organism in special-care neonatal units seemed to be determined more by extrahospital than by intrahospital factors.

Relation between nursing procedures, other local characteristics and transmission of enteric bacteria in neonatal wards.

Faecal colonization patterns were studied in 22 neonatal special care units (N = 953 babies) using a novel method for typing of Escherichia coli, Klebsiella spp. and Enterobacter spp. isolates. Sporadic strains of E. coli (found in only one infant in a ward) were taken to indicate natural colonization, whereas local spread of E. coli strains or colonization with sporadic or spreading strains of Klebsiella spp. and Enterobacter spp. was regarded as abnormal (non-maternal) colonization. All apparent risk factors for abnormal neonatal colonization with enteric bacteria identified were modifiable (ward size, staff work load, antibiotic policy, hygienic precautions). Another encouraging finding was that variables harder to modify (crowding, intensity of care) appeared to be unimportant in influencing neonatal colonization patterns with such bacteria.

Importance of the environment and the faecal flora of infants, nursing staff and parents as sources of gram-negative bacteria colonizing newborns in three neonatal wards.

Gram-negative bacteria are an important cause of invasive infection among neonates. In this study a novel fingerprinting method was used for the first time to assess the importance of various potential reservoirs of the major gram-negative enterobacteria that colonized 46 consecutive infants in three neonatal special care units during a three to four week period. Such bacteria were isolated from the oropharynx, umbilical cord and faeces in 24%, 33% and 100% of the infants, respectively. Klebsiella/Enterobacter spp. dominated over Escherichia coli and spreading (shared) over sporadic strains. Sixty-one percent of the neonates were colonized with at least one and up to six different strains shown to exist in the ward, mainly in other infants. Environmental reservoirs and the faecal flora of mothers and staff were of minor importance. Vertical transmission occurred in 12% of vaginally delivered infants and in 0% of those delivered by caesarean section.

Prevention of excess neonatal morbidity associated with group B streptococci by vaginal chlorhexidine disinfection during labour. The Swedish Chlorhexidine Study Group.

Streptococcus agalactiae transmitted to infants from the vagina during birth is an important cause of invasive neonatal infection. We have done a prospective, randomised, double-blind, placebo-controlled, multi-centre study of chlorhexidine prophylaxis to prevent neonatal disease due to vaginal transmission of S agalactiae. On arrival in the delivery room, swabs were taken for culture from the vaginas of 4483 women who were expecting a full-term single birth. Vaginal flushing was then done with either 60 ml chlorhexidine diacetate (2 g/l) (2238 women) or saline placebo (2245) and this procedure was repeated every 6 h until delivery. The rate of admission of babies to special-care neonatal units within 48 h of delivery was the primary end point. For babies born to placebo-treated women, maternal carriage of S agalactiae was associated with a significant increase in the rate of admission compared with non-colonised mothers (5.4 vs 2.4%; RR 2.31, 95% CI 1.39-3.86; p = 0.002). Chlorhexidine reduced the admission rate for infants born of carrier mothers to 2.8% (RR 1.95, 95% CI 0.94-4.03), and for infants born to all mothers to 2.0% (RR 1.48, 95% CI 1.01-2.16; p = 0.04). Maternal S agalactiae colonisation is associated with excess early neonatal morbidity, apparently related to aspiration of the organism, that can be reduced with chlorhexidine disinfection of the vagina during labour.

Host factors versus virulence-associated bacterial characteristics in neonatal and infantile bacteraemia and meningitis caused by Escherichia coli.

Possession of P fimbriae, virulence-associated O and K antigens, haemolysin and aerobactin production, and susceptibility to 10 antimicrobial agents were studied in 63 Escherichia coli strains isolated from blood or CSF of infants who were grouped according to their clinical characteristics. These isolates were compared with 35 faecal E. coli strains from healthy infants. Individual virulence factors showed a relatively weak association with invasive infection except for P fimbriae in urosepsis and aerobactin production in meningitis. Combinations of factors were generally more predictive for defining virulent clones, particularly in infants defined as being at normal risk of developing septicaemia. Thus, 62% of isolates from such infants had characteristics typical of previously described uropathogenic or meningitis-associated clones of E. coli, compared with 32% of the isolates from high-risk infants (i.e., those defined as being at high risk of developing septicaemia) and only 9% of the faecal isolates (p less than 0.001 and less than 0.05, respectively). Overall, 45% of the episodes of invasive infection were caused by such clones, whereas risk factors (conditions considered to be associated with increased risk of invasive infection) were present in 59% of the infected infants (39% in meningitis and urosepsis, 78% in cryptogenic septicaemia and untreated bacteraemia). The results indicated that bacterial factors played a significant causative role in neonatal meningitis and urosepsis, particularly in normal-risk infants, whereas predisposing host factors contributed greatly to cryptogenic septicaemia and untreated bacteraemia.

Epidemiology of enteric bacteria in neonatal units--influence of procedures and patient variables.

Among 953 infants in 22 neonatal care units studied, 23% (median value, range 0-78) were found to be faecally colonized with one of 21 distinct nosocomial strains of Escherichia coli, Klebsiella or Enterobacter spp. Lower birth weight was associated with such colonization, particularly with nosocomial phenotypes of E. coli. Caesarean section followed by prolonged incubator care, and hospital stay, were additional factors associated with colonization by such strains of E. coli. Antibiotic therapy of the infant and type of feeding were not found to be associated with acquisition of nosocomial strains of enteric bacteria among neonates.

Influence of antibiotic therapy on faecal carriage of P-fimbriated Escherichia coli and other gram-negative bacteria in neonates.

The influence of previous antibiotic therapy on the aerobic faecal flora, including P-fimbriated Escherichia coli, was studied in 953 neonates at discharge from 22 neonatal wards in Sweden. Antibiotics, mainly ampicillin (with or without gentamicin) or cefuroxime, had been received by 37% of the infants. Treatment with ampicillin (with or without gentamicin) increased Klebsiella/Enterobacter and reduced Esch. coli colonization. Cephalosporin therapy (71% cefuroxime) reduced the frequency of colonization with both Esch. coli and Klebsiella/Enterobacter spp. but doubled the isolation rate of other Gram-negative bacteria (Citrobacter, Pseudomonas, Proteus and Acinetobacter spp.) and tripled the incidence of specimens yielding no aerobic Gram-negative growth. Gentamicin showed no significant ecological impact. The selection of Klebsiella/Enterobacter and P-negative Esch. coli strains by ampicillin was correlated with their resistance to this agent, while the association between P-fimbriated Esch. coli and cefuroxime therapy was not related to cefuroxime resistance.