Higher Dosages of Azithromycin Are More Effective in Treatment of Group A Streptococcal Tonsillopharyngitis

BACKGROUND

Azithromycin has become a frequent choice for the treatment of group A streptococcal (GAS) tonsillopharyngitis. In this study, our objective was to determine the optimal dose of azithromycin for treatment of GAS tonsillopharyngitis in children and adults by analyzing trials that used different dose regimens.

METHODS

We performed a meta-analysis of randomized, controlled trials that involved bacteriological confirmation of GAS tonsillopharyngitis, random assignment to receive either azithromycin or a 10-day comparator antibiotic, and assessment of bacteriological eradication by throat culture after therapy. The primary outcomes of interest were bacteriological and clinical cure rates.

RESULTS

Nineteen trials involving 4626 patients were included in the analysis. One trial used 10-day course of 2 different comparator antibiotics, and 2 trials compared 2 dose regimens of azithromycin with a 10-day course of comparator antibiotic; all other trials compared 1 dose regimen of azithromycin with a single 10-day course of comparator antibiotic. In children, azithromycin administered at 60 mg/kg per course was superior to the 10-day courses of comparators (P < .00001), with bacterial failure occurring 5 times more often in patients receiving the 10-day courses of antibiotics. Azithromycin administered at 30 mg/kg per course was inferior to the 10-day courses of comparators (P = .02), with bacterial failure occurring 3 times more frequently in patients receiving azithromycin. Three-day regimens were inferior to 5-day regimens (P = .002). In adults, no studies compared dosages by weight. Three-day regimens of 500 mg/day showed a trend favoring azithromycin over the 10-day courses of comparators (P = .14); 5-day regimens were inferior to 3-day regimens (P = .006). Clinical cure rates were significantly different for the different azithromycin regimens, with differences that resembled those for bacterial cure rate.

CONCLUSION

This analysis suggests that azithromycin administered at a dosage of 60 mg/kg in children or administered for 3 days at a dosage of 500 mg/day in adults is more effective than other treatment regimens in producing eradication and clinical cure of GAS tonsillopharyngitis.

Acellular pertussis vaccines for adolescents

BACKGROUND

The epidemiology of pertussis is changing, with a clear increase in the number of cases diagnosed in adolescents and adults. This development has spurred studies and anticipated licensure of safer diphtheria, tetanus, acellular pertussis combined (Tdap) vaccines for this older population.

METHODS

Literature review.

RESULTS

Tdap vaccines are safe and immunogenic when administered to adolescents and adults. Correlates of immunity to pertussis after Tdap vaccination have not been established, but various combinations of antibody to pertussis antigens (pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae) provide protection. The importance of the number of antigens in Tdap vaccines for protection against mild pertussis disease is unclear. Pertussis vaccination establishes herd immunity after sufficient uptake within communities and countries. As experience with TdaP vaccines has accumulated, a 1-2% occurrence of large, local injection-site reactions with all TdaP vaccine products have been observed for booster doses in children 4-6 years of age. The frequency of large local reactions appears lower in adolescents and adults. The pathophysiologic mechanisms for the local reactions are not established, but a majority appears to be immunoglobulin E-mediated-reactive edema, and a minority appears to be immunoglobulin G-mediated Arthus-type reactions.

CONCLUSIONS

Tdap vaccines appear safe and immunogenic. The economic impact of pertussis provides a cost-benefit justification for widespread use of Tdap vaccine boosting in adolescents.

A review of evidence supporting the American Academy of Pediatrics recommendation for prescribing cephalosporin antibiotics for penicillin-allergic patients

The American Academy of Pediatrics, evidence-based guidelines endorse the use of cephalosporin antibiotics for patients with reported allergies to penicillin, for the treatment of acute bacterial sinusitis and acute otitis media. Many physicians, however, remain reluctant to prescribe such agents. Although such concern is understandable, lack of consistent data regarding exactly what constitutes an initial penicillin-allergic reaction and subsequent cross-sensitivity to cephalosporins may be preventing many patients from receiving optimal antibiotic therapy. This article reviews evidence in support of the American Academy of Pediatrics recommendation. Included is an examination of the types and incidence of reactions to penicillins and cephalosporins; the frequency of cross-reactivity between these 2 groups of agents; experimental and clinical studies that suggest that side chain-specific antibodies predominate in the immune response to cephalosporins, thereby explaining the lack of cross-sensitivity between most cephalosporins and penicillins; the role of skin testing; and the risks of anaphylaxis. Specific recommendations for the treatment of patients on the basis of their responses to previously prescribed agents are summarized.

Acute otitis media: making sense of recent guidelines on antimicrobial treatment

High-dose amoxicillin (80 to 90 mg/kg/d divided twice daily) remains the drug of choice for treatment of acute otitis media despite increasing antimicrobial resistance. For persistent or recurrent acute otitis media, guidelines recommend high-dose amoxicillin/clavulanate (90/6.4 mg/kg/d), cefdinir, cefprozil, cefpodoxime, cefuroxime, or ceftriaxone. Increasing the dose of amoxicillin does not cover infection with beta-lactamase-producing pathogens; add the beta-lactamase inhibitor clavulanate to amoxicillin, or choose a cephalosporin with good activity against S pneumoniae and good beta-lactamase stability. Key factors for enhancing compliance are taste of suspension, dosing frequency, and duration of therapy.

Comparison of performance by otolaryngologists, pediatricians, and general practioners on an otoendoscopic diagnostic video examination

OBJECTIVE

To compare the performance of United States, South African, and Greek otolaryngologists, pediatricians, and general practitioners in recognizing the otoscopic examination findings of acute otitis media (AOM) and otitis media with effusion (OME) as presented in an otoendoscopic video evaluation test.

DESIGN/SUBJECTS

Otolaryngologists, pediatricians, and general practitioners from the United States (n = 273, 2190, and 360 respectively), South Africa (n = 36, 36, and 206), and Greece (n = 58, 115, and 126) viewed nine different video-recorded otoscopic examinations, including pneumatic otoscopy of tympanic membranes. The ability to differentiate AOM, OME, and normal was ascertained.

RESULTS

Overall, the average +/- standard deviation correct diagnosis on the otoscopic video exam by otolaryngologists was superior to pediatricians and general practitioners in all three countries: from the United States, it was 74 +/- 16% for otolaryngologists versus 51 +/- 11% for pediatricians (p < 0.000l) and 46+/-21% for general practitioners (p < 0.0001); from South Africa, it was 72 +/- 16% versus 53 +/- 21% (p = 0.16) and 47 +/- 19% (p = 0.002); and from Greece, it was 61 +/- 15% versus 36 +/- 12% (p < 0.003) and 39 +/- 10% (p = 0.009).

CONCLUSIONS

A video-based otoscopy examination test may be a useful tool for evaluation of otoscopy-based diagnostic skills. Otolaryngologists performed significantly better than pediatricians in differentiating AOM, OME, and normal in such a test described here. However, all specialists who examine patients with AOM or OME may benefit from viewing video otoscopies to improve diagnostic accuracy.

Acellular Pertussis Vaccine Safety and Efficacy in Children, Adolescents and Adults

This review offers a perspective on the acellular pertussis vaccine efficiency trials concluded in the 1990s and presents the main conclusions of a meta-analysis of 52 studies that assessed the safety and efficacy of the diphtheria-tetanus (DT)-whole cell pertussis (DTwP) and DT-acellular pertussis (DTaP) vaccines administered to children. A clear serological correlate of immunity to pertussis following DTaP vaccination was not identified despite an intensive analysis. It can be speculated that this may be because various combinations of antibody to agglutinogens (pertussis toxin, filamentous haemagglutinin, pertactin and fimbriae) provide protection, or because serum antibody levels and responses do not uniformly reflect mucosal IgA antibody levels.Long-term efficacy following DTaP vaccination is becoming characterised and cell-mediated immunity (T-cell memory) may have importance. DTaP vaccination appears to establish herd immunity after sufficient uptake within communities and countries. As experience with DTaP vaccine safety has accumulated, a 1-2% occurrence of large, local injection reactions with all products has been defined for booster doses. The pathophysiological mechanisms for the reactions are not established but a majority appear likely to be IgE-mediated reactive oedema and a minority to be IgG-mediated reactive Arthus-type reactions. DTwP and DTaP combinations with other vaccines have been studied and licensed; the most controversial combination products are the DTaP/Haemophilus influenzae type B polysaccharide conjugate vaccines. Pertussis epidemiology is changing with a clear increase in occurrence in adolescents and adults. This development has spurred studies and licensure of safer DTaP vaccines for this older population. The economic impact of pertussis and transmission from adults to vulnerable infants provides a cost-benefit justification for widespread use of DTaP vaccines in all age groups with routine boosting every 10 years.

Does group A beta-hemolytic streptococcal infection increase risk for behavioral and neuropsychiatric symptoms in children?

OBJECTIVE

To determine whether group A beta-hemolytic streptococcal infections increase the risk of developing symptoms characteristic of the diagnosis pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS).

DESIGN

Prospective cohort study.

METHODS

Children (N = 814) aged 4 to 11 years seen for sore throat or well-child care in a large pediatric practice in Rochester, NY, were enrolled from October 2001 to June 2002 (group A beta-hemolytic streptococcal [GAS] infected, n = 411; GAS uninfected, n = 403, of whom 207 had a sore throat of presumed viral etiology and 196 were well children). Symptomatic children with GAS infection (n = 399) were treated with antibiotics. At baseline and 2 and 12 weeks following baseline, all parents completed a 20-item questionnaire about the presence/absence of recent PANDAS symptoms in their children, and capable children answered 10 items about worries, obsessions, and compulsions. The relative risk of developing a "mild PANDAS variant" (> or = 2 new PANDAS symptoms) by illness type (GAS positive, presumed viral, or well child) and by parent and child report was determined and adjusted for potential covariates.

RESULTS

By parent report, ill children more frequently manifested several PANDAS symptoms at baseline than well children. However, neither new symptoms nor the risk of developing a mild PANDAS variant developed during the subsequent 12 weeks more commonly in children with GAS infection than in those with presumed viral illness or in well children by parent or child report.

CONCLUSIONS

Ill children with GAS infection, treated for their GAS infection, were not at increased risk for developing PANDAS symptoms or a mild PANDAS variant compared with children with presumed viral illness or well children. The role of antibiotics in the prevention or treatment of PANDAS as well as the investigation of PANDAS in the asymptomatic, infectious host deserves future research.

Changes in frequency and pathogens causing acute otitis media in 1995-2003

OBJECTIVE

This study was undertaken to determine whether a change in the frequency or distribution of the causative pathogens in persistent acute otitis media (AOM) and AOM treatment failure (AOMTF) occurred after publication of the Centers for Disease Control and Prevention AOM treatment guidelines advocating high dose amoxicillin in 1998 and the universal use of the pneumococcal conjugate vaccine in 2000.

METHODS

This was a 9-year prospective study in a suburban, community-based private practice. To identify bacterial isolate(s), 551 children with AOM who had not responded after 1 or 2 empiric antimicrobial treatment courses (termed persistent AOM) and those who were failures after 48 h on treatment (AOMTF) underwent tympanocentesis. Three periods were compared: (1) 1995-1997 when all enrolled received standard dose amoxicillin (40-50 mg/kg/day divided 3 times daily) as the initial empiric treatment; (2) 1998-2000 when all received high dose amoxicillin (80-100 mg/kg/day divided twice daily); and (3) 2001-2003 when high dose amoxicillin and pneumococcal conjugate vaccinations were used.

RESULTS

Persistent AOM or AOMTF for which tympanocentesis was performed occurred in 195 (16.2%) of 1,207, 204 (16.1%) of 1,278 and 152 (12.3%) of 1,232 AOM visits for 1995-1997, 1998-2000 and 2001-2003, respectively; the 24% decline in 2001-2003 in persistent AOM and AOMTF was significant (P = 0.007). Middle ear aspirates grew Streptococcus pneumoniae (48, 44 and 31%) and Haemophilus influenzae (38, 43 and 57%) for time periods 1, 2 and 3, respectively. There was a significant decline in S. pneumoniae (P = 0.017) and increase in H. influenzae (P = 0.012) isolations and of H. influenzae that were beta-lactamase-producing (P = 0.04) among middle ear fluid isolates. Also there was a trend for an increased proportion of S. pneumoniae in 2001-2003 that were penicillin-susceptible (P = 0.17).

CONCLUSIONS

In our experience, persistent AOM and AOMTF has decreased in frequency since the introduction of high dose amoxicillin therapy and pneumococcal conjugate vaccination. It appears that H. influenzae has become the predominant pathogen of persistent AOM and AOMTF since universal immunization with the pneumococcal conjugate vaccine. Fewer S. pneumoniae AOM isolates are penicillin-resistant and more H. influenzae are beta-lactamase-producing.

Meta-analysis of Cephalosporins versus Penicillin for Treatment of Group A Streptococcal Tonsillopharyngitis in Adults

We conducted a meta-analysis of 9 randomized controlled trials (involving 2113 patients) comparing cephalosporins with penicillin for treatment of group A beta -hemolytic streptococcal (GABHS) tonsillopharyngitis in adults. The summary odds ratio (OR) for bacteriologic cure rate significantly favored cephalosporins, compared with penicillin (OR,1.83; 95% confidence interval [CI], 1.37-2.44); the bacteriologic failure rate was nearly 2 times higher for penicillin therapy than it was for cephalosporin therapy (P=.00004). The summary OR for clinical cure rate was 2.29 (95% CI, 1.61-3.28), significantly favoring cephalosporins (P<.00001). Sensitivity analyses for bacterial cure significantly favored cephalosporins over penicillin in trials that were double-blinded and of high quality, trials that had a well-defined clinical status, trials that performed GABHS serotyping, trials that eliminated carriers from analysis, and trials that had a test-of-cure culture performed 3-14 days after treatment. This meta-analysis indicates that the likelihood of bacteriologic and clinical failure in the treatment of GABHS tonsillopharyngitis is 2 times higher for oral penicillin than for oral cephalosporins.

Meta-analysis of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis in children

OBJECTIVE

To conduct a meta-analysis of randomized, controlled trials of cephalosporin versus penicillin treatment of group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis in children.

METHODOLOGY

Medline, Embase, reference lists, and abstract searches were conducted to identify randomized, controlled trials of cephalosporin versus penicillin treatment of GABHS tonsillopharyngitis in children. Trials were included if they met the following criteria: patients <18 years old, bacteriologic confirmation of GABHS tonsillopharyngitis, random assignment to antibiotic therapy of an orally administered cephalosporin or penicillin for 10 days of treatment, and assessment of bacteriologic outcome using a throat culture after therapy. Primary outcomes of interest were bacteriologic and clinical cure rates. Sensitivity analyses were performed to assess the impact of careful clinical illness descriptions, compliance monitoring, GABHS serotyping, exclusion of GABHS carriers, and timing of the test-of-cure visit.

RESULTS

Thirty-five trials involving 7125 patients were included in the meta-analysis. The overall summary odds ratio (OR) for the bacteriologic cure rate significantly favored cephalosporins compared with penicillin (OR: 3.02; 95% confidence interval [CI]: 2.49-3.67, with the individual cephalosporins [cephalexin, cefadroxil, cefuroxime, cefpodoxime, cefprozil, cefixime, ceftibuten, and cefdinir] showing superior bacteriologic cure rates). The overall summary OR for clinical cure rate was 2.33 (95% CI: 1.84-2.97), significantly favoring the same individual cephalosporins. There was a trend for diminishing bacterial cure with penicillin over time, comparing the trials published in the 1970s, 1980s, and 1990s. Sensitivity analyses for bacterial cure significantly favored cephalosporin treatment over penicillin treatment when trials were grouped as double-blind (OR: 2.31; 95% CI: 1.39-3.85), high-quality (OR: 2.50; 95% CI: 1.85-3.36) trials with well-defined clinical status (OR: 2.12; 95% CI: 1.54-2.90), with detailed compliance monitoring (OR: 2.85; 95% CI: 2.33-3.47), with GABHS serotyping (OR: 3.10; 95% CI: 2.42-3.98), with carriers eliminated (OR: 2.51; 95% CI: 1.55-4.08), and with test of cure 3 to 14 days posttreatment (OR: 3.53; 95% CI: 2.75-4.54). Analysis of comparative bacteriologic cure rates for the 3 generations of cephalosporins did not show a difference.

CONCLUSIONS

This meta-analysis indicates that the likelihood of bacteriologic and clinical failure of GABHS tonsillopharyngitis is significantly less if an oral cephalosporin is prescribed, compared with oral penicillin.

Optimizing antibacterial therapy for community-acquired respiratory tract infections in children in an era of bacterial resistance

The spread of antibacterial resistance in bacteria that commonly cause childhood community-acquired respiratory tract infections (RTIs), such as acute otitis media, community-acquired pneumonia, and acute pharyngitis, is a major healthcare problem. One of the foremost concerns is the rapid increase in penicillin, macrolide, and multidrug resistance in Streptococcus pneumoniae. There is also a rising prevalence of macrolide resistance in Streptococcus pyogenes in pockets of the United States, and beta-lactamase production in Haemophilus influenzae is widespread. Although data are limited, some evidence suggests that resistance to antibacterials can impair bacteriologic and clinical outcomes in childhood RTIs. Optimizing antibacterial use is important both in the care of individual patients and within strategies to address the wider problem of antibacterial resistance. This involves encouraging judicious antibacterial use (i.e., reducing overuse for viral infection and prophylaxis), and preventing misuse through the wrong choice, dosage, and duration of therapy. Given that initial therapy is usually empiric, antibacterials used to treat community-acquired RTIs in children should ideally have the following properties: an optimal targeted spectrum of activity; high clinical and bacteriologic efficacy against respiratory pathogens, including resistant strains; simple, short-course therapy; and good tolerability and palatability. New antibacterials will continue to have a role in the treatment of RTIs in children, especially where resistance compromises existing therapies.

Acute otitis media disease management

A first step in management decisions regarding otitis media must focus on accurate diagnosis to distinguish normal from acute otitis media (AOM) from otitis media with effusion (OME) or a retracted tympanic membrane without middle ear effusion. There are several classification schemes for AOM that may impact management decisions: patients with acute, persistent, recurrent, or chronic AOM may have a different distribution of bacterial pathogens and a different likelihood of success from antimicrobial therapy. Patient age, prior treatment history and daycare attendance are other important variables. The natural history of AOM without antibiotic treatment is generally favorable; however, from the few studies available, this is difficult to quantitate because the diagnosis was infrequently confirmed by tympanocentesis leaving the possibility that many patients entered into these trials may not have had bacterial AOM. Antibiotic choices should reflect pharmacokinetic/pharmacodynamic data and clinical trial results demonstrating effectiveness in eradication of the most likely pathogens based on tympanocentesis sampling and antibiotic sensitivity testing. Thereafter, compliance factors such as formulation, dosing schedule and duration of treatment and accessibility factors such as availability and cost should be taken into account. The increasing prevalence of antibiotic resistance among AOM pathogens and the changing susceptibility profiles of these bacteria should be considered in antibiotic selection. Current best practice recommends amoxicillin for uncomplicated AOM; continuing or switching to an alternative antibiotic based on clinical response after 48 hours of therapy; and selection of second line antibiotics as first line choices when the patient has already been on an antibiotic within the previous month or is otitis prone. Preferred second-line agents frequently noted in various guidelines include amoxicillin/clavulanate, cefdinir, cefpodoxime, cefprozil, and cefuroxime. Three injections of ceftriaxone or gatifloxacin (when approved) or diagnostic/therapeutic tympanocentisis (when approved) become a third-line treatment option. No single antibiotic or management strategy is ideal for all patients.

Diagnostic accuracy of otitis media and tympanocentesis skills assessment among pediatricians

The comparative study presented here evaluated pediatricians from Italy, Greece, South Africa, and a reference group in the USA to determine (i) their ability to accurately diagnose acute otitis media (AOM) and otitis media with effusion (OME) using otoscopy, (ii) their knowledge of antibiotics, and (iii) their technical competence in performing tympanocentesis. The participants included 66 pediatricians from Italy, 115 from Greece, 36 from South Africa and 2,190 from the USA (reference group). Each pediatrician viewed nine video-recorded otoscopic examinations of tympanic membranes, after which their ability to differentiate AOM, OME and normal was ascertained. Questions were posed regarding appropriate, pathogen-directed antibiotic selection for AOM. A mannequin model was used to assess the technical proficiency of each pediatrician in performing tympanocentesis. Results were recorded for each group as the mean percentage +/- standard deviation. The correct diagnosis was made by each group of pediatricians in the following frequencies: Italy, 54+/-27% (range, 18-94%); Greece, 36+/-12% (range, 23-56%); South Africa, 53+/-21% (range, 22-88%); and the USA, 51+/-11% (range, 29-72%). The difference between results from Greece and the US reference group was statistically significant ( P=0.002). Pediatricians from each group over-diagnosed AOM with the following frequencies: Italy, 18+/-19% (range, 2-49%); Greece, 34+/-13% (8-50%); South Africa, 23+/-14% (7-44%); and the US reference group, 26+/-19% (7-51%). Pediatricians correctly selected an antibiotic recommended for treatment of AOM caused by drug-resistant Streptococcus pneumoniae as follows: Italy, 89%; Greece, 77%; South Africa, 82%; and the USA, 80%. For treatment of beta-lactamase-producing Haemophilus influenzae, the results were: Italy, 90%; Greece, 70%; South Africa, 81%; and the USA, 77%. Tympanocentesis was optimally performed by >/=86% of all pediatricians. The results indicate that pediatricians may often misdiagnose OME as AOM, but they select appropriate antibiotics about 80% of the time and can be trained to accurately perform tympanocentesis.

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Detection and characterization of pediatric serum antibody to the OMP P5-homologous adhesin of nontypeable Haemophilus influenzae during acute otitis media

We reported earlier that antibody in sera collected from seven children with acute otitis media (AOM) due to nontypeable Haemophilus influenzae (NTHI) recognized immunodominant regions of P5-fimbrin just as we had observed in a chinchilla model of experimental NTHI-induced AOM. To expand upon those preliminary findings, we further characterized pediatric serum antibodies directed against this adhesin during AOM. Collectively, the data show that children respond immunologically to P5-fimbrin and they do so in a manner that allows for the distinction of sequence diversity within short linear peptides representing a focused region of this surface-exposed protein. The immune recognition we observed encourages us to further develop a P5-fimbrin based vaccine component.

Efficacy of penicillin vs. amoxicillin in children with group A beta hemolytic streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral penicillin versus amoxicillin as first-line therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. The prospective observational study was conducted over 18 months (January 2000-June 2001). Children enrolled had acute onset of symptoms and signs and a laboratory-documented GABHS tonsillopharyngitis illness. Follow-up examination and laboratory testing occurred 10 +/- 4 days following completion of treatment. In total, 389 patients were enrolled (intent-to-treat group): 195 received penicillin V and 194 received amoxicillin. Fifty-six of the penicillin-treated and 57 amoxicillin-treated patients refused to take the drug, or were noncompliant, or did not return for the follow-up visit, leaving 276 patients in the per-protocol group: 139 penicillin-treated and 137 amoxicillin-treated. Bacteriologic cure for amoxicillin-treated children occurred in 76% versus 64% in the penicillin-treated children (p = 0.04). The clinical cure rate for amoxicillin-treated children was 84% compared to 73% in the penicillin-treated children (p = 0.03). Since treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. The odds ratio (OR) estimate for cure for patients in the amoxicillin versus penicillin V treatment group remained significant (OR = 1.84, 95% confidence interval 1.02-3.29); the same was true for dinical cure (OR = 1.99, 95% CI = 1.02-3.87). Amoxicillin may be superior to penicillin for bacteriologic and clinical cure of GABHS tonsillopharyngitis.

White blood cell count can aid judicious antibiotic prescribing in acute upper respiratory infections in children

Fifty percent or more of children with upper respiratory infections (URIs) and nonspecific febrile illnesses (e.g., children febrile, anorexic, decreased activity, irritable) receive unnecessary antibiotics from community-based physicians. This study was undertaken to show that white blood cell (WBC) count testing can aid physicians in avoiding antibiotic prescribing when managing children with URIs, and nonspecific febrile illnesses. A prospective, 3-year study was conducted in a community-based pediatric practice. A weekly convenience sample (Tuesdays) of acute URI and febrile patients ages 3 months to 21 years was studied. Data collected on enrollment included: age, gender, duration of illness, recent/current antibiotic use, temperature, symptoms, signs, laboratory testing (WBC count, cultures), diagnosis and treatment. Similar data on any illness visits in the previous 2 weeks and the subsequent 2 weeks after enrollment were collected. Viral culture specimens were obtained on a subset. The use of the WBC count was assessed, including obviating antibiotic prescription, frequency of related follow-up visits, and the occurrence of subsequent bacterial infections. Of 1,956 patients with respiratory or febrile illness enrolled, 1,219 (62%) had a diagnosis established by history and examination (e.g., acute otitis media) and 737 (38%) did not. Of the 737 patients without an established diagnosis, 386 (52%) did not receive an antibiotic because they did not appear particularly ill, their temperature was less than 101 degrees F, and parents were not demanding antibiotics, leaving 351 (48%) patients who appeared ill, had a temperature greater than 101 degrees F, and parents were demanding an antibiotic or physicians were inclined to give an antibiotic. A WBC count was performed on these 351 children; 337 children (96%) had a WBC count less than 15,000/mm3, and 14 (4%) had a WBC 15,000/mm3 or greater. An antibiotic was prescribed for 13 of the 14 children with a WBC count greater than 15,000/mms. With this approach, return office visits in the following 2 weeks were infrequent (13% of 737 patients), and no child had significant bacterial illness that was missed. With selective use of WBC count testing

Diagnostic accuracy, tympanocentesis training performance, and antibiotic selection by pediatric residents in management of otitis media

OBJECTIVE

To assess the accuracy of pediatric residents in recognizing the physical examination findings of acute otitis media (AOM) and otitis media with effusion (OME), technical competence to perform tympanocentesis, and knowledge of guideline-recommended antibiotic management of AOM.

METHODS

A total of 383 pediatric residents from various programs in the United States viewed 9 different video-recorded pneumatic otoscopic examinations of tympanic membranes during a continuing medical education course. The ability to differentiate AOM, OME, and normal was ascertained. A mannequin of a child was used to assess technical proficiency of performing tympanocentesis on artificial tympanic membranes. A series of questions was posed regarding appropriate, pathogen-directed, second-line antibiotic selection for AOM.

RESULTS

The average +/- standard deviation correct diagnosis on the otoscopic video examination was 41% +/- 16% (range: 19%-70%; median: 38%) by pediatric residents, tympanocentesis was optimally performed by 89%, and appropriate antibiotic therapy for drug-resistant Streptococcus pneumoniae was selected by 78% and appropriate therapy for beta-lactamase-producing Haemophilus influenzae was selected by 74%.

CONCLUSIONS

According to this video-based examination, pediatric residents misdiagnose OME frequently. Pediatric residents have the skills to be trained to perform tympanocentesis. Approximately 75% of pediatric residents have knowledge of the appropriate antibiotics to select for treatment of resistant AOM pathogens. Interactive instruction with simulation technology may enhance skills and lead to improved diagnostic accuracy and treatment paradigms.

Zanamivir prophylaxis: an effective strategy for the prevention of influenza types A and B within households

A double-blind, randomized study of inhaled zanamivir for the prevention of influenza in families was conducted. Once a person with a suspected case of influenza was identified (index patient), treatment of all other household members (contacts) > or =5 years old was initiated. Contacts received either 10 mg zanamivir or placebo inhaled once daily for 10 days. Index patients received relief medication only. In total, 487 households (242 placebo and 245 zanamivir) were enrolled, with 1291 contacts randomly assigned to receive prophylaxis. Four percent of zanamivir versus 19% of placebo households (P<.001) had at least 1 contact who developed symptomatic, laboratory-confirmed influenza, representing 81% protective efficacy (95% confidence interval, 64%-90%). Protective efficacy was similarly high for individuals (82%) and against both influenza types A and B (78% and 85%, respectively, for households). Zanamivir was well tolerated and was effective in preventing influenza types A and B within households where the index patient was not treated.

Mercury concentrations and metabolism in infants receiving vaccines containing thiomersal: a descriptive study

BACKGROUND

Thiomersal is a preservative containing small amounts of ethylmercury that is used in routine vaccines for infants and children. The effect of vaccines containing thiomersal on concentrations of mercury in infants' blood has not been extensively assessed, and the metabolism of ethylmercury in infants is unknown. We aimed to measure concentrations of mercury in blood, urine, and stools of infants who received such vaccines.

METHODS

40 full-term infants aged 6 months and younger were given vaccines that contained thiomersal (diptheria-tetanus-acellular pertussis vaccine, hepatitis B vaccine, and in some children Haemophilus influenzae type b vaccine). 21 control infants received thiomersal-free vaccines. We obtained samples of blood, urine, and stools 3-28 days after vaccination. Total mercury (organic and inorganic) in the samples was measured by cold vapour atomic absorption.

FINDINGS

Mean mercury doses in infants exposed to thiomersal were 45.6 microg (range 37.5-62.5) for 2-month-olds and 111.3 microg (range 87.5-175.0) for 6-month-olds. Blood mercury in thiomersal-exposed 2-month-olds ranged from less than 3.75 to 20.55 nmol/L (parts per billion); in 6-month-olds all values were lower than 7.50 nmol/L. Only one of 15 blood samples from controls contained quantifiable mercury. Concentrations of mercury were low in urine after vaccination but were high in stools of thiomersal-exposed 2-month-olds (mean 82 ng/g dry weight) and in 6-month-olds (mean 58 ng/g dry weight). Estimated blood half-life of ethylmercury was 7 days (95% CI 4-10 days).

INTERPRETATION

Administration of vaccines containing thiomersal does not seem to raise blood concentrations of mercury above safe values in infants. Ethylmercury seems to be eliminated from blood rapidly via the stools after parenteral administration of thiomersal in vaccines.

Impact of a birth dose of hepatitis B vaccine on the reactogenicity and immunogenicity of diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b combination vaccination

OBJECTIVES

To assess the impact of a birth dose of hepatitis B vaccine (HepB) on the reactogenicity and immunogenicity of a novel diphtheria-tetanus-acellular pertussis (DTaP)- HepB-inactivated poliovirus (IPV)/ type b (Hib) combination vaccine administered subsequently at 2, 4 and 6 months of age.

METHODS

Neonates ( = 550) were randomized into two groups with regard to receipt of HepB at birth. All subjects in both groups received DTaP-HepB-IPV/Hib at 2, 4 and 6 months of age. Solicited local and general adverse events were recorded for 8 days after each dose. Antibodies to hepatitis B surface antigen were measured 1 month after the third dose of DTaP-HepB-IPV/Hib in a subset of 170 infants; titers of at least 10 mIU/ml were considered protective.

RESULTS

The DTaP-HepB-IPV/Hib combination vaccine was well-tolerated in both groups. Of the infants who received a birth dose of HepB, 22.6% had severe (Grade 3) reactions after any of the three doses of DTaP-HepB-IPV/Hib combination vaccine compared with 23.2% of subjects who did not receive a birth dose of HepB (difference, -0.5%; 90% confidence interval, -7.4 to 6.1). Antibody to hepatitis B surface antigen titers were > or =10 mIU/ml for all tested infants. Geometric mean titers were 2996.2 and 1240.1 mIU/ml with and without a birth dose of HepB, respectively.

CONCLUSIONS

A HepB birth dose does not increase the reactogenicity of a combination DTaP-HepB-IPV/Hib vaccine administered at 2, 4 and 6 months of age, and all tested subjects achieved protective anti-HBs titers (> or =10 mIU/ml), although geometric mean titers were higher when a birth dose of HepB was given.

Otitis media

Bacterial pathogens are isolated from middle ear fluid in up to 90% of children with acute otitis media (OM). Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis predominate. Acute OM can be classified as uncomplicated, persistent, recurrent or chronic. Patient age, symptom severity, prior treatment history and exposure through day-care attendance in children influences pathogen distribution, antimicrobial susceptibility and anticipated clinical and microbiological responses to empirical and pathogen-directed therapies. The natural history of acute OM without intervention is favourable. However, meta-analysis of clinical trials shows an improvement in symptom and middle ear effusion resolution with antimicrobials. Aminopenicillins, cephalosporins and macrolides are often selected as therapy for acute OM. The various agents have differing activity against acute OM pathogens, particularly organisms with resistance mechanisms and they differ in dosing schedule, side effects and compliance enhancing factors. Consideration should be given to pharmacokinetic and pharmacodynamic principles in antibiotic selection. Selection criteria include antibiotic activity against drug-resistant S. pneumoniae and efficacy against beta-lactamase-producing Gram-negative organisms. The necessary duration of treatment for acute OM varies according to multiple factors, including local preferences, but there is growing, compelling data to support short-course therapy. Tympanocentesis has been endorsed in various guidelines as a diagnostic and therapeutic procedure. Best-practice for management of acute OM continues to advocate antibiotic therapy with careful, accurate diagnosis and consideration of the major pathogens and their mechanisms of resistance.

Lack of consistent relationship between quantity of aluminum in diphtheria-tetanus-acellular pertussis vaccines and rates of extensive swelling reactions

The precise role that aluminum plays in local reactogenicity is not clear. We explored the relationship between rates of severe local reactions following the fourth and fifth booster doses of several diphtheria-tetanus-acellular pertussis vaccines (DTaP) and the quantity of aluminum contained in the different vaccines. Although there was a significant relationship between higher aluminum contents and swelling reactions >50 mm after dose 5, no relationship was seen with entire thigh swelling or with swelling >50 mm after dose 4. Because of the inconsistency of the data, a dose response between local reactogenicity and aluminum is questionable.

Prospective identification and treatment of children with pediatric autoimmune neuropsychiatric disorder associated with group A streptococcal infection (PANDAS)

BACKGROUND

The current diagnostic criteria for pediatric autoimmune neuropsychiatric disorder associated with group A streptococcal infection (PANDAS) are pediatric onset, neuropsychiatric disorder (obsessive-compulsive disorder [OCD]) and/or tic disorder; abrupt onset and/or episodic course of symptoms; association with group A beta-hemolytic streptococcal (GABHS) infection; and association with neurological abnormalities (motoric hyperactivity or adventitious movements, including choreiform movements or tics).

OBJECTIVE

To assess new-onset PANDAS cases in relation to acute GABHS tonsillopharyngitis.

DESIGN

Prospective PANDAS case identification and follow-up.

RESULTS

Over a 3-year period (1998-2000), we identified 12 school-aged children with new-onset PANDAS. Each patient had the abrupt appearance of severe OCD behaviors, accompanied by mild symptoms and signs of acute GABHS tonsillopharyngitis. Throat swabs tested positive for GABHS by rapid antigen detection and/or were culture positive. The GABHS serologic tests, when performed (n = 3), showed very high antideoxyribonuclease antibody titers. Mean age at presentation was 7 years (age range, 5-11 years). In children treated with antibiotics effective in eradicating GABHS infection at the sentinel episode, OCD symptoms promptly disappeared. Follow-up throat cultures negative for GABHS were obtained prospectively after the first PANDAS episode. Recurrence of OCD symptoms was seen in 6 patients; each recurrence was associated with evidence of acute GABHS infection and responded to antibiotic therapy, supporting the premise that these patients were not GABHS carriers. The OCD behaviors exhibited included hand washing and preoccupation with germs, but daytime urinary urgency and frequency without dysuria, fever, or incontinence were the most notable symptoms in our series (58% of patients). Symptoms disappeared at night, and urinalysis and urine cultures were negative.

CONCLUSION

To our knowledge, this is the first prospective study to confirm that PANDAS is associated with acute GABHS tonsillopharyngitis and responds to appropriate antibiotic therapy at the sentinel episode.

Interchangeability of 2 diphtheria-tetanus-acellular pertussis vaccines in infancy

OBJECTIVE

Currently, 4 diphtheria-tetanus-acellular pertussis (DTaP) vaccines are licensed for pediatric use in the United States, and 2 are commercially available. Although a single manufacturer's DTaP vaccine should be used for all 3 doses of the primary immunization series, some circumstances result in infants receiving DTaP vaccines from more than 1 manufacturer. The purpose of this study was to evaluate the safety and immunogenicity of a mixed sequence of 2 different DTaP vaccines.

METHODS

In this multicenter, observer-blinded, controlled study, 449 infants were randomized into 1 of 3 groups (1:1:1 ratio) to receive Tripedia at 2, 4, and 6 months of age (control group); Tripedia at 2 and 4 months of age and Infanrix at 6 months of age; or Tripedia at 2 months and Infanrix at 4 and 6 months of age. Other vaccines were administered concurrently as separate injections according to the recommended childhood immunization schedule. Safety was monitored closely, and standard enzyme immunoassays were used to measure antibody concentrations to each antigen of the DTaP vaccines.

RESULTS

The rates of injection-site and systemic adverse events were similar in each study group, and there were no clinically significant differences among groups after any dose. Infants in all 3 groups responded well to each antigen contained in both vaccines, with 97% to 100% seroprotection or vaccine response rates after the 3-dose primary series. Postvaccination geometric mean antibody concentrations and seroprotection or vaccine response rates to nearly all vaccine antigens were as high or higher in the mixed-sequence groups as in the control group.

CONCLUSION

Initiating the primary immunization series with 1 or 2 doses of Tripedia and completing the 3-dose series with Infanrix is as safe and at least as immunogenic as administering Tripedia for all 3 doses.

Seven-year follow-up of vaccine response in extremely premature infants

OBJECTIVE

To assess the immune response of 7-year-old former extremely preterm (PT) infants to routine childhood immunizations.

METHODS

Sixteen PT (<29 weeks and <1000 g) infants, followed since their primary immunizations at the recommended chronological ages, and 16 age-matched full-term (FT) control subjects were evaluated at 7 years of age. Antibodies to Haemophilus influenzae type b polyribosylribitol phosphate (Hib-PRP), tetanus, pertussis, diphtheria, polio, and hepatitis B (HBsAb) were measured.

RESULTS

The FT group had higher antidiphtheria geometric mean titers (GMT) than the PT group (1.07 vs 0.36 IU/mL). All FT and 13 of 16 PT had protective diphtheria antibody titers (>0.1 IU/mL). The tetanus GMT were 4.22 IU/mL (FT) and 1.99 IU/mL (PT). All children had protective tetanus titers (>0.01 IU/mL). Pertussis titers did not differ between FT and PT. Hib-PRP GMT were higher in FT than in PT (3.21 vs 1.41 microg/mL). All children had anti-PRP > or = 0.15 microg/mL; 12 of 16 FT and 10 of 16 PT had levels > or = 1.0 microg/mL. Polio serotype 1 and 2 GMT were similar between groups, and all children had protective titers (> or = 8). Polio serotype 3 GMT were 59 (FT) and 24 (PT) Karber units; all FT and 12 of 16 PT had protective titers. Among children who had received hepatitis B vaccine, GMT were similar in FT and PT children (120 vs 186 mIU/mL, and similar proportions of children (11 of 16 FT and 12 of 14 PT) had protective HBsAb titers (>10 mIU/mL).

CONCLUSIONS

At 7 years of age, PT children had lower antibody titers to many vaccine antigens than FT children. However, most PT children maintained antibody titers in the protective range.

Low baseline antibody level to diphtheria is associated with poor response to conjugated pneumococcal vaccine in adults

Joining polysaccharide antigens to protein increases immunogenicity in infants. In older adults, using conjugation to protein carriers to improve the immune response to pneumococcal polysaccharide vaccine has thus far proved disappointing. Low immunity to the carrier protein in the elderly may explain the failure of conjugated vaccines to elicit a T-cell-dependent response. We immunized 49 older adults (ages 60-78) and 50 younger adults (ages 18-45) with either 23-valent pneumococcal polysaccharide (PS) vaccine or 5-valent CRM197-conjugated pneumococcal oligosaccharide. Sera obtained before and after vaccination were analyzed for antibody to pneumococcal serotypes 14 and 6B and diphtheria toxin by ELISA. Baseline diphtheria toxin antibody level was lower in older adults than in younger adults (0.31 and 0.88 IU/ml, respectively; p < 0.0001). Adults with higher diphtheria antibody level had a higher antibody level to PS type 6B after vaccination than those with lower diphtheria antibody level (9.9 vs. 3.5 microg/ml, respectively; p = 0.01). Antibody level to PS type 14 was higher, but differed by baseline anti-diphtheria antibody level only when the older group was evaluated alone. Low levels of antibody to diphtheria protein may explain some of the lower responses to conjugate pneumococcal vaccine in older adults.

Assessing diagnostic accuracy and tympanocentesis skills by nurse practitioners in management of otitis media

PURPOSE

To assess healthcare provider accuracy in recognizing the physical examination findings of acute otitis media (AOM) and otitis media with effusion (OME) and technical competence in performing tympanocentesis using a simulation model.

DATA SOURCES

A descriptive study of 1,271 pediatricians and 206 nurse practitioners (NPs) who viewed 9 different video-recorded pneumatic otoscopic examinations of tympanic membranes (TMs) during a continuing medical education (CME) course. Diagnostic differentiation of AOM, OME and normal was ascertained. A mannequin model of a one-two year old child was used to assess technical proficiency of performing tympanocentesis on artificial tympanic membranes.

CONCLUSIONS

Overall, the average correct diagnosis by all healthcare providers was 46% (range = 25% to 71%); by pediatricians it was 50% (25% to 71%) and by NPs 42% (25% to 68%). Pediatricians and NPs correctly recognized the absence of normality 86% to 99% and 68% to 99% of the time; they over-diagnosed AOM in 7% to 58% (average 27%) and 10% to 65% of examinations (average 31%), respectively. Performance of tympanocentesis was optimally performed by 73% of NPs.

IMPLICATIONS FOR PRACTICE

The distinction between AOM and OME is important for antibiotic management decisions; tympanocentesis may be useful in diagnosis of AOM in selected patients. Healthcare providers may misdiagnose AOM and OME with some frequency. Nurse practitioners and pediatricians have the skills to be trained in the tympanocentesis procedure. Interactive CME courses with simulation technology may enhance skills and lead to a willingness to change and improve diagnostic accuracy and treatment paradigms.

Open-Label, parallel-group, multicenter, randomized study of cefprozil versus erythromycin in children with group A streptococcal pharyngitis/tonsillitis

BACKGROUND

Cefprozil and erythromycin are acceptable alternatives to penicillin in the treatment of pharyngitis/tonsillitis due to group A beta-hemolytic streptococcus (GABHS).

OBJECTIVE

The purpose of this trial was to determine the relative efficacy and tolerability of cefprozil and erythromycin in the treatment of pediatric pharyngitis/tonsillitis due to GABHS.

METHODS

This trial compared the bacteriologic and clinical efficacy of erythromycin and cefprozil in children 2 to 12 years of age with culture-documented GABHS pharyngitis/ tonsillitis. Children who were allergic to penicillin, cefprozil, or erythromycin were excluded. Patients were prospectively randomly assigned to receive 10 days of oral therapy with either cefprozil suspension 15 mg/kg per day in 2 divided doses or erythromycin ethylsuccinate suspension 30 mg/kg per day in 3 divided doses. Primary efficacy end points were bacteriologic and clinical response 2 to 8 days after treatment ended. The frequency and severity of adverse events and their relationship to treatment were also assessed.

RESULTS

A total of 199 patients were enrolled and treated (cefprozil, 99; erythromycin, 100); 12 patients in the cefprozil group and 15 in the erythromycin group were not evaluable. The GABHS eradication rate was significantly higher with cefprozil (95%) than with erythromycin (74%) (P = 0.001). The posttreatment carrier rate was lower in the cefprozil group (5%) than in the erythromycin group (18%) (95% CI, -22.3 to -3.8). Clinical cure rate was 90% (78/87) with cefprozil and 91% (77/85) with erythromycin (P = 0.95) (treatment group difference, -0.93; 95% CI, -9.9% to 8.0%). The overall incidence of drug-related adverse events was not significantly different in the 2 groups (11% with cef- prozil, 18% with erythromycin). The most common adverse events were diarrhea and vomiting. Two patients in the erythromycin group discontinued therapy because of adverse events.

CONCLUSIONS

The bacteriologic eradication rate was significantly greater with cefprozil compared with erythromycin in children with pharyngitis/tonsillitis. Both cefprozil and erythromycin produced a clinical cure in >90% of patients.

Assessing diagnostic accuracy and tympanocentesis skills in the management of otitis media

BACKGROUND

The distinction between acute suppurative otitis media (AOM) and otitis media with effusion (OME) is important for antibiotic treatment decisions. Tympanocentesis may be useful in the diagnosis of AOM in selected patients.

OBJECTIVES

To assess physician accuracy in diagnosing AOM and OME from physical examination findings and technical competence in performing tympanocentesis.

DESIGN AND SUBJECTS

Five hundred fourteen pediatricians and 188 otolaryngologists viewed 9 different videotaped pneumatic otoscopic examinations of tympanic membranes during a continuing medical education course. Diagnostic differentiation of AOM, OME, and a normal tympanic membrane was ascertained. An infant mannequin model was used to assess the technical proficiency of performing tympanocentesis on artificial tympanic membranes.

RESULTS

Overall, the average correct diagnosis by pediatricians was 50% (range, 25%-73%) and by otolaryngologists was 73% (range, 48%-88%). Pediatricians and otolaryngologists correctly recognized the absence of normality 89% to 100% and 93% to 100% of the time, respectively, but overdiagnosed AOM in 7% to 53% (mean, 27%) and in 3% to 23% (mean, 10%) of examinations. Performance of tympanocentesis was optimally performed by 89% of otolaryngologists and by 83% of pediatricians.

CONCLUSIONS

The use of video-presented examinations to assess diagnostic ability suggests that AOM and OME may be misdiagnosed often. Interactive continuing medical education courses with simulation technology may enhance skills and improve diagnostic accuracy and treatment paradigms.

A prospective observational study of 5-, 7-, and 10-day antibiotic treatment for acute otitis media

OBJECTIVE

To compare 5-, 7- and 10-day duration of antibiotic therapy for acute otitis media (AOM) in children.

STUDY DESIGN AND SETTING

Prospective nonrandomized 1-year evaluation of 3 treatment durations for AOM in a private pediatric setting. Outcomes assessed at 14 +/- 4 days after start of therapy with clinical response categorized as cure, improvement, or failure.

RESULTS

A total of 2172 children were studied; 46.4% were < or =2-years-old. Antibiotics used were amoxicillin (61.9% of patients), trimethoprim/sulfamethoxazole (11.7%), cephalosporins (14.2%), amoxicillin/clavulanate (5.2%), and macrolides/azalides (4.8%). No overall difference in outcome was observed comparing the 5-day (n = 707), 7-day (n = 423), or 10-day (n = 1042) treatments, including children < or =2-years-old. However, in the subset who had an episode of AOM in the preceding month, outcome differed; 5-day treatment was followed by more frequent failure than 10-day treatment (P < 0.001). In logistic regression analysis, variables identified as contributing to a cure were: >2-years-old (P < 0.0001), no AOM in the preceding month (P = 0.07), or preceding 12 months (P = 0.03).

CONCLUSIONS

Our study supports the transition from 10 to 5 days for standard AOM antibiotic treatment duration in most patients. A 10-day regimen may be superior in children who have experienced an episode of AOM within the preceding month, a known risk factor for resistant bacterial infection in the otitis-prone patient.

Fifth vaccination with dipthteria, tetanus and acellular pertussis is beneficial in four- to six-year-olds

OBJECTIVE

Diphtheria, tetanus and pertussis serum antibody titers were assessed before a fifth dose of diphtheria-tetanus-acellular pertussis (DTaP) or diphtheria-tetanus-whole cell pertussis (DTwP) vaccination at age 4 to 6 years.

METHODS

Healthy children who had participated in a series of National Institutes of Health-sponsored trials assessing DTwP and DTaP vaccines provided prevaccination sera before a fifth dose of DTwP or DTaP. The trial design was prospective, randomized and double blind. Diphtheria, tetanus and pertussis antibody titers were measured by enzyme-linked immunosorbent assay. Pertussis results are expressed in enzyme-linked immunosorbent assay units/ml based on US Food and Drug Administration reference sera. Tetanus and diphtheria toxin concentrations are expressed in IU/ml with a WHO international reference sera as a standard.

RESULTS

For diphtheria 100% of the children had antibody titers above the minimum protective level of 0.01 IU/ml and 86 to 100% (depending on prior vaccine product) had titers >0.1 IU/ml. However, only 0 to 40% of the children had antibody titers > or =1.0 IU/ml, a titer associated with more certain durable protection. For tetanus none of the children had an antibody titer below 0.01 IU/ml, and 93 to 100% had titers > or =0.1 IU/ml, a titer associated with more certain, durable protection. For pertussis the geometric mean concentrations of antibody before booster were uniformly very low, and the percentage of children exceeding the minimum detectable titer of antibody by 4-fold was also low.

CONCLUSION

Before a 4- to 6-year-old booster, a large proportion of children have titers of antibody to diphtheria below the certain, durable protective level. Because serologic correlates and minimum protective titers of antibody to pertussis antigens have not been established, the relevance of the low titers determined in the current study is unknown but a potential concern.

Are follow-up throat cultures necessary when rapid antigen detection tests are negative for group A streptococci?

The frequency of obtaining false-negative Group A Streptococcal (GAS) rapid antigen detection (RAD) tests utilizing currently available kits in a private practice setting and the cost effectiveness of requiring follow-up throat cultures were studied. Laboratory records of the Elmwood Pediatric Group (EPG), Rochester, NY, were retrospectively reviewed to identify all patients with pharyngeal RAD tests for GAS performed from January 1996 through May 1999. From January 1996 through October 1997 (study period 1), EPG physicians used either a RAD test or a throat culture to identify GAS; from November 1997 through May 1999 (study period 2), RAD tests were used as the primary test on all patients. Rapid antigen detection test negative results were confirmed with culture. During the 3-year study 11,427 RAD tests were performed. 8,385 (73.4%) were negative and 3,042 (26.6%) were positive. In study period 1, 3,547 (73.2%) were negative and 1,299 (26.8%) were positive; in study period 2 4,837 (73.5%) were negative and 1,743 (26.5%) were positive. Of the 8,385 negative tests, 8,234 (98.2%) were followed up with throat cultures. Of these, 200 (2.4%) were identified to have been negative RAD tests that were throat culture positive (132 [3.8%] of 3,474 in study period 1 and 68 [1.4%] of 4,764 in study period 2). A cost analysis was performed for study period 2, which showed that abandoning throat culture confirmation would generate a cost saving of $13,521 per year to the practice. Throat culture confirmation of RAD test negative results in pharyngitis patients may not be medically necessary for most patients with currently available RAD tests and is costly.

Evaluating the need, timing and best choice of antibiotic therapy for acute otitis media and tonsillopharyngitis infections in children

Deciding whether an antibiotic is necessary, when to begin therapy and selecting an optimal drug is an everyday challenge in clinical practice. In vitro susceptibility testing which determines the minimum concentration necessary for a particular antibiotic to inhibit or kill most strains of a bacterial species and pharmacodynamic modeling are useful but have limitations. The need for antibiotic therapy for acute otitis media (AOM) has been recently questioned. However, explanations for uniformly positive results with many antibiotic and placebo comparative trials include overdiagnosis of AOM at study entry, inclusion of patients with mild or uncomplicated AOM and broad criteria for the definition of clinical success. Recurrent and persistent AOM does not have as favorable a natural history as uncomplicated AOM; children below 2 years of age benefit most from antibiotic therapy. Selecting the best choice among the many antibiotics that can be used to treat AOM has become more complex over the last decade due to escalating antibiotic resistance among the pathogens that cause this infection. Broader spectrum antibiotics such as cefdinir, the newly introduced third generation cephalosporin, have their most prominent use in the treatment of persistent and recurrent AOM. In the early 1950s and 1960s penicillin clearly was the best available agent for the treatment of group A streptococcal (GAS) infections. In the 1970s the situation began to change as cephalosporin antibiotics became available. Superior eradication rates with cephalosporins such as cefdinir have now been well-documented. The leading hypothesis to explain the widening gap in efficacy between penicillin and cephalosporins relates to two major concepts: the presence of copathogens and differential alteration of the normal microbial ecology in the throat as a consequence of the selected therapy. There are positive and negative consequences to early initiation of antibiotic therapy for GAS tonsillopharyngitis. Penicillin has persisting good efficacy in patients older than the age of 12 years and in those who have been ill for >2 days. Shortening therapy for GAS tonsillopharyngitis offers a therapeutic advantage. Cefpodoxime proxetil and cefdinir have a 5-day indication for the treatment of GAS tonsillopharyngitis. Antibiotics with lower side effect profile, infrequent dosing, good palatability in suspension formulation and efficacy with short duration of treatment may lead to better outcomes because noncompliance often results in failed therapy, persistence of infection and morbidity.

Comparison of cefdinir and penicillin V in the treatment of pediatric streptococcal tonsillopharyngitis

BACKGROUND

Group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis continues to be a prevalent pediatric infectious disease that requires prompt treatment for relief of symptoms and to prevent complications.

OBJECTIVE

To compare the efficacy/tolerability of cefdinir and penicillin V in the treatment of pediatric GABHS tonsillopharyngitis as demonstrated in two clinical trials of similar design.

DESIGN

Multicenter, randomized, investigator-blinded trials.

PATIENTS

Children < or =12 years of age with sore throat, pharyngeal erythema and positive rapid streptococcal antigen test results.

INTERVENTION

In Study A patients took cefdinir 7 mg/kg twice daily or 14 mg/kg once daily or penicillin V 10 mg/kg 4 times daily (all regimens for 10 days). In Study B patients took cefdinir 7 mg/kg twice daily for 5 days or penicillin V 10 mg/kg 4 times daily for 10 days.

MEASUREMENTS

Clinical and microbiologic evaluations were conducted at multiple times during and after therapy.

RESULTS

Of 1274 patients 1122 were evaluable (679 patients received cefdinir; 443 received penicillin V). Clinical cure and microbiologic eradication rates were superior in the combined cefdinir treatment groups (94.9 and 92.7%, respectively), whether given once or twice daily for 10 days or twice daily for 5 days, compared with the penicillin treatment group (88.5 and 70.9%, respectively; P<0.001 for both). Adverse event rates were comparable in the 2 groups.

CONCLUSION

Cefdinir is a reliable and well-tolerated drug for the management of GABHS tonsillopharyngitis in children.

Fewer symptoms occur in same-serotype recurrent streptococcal tonsillopharyngitis

BACKGROUND

Most patients with acute rheumatic fever report no antecedent pharyngitis.

OBJECTIVE

To determine the clinical and microbiological characteristics of recurrent group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis.

DESIGN

Prospective randomized trial.

SUBJECTS

Symptoms were recorded and throat cultures were obtained at 4 to 6, 18 to 21, and 32 to 35 days following the start of treatment. A subset of 60 patients with subsequent GABHS episodes occurring were evaluated for a 0.2-or greater log rise in either antistreptolysin O or anti-deoxyribonuclease B titer to confirm a bona fide recurrence.

RESULTS

Sixteen (27%) of 60 patients had recurrent GABHS tonsillopharyngitis of the same serotype that occurred 21 days or longer following the onset of the initial GABHS infection and was associated with a 0.2- or greater log rise in either antistreptolysin O or anti-deoxyribonuclease B titer, indicating bona fide recurrent infection; these recurrences all occurred within 55 days. Fewer patients with recurrent GABHS pharyngitis of the same serotype had headache (P =.02), sore throat (P =.006), fever (P =. 008), pharyngeal erythema (P<.001), pharyngeal edema (P<.001), pharyngeal exudate (P =.04), and adenitis (P =.03) compared with the initial episode. Chills, stomachache, scarlatina, tonsillar enlargement, and palatal petechiae were similar for both episodes.

CONCLUSIONS

Fewer symptoms occur during recurrent GABHS pharyngitis of the same serotype compared with the initial infection. These patients may be less likely to seek physician attention, yet their infections put them at risk for sequelae.

Costs of illness due to Bordetella pertussis in families

OBJECTIVE

To assess costs of pertussis morbidity among families in a community setting.

DESIGN

Prospective survey.

RESULTS

Sixty-nine families (87 individuals) were studied. Twelve of 14 families with household contacts included an ill adolescent or parent. This individual was the first identified pertussis case within the household in 8 families. A family member required an average of 1.6 visits before (range, 0-7 visits) and after (range, 0-9 visits) pertussis was diagnosed; children younger than 1 year needed 2.5 and 2 visits, respectively. Symptomatic improvement occurred after a mean of 31 days (range, 4-134 days) after pertussis diagnosis and full recovery after a mean of 66 days (range, 5-383 days). Adults experienced the longest recovery time (median, 93 days) compared with other age groups. The average medical costs for an infant, child, adolescent, and adult were $2822, $308, $254, and $181, respectively. Parents lost an average of 6 workdays (range, 1-35 days) to care for an ill child; for these parents, costs associated with work loss averaged $767 per family. An average of 1.7 and 0.7 lost workdays accrued to bring an ill child to a physician's office and the emergency department, respectively. A majority (58%) of parents working while family members were ill with pertussis reported decreased work productivity ranging from 25% to 99%. Work-related costs contributed more than 60% of the overall costs of pertussis.

CONCLUSIONS

The adverse financial effect of pertussis on 69 families in Monroe County, New York, was $145,903 ($2115 per family) and supports the need for booster immunizations in adolescents and adults. Arch Fam Med. 2000;9:989-996

Human immune response to streptococcal inhibitor of complement, a serotype M1 group A Streptococcus extracellular protein involved in epidemics

Streptococcal inhibitor of complement (Sic) is a highly polymorphic extracellular protein made by serotype M1 group A Streptococcus strains that contributes to bacterial persistence in the mammalian upper respiratory tract. New variants of the Sic protein arise very rapidly by positive selection in human populations during M1 epidemics. The human antibody response to Sic was analyzed. Of 636 persons living in diverse localities, 43% had anti-Sic serum antibodies, but only 16.4% had anti-M1 protein serum antibody. Anti-Sic antibody was also present in nasal wash specimens in high frequency. Linear B cell epitope mapping showed that serum antibodies recognized epitopes located in structurally variable regions of Sic and the amino terminal hypervariable region of the M1 protein. Phage display analyses confirmed that the polymorphic regions of Sic are primary targets of host antibodies. These results support the hypothesis that selection of Sic variants occurs on mucosal surfaces by a mechanism that involves acquired host antibody.

Short course antibiotic therapy for respiratory infections: a review of the evidence

BACKGROUND

The judicious use of antibiotics entails achieving the appropriate balance between prescribing them with sufficient frequency and duration to effect a clinical cure for bacterial infections and overprescribing them, a practice that increases prescription drug costs as well as the risks of bacterial resistance, noncompliance with therapy and side effects. The recognition that the traditional 10-day or greater duration of therapy for acute otitis media, tonsillopharyngitis and sinusitis does not derive from a strong scientific or medical rationale (with the exception of penicillin therapy for tonsillopharyngitis) and the increasing awareness of the adverse sequelae of long-duration antibiotic therapy have led some clinicians to call for shortening the duration of antibiotic therapy in these infections. The soundness of this recommendation hinges on the demonstration that shortened courses of antibiotic therapy are at least as effective as traditional courses of therapy.

SYNOPSIS

Data relevant to determining the optimum duration of therapy in acute otitis media, tonsillopharyngitis and sinusitis are reviewed in this article. The review demonstrates particularly strong justification for shortening the duration of therapy from the standard 10 days to 5 days in acute otitis media, in which numerous open label and controlled studies have shown equivalent efficacy of the two durations of regimen. A growing body of evidence indicates that tonsillopharyngitis, too, can be effectively treated with non-penicillin antibiotics given for fewer than 10 days. Although sinusitis data are less plentiful than those for acute otitis media and tonsillopharyngitis, the results available to date are encouraging in suggesting that shortened courses of therapy may also be appropriate for acute maxillary sinusitis.

Penicillin failure in streptococcal tonsillopharyngitis: causes and remedies

Penicillin administered for 10 days has been the treatment of choice for group A beta-hemolytic streptococcal tonsillopharyngitis since the 1950s. The bacteriologic failure rate of 10 days of penicillin therapy ranged from approximately 2 to 10% until the early 1970s. Beginning in the late 1970s bacteriologic and clinical failure rates with penicillin therapy began to increase steadily over time and are now reported to be approximately 30%. The primary cause of penicillin treatment failure in streptococcal tonsillopharyngitis may be lack of compliance with the 10-day therapeutic regimen. Other causes of penicillin treatment failure include reexposure to Streptococcus-infected family members or peers; copathogenicity, in which bacteria susceptible to a class of drugs are protected by other, colocalized bacterial strains that lack the same susceptibility; antibiotic-associated eradication of normal protective pharyngeal flora; and penicillin tolerance, whereby streptococcal bacteria repeatedly or continuously exposed to sublethal concentrations of antibiotic become increasingly resistant to eradication. Although 10 days of penicillin therapy is effective in the management of tonsillopharyngitis for many patients, multiple factors may, singly or together, cause treatment failure. A number of antibiotics, particularly the cephalosporins, have been demonstrated to be superior to penicillin at eradicating group A beta-hemolytic Streptococcus, and several are effective when administered for 4 to 5 days.

CONCLUSIONS

Ten days of penicillin therapy may not be the best therapeutic choice for all pediatric patients. Other antibiotics, shortened courses of the cephalosporins in particular, may be preferable in some cases.