Purification and characterization of Haemophilus influenzae pili, and their structural and serological relatedness to Escherichia coli P and mannose-sensitive pili.

Haemophilus influenzae pili were purified, and their physical and serological properties were examined. The solution properties of the pili were determined, and then a purification scheme involving repeated cycles of precipitation and solubilization was developed. The purified pili from one type b isolate (A02) were found to consist of multiple copies of a 25,000 mol wt subunit. Amino-terminal sequence analysis of A02 pili was carried out to 40 amino acid residues, and a remarkable degree of sequence homology was found with E. coli P and mannose-sensitive (MS) pili (27.5 and 25% homology, respectively). Purified A02 pili were found to be highly immunogenic, and serological analysis by enzyme-linked immunosorbent assay and whole piliated cell agglutination revealed significant cross-reactivity between A02 pilus antiserum and the pili of seven other H. influenzae strains tested (heterologous titers = 2-100% of the homologous titer). Cross-reactivity was also observed between the H. influenzae pili (five of eight strains tested) and the P pili from E. coli strains HU849 and 3669; no cross-reactivity was detected with MS pili from E. coli strain H10407 and C94. The structural similarities between H. influenzae and E. coli P and MS pili suggest a common gene ancestry.

Broadly protective vaccine for Staphylococcus aureus based on an in vivo-expressed antigen.

Vaccines based on preferential expression of bacterial antigens during human infection have not been described. Staphylococcus aureus synthesized poly-N-succinyl beta-1-6 glucosamine (PNSG) as a surface polysaccharide during human and animal infection, but few strains expressed PNSG in vitro. All S. aureus strains examined carried genes for PNSG synthesis. Immunization protected mice against kidney infections and death from strains that produced little PNSG in vitro. Nonimmune infected animals made antibody to PNSG, but serial in vitro cultures of kidney isolates yielded mostly cells that did not produce PNSG. PNSG is a candidate for use in a vaccine to protect against S. aureus infection.

Reducing infections among women undergoing cesarean section in Colombia by means of continuous quality improvement methods.

BACKGROUND: Improving obstetric care in resource-limited countries is a major international health priority. OBJECTIVE: To reduce infection rates after cesarean section by optimizing systems of obstetric care for low-income women in Colombia by means of quality improvement methods. METHODS: Multidisciplinary teams in 2 hospitals used simple methods to improve their systems for prescribing and administering perioperative antibiotic prophylaxis. Process indicators were the percentage of women in whom prophylaxis was administered and the percentage of these women in whom it was administered in a timely fashion. The outcome indicator was the surgical site infection rate. RESULTS: Before improvement, prophylaxis was administered to 71% of women in hospital A; 24% received prophylaxis in a timely fashion. Corresponding figures in hospital B were 36% and 50%. Systems improvements included implementing protocols to administer prophylaxis to all women and increasing the availability of the antibiotic in the operating room. These improvements were associated with increases in overall and timely administration of prophylaxis (P<.001) in both hospitals by time series analysis, with adjustment for volume and case mix. After improvement, overall and timely administration of prophylaxis was 95% and 96% in hospital A and 89% and 96% in hospital B. In hospital A, the surgical site infection rate decreased immediately after the improvements (P<.001). In hospital B, the infection rate began a downward trend before the improvements that continued after their implementation (P =.04). CONCLUSION: Simple quality improvement methods can be used to optimize obstetric services and improve outcomes of care in resource-limited settings.

Control of multiply resistant cocci: do international comparisons help?

Antibiotic resistance has become a worldwide problem. However, the reasons for the uneven geographic distribution of antibiotic-resistant microorganisms are not fully understood. For instance, there are striking differences in the epidemiology of multiresistant gram-positive cocci between the USA and Germany. According to recent reports, the prevalence of high-level penicillin-resistant pneumococci (PRP), meticillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE) in clinically relevant isolates of hospitalised patients in the USA and Germany are: PRP, 14% versus less than 1%; MRSA, 36% versus 15%; and VRE, 15% versus 1%. These disparities may be explained by several determinants: (1) diagnostic practice and laboratory recognition (all three pathogens); (2) clonal differences and pathogen transmissibility (VRE); (3) antibiotic prescribing practices (all three pathogens); (4) population characteristics, including extensive daycare exposure in the USA (PRP); (5) cultural factors (all three pathogens); (6) factors related to the health-care and legal system (all three pathogens); and (7) infection-control practices (MRSA and VRE). Understanding these determinants is important for preventing further spread of multiresistant cocci within the USA. A rational approach to national surveillance is urgently needed in Germany to preserve the favourable situation and decrease MRSA transmission. Finally, we suggest that a macro-level perspective on antibiotic resistance can broaden the understanding of this worldwide calamity, and help prevent further dissemination of multiply resistant microorganisms.

Contemporary challenges for hospital epidemiology.

According to conventional wisdom, it is time for hospital epidemiologists to look beyond traditional infection control responsibilities and to shoulder an "expanded role," including quality assurance, risk management, and pharmacoepidemiology. Some see this as a matter of survival as the profession reacts to potent external forces that seek to curb the cost of health care while assuring quality service. Infection control specialists, it is argued, have the epidemiologic skills to measure adverse outcomes of hospitalization, adjust for confounding variables, and evaluate the impact of targeted interventions. Before embracing these new responsibilities, however, it should be noted that many hospital epidemiologists would require additional training in basic epidemiologic principles. Although hospital epidemiologists may seek a leadership role in hospital quality assurance and health policy research, they have generally not been innovators in these fields, even in some specific areas relevant to infection control. For example, while hospital epidemiologists have begun to consider severity of illness as a potential confounder in epidemiologic analyses, they have not participated in the development or validation of any of the most widely used indicators. For those hospital epidemiologists who wish to capitalize on their traditional background in infectious diseases, contemporary infection control provides numerous challenges. For example, the epidemiology of many common nosocomial infections, such as bacterial pneumonia in immunocompromised hosts, remains to be defined. Hospital epidemiologists need to incorporate a variety of sophisticated microbiologic methods into their practice to help them trace the spread of nosocomial pathogens. Finally, they should collaborate more closely with clinical and bench investigators in a number of areas, including microbial pathogenesis, immunology, and biotechnology.

Adaptation of the Centers for Disease Control guidelines for the prevention of nosocomial infection in a pediatric intensive care unit in Jakarta, Indonesia.

We attempted to implement a nosocomial infection control program based on the Centers for Disease Control (CDC) guidelines in an urban Indonesian public hospital at the request of Project Hope. Adoption of unmodified CDC guidelines was impeded by a substandard physical plant, absence of an infection control infrastructure, limited sterilization capabilities, lack of clinical microbiologic laboratory support, and the expense of single use medical devices. After on-site evaluations, CDC guidelines were extensively modified so that they were appropriate for local conditions and culture. Strategies included inexpensive architectural modifications, addition of sinks and a commode, introduction of disinfection procedures for reuse of disposable medical devices, and adaptation of available supplies for maintenance of aseptic technique. On subsequent site visits, many physical changes had been accomplished, and handling of reusable and disposable medical devises had improved considerably but adoption of clinical practice policies was incomplete. We conclude that it may be difficult to implement and sustain improvements in clinical practice in the absence of an infection control infrastructure and a strong commitment by hospital clinicians and administrators. Additional research is needed to refine flexible methods for rapidly assessing the specific infection control needs of institutions with widely disparate resources, patient populations, environments, and cultures.

Complications of intravenous therapy with steel needles and Teflon catheters. A comparative study.

Complications of intravenous therapy with steel needles and small-bore Teflon catheters were compared in a randomized study of 954 cannula insertions. Cannulas were inserted and cared for by an intravenous team following a standard protocol. There were no cases of cannula-related septicemia and only one case of local infection, a cellulitis in the group in which Teflon catheters were used. There was a low incidence of positive semiquantitative cannula cultures in both treatment groups (steel needles 1.5 percent, Teflon catheters 1.4 percent). The risk of phlebitis was significantly greater with Teflon catheters (18.8 percent with Teflon catheters, 8.8 percent with steel needles, adjusted odds ratio 1.87). Steel needles were significantly associated with infiltration (17.9 percent with Teflon catheters, 40.1 percent with steel needles, adjusted odds ratio 0.39). The over-all rate of complications was significantly greater for the group in which steel needles were used (53.8 versus 64.0 percent, adjusted odds ratio 0.72), principally due to the increased risk of infiltration with steel needles. Analysis of the per day risk of infiltration and phlebitis revealed that these relationships were present for each day the cannulas remained in place. We conclude (1) that steel needles and small-bore Teflon catheters can both be used with low risk of infection and (2) that Teflon catheters more frequently cause phlebitis, whereas steel needles infiltrate more readily.

Multi-state investigation of the actual disinfection/sterilization of endoscopes in health care facilities.

PURPOSE: The purpose of this investigation was to observe and assess the actual disinfection or sterilization of endoscopes in health care facilities. MATERIALS AND METHODS: A total of 22 hospitals and four ambulatory care centers in three states were studied. Facility protocols were reviewed, interviews conducted with relevant personnel, actual disinfection or sterilization procedures observed, and biologic tests performed to determine and assess disinfection/sterilization procedures. RESULTS: Fundamental errors observed during the course of the investigation included respective failures to time the period of disinfection, to clean all channels, to flush all channels with disinfectant, to fully immerse the endoscope in the disinfectant solution, and to use a disinfectant. At 78% of the facilities, failure to sterilize all biopsy forceps was observed. A total of 23.9% of the bacterial cultures from the internal channels of 71 gastrointestinal endoscopes grew 100,000 colonies or more of bacteria. These cultures were obtained after the completion of all disinfection/sterilization procedures and the device was deemed ready for use in the next patient. CONCLUSIONS: These data indicate that actual disinfection/sterilization procedures for endoscopes are not always optimal, and high-level disinfection of gastrointestinal endoscopes is not always achieved.

Score for Neonatal Acute Physiology: a physiologic severity index for neonatal intensive care.

The substantial variation in birth weight-adjusted mortality among neonatal intensive care units (NICUs) may reflect differences in population illness severity. Development of an illness severity measure is essential for comparisons of outcomes. The Score for Neonatal Acute Physiology (SNAP) was developed and validated prospectively on 1643 admissions (114 deaths) in three NICUs. SNAP scores the worst physiologic derangements in each organ system in the first 24 hours. SNAP showed little correlation with birth weight and was highly predictive of neonatal mortality even within narrow birth weight strata. It was capable of separating patients into groups with 2 to 20 times higher mortality risk. It also correlated highly with other indicators of severity including nursing workload (r = .59), therapeutic intensity (r = .78), physician estimates of mortality risk (r = .65), and length of stay (R2 = .59). SNAP is an important new tool for NICU research.

Estimating neonatal mortality risk: an analysis of clinicians' judgments.

BACKGROUND: Clinicians' estimates of mortality risk in the neonatal intensive care unit (NICU) have implications for patient triage, transfer, initiation and termination of life support, and allocation of medical resources. The accuracy of these judgments has not been studied, nor the differences between nurses and attending physicians. OBJECTIVES: 1) evaluate the accuracy of subjective judgments of NICU unit mortality risk, 2) identify the key components of clinician judgments, 3) compare accuracy between attending physicians and nurses, and 4) examine the utility of combining an objectively computed risk and clinician judgments to improve predictions. METHODS: We obtained estimates of mortality risk on 544 admissions to two NICUs on the day of admission from the attending physician and primary nurse. These were compared with an objective computed mortality risk based on birth weight and the Score for Neonatal Acute Physiology (SNAP) using a linear judgment analysis model, as well as with actual outcomes. RESULTS: Physicians and nurses had good discriminating power with actual mortality rates ranging from 0% among low risk patients to 67% among those with the highest mortality estimates. Physicians had a tendency to overestimate mortality risk. Clinicians base their estimates on the same factors and similar judgment weights as the empiric mortality risk model (22% birth weight, 62% illness severity (SNAP), 13% low Apgar, and 3% for intrauterine growth restriction). Clinicians place additional emphasis on therapeutic as well as physiologic factors. When the computed risk and physician judgment were combined, both made significant contributions in a logistic mortality risk model. CONCLUSIONS: Clinician judgments of mortality risk are fairly accurate and similar to an objective illness severity index. This simple method provides insight into clinical decision making and has important applications in improving direct patient care, appropriate allocation of medical resources, and medical training.

Coagulase-negative staphylococcal bacteremia among very low birth weight infants: relation to admission illness severity, resource use, and outcome.

OBJECTIVE: To examine the impact of admission-day illness severity on nosocomial bacteremia risk after consideration of traditional risk determinants such as birth weight and length of stay. METHODS: The hospital courses for 302 consecutive very low birth weight (less than 1500 g) infants admitted to two neonatal intensive care units were examined for the occurrence of nosocomial coagulase-negative staphylococcal bacteremia. Using both cumulative incidence and incidence density as measures of bacteremia risk, we explored the relation between illness severity (as measured by the Score for Neonatal Acute Physiology [SNAP]) and bacteremia both before and after birth weight adjustment. In addition, the effect of bacteremia on hospital resource use was estimated. RESULTS: Coagulase-negative staphylococcus was the most common pathogen noted in blood cultures drawn at 48 hours after admission or later. It was isolated on at least one occasion in 53 patients (cumulative incidence of 17.5 first episodes per 100 patients). These episodes occurred during 7652 days at risk, giving an incidence density of 6.9 initial bacteremias per 1000 patient-days at risk. As expected, when compared with the nonbacteremic group, bacteremic patients were of lower birth weight (888 +/- 231 vs 1127 +/- 258 g; P < .01) and gestational age (26.4 +/- 2.1 vs 28.9 +/- 2.8 weeks; P < .01). In addition, these patients were more severely ill on admission (SNAP 17.3 +/- 6.5 vs 12.2 +/- 5.8; P < .01). Even after birth weight stratification, the risk of bacteremia by both measures increased with higher SNAP scores. For example, among infants with birth weights greater than 1 kg, 25% of the most severely ill patients (SNAP 20 and higher) experienced at least one bacteremic episode, whereas the rates seen in infants with intermediate (SNAP 10 to 19) and low illness severity (SNAP 0 to 9) were 8.6% and 3.0%, respectively (chi 2 for trend = 7.25; P < .01). Multivariate linear regression showed that bacteremia was associated with a prolongation of neonatal intensive care unit stay of 14.0 +/- 4.0 days (P < .01) and an increase in hospital charges of $25,090 +/- 12,051 (P < .05), even after adjustment for birth weight and admission-day SNAP. CONCLUSIONS: Nosocomial coagulase-negative bacteremia is an important complication among very low birth weight infants. Assessment of illness severity with SNAP provides information regarding nosocomial infection risk beyond that available from birth weight alone.

Neonatal therapeutic intervention scoring system: a therapy-based severity-of-illness index.

Severity-of-illness scales have proven valuable in assessing clinical outcomes and resource consumption in adult and pediatric intensive care, but they have been less extensively developed for neonatal care. The National Therapeutic Intervention Scoring System (NTISS) was created by modifying the Therapeutic Intervention Scoring System (TISS). From the 76 original TISS items, 42 were deleted and 28 added to form the NTISS. Like TISS, NTISS assigns score points from 1 to 4 for various intensive care therapies. Admission-day NTISS scores were calculated for 1643 newborns admitted to three neonatal intensive care units (NICUs) between November 1, 1989, and September 30, 1990. NTISS scores ranged from 0 to 47 with a mean of 12.3 +/- 8.7 (SD). There was little correlation with birth weight (r = -.11) or gestational age (r = -.17), but NTISS scores were highly correlated with expected markers of illness severity, including mortality risk estimates by neonatal attending physicians (r = .70, P < .0001), in-hospital mortality rates (P < .05), and a measure of nursing acuity (Medicus) (r = .69, P < .0001). In addition, admission-day NTISS scores were found to be predictive of both NICU length of stay (r = .37, P < .0001) and total hospital charges for survivors (r = .65, P < .0001). It is concluded that NTISS is a valid measure of therapeutic intensity that is independent of birth weight and can be used as an indicator of neonatal illness severity and resource utilization. Further validation in other NICUs is required.

A service chief model for general pediatric inpatient care and residency training.

Pediatric training programs are faced with rapid, fundamental changes in hospital practice and an increasingly rigorous regulatory and fiscal environment. Traditional models for providing care and teaching students and house officers may not be sufficiently responsive to these challenges. In 1986, the Department of Medicine at Children's Hospital, Boston, reorganized the general inpatient program and implemented a "service chief" system adapted from British hospital "firms." Three age-based inpatient services (Thomas Morgan Rotch infant/toddler service, Kenneth Daniel Blackfan school-age service, and Charles Alderson Janeway adolescent/young adult service) were created, each headed by an experienced clinician and teacher (service chief). The service chiefs developed age-appropriate curricula, recruited a balanced faculty of generalists and specialists to serve as attending physicians and provide teaching in their areas of expertise, and established strong collaborative relationships with nurse managers on their respective wards. Implementation of the service chief system has been associated with development of faculty esprit de corps, standardized tracking of faculty performance, enhanced supervision and counseling of housestaff, and improved continuity of patient care. Relationships with referring physicians have improved dramatically, as measured by formal satisfaction surveys. Accountability and documentation have been emphasized, and departmental billings have increased sharply. Ongoing quality indicators have been developed, and collaborative patient care, teaching, and quality-improvement projects have been initiated with the nursing staff. Naming the services for distinguished past physicians-in-chief has provided a focus for fund-raising.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth weight and illness severity: independent predictors of neonatal mortality.

BACKGROUND: Low birth weight is a major determinant of neonatal mortality. Yet birth weight, even in conjunction with other demographic markers, is inadequate to explain the large variations in neonatal mortality between intensive care units. This variation probably reflects differences in admission severity. The authors have recently developed the Score for Neonatal Acute Physiology (SNAP), an illness severity index specific for neonatal intensive care, and demonstrated illness severity to be a major determinant of neonatal mortality. OBJECTIVE: To define the relative contributions of birth weight and illness severity to the risk of neonatal mortality and to identify other significant independent risk factors. METHODS: Logistic regression was used to analyze data from a cohort of 1621 consecutive admissions to three neonatal intensive care units (92 deaths), to test six alternative predictive models. The best logistic model was then used to develop a simple additive clinical score, the SNAP Perinatal Extension (SNAP-PE). RESULTS: These analyses demonstrated that birth weight and illness severity are powerful independent predictors across a broad range of birth weights and that their effects are additive. Below 750 g, there is an interaction between birth weight and SNAP. Other factors that showed independent predictive power were low Apgar score at 5 minutes and small size for gestational age. Separate derivation and test samples were used to demonstrate that the SNAP-PE is comparable to the best logistic model and has a sensitivity and specificity superior to either birth weight or SNAP alone (receiver-operator characteristic area .92 +/- .02) as well as excellent goodness of fit. CONCLUSION: This simplified clinical score provides accurate mortality risk estimates for application in a broad array of clinical and research settings.

Quality of care for preschool children with asthma: the role of social factors and practice setting.

OBJECTIVE: To determine whether patient race or source of payment is associated with differences in the quality of inpatient and outpatient treatment for young children with asthma. DESIGN: Structured medical record review. SETTING: Tertiary care pediatric hospital. PATIENTS: We studied 354 patients aged 1 to 6 years discharged with asthma between October 1, 1989 and September 30, 1990. MEASURES: We developed indicators of the quality of asthma care provided before and during hospitalization and planned after discharge. Outpatient indicators were the use of inhaled beta-agonists and the use of preventive anti-inflammatory medications (inhaled steroids or cromolyn sodium) before admission. In-hospital indicators were the intensity of inhaled beta-agonist therapy in the emergency department and length of stay. Planning for post-hospital care was assessed by the prescription of a nebulizer for home use. We examined associations between these indicators and patient race and source of payment, and explored the influence of primary-care practice type on these associations. RESULTS: After adjustment for potential confounders, we found that Hispanic patients were less likely than white patients to have taken inhaled beta-agonists before admission. Both black and Hispanic patients were less likely than white patients to have taken anti-inflammatory medications. When we adjusted for the patients' primary-care practice type, the effect of patient race did not persist for these indicators of outpatient care. We found no differences by patient race in emergency department care or length of hospital stay. However, black and Hispanic patients were much less likely to be prescribed a nebulizer for home use upon discharge. After adjustment for confounders, there were no differences in the quality of asthma care by source of payment. CONCLUSIONS: We found that young children of racial minorities admitted for an asthma exacerbation were less likely to have received maximally effective preventive therapy. We also identified marked differences in the quality of care planned after hospital discharge for black and Hispanic patients, compared with white patients. Particularly in an era of health reform, attention should focus on barriers to high-quality care for underserved children, who are already at high risk for asthma-related morbidity.

Declining severity adjusted mortality: evidence of improving neonatal intensive care.

OBJECTIVES: Declines in neonatal mortality have been attributed to neonatal intensive care. An alternative to the "better care" hypothesis is the "better babies" hypothesis; ie, very low birth weight infants are delivered less ill and therefore have better survival. DESIGN: We ascertained outcomes of all live births <1500 g in two prospective inception cohorts. We estimated mortality risk from birth weight and illness severity on admission and measured therapeutic intensity. We calculated logistic regression models to estimate the changing odds of mortality between cohorts. PATIENTS AND SETTING: Two cohorts in the same two hospitals, 5 years apart (1989-1990 and 1994-1995) (total n = 739). RESULTS: Neonatal intensive care unit mortality declined from 17.1% to 9.5%, and total mortality declined from 31.6% to 18.4%. Cohort 2 had lower risk (higher birth weight, gestational age, and Apgar scores and lower admission illness severity for newborns >/=750 g). Risk-adjusted mortality declined (odds ratio, 0.52; confidence interval, 0.29-0. 96). One third of the decline was attributable to "better babies" and two thirds to "better care." Use of surfactant, mechanical ventilation, and pressors became more aggressive, but decreases in monitoring, procedures, and transfusions resulted in little change in therapeutic intensity. CONCLUSIONS: Mortality decreased nearly 50% for infants <1500 g in 5 years. One third of this decline is attributable to improved condition on admission that reflects improving obstetric and delivery room care. Two thirds of the decline is attributable to more effective newborn intensive care, which was associated with greater aggressiveness of respiratory and cardiovascular treatments. Attribution of improved birth weight specific mortality solely to neonatal intensive care may underestimate the contribution of high-risk obstetric care in providing "better babies."

Empyema in children: clinical course and long-term follow-up.

Sixteen patients, aged 1 month to 15 years, were studied to determine the clinical course and long-term outcome of empyema in previously healthy children. The pathogens responsible were Haemophilus influenzae type b (seven patients), Staphylococcus aureus (five patients), Streptococcus pneumoniae (three patients), and viridans group Streptococcus (one patient). All patients had loculated fluid showing on chest roentgenographs. Chest tube drainage yielded 20 to 1,495 mL (mean 293 mL) during the first three days, accounting for 83% of total drainage. Chest tubes were removed after three to 17 days (mean ten days). Only slight roentgenographic improvement showed during chest tube drainage. Three patients required an open thoracotomy because of an unsatisfactory clinical response. Hospitalization ranged from eight to 77 days (mean 25 days). All patients had residual pleural thickening shown on chest roentgenographs taken at discharge. Thirteen patients were seen 5 to 140 months (mean 66 months) after discharge. Findings from physical examination were normal in 12 of the 13 patients. Pulmonary function tests in ten of the 13 patients revealed (mean percent predicted +/- 1 SD): vital capacity 92 +/- 12, residual volume 85 +/- 31, total lung capacity 92 +/- 13, peak flow rate 96 +/- 17, forced expiratory volume in 1 second 90 +/- 13, and maximal mid-expiratory flow rate 93 +/- 25. In all but one patient, findings on chest roentgenograms were normal or showed slight pleural thickening. Children with loculated empyema can be treated successfully with antibiotics and chest tube drainage. Few patients require open drainage, and further surgery is rarely required. The long-term outcome is excellent.

Cephalothin prophylaxis in cardiac valve surgery. A prospective, double-blind comparison of two-day and six-day regimens.

A prospective, double-blind study comparing a 6 day with a 2 day regimen of cephalothin prophylaxis was conducted among 200 patients undergoing prosthetic valve replacement. No cases of endocarditis occurred during the 2 month follow-up. Sternal wound infection developed in 2.8 per cent of the 6 day group and 2.1 per cent of the 2 day group. Pneumonia developed in 8.5 per cent of the 6 day and 5.3 per cent of the 2 day group; most of the bacteria isolated were susceptible to cephalothin. Urinary tract infection developed more frequently in the 2 day group (17.0 versus 8.5 per cent), particularly during the first 6 postoperative days. Three of 11 patients with no detectable cephalothin in their sera at the close of operation developed staphylococcal wound infections, compared with 2 of 175 patients whose sera contained cephalothin at the close of surgery (p = 0.002, Fisher's exact test). A short course of prophylactic antibiotics is prudent, but there is no justification for prolonging their administration.

Transmission of viral respiratory infections in the home.

Respiratory viruses in the home exploit multiple modes of transmission. RSV is transmitted primarily by contact with ill children and contaminated objects in the environment. Influenza appears to be spread mainly by airborne droplet nuclei. Despite many years of study, from the plains of Salisbury, to the hills of Virginia, to the collegiate environment of Madison, WI, the precise routes rhinovirus takes to inflict the misery of the common cold on a susceptible population remain controversial.

Intravenous lipid emulsions are the major determinant of coagulase-negative staphylococcal bacteremia in very low birth weight newborns.

BACKGROUND: Intravenous lipid emulsions and the i.v. catheters through which they were administered were the major risk factors for nosocomial coagulase-negative staphylococcal (CONS) bacteremia among newborns in our neonatal intensive care units a decade ago. However, medical practice is changing, and these and other interventions may have different effects in the current setting. OBJECTIVES: We determined the independent risk factors for CONS bacteremia in current very low birth weight newborns after adjusting for severity of underlying illness. METHODS: We surveyed 590 consecutively admitted newborns with birth weights < 1500 g hospitalized in 2 neonatal intensive care units and conducted a case-control study in a sample of 74 cases of CONS bacteremia and 74 pairs of matched controls. Adjusted relative odds of bacteremia were estimated for a number of attributes and therapeutic interventions in 2 time intervals before CONS bacteremia: any time before bacteremia and the week before bacteremia. RESULTS: Using conditional logistic regression to adjust for indicators of severity of illness, two procedures were independently associated with subsequent risk of CONS bacteremia at any time during hospitalization: i.v. lipids, odds ratio (OR) = 9.4 [95% confidence interval (CI) 1.2 to 74.2]; and any surgical or percutaneously placed central venous catheter, OR = 2.0 (95% CI 1.1 to 3.9). Considering only the week immediately preceding bacteremia, the independent risk factors were: mechanical ventilation, OR = 3.2 (95% CI 1.3 to 7.6); and short peripheral venous catheters, OR = 2.6 (95% CI 1.0 to 6.5). CONCLUSIONS: During the last decade exposure to i.v. lipids any time during hospitalization has become an even more important risk factor for CONS bacteremia (OR = 9.4). Of these bacteremias 85% are now attributable to lipid therapy. In contrast the relative importance of intravenous catheters as independent risk factors has declined. Mechanical ventilation in the week before bacteremia has emerged as a risk factor for bacteremia.