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Natasha B Halasa

Publications and source records attributed to Natasha B Halasa.

15 recordsLinked to original sources
PubMed2025

Respiratory Syncytial Virus Disease Burden and Nirsevimab Effectiveness in Young Children From 2023-2024.

IMPORTANCE: During the 2023-2024 respiratory syncytial virus (RSV) season in the United States, 2 new RSV prevention products were recommended to protect infants in their first RSV season: nirsevimab and Pfizer's maternal RSV vaccine. Postlicensure studies are needed to assess prevention product impact and effectiveness. OBJECTIVE: To compare the epidemiology and disease burden of medically attended RSV-associated acute respiratory illness (ARI) among children younger than 5 years during the 2023-2024 RSV season with 3 prepandemic RSV seasons (2017-2020), estimate nirsevimab effectiveness against medically attended RSV-associated ARI, and compare nirsevimab binding site mutations among circulating RSV in infants with and without nirsevimab receipt. DESIGN, SETTING, AND PARTICIPANTS: This study included prospective population-based surveillance for medically attended ARI with systematic molecular testing for RSV and whole-genome sequencing of RSV positive samples, as well as a test-negative case-control design to estimate nirsevimab effectiveness. The study was conducted in 7 academic pediatric medical centers in the United States with data from RSV seasons (September 1 through April 30) in 2017 through 2020. Participants were children younger than 5 years with medically attended ARI. EXPOSURE: For the nirsevimab effectiveness analyses, nirsevimab receipt among infants younger than 8 months as of or born after October 1, 2023. MAIN OUTCOME AND MEASURE: Medically attended RSV-associated ARI. RESULTS: Overall, 28 689 children younger than 5 years with medically attended ARI were enrolled, including 9536 during September 1, 2023, through April 30, 2024, and 19 153 during the same calendar period of 2017-2020. Of these children, 16 196 (57%) were male, and 12 444 (43.4) were female; the median (IQR) age was 15 (6-29) months. During 2023-2024, the proportion of children with RSV was 23% (2199/9490) among all medically attended episodes, similar to 2017-2020. RSV-associated hospitalization rates in 2023-2024 were similar to average 2017-2020 seasonal rates with 5.0 (95% CI, 4.6-5.3) per 1000 among children younger than 5 years; the highest rates were among children aged 0 to 2 months (26.6; 95% CI, 23.0-30.2). Low maternal RSV vaccine uptake precluded assessment of effectiveness. Overall, 10 of 765 case patients (1%) who were RSV positive and 126 of 851 control patients (15%) who were RSV negative received nirsevimab. Nirsevimab effectiveness was 89% (95% CI, 79%-94%) against medically attended RSV-associated ARI and 93% (95% CI, 82%-97%) against RSV-associated hospitalization. Among 229 sequenced specimens, there were no differences in nirsevimab binding site mutations by infant nirsevimab receipt status. CONCLUSIONS AND RELEVANCE: This analysis documented the continued high burden of medically attended RSV-associated ARI among young children in the US. There is a potential for substantial public health impact with increased and equitable prevention product coverage in future seasons.

Humans↗
PubMed2006

Multicenter surveillance of invasive meningococcal infections in children.

OBJECTIVES: Meningococcal disease continues to result in substantial morbidity and mortality in children, but there is limited recent surveillance information regarding serogroup distribution and outcome in children in the United States. The objective of this study was to collect demographic, clinical, laboratory, and outcome information for infants and children who had Neisseria meningitidis infections of various serogroups and were cared for in 10 pediatric hospitals. METHODS: Investigators at each of the participating hospitals identified children with meningococcal infections and collected demographic and clinical information using a standard data form. Meningococcal isolates were sent to a central laboratory for serogrouping by slide agglutination and penicillin susceptibility. RESULTS: From January 1, 2001, through March 15, 2005, 159 episodes of systemic meningococcal infections were detected. The greatest numbers of children were younger than 12 months (n = 41) or were 12 to 24 months of age (n = 22). Meningitis was the most common clinical manifestation of disease accounting for 112 (70%) cases; 43 (27%) children had bacteremia only. Children who were younger than 5 years (17 of 102) were significantly less likely to require mechanical ventilation than children who were 5 to 10 years of age (12 of 24) or children who were older than 10 years (13 of 33). Overall, 55 (44%) isolates were serogroup B, 32 (26%) were serogroup C, and 27 (22%) were serogroup Y. All but 1 isolate (intermediate) were susceptible to penicillin. The overall mortality rate was 8% (13 of 159) but was greater for children who were > or = 11 years of age (7 [21.2%] of 33) than for children who were younger than 11 years (6 [4.8%] of 126). Unilateral or bilateral hearing loss occurred in 14 (12.5%) of 112 children with meningitis. CONCLUSIONS: The morbidity and the mortality of meningococcal infections are substantial. With the recent licensure of meningococcal conjugate vaccines, our baseline trends in meningococcal disease can be compared with those seen after widespread vaccination to assess the success of routine immunization.

Adolescent↗
PubMed2005

Asthma as a risk factor for invasive pneumococcal disease.

BACKGROUND: The risk of invasive pneumococcal disease among persons with asthma is unknown. METHODS: We conducted a nested case-control study to examine the association between asthma and invasive pneumococcal disease. The study population included persons 2 to 49 years of age who were enrolled in Tennessee's Medicaid program (TennCare) for more than one year during the study period (1995 through 2002) and who resided in counties participating in a prospective laboratory-based program of surveillance for invasive pneumococcal disease. For each subject with invasive pneumococcal disease, 10 age-matched controls without invasive pneumococcal disease were randomly selected from the same population. TennCare files were queried to identify the presence of coexisting conditions that confer a high risk of pneumococcal disease. For the purpose of our study, asthma was defined by documentation of one or more inpatient or emergency-department diagnoses of asthma, two outpatient diagnoses, or the use of asthma-related medications. High-risk asthma was defined as asthma requiring admission to a hospital or a visit to an emergency department, the use of rescue therapy or long-term use of oral corticosteroids, or the dispensing of three or more prescriptions for beta-agonists within the year before enrollment in the study. RESULTS: A total of 635 persons with invasive pneumococcal disease and 6350 controls were identified, of whom 114 (18.0 percent) and 516 (8.1 percent), respectively, had asthma. Persons with asthma had an increased risk of invasive pneumococcal disease (adjusted odds ratio, 2.4; 95 percent confidence interval, 1.9 to 3.1) as compared with controls. Among those without coexisting conditions, the annual incidence of invasive pneumococcal disease was 4.2 episodes per 10,000 persons with high-risk asthma and 2.3 episodes per 10,000 persons with low-risk asthma, as compared with 1.2 episodes per 10,000 persons without asthma. CONCLUSIONS: Asthma is an independent risk factor for invasive pneumococcal disease. The risk among persons with asthma was at least double that among controls.

Adolescent↗
PubMed2005

Seasonality of invasive pneumococcal disease: temporal relation to documented influenza and respiratory syncytial viral circulation.

BACKGROUND: Seasonal fluctuation in the incidence of invasive pneumococcal disease has been attributed to winter virus exposure (e.g., influenza and respiratory syncytial virus [RSV]). Evidence of a direct correlation of invasive pneumococcal disease with laboratory-confirmed virus seasons, however, is limited. Using two prospective surveillance networks, the temporal relation between invasive pneumococcal disease and isolation of circulating winter viruses was explored. METHODS: Episodes of invasive pneumococcal disease in five Tennessee counties were collected prospectively from January 1995 through June 2002. Virus seasons were defined using prospective laboratory-based surveillance. Correlation between weekly identification of invasive pneumococcal disease and laboratory isolation of RSV and influenza, as well as comparisons of the frequencies of invasive pneumococcal disease episodes during viral and nonviral seasons were determined. RESULTS: A total of 4147 invasive pneumococcal disease episodes were identified. Weekly frequency of invasive pneumococcal disease correlated directly with the weekly frequency of isolation of RSV (r = 0.56, P <0.001) and influenza (r= 0.40, P <0.001). The average weekly frequency of invasive pneumococcal disease during RSV and influenza seasons was higher than during the nonviral seasons (P <0.001 for each year). CONCLUSION: Weekly episodes of invasive pneumococcal disease correlated temporally with laboratory-confirmed weekly isolation of RSV and influenza, and the incidence of invasive pneumococcal disease was increased when these viruses were circulating in the community.

Adolescent↗
PubMed2005

Differences in antibiotic prescribing among physicians, residents, and nonphysician clinicians.

PURPOSE: State legislatures have increased the prescribing capabilities of nurse practitioners and physician assistants and broadened the scope of their practice roles. To determine the impact of these changes, we compared outpatient antibiotic prescribing by practicing physicians, nonphysician clinicians, and resident physicians. METHODS: Using the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS), we conducted a cross-sectional study of patients >/=18 years of age receiving care in 3 outpatient settings: office practices, hospital practices, and emergency departments, 1995-2000. We measured the proportion of all visits and visits for respiratory diagnoses where antibiotics are rarely indicated in which an antibiotic was prescribed by practitioner type. RESULTS: For all patient visits, nonphysician clinicians were more likely to prescribe antibiotics than practicing physicians for visits in office practices (26.3% vs 16.2%), emergency departments (23.8% vs 18.2%), and hospital clinics (25.2% vs 14.6%). Similarly, for the subset of visits for respiratory conditions where antibiotics are rarely indicated, nonphysician clinicians prescribed antibiotics more often than practicing physicians in office practices (odds ratio [OR] 1.86, 95% confidence intervals [CI]: 1.05 to 3.29), and in hospital practices (OR 1.55, 95% CI: 1.12 to 2.15). In hospital practices, resident physicians had lower prescribing rates than practicing physicians for all visits as well as visits for respiratory conditions where antibiotics are rarely indicated (OR 0.56, 95% CI: 0.36 to 0.86). CONCLUSION: Nonphysician clinicians were more likely to prescribe antibiotics than practicing physicians in outpatient settings, and resident physicians were less likely to prescribe antibiotics. These differences suggest that general educational campaigns to reduce antibiotic prescribing have not reached all providers.

Adult↗
PubMed2005

Medical and economic impact of a respiratory syncytial virus outbreak in a neonatal intensive care unit.

BACKGROUND: Respiratory syncytial virus (RSV) causes frequent nosocomial outbreaks in general pediatric wards but is less commonly reported in neonatal intensive care units (NICUs). We investigated an outbreak of RSV infection in a NICU and its impact on health care delivery, outcomes and costs. METHODS: Retrospective chart review was performed after an RSV outbreak occurred in the NICU. A case was defined as an infant with a nasopharyngeal aspirate positive for RSV by viral culture. Nucleotide sequencing of the isolates was done to determine relatedness. Hospital bills for all RSV culture-positive infants were reviewed. RESULTS: Nine infants (mean age, 34 days; mean birth weight, 1757 g; and mean estimated gestational age 31 weeks and 5 days) were infected with RSV subgroup B during this outbreak. By nucleotide sequencing, the isolates were identical. Clinical manifestations included cough, congestion, increased oxygen requirement, apnea and respiratory failure. The 5 infants requiring intubation had a significantly lower mean birth weight (1301 g versus 2328 g, P = 0.027), mean estimated gestational age (28 weeks and 5 days versus 35 weeks and 2 days, P = 0.014) and mean weight at onset of symptoms (2093 g versus 2989 g, P = 0.049) than the 4 nonintubated infants. More than 1.15 million dollars in hospital charges were attributable to the outbreak. All infants survived. CONCLUSION: Infants in a NICU who develop cough, congestion or apnea should be tested for RSV and other common respiratory viruses during the winter respiratory season. Even in a closed NICU, nosocomial outbreaks of these viruses can occur and have a major effect on healthcare delivery, costs and outcomes.

Cross Infection↗
PubMed2005

Trends in antibiotic prescribing for adults in the United States--1995 to 2002.

CONTEXT: The impact of national efforts to limit antibiotic prescribing has not been fully evaluated. OBJECTIVES: To analyze trends in outpatient visits associated with antibiotic prescription for U.S. adults. DESIGN: Cross-sectional study of data (1995 to 2002) from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey. PARTICIPANTS: Adults > or =18 years with an outpatient visit to an office- or hospital-based medical practice or to an emergency department. All visits were classified into 1 of 4 diagnostic categories: (1) acute respiratory infection (ARI)-antibiotics rarely indicated, (2) ARI-antibiotics often indicated, (3) nonrespiratory infection-antibiotics often indicated, and (4) all others. MEASUREMENTS: Trends in: (1) Proportion of outpatient visits associated with an antibiotic prescription; (2) proportion of antibiotic prescriptions that were broad spectrum; and (3) number of visits and antibiotic prescriptions per 1,000 U.S. adults > or =18 years of age. RESULTS: From 1995-1996 to 2001-2002, the proportion of all outpatient visits that generated an antibiotic prescription decreased from 17.9% to 15.3% (adjusted odds ratio [OR] 0.84, 95 % confidence interval [CI] 0.76 to 0.92). The entire reduction was because of a decrease in antibiotic prescriptions associated with visits for ARIs where antibiotics are rarely indicated from 59.9% to 49.1% (adjusted OR 0.64 95% CI 0.51 to 0.80). However, the proportion of prescribed antibiotics for these visits that were classified as broad-spectrum antibiotic prescription increased from 41.0% to 76.8%. Overall outpatient visits increased from 1693 to 1986 per 1,000 adults over the 8 years studied, but associated antibiotic prescriptions changed little, from 302 to 304 per 1,000 adults. CONCLUSION: During the study period, outpatient antibiotic prescribing for respiratory infections where antibiotics are rarely indicated has declined, while the proportion of broad-spectrum antibiotics prescribed for these diagnoses has increased significantly. This trend resulted in a 15% decline in the total proportion of outpatient visits in which antibiotics were prescribed. However, because outpatient visits increased 17% over this time period, the population burden of outpatient antibiotic prescriptions changed little.

Adult↗
PubMed2004

Reduction in high rates of antibiotic-nonsusceptible invasive pneumococcal disease in tennessee after introduction of the pneumococcal conjugate vaccine.

BACKGROUND: Invasive pneumococcal disease (IPD) is a burgeoning problem, with rates of antibiotic-nonsusceptible IPD, in particular, increasing during the past decade. One measure to combat IPD is vaccination with the recently introduced 7-valent pneumococcal conjugate vaccine (PCV). METHODS: To evaluate the effects of the introduction of PCV in 2000 on the epidemiology of antibiotic-nonsusceptible IPD, a database of IPD cases from January 1995 through December 2002 identified through active surveillance in 5 Tennessee counties was examined. For each case, clinical data were collected, and antibiotic susceptibility testing and serotyping were performed on available isolates. RESULTS: Among children younger than 2 years, IPD rates peaked at 235 cases per 100,000 in 1999 before decreasing, after PCV licensure, to 46 cases per 100,000 in 2002 (P<.001). The proportion of penicillin-nonsusceptible IPD isolates from this age group declined from 59.8% in 1999 to 30.4% in 2002 (P<.01). After 2001, similar decreases in IPD rates and in the proportion of antibiotic-nonsusceptible isolates recovered were seen among persons aged 2 years and older (P<.01). Rates of IPD due to PCV-associated serotypes declined after PCV introduction in all age groups (P<.001), whereas the rate of IPD due to nonvaccine serotypes increased among persons aged 2 years and older. CONCLUSIONS: In the 2 years since licensure, widespread PCV vaccination of children has resulted in dramatic declines in the proportion of antibiotic-nonsusceptible isolates in Tennessee. PCV vaccination of children also appears to be a highly effective method for reducing the burden of IPD in adults.

Anti-Bacterial Agents↗
PubMed2004

Prevalence of pertussis antibodies in maternal delivery, cord, and infant serum.

BACKGROUND: Passively acquired maternal antibodies protect infants from many pathogens. With increasing reports of infant pertussis, we evaluated pertussis antibodies in maternal-infant paired sera from 1999-2000. METHODS: Antibodies to pertussis toxin (PT), filamentous hemagglutinin (FHA), and fimbrial proteins (FIM) were measured by validated IgG-specific enzyme-linked immunosorbant assay (ELISA) in 64 maternal-umbilical cord serum pairs and in 61 of 64 infant sera. Geometric mean concentrations (GMCs) of pertussis antibodies and cord : maternal GMC ratios were calculated. RESULTS: Mean maternal age and gestation were 29.7 years (range, 19-42) and 39.3 weeks (range, 35.6-40.9), and 81% of mothers were white. GMCs of maternal antibodies at delivery (ELISA units/mL) were 2.4 for PT, 6.9 for FHA, and 13 for FIM. Cord GMCs were 169%, 178%, and 157% of maternal delivery values for PT, FHA, and FIM, respectively, demonstrating active placental transfer (P<.001). Pertussis-specific IgG values for each antigen decayed to below the threshold of detection by age 2 months. CONCLUSIONS: Despite efficient placental transfer, low maternal pertussis antibody levels and their rapid decay in infant sera leave infants with little humoral protection against pertussis. These data support the rationale for maternal or neonatal immunization, with acellular pertussis vaccines, to prevent life-threatening pertussis in early infancy.

Adhesins, Bacterial↗
PubMed2004

Differences in antibiotic prescribing patterns for children younger than five years in the three major outpatient settings.

OBJECTIVES: To perform a comprehensive analysis of the use of antibiotics in three major sites for outpatient care: private office-based clinics, emergency departments (ED), and hospital-based clinics. STUDY DESIGN: Data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) were used to determine visit rates and antibiotic prescribing patterns for the three major outpatient care settings from 1994 to 2000 for children <5 years of age. RESULTS: Antibiotic prescription rates declined from 1405 to 1088 per 1000 children over the study years (P=.032) [correction]. Significant declines in antibiotic prescriptions were noted in both the office-based setting and ED: 1119 to 841 (P=.049) in the office-based setting and 237 to 198 antibiotic prescriptions per 1000 children in the ED (P=.003) [correction]. Sites of care differed markedly with white children receiving 82.5%, 14.3%, and 3.2% of antibiotics in the office-based settings, ED, and hospital-based clinics, respectively, compared with 60%, 31%, and 9% for black children (P<.001). However, total visits, visits resulting in a diagnosis of otitis media, and antibiotic prescribing rates were similar for white and black children during the latter study years. CONCLUSIONS: There has been a decline in antibiotic prescribing in children <5 years of age, which was most notable in office-based and emergency department settings.

Ambulatory Care Facilities↗
PubMed2004

Elimination of racial differences in invasive pneumococcal disease in young children after introduction of the conjugate pneumococcal vaccine.

BACKGROUND: Racial differences in the epidemiology of invasive pneumococcal disease (IPD) have been widely recognized, but the impact of conjugate pneumococcal vaccine (PCV) introduction in 2000 on these differences has not been extensively studied. METHODS: IPD episodes in 5 Tennessee counties from January 1995 through December 2002 were collected prospectively using the Centers for Disease Control and Prevention's Active Bacterial Core Surveillance system (ABCs). Trained nurses collected clinical data, and antibiotic susceptibility testing was performed on available isolates. RESULTS: Before vaccine licensure, IPD rates were highest in children younger than 2 years and in blacks. The disparity in IPD rates between blacks and whites younger than 2 years of age substantially diminished after PCV introduction. In 1999, the IPD rate in black children younger than 2 years was 340.2 per 100,000, representing 176.5 more events per 100,000 than in white children (P < 0.001). In 2002, this rate had decreased 83% to 57.4 per 100,000, similar to the rate in white children (39.6 per 100,000; P = 0.31). Before vaccine licensure, a higher percentage of isolates from whites were antibiotic-nonsusceptible. In 2002, the proportion of antibiotic-nonsusceptible pneumococcal isolates was similar in whites and blacks of all ages for the first time during the study period (P > 0.05 for separate comparisons of penicillin, cephalosporin and erythromycin nonsusceptibility). These changes occurred despite a lower PCV vaccination coverage in Tennessee in blacks than in whites (31.2% versus 47.6%). CONCLUSIONS: With conjugate pneumococcal vaccine introduction in Tennessee, racial differences in the incidence rates of IPD have largely been eliminated, particularly in young children.

Adolescent↗
PubMed2003

Fatal hemophagocytic lymphohistiocytosis associated with Epstein-Barr virus infection in a patient with a novel mutation in the signaling lymphocytic activation molecule-associated protein.

Individuals with X-linked lymphoproliferative disease are susceptible to severe Epstein-Barr virus (EBV) infections that are often fatal. Mutations in signaling lymphocytic activation molecule-associated protein (SAP) are associated with this illness. We describe a patient with a novel serine-to-proline mutation at aa 57 in SAP and compare the location of the altered amino acid with all known missense mutations in the SAP-encoding SH2D1A gene, including those of 4 additional individuals whose cases have not been described elsewhere. The patient's genetic condition was discovered only after he exhibited an abnormal host response to primary EBV infection that resulted in hemophagocytic lymphohistiocytosis syndrome, which was complicated by marrow aplasia with terminal disseminated aspergillosis.

Adolescent↗
PubMed2003

Fatal pulmonary hypertension associated with pertussis in infants: does extracorporeal membrane oxygenation have a role?

OBJECTIVE: The deaths of 4 infants who had confirmed pertussis infection at our hospital during the past year motivated us to review their cases as well as the use of extracorporeal membrane oxygenation (ECMO) in respiratory failure caused by pertussis. METHODS: Retrospective chart reviews of the 4 infants who had pertussis and died at Vanderbilt University Medical Center (VUMC) from May 2001 to May 2002 were conducted. The Extracorporeal Life Support Organization (ELSO) database is an international voluntary registry established in 1986 to compile passive reports of adult and pediatric patients placed on ECMO. We searched this database for pertussis cases and analyzed the clinical outcomes by age, ventilatory management, and measurements of cardiopulmonary status. RESULTS: All 4 infants who died from pertussis infection at VUMC were younger than 3 months and had severe pulmonary hypertension, and ECMO therapy was considered for respiratory failure. Review of the international ELSO database, focusing only on children from 1986 to July 2002, revealed a total of 23,970 patients placed on ECMO. Since the first pertussis case treated with ECMO in 1990, a total of 61 children with pertussis have been treated with ECMO, representing an increase from 0.09% to 1% of the total cases. Mean age of the pertussis patients placed on ECMO was 88 days (1 day-2.7 years). The overall mortality was 70.5% (43 of 61) but was significantly higher for infants who were younger than 6 weeks (84%) compared with infants who were older than 6 weeks (61%). When evaluating pre-ECMO management, survivors had received significantly higher mean positive end expiratory pressures than nonsurvivors (11.1 +/- 4.5 vs 7.3 +/- 3.1 cmH(2)O) and had significantly higher serum pH than nonsurvivors (7.31 +/- 0.14 vs 7.14 +/- 0.19). There was no effect of duration of ECMO, positive inspiratory pressure, mean arterial pressure, ECMO mode (venoarterial vs venovenous mode), or sex on mortality. CONCLUSIONS: Although the ECMO registry is not an active surveillance system, it suggests that the numbers of children who require ECMO for pertussis have significantly increased. The high fatality rates of pertussis patients who have placed on ECMO are alarming and should stimulate reevaluation of whether this high-risk intervention is beneficial to patients with pertussis. This review, coupled with the 4 infants who died of pertussis at VUMC, suggests that improved measures are needed to prevent pertussis in infants.

Extracorporeal Membrane Oxygenation↗
PubMed2002

Decreased number of antibiotic prescriptions in office-based settings from 1993 to 1999 in children less than five years of age.

OBJECTIVE: Increasing rates of antibiotic resistance have stimulated efforts to decrease antibiotic use. To assess the success of these efforts, we analyzed antibiotic prescribing trends in children younger than 5 years old, the group with the highest use, from 1993 to 1999. METHODS: Data from the National Ambulatory Medical Care Survey were analyzed to determine antibiotic prescribing patterns for office-based visits from 1993 to 1999 for children <5 years old. Data were stratified by US regions, patient's race and gender. Antibiotic prescription rates per 1,000 population were calculated with population data from the US Census Bureau as the denominator. Specific prescribing of penicillins, cephalosporins, macrolides and sulfas was also assessed. RESULTS: Overall antibiotic prescribing in the office-based setting peaked in 1995 at 1,191 antibiotic courses per 1,000 children, then declined to 698 per 1,000 in 1999, a decrease of 41%. Antibiotic prescribing was consistently higher in whites than blacks; however, declines in prescribing over time were observed in both groups. Although there was wide regional variation in antibiotic prescribing in the early 1990's, by the late 1990's prescribing rates were similar in all regions. Prescriptions for penicillins and cephalosporins combined comprised 77 and 70% of total prescriptions during 1993 to 1997 and 1998 to 1999, respectively. Macrolide prescriptions reached a nadir during 1993 to 1997, accounting for 9% of the total, but increased to 16% during 1998 to 1999. CONCLUSION: Since 1995 the rates of antibiotic prescriptions in children <5 years of age have declined substantially. At the same time changes have occurred in the types of antibiotics prescribed. It appears that efforts to reduce antibiotic use have been successful. Whether this decrease in use will be accompanied by lower rates of antibiotic resistance will need to be determined.

Anti-Bacterial Agents↗