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Biomedical subjects

Tasnee Chonmaitree

Publications and source records attributed to Tasnee Chonmaitree.

17 recordsLinked to original sources
PubMed2006

Role of respiratory syncytial virus in acute otitis media: implications for vaccine development.

We summarize herein the results of various virologic studies of acute otitis media (AOM) conducted at our site over a 10-year period. Among 566 children with AOM, respiratory syncytial virus (RSV) was the most common virus identified in either middle ear fluid or nasal wash; it was found in 16% of all children and 38% of virus-positive children. Seventy-one percent of the children with RSV were 1 year of age or older, which was significantly older than all other viruses combined (P=0.045). RSV infection was associated with the common bacterial pathogens causing AOM. Past efforts to develop vaccines for RSV have emphasized prevention of lower respiratory tract infection in infants, which is a more serious problem but less common than AOM. Our results suggest that RSV vaccines that work only against infection in older children may have value in preventing AOM, the most common pediatric disease.

Acute Disease↗
PubMed2006

Association of human metapneumovirus with acute otitis media.

OBJECTIVE: Human metapneumovirus (hMPV) is a recently described paramyxovirus that has been associated with acute upper and lower respiratory infection (LRI) in infants and children worldwide. We previously observed that one-third of the children with hMPV-associated LRI had been diagnosed with a concomitant acute otitis media (AOM). In the current study, we sought to investigate an association between hMPV and children presenting with AOM as a primary diagnosis. METHODS: We used realtime RT-PCR for hMPV to retrospectively test 144 paired nasal wash (NW) and middle ear fluid (MEF) specimens that had been prospectively collected from children with AOM during a 3-year period from 1990-1992. RNA was extracted from archived, frozen samples and realtime RT-PCR for hMPV was performed. RESULTS: We detected hMPV in 8/144 (6%) NW and 1/144 MEF. Several of the children still tested positive for hMPV in NW 3 days later, showing persistent virus shedding. All were detected from November-May and six had bacterial co-pathogens. Two of the eight (25%) hMPV-infected children had no bacterial pathogen isolated, suggesting that hMPV may be associated with AOM as a sole pathogen. CONCLUSIONS: These data show that hMPV is associated with a proportion of AOM and thus has additional morbidity and healthcare impact related to these illnesses.

Acute Disease↗
PubMed2006

Development of a practical tool for assessing the severity of acute otitis media.

BACKGROUND: Watchful waiting management of nonsevere acute otitis media (AOM) can reduce the use of antibiotics, but it requires a reliable means of assessing clinical severity. OBJECTIVE: We present the development of a pocket AOM card with which the clinician can rapidly assess total AOM severity. DESIGN/METHODS: The components of the pocket card consisted of a faces scale, to assess parent perception of severity, and a standard set of tympanic membrane photographs, with which the pediatrician can grade the severity of tympanic membrane inflammation. The components of the pocket card were tested for validity, reliability and responsiveness with the use of data from parents, pediatricians and pediatric otolaryngologists. STATISTICS: Instruments were assessed for concurrent correlation, sequence validity and reliability against previously published questionnaires with the use of Spearman correlation. Responsiveness was calculated with the use of enrollment, day 12 and day 30 data from a randomized clinical trial. RESULTS: The components of the pocket AOM card demonstrated excellent sequence validity, concurrent correlation and reliability (r = 0.58-0.99). Total AOM card severity, consisting of the sum of the 2 scales, demonstrated better responsiveness to change than any of the scales taken individually. CONCLUSIONS: The AOM card combines a parent assessment of symptoms and the clinician assessment of the tympanic membrane to provide an assessment of total AOM severity that can be used to facilitate shared decision making between parent and clinician. The combined score of the AOM card was more responsive to change than any of the instruments used alone. The AOM card provides a useful tool for teaching and research.

Acute Disease↗
PubMed2006

Effect of pneumococcal conjugate vaccine on nasopharyngeal bacterial colonization during acute otitis media.

The heptavalent pneumococcal conjugate vaccine (PCV7) has been shown to reduce the incidence of acute otitis media (AOM) caused by Streptococcus pneumoniae by 34% and reduces the overall incidence of AOM by 6% to 8%. More recent studies have shown increases in the proportion of Haemophilus influenzae and Moraxella catarrhalis in the middle-ear fluid of PCV7-immunized children. There has been no report on the effect of PCV7 on all 3 bacterial pathogens combined, either in the middle-ear fluid or nasopharynx of individual children with AOM. We investigated the impact of PCV7 on nasopharyngeal colonization with bacterial pathogens during AOM in the pre-PCV7 and post-PCV7 vaccination eras. Four hundred seventeen children (6 months to 4 years of age) were enrolled onto AOM studies between September 1995 and December 2004. Of these, 200 were enrolled before the vaccine use (historical controls), and 217 were enrolled after the initiation of PCV7 vaccination (101 were underimmunized, and 116 were immunized). Although the nasopharyngeal colonization rate for S pneumoniae was not different between the 3 groups, a significantly higher proportion of PCV7-immunized children with AOM were colonized with M catarrhalis. Overall, the mean number of pathogenic bacteria types isolated from immunized children (1.7) was significantly higher than in controls (1.4). The increase in bacterial colonization of the nasopharynx during AOM could be associated with an increase in AOM pathogens and theoretically can predispose PCV7-immunized children with AOM to a higher rate of antibiotic treatment failure or recurrent AOM.

Acute Disease↗
PubMed2006

Association of proinflammatory cytokine gene polymorphisms with susceptibility to otitis media.

OBJECTIVE: Susceptibility to otitis media results from complex interactions among genetic factors of the host, exposure to pathogens, and environmental influences. The objective of this study was to study the role of single-nucleotide polymorphisms of regulatory elements of proinflammatory cytokine genes tumor necrosis factor-alpha(-308), interleukin-1beta(+3953), and interleukin-6(-174), in susceptibility to recurrent otitis media in childhood. METHODS: A total of 505 children (296 otitis media susceptible, 209 nonsusceptible as control) were enrolled at 2 sites (Texas and Kentucky). DNA of the children was studied for specific single-nucleotide polymorphisms by restriction fragment length polymorphism assay and confirmed by gene sequencing. RESULTS: In the overall study group, tumor necrosis factor-alpha(-308) and interleukin-6(-174) heterozygous or homozygous polymorphisms (high cytokine-producing genotypes) were significantly associated with otitis media susceptibility. The same association was found in a match-paired subgroup of 384 subjects. In the overall study group, there was a significant step-wise increase in otitis media susceptibility with increasing number of concomitant polymorphic genotypes. Simultaneous combination of tumor necrosis factor-alpha(-308) and interleukin-6(-174) polymorphisms further increased the risk for otitis media susceptibility. These 2 polymorphic genotypes also were associated with the increased risk for tympanostomy tube placement. Children who had tumor necrosis factor-alpha(-308) polymorphism and were breastfed for <1 month or exposed to cigarette smoke were more likely to be otitis media susceptible. CONCLUSIONS: Our data suggest that tumor necrosis factor-alpha(-308) and interleukin-6(-174) polymorphisms are associated with increased risk for otitis media susceptibility and placement of tympanostomy tubes. Environmental factors such as breastfeeding may modify the risk for otitis media susceptibility in polymorphic individuals.

Child, Preschool↗
PubMed2005

Nonsevere acute otitis media: a clinical trial comparing outcomes of watchful waiting versus immediate antibiotic treatment.

OBJECTIVE: The widespread use of antibiotics for treatment of acute otitis media (AOM) has resulted in the emergence of multidrug-resistant pathogens that are difficult to treat. However, it has been shown that most children with nonsevere AOM recover without ABX. The objective of this study was to evaluate the safety, efficacy, acceptability, and costs of a non-ABX intervention for children with nonsevere AOM. METHODOLOGY: Children 6 months to 12 years old with AOM were screened by using a novel AOM-severity screening index. Parents of children with nonsevere AOM received an educational intervention, and their children were randomized to receive either immediate antibiotics (ABX; amoxicillin plus symptom medication) or watchful waiting (WW; symptom medication only). The investigators, but not the parents, were blinded to enrollment status. Primary outcomes included parent satisfaction with AOM care, resolution of symptoms, AOM failure/recurrence, and nasopharyngeal carriage of Streptococcus pneumoniae strains resistant to ABX. Secondary outcomes included medication-related adverse events, serious adverse events, unanticipated AOM-related office and emergency department visits and telephone calls, the child's absence from day care or school resulting from AOM, the parent's absence from school or work because of their child's AOM, and costs of treatment. Subjects were defined as failing (days 0-12) or recurring (days 13-30) if they experienced a higher AOM-severity score on reexamination. RESULTS: A total of 223 subjects were recruited: 73% were nonwhite, 57% were <2 years old, 47% attended day care, 82% had experienced prior AOM, and 83% had not been fully immunized with heptavalent pneumococcal vaccine. One hundred twelve were randomized to ABX, and 111 were randomized to WW. Ninety-four percent of the subjects were followed to the 30-day end point. Parent satisfaction with AOM care was not different between the 2 treatment groups at either day 12 or 30. Compared with WW, symptom scores on days 1 to 10 resolved faster in subjects treated with immediate ABX. At day 12, among the immediate-ABX group, 69% of tympanic membranes and 25% of tympanograms were normal, compared with 51% of normal tympanic membranes and 10% of normal tympanograms in the WW group. Parents of children in the ABX group gave their children fewer doses of pain medication than did parents of children in the WW group. Subjects in the ABX group experienced 16% fewer failures than subjects in the WW group. Of the children in the WW group, 66% completed the study without needing ABX. Immediate ABX resulted in eradication of S pneumoniae carriage in the majority of children, but S pneumoniae strains cultured from children in the ABX group at day 12 were more likely to be multidrug-resistant than strains from children in the WW group. More ABX-related adverse events were noted in the ABX group, compared with the WW group. No serious AOM-related adverse events were observed in either group. Office and emergency department visits, phone calls, and days of work/school missed were not different between groups. Prescriptions for ABX were reduced by 73% in the WW group compared with the ABX group. Costs of ABX averaged $47.41 per subject in the ABX group and $11.43 in the WW group. CONCLUSIONS: Sixty-six percent of subjects in the WW group completed the study without ABX. Parent satisfaction was the same between groups regardless of treatment. Compared with WW, immediate ABX treatment was associated with decreased numbers of treatment failures and improved symptom control but increased ABX-related adverse events and a higher percent carriage of multidrug-resistant S pneumoniae strains in the nasopharynx at the day-12 visit. Key factors in implementing a WW strategy were (a) a method to classify AOM severity; (b) parent education; (c) management of AOM symptoms; (d) access to follow-up care; and (e) use of an effective ABX regimen, when needed. When these caveats are observed, WW may be an acceptable alternative to immediate ABX for some children with nonsevere AOM.

Amoxicillin↗
PubMed2004

Otoscopic and tympanometric findings in acute otitis media yielding dry tap at tympanocentesis.

BACKGROUND: The value of tympanometry in detection of middle ear effusion (MEE) has been widely studied in otitis media with effusion. There has been no direct comparison of tympanometric and tympanocentesis (TAP) findings in acute otitis media (AOM). We compared otoscopic, tympanometric and TAP findings in AOM including cases of AOM without effusion. METHODS: In a study of AOM treatment of 90 children, a tympanogram was obtained, and TAP was performed before and after 5 days of treatment. Subjects were followed with otoscopy and tympanometry every 2 weeks for 3 months or until the MEE cleared. RESULTS: In 130 AOM ears, otoscopic, tympanometric and TAP findings were available; MEE was obtained from 110 ears. Of 20 ears with a dry tap, 18 had abnormal tympanogram and otoscopic findings. With TAP findings as the standard, sensitivity and positive predictive value of type B tympanogram were 97 and 87%, respectively. Of 18 AOM ears yielding dry tap, 2 yielded MEE 5 days later, and 8 continued with evidence of MEE 5 days-12 weeks later. Five subjects with 8 AOM ears yielding dry tap were lost to follow-up; all had short duration of clinical symptoms. CONCLUSIONS: Although otoscopic and tympanometric findings suggested the presence of MEE in AOM, MEE was unobtainable by TAP in 14% of cases. Dry tap cases likely represent early AOM before accumulation of detectable MEE. However, technical difficulty in obtaining small amounts of or highly viscous MEE could not be excluded. Sensitivity and positive predictive value of abnormal tympanograms in detection of MEE in AOM cases are comparable with those in otitis media with effusion.

Acoustic Impedance Tests↗
PubMed2003

Middle ear fluid histamine and leukotriene B4 in acute otitis media: effect of antihistamine or corticosteroid treatment.

OBJECTIVE: Two potent mediators of acute inflammation, histamine and leukotriene B4 (LTB4), have been shown to play important roles in the pathogenesis and clinical course of acute otitis media (AOM) in children. The purpose of this study was to evaluate the ability of adjuvant drugs, antihistamine and corticosteroid, in reduction of the levels of histamine and LTB4 in the middle ear and their ability to improve outcomes of AOM. METHODS: Eighty children with AOM (aged 3 months to 6 years) were enrolled in a prospective, randomized, double-blind, placebo controlled study. All children received one dose of intramuscular ceftriaxone and were randomly assigned to receive either chlorpheniramine maleate (0.35 mg/kg per day) and/or prednisolone (2 mg/kg per day) or placebos three times a day for 5 days. Tympanocentesis was performed at enrollment and after 5 days of adjuvant drug treatment. MEFs were collected for bacterial and viral studies and histamine and LTB4 levels. The subjects were followed for the duration of middle ear effusion or up to 3 months. RESULTS: Histamine or LTB4 levels in the MEF after 5 days of treatment were not significantly reduced by adjuvant drug treatment. However, subjects receiving corticosteroid had a lower rate of treatment failure during the first 2 weeks and shorter duration of middle ear effusion. CONCLUSIONS: Five day of antihistamine or corticosteroid treatment does not reduce the levels of histamine or leukotriene B4 in the MEF of children with AOM. Positive clinical outcomes of AOM cases associated with corticosteroid treatment needs to be confirmed in a larger clinical trial of children with intact tympanic membranes, who do not receive tympanocentesis.

Acute Disease↗
PubMed2003

A randomized, placebo-controlled trial of the effect of antihistamine or corticosteroid treatment in acute otitis media.

OBJECTIVES: To determine whether the adjunctive drugs antihistamine and corticosteroid improve immediate and long-term outcomes of acute otitis media (AOM). STUDY DESIGN: Children with AOM (3 mos-6 y) were enrolled in a randomized, double-blind, placebo-controlled trial. All 179 children received one dose of intramuscular ceftriaxone and were assigned to receive either chlorpheniramine maleate (0.35 mg/kg/d) and/or prednisolone (2 mg/kg/day) or placebo for 5 days. Main outcome measures were rate of treatment failure during the first 2 weeks, duration of middle ear effusion, and rate of recurrences of AOM to 6 months. RESULTS: Clinical outcomes and recurrence rates did not differ significantly with treatment. Children who received antihistamine alone had significantly longer duration of middle ear effusion (median, 73 days) than subjects in other treatment groups (median, 23 to 36 days, P=.04). Temporary normalization of tympanometric findings on day 5 occurred more frequently in the corticosteroid-treated group (P=.04). CONCLUSIONS: Five-day treatment with antihistamine or corticosteroid, in addition to antibiotic, did not improve AOM outcomes. Antihistamine use during an acute episode of OM should be avoided, since the drug may prolong the duration of middle ear effusion. The efficacy of 7- to 10-day treatment of AOM with corticosteroid, in addition to antibiotic, deserves further investigation.

Acute Disease↗
PubMed2003

Importance of respiratory viruses in acute otitis media.

Acute otitis media is usually considered a simple bacterial infection that is treated with antibiotics. However, ample evidence derived from studies ranging from animal experiments to extensive clinical trials supports a crucial role for respiratory viruses in the etiology and pathogenesis of acute otitis media. Viral infection of the upper respiratory mucosa initiates the whole cascade of events that finally leads to the development of acute otitis media as a complication. The pathogenesis of acute otitis media involves a complex interplay between viruses, bacteria, and the host's inflammatory response. In a substantial number of children, viruses can be found in the middle-ear fluid either alone or together with bacteria, and recent studies indicate that at least some viruses actively invade the middle ear. Viruses appear to enhance the inflammatory process in the middle ear, and they may significantly impair the resolution of otitis media. Prevention of the predisposing viral infection by vaccination against the major viruses would probably be the most effective way to prevent acute otitis media. Alternatively, early treatment of the viral infection with specific antiviral agents would also be effective in reducing the occurrence of acute otitis media.

Acute Disease↗
PubMed2003

Bullous myringitis: a case-control study.

Prior studies have shown that bullous myringitis (BM) accounts for <10% of acute otitis media (AOM) cases, and that the distribution of viral and bacterial pathogens in BM is similar to that in AOM without BM, except for a relative increase in the proportion of Streptococcus pneumoniae in BM. We studied 518 cases of AOM in children aged 6 months to 12 years. Using tele-otoscopy to assist the diagnosis, we identified 41 cases (7.9%) with BM. Children who had AOM with BM were older than AOM patients without BM (median age: 4.3 years vs 18 months). We compared 41 cases of AOM with BM to 41 control cases of age-, race-, and gender-matched AOM patients without BM. When compared with this matched control group, children with BM had more severe symptoms at the time of diagnosis and were more likely to have bulging of the tympanic membrane in the quadrants that were not obscured by the bulla. Children with AOM and BM may require aggressive pain management. Although parents and clinicians may agree that a watchful waiting approach is appropriate for older children with mild AOM, children experiencing painful AOM with BM may not be successful candidates for a watchful-waiting approach, because parents may resist postponement of antibiotic therapy in children who are more symptomatic.

Acute Disease↗