Unique epidemiology of nosocomial urinary tract infection in children.

BACKGROUND: Nosocomial urinary tract infection (NUTI) occurs with varying frequency in children and is thought to be associated with urethral instrumentation. In response to changing infection control resources at our facility, we reviewed NUTI to determine whether the frequency of NUTI, associated complications, or presence of a remediable risk factor (instrumentation) justified ongoing routine infection control surveillance. METHODS: Prospective surveillance was conducted on all wards 8 months per year from January 1991 through December 1997 by an infection control nurse coordinator. NUTI was defined by laboratory evidence according to Center for Disease Control and Prevention definitions and detected 48 hours after admission. Urinary catheterization in the previous 7 days was categorized as continuous/indwelling or intermittent. RESULTS: NUTI was the fifth most common nosocomial infection (129/1375; approximately 9%) and decreased in frequency during the decade from 0.9 to approximately 0.6 cases/1000 patient days. Incidence was equal among men and women. Only 50% of cases had prior instrumentation of the urinary tract. NUTI occurred disproportionately in newborns and infants (P <.001). The most common pathogen was Escherichia coli (28%; 38/132), followed by Candida sp (18%; 24/134), Enterococcus (13%; 18/134), gram-negative nonfermenters (13%; 17/132), Enterobacter (approximately 10%; 13/134), Pseudomonas (9.7%; 13/134), and other (16%; 22/134). Three cases of secondary bacteremia occurred (2.3%; 95% confidence interval 0.5-6.6); there was no mortality. CONCLUSIONS: NUTI poses a less significant burden of illness (incidence, associated morbidity) than other nosocomial infection in children. If resources do not permit hospital-wide surveillance, high-risk children with urethral instrumentation and newborns and infants could be targeted. Although E coli remains the most common cause of pediatric NUTI, fungi have become the second most common pathogen in this tertiary care population. Risk factors for NUTI in noncatheterized children remain to be delineated.

Variation in risk for nosocomial chickenpox after inadvertent exposure.

Inadvertent exposure to chickenpox in the healthcare setting results in time-consuming and expensive infection control management strategies. In households, secondary cases occur in up to 96% of susceptibles, but transmission risk after exposure in an occupational setting is less well defined. In this prospective cohort study of inadvertent exposures in a 180-bed paediatric hospital, the secondary transmission rate was 4.5% (4/89; 95% confidence interval 1.2, 11.1%). Fourteen index cases exposed 158 patients and 93 healthcare workers over a 36-month study period. Exposures occurred in inpatient and ambulatory settings, with patients, staff and siblings serving as index cases. Transmission only occurred when the index case and contacts were in the same room and not in a multi-room setting (12% v. 0%, Fisher exact test, P = 0.02). Occupational exposures present a lesser transmission risk than those in households. Definition of those exposure variables that increase risk of transmission in the occupational setting should be explored in future studies.

Cross-Canada spread of methicillin-resistant Staphylococcus aureus via transplant organs.

We report our investigation of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) through transplantation. The kidneys, liver, and corneas were harvested from a child who died in Nova Scotia. Several days postmortem it was learned that culture of a premortem endotracheal tube aspirate from the donor yielded MRSA. Both kidneys were transplanted into a child in Nova Scotia and the liver into a child in Alberta. Both recipients subsequently became blood culture-positive for MRSA. One corneal ring from the donor was MRSA-positive. All four MRSA isolates were mecA-positive by polymerase chain reaction (PCR). The relatedness of the MRSA isolates was examined by restriction fragment length polymorphism (RFLP) analysis, a 16S-23S ribosomal PCR typing method, and comparison of antibiograms. Results were identical for all four MRSA isolates. These findings indicate that MRSA from the donor was transferred to recipients during implantation of harvested organs in Alberta and Nova Scotia, a cross-Canada spread.

Surveillance methods for central venous access device-associated infections in Canadian pediatric hospitals.

The most common complication of central venous access device (CVAD) use is infection, which occurs in 3 to 48% of hospitalized patients. It is recommended that regular surveillance of adverse events with CVADs be conducted, expressed as a proportion of 1000 device days and reviewed and acted upon by the institution's infection control committee. In the process of developing a CVAD program the authors attempted to determine the standard of practice at other Canadian pediatric hospitals. A telephone survey of infection control practitioners (ICPS) or CVAD nurses in 15 university-affiliated Canadian pediatric hospitals was conducted using a standard questionnaire. Fourteen hospitals (93%) conduct surveillance for infections associated with CVADS. One program, a pilot project, follows mechanical complications of CVAD use. Eleven centres conduct comprehensive surveillance; in three, selected patients are followed. Only three programs have sufficient staff to follow out-patients. Definitions for CVAD infections varied widely. A positive blood culture from the catheter is sufficient for diagnosis in eight of the 14 centres (57%); the rest use Centers for Disease Control and Prevention (CDC) or modified CDC criteria. In the four centres where CVAD line days are collected on most or all patients, multiple personnel other than the ICP assist in data collection. Four hospitals report number of infections per 100 discharges, four report absolute number of infections and two use more than one denominator. Surveillance methods rely largely on paper-based chart and microbiology record review; no hospital had access to computerized patient data for direct data retrieval. Eight centres have CVAD committees for policy development, and all 15 have or are developing hospital-wide protocols for CVAD use. Canadian pediatric hospitals recognize the importance of CVAD infections, but it appears that insufficient resources are available to meet recommended data collection methods. Interhospital comparison of rates is not possible at present because of variation in definitions and denominators and in types of patients surveyed.

Demand for isolation beds in a pediatric hospital.

OBJECTIVE: To determine isolation bed use for community-acquired and nosocomial infections in a pediatric hospital. DESIGN: A prospective repeated point prevalence survey was conducted during a 14-month period. A questionnaire was sent to other free-standing Canadian children's hospitals to determine isolation practice and perceived needs. SETTING: A university-affiliated, 218-bed pediatric hospital in Halifax, Nova Scotia, Canada. PATIENTS: All inpatients on surveyed wards during the study period (n = 1634). RESULTS: Overall, 13.5% of patients required isolation (range 5.6% to 31% per month). Demand was seasonal, with 71% of isolation occurring from November to April. Demand exceeded supply by 2 to 22 beds (11% to 122%). Respiratory and enteric infections requiring contact isolation accounted for 80% of use (53% and 27%, respectively). Children younger than 24 months comprised 28% of admissions and used 57% of isolation beds. Of patients isolated, 25% had nosocomial infections and 75% had community-acquired infections. The percentage of infant rooms in Canadian children's hospitals that were single bed (considered optimal for infant isolation) varied: 0% to 20% for hospitals built before 1965 and 25% to 47% for newer hospitals. All hospitals with less than 33% single-bed infant rooms perceived this allocation to be inadequate (p < 0.01 Fisher Exact Test). CONCLUSIONS: Pediatric isolation bed use varies with patient age, season of year, and category-specific isolation requirements. An increasing need for single-bed rooms is identified. Isolation requirements must be considered during the design of new hospitals or renovation of existing ones.