Chlamydia pneumoniae Induces Interferon Gamma Responses in Peripheral Blood Mononuclear Cells in Children with Allergic Asthma.

Respiratory infections caused by Chlamydia pneumoniae have been associated with exacerbations of asthma. Cell-mediated immunity (CMI) is critical for maintaining immunity. We compared interferon (IFN)-γ responses in C. pneumoniae-infected peripheral blood mononuclear cells (PBMC) in paediatric patients ± asthma. Presence of C. pneumoniae was tested from asthma patients (N = 17) and non-asthmatic controls (N = 16) (PCR). PBMC were infected for 1 h ± C. pneumoniae AR-39 (MOI = 0.1) and cultured for 48 h. IFN-γ levels were measured in supernatants (ELISA). C. pneumoniae-IgG antibodies in serum were determined (MIF). All subjects tested negative for C. pneumoniae (PCR). C. pneumoniae-induced IFN-γ production in vitro was more prevalent in asthma compared with non-asthma; levels of IFN-γ were higher in asthma compared with non-asthma (P = 0.003). There was no association between recent respiratory infection and positive IFN-γ responses. These data show that C. pneumoniae modulates IFN-γ responses in patients with asthma, even in absence of active infection.

Increased seroprevalence of Enterovirus 71 IgE antibodies in asthmatic compared with non-asthmatic children.

BACKGROUND: Asthma is a common pediatric chronic inflammatory airway disease. Respiratory viral infections are frequent infectious triggers for exacerbations of asthma. OBJECTIVE: We sought to determine whether Enterovirus 71 (EV71), a ubiquitous virus that causes systemic inflammatory responses in children but is not a known respiratory pathogen, can also serve as an infectious trigger for asthma. METHODS: Specific EV71 IgE and IgM antibodies (Abs), total serum IgE, and IL-2 and IL-4 cytokine levels in serum of asthmatic and non-asthmatic children (N = 42, ages 5-19; N = 35, ages 1-20, respectively) were measured (ELISA). RESULTS: Asthmatic children had higher EV71 IgE Ab levels than non-asthmatic (P < 0.001). Non-asthmatic children had significantly higher EV71 IgM Ab levels than asthmatic (P < 0.001). Despite low serum IgE levels of non-asthmatic, compared with asthmatic (P < 0.001), the non-asthmatic children produced significantly more IL-2 and IL-4 than asthmatic (P < 0.001; P < 0.001). The ages of the asthmatics, but not the non-asthmatics had a significant effect on the levels of EV 71 IgE Abs (P = 0.02; P = 0.356). A test of difference between these two slopes was significant. However, the ages of the non-asthmatic, but not the asthmatic children had a significant effect on the levels of EV 71 IgM Abs; a test of difference between these two slopes was significant. CONCLUSIONS: Increased specific EV71 IgE Ab responses may indicate that EV71 infection may also be an infectious trigger in asthma. However, the role of specific EV71 IgM Abs, Th2 cytokines, and age in non-asthmatic children should be further studied.

Chlamydia pneumoniae induces interleukin-12 responses in peripheral blood mononuclear cells in asthma and the role of toll like receptor 2 versus 4: a pilot study.

BACKGROUND: Chlamydia pneumoniae causes respiratory infection in adults and children, and has been associated with asthma exacerbations and induction of Immunoglobulin (Ig) E responses. We previously reported that C. pneumoniae enhances T helper (Th) 2 responses of peripheral blood mononuclear cells (PBMC) from asthmatic patients. It is likely that toll like receptor (TLR)-2 and TLR-4 mediate cytokine responses and host defense against C. pneumoniae. Thus, we sought to determine whether engagement of TLR-2 or TLR-4 may induce IL-12 production in our C. pneumoniae model. METHODS: PBMC (1.5 × 106) from asthmatic patients (N = 10) and non-asthmatic controls (N = 5) were infected or mock-infected for 1 h ± C. pneumoniae TW183 at a multiplicity of infection (MOI) = 1 and MOI = 0.1, and cultured for 48 h ± anti- TLR-2 and TLR-4 antibodies (Abs) (1 mg/mL). Interleukin (IL)-12 (48 h p.i.) and total IgE levels (day 10) were measured in supernatants (ELISA). RESULTS: High IgE levels were detected in supernatants of C. pneumoniae- infected PBMC from asthmatics on day 10, compared with mock-infected PBMC (p < 0.03). In contrast, IgE was not detected (<0.3 ng/mL) in either C. pneumoniae infected or mock-infected PBMC from non-asthmatics. IL-12 production by C. pneumoniae-infected asthmatic and non-asthmatic PBMC were similar. When anti-TLR4, but not anti-TLR2, was included in culture, IL-12 production by C. pneumoniae- infected asthmatic PBMC decreased. CONCLUSIONS: C. pneumoniae infection induces IgE production and modulates IL-12 responses in patients with asthma, which may be caused, in part, by differences in TLR-2 and TLR-4 stimulation.

Chlamydia pneumoniae pneumonia with pleural effusion: diagnosis by culture.

A case of Chlamydia pneumoniae pneumonia with pleural effusion in an otherwise healthy 19-year-old man is described. Diagnosis was made by serologic means as well as by culture of both the nasopharynx and the pleural fluid.

Inappropriate use of nonculture tests for the detection of Chlamydia trachomatis in suspected victims of child sexual abuse: A continuing problem.

The introduction of nonculture tests for detection of Chlamydia trachomatis has revolutionized the management of chlamydial infections in sexually active adolescents and adults. However, these tests are insufficiently specific for use in genital and rectal sites in children; false-positive tests can be frequent. We report here 4 cases involving inappropriate use of nonculture tests in children in New York City during 1998. Two cases involved the use of enzyme immunoassays with vaginal specimens. In both cases the initial results were positive, however, cultures for C trachomatis performed later were negative. In the third case, the DNA probe test for C trachomatis was used. The fourth child was being evaluated for sexually transmitted diseases after rape. Although the pediatrician sent a rectal culture to a large commercial laboratory it was later determined that the laboratory was using an enzyme immunoassay for culture confirmation leading to a false-positive result. At the least the use of these inappropriate tests resulted in unnecessary retesting and at the worst, unnecessary hospitalization, erroneous reports of sexual abuse and possibly unjustified prosecution and incarceration. Because of the social and legal implications it is important that practitioners be aware of these recommendations and require that commercial laboratories adhere to approved C trachomatis culture methods.

Nonspecific vaginitis following sexual abuse in children.

Nonspecific vaginitis, one of the most common causes of vaginitis in adults, is a polymicrobial infection in which vaginal anaerobes act synergistically with Gardnerella vaginalis. The diagnosis is made by examination of the vaginal secretions for clue cells, the development of a fishy odor after the addition of 10% KOH to vaginal secretions, and a vaginal pH greater than 4.5. To determine whether nonspecific vaginitis occurs in sexually abused children, we obtained vaginal washes from 31 abused and 23 nonabused children, 21/2 to 13 years of age. A child was considered to have definite nonspecific vaginitis if her wash contained both clue cells and odor; she was considered to have possible nonspecific vaginitis if her wash contained either clue cells or odor. We did not use vaginal pH as a diagnostic criterion because the normal range has not been standardized in prepubertal girls. Possible nonspecific vaginitis (odor only) was found in only 1/23 (4%) of nonabused children. This girl was asymptomatic and findings from her examination were normal. Only one of the 31 abused children had possible nonspecific vaginitis (odor) detected at the initial examination, less than 48 hours after the episode of abuse, whereas 4/31 (13%) developed definite, and 4/31 (13%) possible nonspecific vaginitis at the follow-up visit more than seven days after the episode of abuse or rape. Five of these eight girls developed either a new vaginal discharge or dysuria; three were treated with metronidazole with resolution of their symptoms and reversion of the vaginal wash to normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbiology of the vagina in children: normal and potentially pathogenic organisms.

Vaginal cultures from 100 healthy girls, 2 months to 15 years of age, were examined for the presence of normal and potentially pathogenic microorganisms. Corynebacterium vaginale, yeast species, and genital mycoplasmas were isolated from vaginal cultures from 13.5 %, 28%, and 28% of the girls examined, respectively. Colonization with these organisms was not associated with signs or symptoms of vaginitis. Neisseria gonorrhoeae was isolated from a 4-year-old with purulent vaginitis. Trichomonas vaginalis was recovered from two 13-year-olds, both of whom had an abnormal vaginal discharge. Vaginal antibody to Chlamydia trachomatis was found in two girls 4 and 13 years of age. In neither girl was the organism recovered from the vaginal culture. Chlamydia trachomatis was recovered from the vaginal culture of another 4-year-old who had no abnormal findings on examination. Cultures from 59 of the girls were examined for aerobic and facultatively anaerobic bacteria. Diphtheroids and Staphylococcus epidermidis were the most frequently isolated organisms. Lactobacilli were isolated most frequently from the older girls, whereas enteric organisms were isolated most frequently from the younger girls.

Prospective study of maternal and infantile infection with Chlamydia trachomatis.

We examined the prevalence of chlamydial infection in a population of pregnant women and observed their infants to determine the risk of development of ocular or respiratory infection. We examined endocervical and serum specimens from 322 pregnant women for Chlamydia trachomatis and chlamydial antibody. The cultures were obtained at the first prenatal visit. Six (2%) of the women were infected with C trachomatis. Chlamydial antibody was present in the genital secretions of 47% and 73% of the serum samples. The six infants born to infected women, 61 infants born to women who were culture-negative, but local antibody-positive, and 28 control infants born to culture-negative, antibody-negative women were followed for up to six months. Four of six infants born to infected women developed chlamydial infection: two developed culture-positive conjunctivitis, one had asymptomatic nasopharyngeal infection, and one infant developed pneumonitis. Three of 61 infants born to mothers who were culture-negative and local antibody-positive developed conjunctivitis due to C trachomatis. None of the 28 control infants developed chlamydial infection. Most (79%) of the infants had chamydial antibody in their serum at 2 to 4 weeks of age. The correlation between maternal and infant serum antibody titer was r=0.71 suggesting that antibody was placentally transferred.

Colonization with group B streptococci in girls under 16 years of age.

Cultures from the vagina, pharynx, and anal canal of 100 healthy girls, 2 months through 15 years of age, were examined for the presence of group B streptococci. Of the 100 participants, 20% were colonized at one or more of these three sites. Pharyngeal colonization was detected in 15% of the girls under 11 years of age and in 5% of those over 11 years of age. Colonization at anogenital sites were observed in 19% of participants under 3 years of age, in 25% of those 11 years of age and older, and in only 4% of those between the ages of 3 and 10 years (P less than .025). The concentration of serum antibody directed against the polysaccharide capsular antigen isolated from type III, group B Streptococcus appeared, in part, to be related to increasing age.

Activity of quinolones against Chlamydia pneumoniae.

Quinolones are currently being used as empirical therapy for the treatment of community-acquired pneumonia and other respiratory infections as they cover a broad range of conventional bacterial and 'atypical' pathogens, including Chlamydia pneumoniae. C. pneumoniae has been associated with 10 to 20% of community-acquired pneumonia in adults and recently has been implicated as being associated with several nonrespiratory conditions, including atherosclerosis. However, data on the treatment of even respiratory infection due to C. pneumoniae are limited. Although currently available quinolones have good activity against C. pneumoniae in vitro, all published treatment studies have relied on serological diagnosis, thus microbiological efficacy has not been assessed. Anecdotal experience suggests that in vitro activity may not always correlate with efficacy in vivo.

Failure to demonstrate Chlamydia pneumoniae in cardiovascular tissue from children with Kawasaki disease.

Chlamydia pneumoniae has been associated with atherosclerosis and myocardial infarction in adults. Coronary artery tissues of five fatal cases of Kawasaki disease were examined by PCR; none was positive.

False positive results with the use of chlamydial antigen detection tests in the evaluation of suspected sexual abuse in children.

The presence of rectal or genital infection with Chlamydia trachomatis in children is frequently considered an indicator of sexual abuse. The diagnosis of chlamydial infection in these children has been complicated by the use of antigen detection methods instead of culture. We report five cases in which the use of chlamydial antigen detection tests in the evaluation of suspected child abuse gave false positive results. An enzyme immunoassay was used in two cases (Chlamydiazyme; Abbott Diagnostics) and a direct fluorescent antibody test was used in the remaining three cases (Microtrak; Syva). The sites examined were the urethra, vagina and rectum. In all cases chlamydial cultures obtained several days later with no interim antibiotic therapy were negative. Four of the five children examined were probably victims of sexual abuse. The enzyme immunoassay and direct fluorescent antibody tests have been evaluated primarily for urethral and cervical cultures from adults; neither test has been approved or evaluated for rectal or genital sites in children. At these sites use of both tests may be associated with a large proportion of false positives caused by contamination with fecal flora which can cross-react with the antibodies used in the test. These tests also have limited utility in populations where the prevalence of chlamydial infection is low (less than 10%), as has been reported for sexually abused children. Because of the medicolegal implications only "gold standard" methods (i.e. culture) performed by a competent laboratory should be used in evaluating chlamydial infection in sexually abused children.

Mycoplasma hominis and Ureaplasma urealyticum in neonates with suspected infection.

The role of genital mycoplasmas in the pathogenesis of neonatal infection is incompletely understood. We performed nasopharyngeal, blood and cerebrospinal fluid (CSF) cultures for Mycoplasma hominis and Ureaplasma urealyticum in 69 neonates who underwent a diagnostic workup for suspected sepsis. The mean gestational age was 35.9 weeks (range, 25 to 42 weeks) with a mean birth weight of 2386 g (range, 652 to 4420 g). Twenty-seven infants (39.1%) had positive nasopharyngeal cultures; 6 were positive for M. hominis, 10 for U. urealyticum and 11 for both organisms. Seven (26%) of these 27 patients developed chronic lung disease compared with 2 (4.7%) infants in the non-colonized group. Nine infants had positive CSF cultures for M. hominis and one infant had a positive CSF culture for U. urealyticum. All blood cultures were sterile. One of the infants with a positive CSF culture for M. hominis had clinical evidence of systemic infection. All of the infants were treated with antibiotic agents that were not active against mycoplasmas. These data indicate that genital mycoplasmas can be found commonly in the CSF and nasopharynx of infants with suspected sepsis. Their etiologic role in the causation of infection and chronic lung disease, however, remains unclear.

Lack of specificity of Chlamydiazyme for detection of vaginal chlamydial infection in prepubertal girls.

A 1-year prospective study was undertaken of 65 prepubertal girls referred for evaluation of sexual abuse or vulvovaginitis to compare Chlamydiazyme, an enzyme immunoassay (EIA), with culture for the detection of Chlamydia trachomatis i in vaginal specimens. Five (8%) of 65 patients were initially EIA-positive. On repeat sampling without intervening antibiotic treatment, 4 girls who were initially positive became negative and 1 remained persistently positive. Chlamydial cultures were negative in all patients. The patient with the persistently positive EIA also had Group A streptococcal vaginitis. We were able to demonstrate that some strains of Group A Streptococcus can cause a positive reaction with the EIA. Cross-reactions with other bacterial species are also known to occur. We therefore conclude that Chlamydiazyme is not specific for the detection of chlamydial infection in the vagina of prepubertal girls and, for medicolegal reasons, should not be used for evaluation of sexual abuse.

Ceftriaxone treatment of penicillinase-producing Neisseria gonorrhoeae infections in children.

The incidence of penicillinase-producing Neisseria gonorrhoeae (PPNG) among adults with gonorrhea in Brooklyn now exceeds 24%. Because children usually acquire their infection from adults, it follows that we have had a concomitant rise in PPNG among sexually abused children. The Centers for Disease Control now recommends ceftriaxone for the first line treatment of gonorrhea but there are no data as to its use in children for this indication. From May, 1987, through March, 1989, 33 children, 4 days to 10 years of age, were admitted to Kings County Hospital for 34 episodes of gonorrhea. Nine (26.5%) were caused by PPNG. Twenty-three were female; 10 were male. There were 17 isolates from the vagina, 3 from the urethra, 9 from the pharynx, 9 from the rectum and 6 from the eye. Eight children (all girls) had infections at greater than or equal to 1 site; 2 were infected at 3 sites. Twenty-eight children were sexually abused and 5 were neonates with ophthalmia (1 PPNG). All isolates were susceptible to ceftriaxone by disc diffusion testing. Agar dilution was performed for 18 isolates; minimal inhibitory concentrations to ceftriaxone were less than or equal to 0.06 mg/liter. The 5 PPNG isolates tested had minimal inhibitory concentrations to penicillin of 2 to 16 mg/liter and 3 isolates were resistant to tetracycline with minimal inhibitory concentrations of 32 mg/liter. Twenty-eight children were treated with a single dose of ceftriaxone, including the 5 neonates with ophthalmia; the dose was 125 mg if less than 45 kg or 250 mg if greater than 45 kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of polymerase chain reaction for the detection of Chlamydia trachomatis in ocular and nasopharyngeal specimens from infants with conjunctivitis.

BACKGROUND: Chlamydia trachomatis is the most common identifiable infectious cause of neonatal conjunctivitis. Nonculture tests including enzyme immunoassays and direct fluorescent antibody tests have been shown to perform well for the diagnosis of chlamydial conjunctivitis with sensitivities and specificities > or = 90%. However, the performance with respiratory specimens has been less than satisfactory. METHODS: We compared a new, commercially available polymerase chain reaction (PCR) assay, Roche AMPLICOR (Roche Diagnostic Systems, Branchburg, NJ) with culture for the detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis. We also evaluated AMPLICOR for the detection of C. trachomatis in the urine of mothers of positive infants. RESULTS: Ocular and nasopharyngeal specimens from 75 infants with conjunctivitis were obtained for culture and PCR. AMPLICOR was equivalent to culture for eye specimens and more sensitive than culture for nasopharyngeal specimens. The sensitivity, specificity and positive and negative predictive values of PCR compared with culture for conjunctival specimens were 92.3, 100, 100 and 98.4%, respectively. The sensitivity, specificity and positive and negative predictive values for nasopharyngeal specimens were 100, 97.2, 60 and 100%, respectively. We also detected C. trachomatis by PCR in the urine of 12 mothers of culture positive infants. CONCLUSIONS: PCR performed comparably to culture for detection of C. trachomatis in conjunctival and nasopharyngeal specimens from infants with conjunctivitis.

Mycoplasma pneumoniae and Chlamydia pneumoniae in pediatric community-acquired pneumonia: comparative efficacy and safety of clarithromycin vs. erythromycin ethylsuccinate.

We evaluated 260 previously healthy children ages 3 through 12 years who had clinical signs and symptoms of pneumonia, radiographically confirmed. Patients were randomized 1:1 to a 10-day course of either clarithromycin suspension 15 mg/kg/day divided twice a day or erythromycin suspension 40 mg/kg/day divided twice a day or three times a day. Evidence of infection with Chlamydia pneumoniae was detected in 28% (74) of patients: 13% (34) by nasopharyngeal culture and 18% (48) by serology with the microimmunofluorescence assay. Evidence of infection with Mycoplasma pneumoniae was detected in 27% (69) of patients: 20% (53) by nasopharyngeal culture or polymerase chain reaction and 17% (44) by serology with the use of enzyme-linked immunosorbent assay. Serologic confirmation of infection was observed in 23% (8) and 53% (28) of patients with bacteriologically detected C. pneumoniae and M. pneumoniae, respectively. Treatment with clarithromycin vs. erythromycin, respectively, yielded the following outcomes: clinical success 98% (121 of 124) vs. 95% (105 of 110); radiologic success 98% (109 of 111) vs. 94% (92 of 110); and eradication by pathogen, C. pneumoniae 79% (15 of 19) vs. 86% (12 of 14) and M. pneumoniae 100% (9 of 9) vs. 100% (4 of 4). Adverse events were primarily gastrointestinal occurring in almost one-fourth of patients in both groups, and were mild to moderate in severity. Clarithromycin and erythromycin were similarly effective and safe for the treatment of radiographically proved, community-acquired pneumonia in children older than 2 years old.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and efficacy of azithromycin in the treatment of community-acquired pneumonia in children.

OBJECTIVE: To compare the safety and efficacy of azithromycin with amoxicillin/clavulanate or erythromycin for the treatment of community-acquired pneumonia, including atypical pneumonia caused by Mycoplasma pneumoniae and Chlamydia pneumoniae. METHODS: Multicenter, parallel group, double blind trial in which patients 6 months to 16 years of age with community-acquired pneumonia were randomized 2:1 to receive either azithromycin for 5 days or conventional therapy for 10 days (amoxicillin/clavulanate if < or =5 years of age or erythromycin estolate if >5 years of age). Patients from 23 geographically diverse sites were evaluated for clinical outcomes and/or adverse events at Days 3 to 5, Days 15 to 19 and 4 to 6 weeks posttherapy. Microbiology (culture or polymerase chain reaction) was done at baseline and Days 15 to 19 for bacteria, Chlamydia pneumoniae and Mycoplasma pneumoniae. Serology for C. pneumoniae and M. pneumoniae was done at baseline and 4 to 6 weeks posttherapy. RESULTS: Of 456 patients enrolled during 17 consecutive months, 420 were evaluable. Clinical success at Study Days 15 to 19 was 94.6% in the azithromycin group and 96.2% in the comparative treatment group (P = 0.735) and at 4 to 6 weeks posttherapy 90.6 and 87.1%, respectively (P = 0.330). Evidence of infection was identified in 46% of 420 evaluable patients (1.9% bacteria, 29.5% M. pneumoniae and 15% C. pneumoniae). Microbiologic eradication was 81% for C. pneumoniae and 100% for M. pneumoniae in the azithromycin group vs. 100 and 57%, respectively, in the comparator group. Treatment-related adverse events occurred in 11.3% of the azithromycin group and 31% in the comparator group (P < 0.05). CONCLUSION: Azithromycin used once daily for 5 days produced a satisfactory therapeutic outcome similar to those of amoxicillin/clavulanate or erythromycin given three times a day for 10 days for treatment of community-acquired pneumonia. Azithromycin had significantly fewer side effects than comparator drugs.

Chlamydia pneumoniae in acute otitis media.

BACKGROUND: Aerobic bacterial pathogens are recovered from 65 to 85% of patients with acute otitis media (AOM). Although Chlamydia pneumoniae is a common pathogen of pediatric pneumonia, it has rarely been cultured from children with chronic otitis media and its role in AOM is unknown. METHODS: We cultured for C. pneumoniae in tympanocentesis aspirates and nasopharyngeal swabs from 101 consecutive, otherwise healthy children with AOM or refractory AOM. A control group of 50 similarly aged, healthy children was evaluated for nasopharyngeal carriage of C. pneumoniae. Specimens were also evaluated by PCR for C. pneumoniae. RESULTS: C. pneumoniae was recovered by tympanocentesis in 8 (8%) of 101 children with AOM. Among the 8 children with C. pneumoniae-positive-AOM, 5 had C. pneumoniae detected by PCR in middle ear fluid, none had C. pneumoniae recovered by nasopharyngeal culture or PCR and 5 were younger than 16 months. C. pneumoniae was the sole pathogen isolated in 2 patients. Copathogens included beta-lactamase-positive positive Haemophilus influenzae (2), beta-lactamase positive Moraxella catarrhalis (1), penicillin-resistant Streptococcus pneumoniae (2) and penicillin-susceptible S. pneumoniae (1). C. pneumoniae was recovered from nasopharyngeal culture in 2 additional patients with C. pneumoniae-negative AOM and in none of 50 healthy control children, although 2 controls were positive by PCR from the nasopharynx. CONCLUSIONS: This is the first study to report the isolation of C. pneumoniae in middle ear fluid of children with AOM.

The association of Chlamydia pneumoniae infection and reactive airway disease in children.

OBJECTIVE: To determine the possible association of Chlamydia pneumoniae infection and reactive airway disease in children. DESIGN: Prospective observational study. SETTING: Pediatric emergency department in Children's Medical Center of Brooklyn (NY), Kings County Hospital Center. PARTICIPANTS: One hundred eighteen children with acute episodes of wheezing and 41 age- and sex-matched healthy controls, aged 5 to 16 years. INTERVENTIONS: Children with cultures positive for C pneumoniae were treated with antibiotics. MEASUREMENTS/MAIN RESULTS: Cultures for C pneumoniae and serum samples for antibody testing were obtained from subjects and healthy controls. We isolated C pneumoniae from 13 (11%) children with wheezing and from two (4.9%) controls. Seven (58.3%) of 12 children with positive cultures had no detectable antibody to C pneumoniae and only three (25%) children had serologic evidence of acute infection. Six children had positive cultures on multiple occasions, ranging from 1 to 5 months. The children with wheezing were treated with erythromycin or clarithromycin, a new macrolide antibiotic approved for use in adults; all eventually had a negative culture. Nine (75%) of these children demonstrated clinical and laboratory improvement of the reactive airway disease after the eradication of chlamydial infection. CONCLUSIONS: Infection with C pneumoniae can trigger acute episodes of wheezing in children with asthma. Treatment of C pneumoniae infection may improve the course of reactive airway disease in these patients.