Detection of immunoglobulin M and immunoglobulin G antibodies to Mycoplasma pneumoniae in children with community-acquired lower respiratory tract infections.

CONTEXT: Mycoplasma pneumoniae (M. pneumoniae) causes up to 40% of community-acquired pneumonia in children. It is impossible to identify M. pneumoniae infection on the basis of clinical signs, symptoms, and radiological features. Therefore, correct etiological diagnosis strongly depends on laboratory diagnosis. AIMS: This study aims to investigate the role of M. pneumonia e in pediatric lower respiratory tract infections (LRTIs) employing enzyme-linked immunosorbent assays (ELISA) and particle agglutination (PA) test. SETTINGS AND DESIGN: Two hundred and eighty children, age 6 months to 12 years with community-acquired LRTIs were investigated for M. pneumoniae etiology. MATERIALS AND METHODS: We investigated 280 children hospitalized for community-acquired LRTIs, using ELISA and PA test for detecting M. pneumoniae immunoglobulin M (IgM) and immunoglobulin G antibodies. STATISTICAL ANALYSIS USED: The difference of proportion between the qualitative variables was tested using the Chi-square test and Fischer exact test. P ≤ 0.05 was considered as statistically significant. Kappa value was used to assess agreement between ELISA and PA test. RESULTS: M. pneumoniae was positive in 51 (23.2%) <5 years and 33 (54.0%) children in ≥5 years of age group, and this difference was statistically significant (P < 0.001). Clinical and radiological findings in M. pneumoniae positive and negative groups were comparable. ELISA detected M. pneumoniae in 78 (27.8%) and PA test 39 (13.9%) patients; 33 (84.6%) ELISA positive and 6 (15.4%) ELISA negative. ELISA/PA test together detected M. pneumoniae infection in 84 (30%) children. CONCLUSIONS: Our data underline that M. pneumoniae plays an important role in children with community-acquired LRTIs and more particularly in children >5 years of age.

Croup: an 11-year study in a pediatric practice.

The etiology and epidemiology of croup were studied in a pediatric group practice over an 11-year period, 1964 to 1975. Croup was diagnosed in 951 instances in 6,165 cases of lower respiratory tract infection (LRI) studied. As census figures of the practice clientele were available, attack rates were calculated. The incidence of total LRI was highest in the first year of life. In contrast, the attack rate for croup was highest in the second year of life; the rate declined gradually after that age. Croup was not diagnosed in the first month of life. Boys were 1.43 times more likely to develop croup than were girls. Three hundred sixty agents were isolated from the 951 croup cases. The parainfluenza viruses accounted for 74.2% of all isolates; 65% of the parainfluenza isolates were classified as parainfluenza virus type 1. Respiratory syncytial virus, influenza viruses A and B, and Mycoplasma pneumoniae were the only other agents isolated in appreciable numbers. The propensity of various agents to produce croup symptoms in children with LRI due to specific microorganisms was 58% for parainfluenzae type 1,60% for parainfluenzae type 2, and 29% for parainfluenzae type 3; similar figures for the other agents varied from 5% to 16%. The role of the various agents in the etiology of croup varied with patient age and depended on the propensity of the agent to produce the croup syndrome and the frequency of isolation of the agent at that age. The parainfluenza viruses were the most important croup agents at all ages; respiratory syncytial virus caused croup in children less than 5 years of age whereas the influenza viruses and M pneumoniae were significant causes of croup only in children more than 5 to 6 years old. Croup occurred predominately in late fall and early winter, times when the parainfluenza viruses, especially type 1, occurred most frequently. The epidemiology of croup differs from that of bronchiolitis, pneumonia, and tracheobronchitis; knowledge of this should be helpful to the clinician caring for children with LRI.

Parainfluenza viral infections in pediatric outpatients: seasonal patterns and clinical characteristics.

Parainfluenza types 1, 2 and 3 were studied in a pediatric outpatient population from 1976 to 1992 to compare seasonal patterns over time and to define better the spectrum of illness in all ages of children caused by these viruses. Parainfluenza type 1 occurred in the fall of odd numbered years; parainfluenza type 2 was less predictable; and parainfluenza type 3 appeared yearly with peak activity in spring or summer. The parainfluenza viruses were the major cause of croup and also accounted for one-half of the cases of laryngitis and over one-third of all lower respiratory tract illness in children from whom a virus was isolated. The major clinical manifestations of infection with parainfluenza types 1 and 2 were croup, upper respiratory infections and pharyngitis; for parainfluenza type 3 upper respiratory tract infection was predominant in all age groups. The parainfluenza viruses cause appreciable respiratory morbidity each year among infants and young children. They are the major cause of croup but also produce a spectrum of diseases ranging from mild upper respiratory tract infection to bronchiolitis and pneumonia. Most studies have focused on the morbidity of parainfluenza viruses in infants and young children who are hospitalized. Less appreciated is the impact of parainfluenza viral infections in outpatients and in older children. The parainfluenza viruses have a striking epidemiologic pattern which has evolved over the past 30 years. In the early 1960s parainfluenza types 1, 2 and 3 were all reported to be endemic.(ABSTRACT TRUNCATED AT 250 WORDS)

Low risk of bacteremia in febrile children with recognizable viral syndromes.

BACKGROUND: Previous studies of occult bacteremia in febrile children have excluded patients with recognizable viral syndromes (RVS). There is little information in the literature regarding the rate of bacteremia in febrile children with RVS. OBJECTIVE: To determine the rate of bacteremia in children 3 to 36 months of age with fever and RVS. METHODS: We performed a retrospective analysis of all patients 3 to 36 months of age with a temperature > or =39 degrees C seen during a 5 1/2-year period in the Emergency Department of a tertiary care pediatric hospital. From this group those with a discharge diagnosis of croup, varicella, bronchiolitis or stomatitis and no apparent concomitant bacterial infection were considered to have an RVS. The rate of bacteremia was determined for those subjects with RVS who had blood cultures. RESULTS: Of 21,216 patients 3 to 36 months of age with a temperature > or =39 degrees C, 1347 (6%) were diagnosed with an RVS. Blood cultures were obtained in 876 (65%) of RVS patients. Of patients who had blood cultures, true pathogens were found in only 2 of 876 (0.2%) subjects with RVS [95% confidence interval (CI) 0.01, 0.8%]. The rate of bacteremia was 1 of 411 (0.2%) for subjects with bronchiolitis, O of 249 (0%) for subjects with croup, O of 123 (0%) for subjects with stomatitis and 1 of 93 (1.1%) for subjects with varicella. CONCLUSIONS: Highly febrile children 3 to 36 months of age with uncomplicated croup, bronchiolitis, varicella or stomatitis have a very low rate of bacteremia and need not have blood drawn for culture.

Respiratory syncytial virus illnesses in human immunodeficiency virus- and noninfected children.

Respiratory syncytial virus (RSV) lower respiratory tract and febrile upper respiratory tract illnesses were prospectively assessed in cohorts of 83 infants born to human immunodeficiency virus (HIV)- and of 48 infants born to non-HIV-infected mothers. Of the infants born to HIV-infected mothers, 18 were themselves infected with HIV, 26 were indeterminant and 39 were free from HIV. Ten RSV illnesses occurred in 8 HIV-infected, 2 illnesses in 2 indeterminant and 17 illnesses occurred in 17 non-HIV-infected children. RSV shedding was prolonged in HIV class P2- vs. non-HIV-infected children, at medians of 30 days (range, 1 to 199 days) and 6 days (range, 1 to 21 days), respectively (P = 0.02). Ribavirin and intravenous immunoglobulin failed to eradicate RSV from one child who shed virus for 199 days. Wheezing occurred in 1 of 4 vs. 9 of 10 episodes of lower respiratory tract illness in HIV-infected and non-HIV-infected children, respectively (P = 0.04). No differences were noted in duration of illness, temperature, respiratory rate or oxygen saturation between HIV- and non-HIV-infected children. Infection control and public health concerns regarding prolonged shedding of RSV in HIV-infected children must be recognized.

Herpes simplex virus infection. A rare cause of prolonged croup.

Pediatric acute subglottic croup is generally of limited duration (usually 2 to 7 days) and caused by influenza or parainfluenza viruses. Prolonged infections may involve other pathogens. To date and to our knowledge, there has been but a single case report of herpes simplex virus type 1 (HSV-1) infection prolonging croup attributed to prolonged use of corticosteroids. Other authors have reported a wide range of HSV-1 infections of the upper and lower respiratory tracts in all age groups that are usually associated with immunocompromise. Two immunocompetent toddlers with prolonged croup associated with HSV-1-positive subglottic lesions are described herein. In one case the culture was obtained 11 days after just three doses of dexamethasone treatment. In the second case the culture was obtained after 10 days of prednisone therapy; the infection cleared quickly following treatment with acyclovir and rapid taper of the prednisone dose. These cases suggest that prolonged croup-like symptoms warrant thorough airway evaluation. Herpes simplex virus type 1 should be a suspected pathogen in cases of prolonged or atypical croup. Herpes simplex virus type 1 croup is not necessarily associated with immunocompromise or prolonged corticosteroid therapy. Acyclovir seems to be effective in treating other airway HSV infections, and by analogy it is the treatment of choice in recalcitrant herpetic croup. It is unknown whether HSV-1 represents a primary or secondary pathogen in prolonged croup.

Diagnosis and management of croup and epiglottitis.

Viral croup and epiglottitis are two major inflammatory causes of airway obstruction in children. Two conditions, spasmodic croup and membranous laryngotracheobronchitis, are also frequent causes of obstruction on an inflammatory basis. Rapid diagnosis and effective management are required to ensure an uncomplicated outcome. The pharmacologic treatment, role and timing of endoscopy, and airway management principles are discussed.

Acute respiratory tract infections of children in hospital: a viral and Mycoplasma pneumoniae profile.

Respiratory specimens and blood were collected from all infants and children admitted with acute respiratory illness to a paediatric unit in Christchurch from May to November (late autumn, winter and spring) 1983, to define the viral aetiological agents involved. A virus or Mycoplasma pneumoniae was identified in 160 (50%) of 317 children studied by the rapid indirect immunofluorescence, virus culture and/or serological techniques. Aetiological agents were detected in 71% of children with bronchiolitis, 57% with pneumonia, 53% with bronchitis, 40% with laryngotracheitis (croup), and 45% with upper respiratory tract illness. Respiratory syncytial virus was the most frequently identified virus, confirming the importance of this virus as a cause of respiratory illness requiring hospitalisation of young children in Christchurch. An epidemic due to influenza A/Dunedin/7/83 (HINI) and A/New Caledonia/4/83 (HINI) viruses occurred during the study period.

Croup syndrome in children: five-year experience.

To investigate the etiology and clinical features of croup syndrome, clinical records of hospitalized children with a diagnosis of croup syndrome were reviewed from April 1990 to January 1996. There was a total of 132 children, aged between three months and seven years with a mean age of 21.3 +/- 16.8 months. A diagnosis of laryngotracheobronchitis was made in 123 (93.2 percent) children. Twenty-three pathogens were identified in twenty-two of them, including seven parainfluenza viruses, five respiratory syncytial viruses, four influenza A viruses, four Mycoplasma pneumoniae, and three adenoviruses. Bacterial tracheitis was confirmed by bronchoscopic examination in seven cases (5.3 percent). Cultures of the respiratory secretions yielded viridans streptococci in six and Staphylococcus aureus in one child. Two children (1.5 percent) had spasmodic croup. No case with epiglottitis was noted in the present study. A fever lasting for more than three days was noted in five (71 percent) children with bacterial tracheitis and thirty-five (28 percent) children with laryngotracheobronchitis (p = 0.048). Among children with laryngotracheobronchitis, an associated diagnosis of pneumonia, acute otitis media, or paranasal sinusitis was more frequently observed in those with fever > 3 days (40 percent) than those with a shorter duration of fever (17 percent, p = 0.013). In conclusion, a child with a longer duration of fever and more severe manifestations of airway obstruction probably has a bacterial cause of croup syndrome or a bacterial complication. Bacterial tracheitis is more common than epiglottitis in Taiwan.

[Croup in children--results of prospective, multicenter observation]. / Przyczyny ostrej dusznosci krtaniowej u dzieci--wyniki prospektywnych wieloosrodkowych obserwacji.

UNLABELLED: Croup syndrome is an urgent and frequent reason for hospitalization of children. MATERIAL AND METHODS: 632 children with croup syndrome (422 boys and 210 girls aged 2 months-17 years) admitted to 15 pediatric departments in Lower Silesia were prospectively observed for 12 months (from April 2001 to March 2002). We conducted prospective survey of clinical and laboratory data from all study centers. RESULTS: Following diagnoses were accepted as the croup syndrome: subglottic laryngitis in 482 patients (75.4%), laryngotracheobronchitis in 75 (11.8%), laryngitis in 50 (7.8%) and epiglottitis in 20 children (3%). The most severe course was observed in children with epiglottitis. Four of them required airway intervention and had endotracheal intubation. H. influenzae b was cultured from blood of one patient. The most cases of epiglottitis occurred in the 3rd year of life (45%). CONCLUSIONS: 1. The most common reason of croup was subglottic laryngitis. 2. Epiglottitis was rare with serious course of disease; frequency was comparable with the frequency seen in European countries before the implementation of Hib vaccine. The routine use of Hib vaccine in Poland may prevent from children life threatening epiglottis cases.

Bacterial croup caused by Pasteurella haemolytica.

We report a case of bacterial croup caused by Pasteurella haemolytica. A nine-month-old girl was admitted to our hospital because of abrupt onset dyspnea and unconsciousness. From clinical and laboratory findings, she was diagnosed as having bacterial croup. Pasteurella haemolytica was recovered from her tracheal secretion on admission. To our knowledge, this is the first report of bacterial croup caused by P. haemolytica.

Branhamella catarrhalis and croup: toxicity in the upper respiratory tract.

Branhamella catarrhalis has gained increasing recognition as a pathogen in the respiratory tract. During the past 18 years, since its transfer from the genus Neisseria, it has been associated with infection in cavities of the respiratory tract (sinuses and middle ear). It has been recognized as playing a role in laryngitis. Its isolation in large numbers from the surface and core of acutely and chronically infected tonsils indicates a possible role in these infections. Croup (two patients reported here) can now be added to this list. The toxic potential of B catarrhalis, its movement from commensal to pathogen for the upper respiratory tract, and the pathogenic mechanisms by which this has occurred are reviewed.

Acute laryngo-tracheo-bronchitis (croup): an audit of hospital practice.

The objective of this study was to audit the management of acute laryngo-tracheo-bronchitis in a paediatric unit. This was achieved by retrospective case note audit and a review of the investigations and management of all admitted patients in light of the current literature. There was inappropriate use of radiography and outmoded therapies. There has been an increasing use of adrenaline and steroids in the past 4 years. Prescribing of adrenaline was lax and was associated with potential danger to the patient. For a common condition such as croup, an agreed protocol taking into account current published recommendations is warranted and has been introduced into this unit following this audit.

The need for intubation in serious upper respiratory tract infection in pediatric patients (a retrospective study).

Serious bacterial infections occurred in ten children (1.4%) of 710 patients with croup admitted to the Soroka Medical Center during the years 1983-1989. Sixty-four patients (9% of all croup patients) were admitted to the pediatric intensive care unit (PICU), and 13 of them (20%) required intubation. Bacterial infections were noted in nine of the 13 intubated patients, in none of the other 51 PICU patients who did not require intubation and in one of the 646 patients (0.2%) who were not admitted to the PICU (p less than 0.0001). There was no difference in age, ethnic origin, or body temperature on arrival between the two PICU groups. Causative microorganisms were isolated from blood samples (three cases) and tracheal pus (eight cases). All intubated PICU patients were seriously ill: eight had bacterial tracheitis and one supraglottitis. Patients with bacterial tracheitis required frequent suctioning of the trachea for copious purulent secretions. The single patient with bacterial infection who was not admitted to the PICU had transient bacteremia. We conclude that the need for intubation in croup patients was an indicator for the presence of a serious bacterial infection.

Parainfluenza viral infections in children: correlation of shedding with clinical manifestations.

Children presenting with acute respiratory disease to a private group practice in the fall of 1975 were studied to: (1) evaluate the efficacy in a pediatric office of a simple technics of obtaining nasal washes for the diagnosis of parainfluenza virus infections and (2) to determine the quantities of virus shed in relation to clinical characteristics. The nasal wash technic proved feasible for an office or clinic. Parainfluenza virus type 1 was recovered from 26 (74%) of 35 children with croup and from 40 (56%) of the total 72 children presenting with any form of respiratory illness. Virus was recovered significantly more often from children with croup and from those of younger age. The mean quantity of virus in 26 nasal washes was 2.97 log10 TCID50/ml. The shedding of greater quantities was correlated with younger age and the more frequent occurrence of laryngitis, pharyngitis, and fever.

[Protracted croup syndrome. Bacteriologic findings and therapeutic consequences]. / Protrahiertes Croup-Syndrom. Bakteriologische Befunde und therapeutische Konsequenzen.

BACKGROUND: Croup normally is characterized by acute onset and a self limited course of only few days. In 1990 and 1991 at the University Children's Hospital Freiburg an unexpected high number of patients were hospitalized for prolonged Croup syndrome. Expanded microbiological investigations were used to uncover etiologic factors. METHODS: Of a total of 138 inpatients with Croup 60 (17 in their first year of life, 21 in the second year of life and 22 infants older than 2 years) had bacteriological (37 nasopharyngeal-, 4 tracheal-aspirates or 19 throat swabs), and virological (antigen detection in nasopharyngeal aspirates, n = 28) tests. Of these patients 48% were hospitalized longer than 3 days (mean 4,7; range 1-18 days). RESULTS: Bacteria found: B. catarrhalis 24/11 (total/pure-culture), S. pneumoniae 15/6, H. influenzae 10/3, S. group A 5/4 and S. aureus 4/1. Sixteen specimen yielded more than one pathogen, one specimen was sterile. Nasopharyngeal secretions had the most reliable results: Pure cultures (72%) and associations of two pathogens (87%) were found in these aspirates, and only 26% of the unspecific mixed findings (p < 0.005; chi 2-Test). Of the patients hospitalized longer than 3 days 27.6% had positive cultures for H. influenzae, whereas only 6.5% of those hospitalized shorter (p < 0.05; chi 2-Test). The only microorganism with an age-bound distribution was B. catarrhalis found predominantly (54.2%) in the 2nd year of life, with 62% of patients positive (p < 0.05; chi 2-Test). Virus found: RSV (n = 3), Parainfluenza 2 (1) and Parainfluenza 3 (1). CONCLUSIONS: Nasopharyngeal aspirate is the most reliable specimen for a bacteriologic diagnosis in Croup. In the second year of life B. catarrhalis is present in most Croup cases, and H. influenzae was associated with a prolonged course of the disease. An appropriate antibiotic therapy therefore must cover these two pathogens.

Influenza A and B virus infection in infants and young children during the years 1957-1976.

Influenza A virus activity was demonstrated in infants and young children from metropolitan Washington, DC during each of 19 successive August-July respiratory disease years, and during 17 of these years at least 2% of hospitalized respiratory disease patients yielded an influenza A or B virus and/or showed an influenza A or B serum complement-fixing (CF) antibody response. Between October 1957 and July 1976, 14.3% of 860 croup patients and 5.3% of a total of 5655 hospitalized respiratory patients, including croup patients, showed evidence of influenza A or B infection. The mean period of hospitalization with either virus was about 8 days, though serious infection with influenza A virus was 4.5 times more common than with influenza B virus. Both influenza viruses were detected more frequently in respiratory disease outpatients than in respiratory disease inpatients. Patients with serious influenza A virus infections were especially likely to have croup (particularly during the H3N2 era), to be seen during December through February, and to be black male infants. During the peak month of a composite of 13 consecutive influenza A virus outbreaks, influenza A virus infection was demonstrated in 67.6% of croup patients and in 35.6% of all hospitalized respiratory patients including croup patients. During the peak month of a composite of 6 consecutive influenza B virus outbreaks, influenza B virus infection was demonstrated in 36.0% of croup patients and in 10.8% of all hospitalized respiratory disease patients including croup patients.

Quantitative shedding patterns of respiratory syncytial virus in infants.

Quantitative shedding patterns of respiratory syncytial virus in 40 infants hospitalized with acute disease of the lower respiratory tract were determined for elucidation of the pathophysiology of infection with the virus. Nasal wash specimens were collected on admission and daily thereafter and were tested for the presence and quantities of respiratory syncytial virus. The following pattern of shedding was observed. (1) The virus was shed for prolonged periods. For the first seven days of hospitalization, 92%-100% of the infants tested continued to shed virus. At discharge 87% were still shedding the virus. (2) Respiratory syncytial virus was present in high titer in the nasal secretions obtained at the time of admission. The mean titer in these samples was 5.0 log10 TCID50. (3) The titer of respiratory syncytial virus did not fall during the first few days of hospitalization, despite clinical improvement of the infants. Neither peak nor admission titers of virus could be correlated with age or with the severity of disease. However, the mean admission titer in patients with bronchiolitis appeared to be significantly higher than that in those with pneumonia.

Aetiology and epidemiology of viral croup in Glasgow, 1966-72.

A retrospective study of 258 children admitted to Ruchill Hospital, Glasgow, with croup between 1966 and 1972 indicated that the viruses most frequently associated with the syndrome were parainfluenza types 1 and 3 and influenza A. Most cases were admitted in the late autumn and winter months, with a small peak in May and June. This seasonal distribution mirrored the circulation of the main causative agents in the community, parainfluenza 1 being principally associated with the autumn cases, influenza A the winter cases and parainfluenza 3 the summer cases. Two of these ;croup associated' viruses showed regular periodicity, parainfluenza 1 occurring biennially in even years and influenza A in most years. The periodicity of parainfluenza 3 is as yet undetermined.