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PubMed1990

Wood-burning stoves and lower respiratory tract infection in American Indian children.

Some studies suggest that home use of wood-burning stoves is an independent risk factor for lower respiratory tract infection in young children. To test this hypothesis in a population with a high prevalence of wood-burning stove use, we studied Navajo children with diagnosed pneumonia or bronchiolitis. We matched each case (less than or equal to 24 months of age) with a child of identical sex and age who was seen for well-child care or a minor health problem, and we interviewed an adult caretaker about family history and environmental exposures. Analyzing 58 case-control pairs, we found that home wood-burning stove use, recent respiratory illness exposure, family history of asthma, dirt floors, and lack of running water in the home increased the risk of lower respiratory tract infection. On multiple logistic regression analysis, however, only wood-burning stove use and respiratory illness exposure were independently associated with higher risk.

Bronchiolitis↗
PubMedDate not supplied

Increased incidence of asthma and pulmonary dysfunction after severe lower respiratory tract infection in infancy.

In the present study we tried to define the effect of lower respiratory tract infections upon pulmonary function and/or asthma in childhood. Thirty-five children with history of pneumonia in infancy were followed five to ten years later; all were asked to respond questionnaire, received physical examination and were diagnosed for pulmonary function. The results follow: 13 children (37%) had developed asthma, a significantly higher percentage than normal prevalence among students in this area. Simple pulmonary function test, pulmonary function test after distilled water mist and after hypertonic saline (4.5%) mist all showed abnormal values in VC (17%, 14%, 29% respectively), in IVC (46%, 51%, 53%), in FVC (20%, 23%, 24%), in FEVl (17%, 23%, 29%), in FEF25-75% (37%, 49%, 47%), in FEF75% (26%, 23%, 29%) and in FEVl/VC (20%, 14%, 29%). Methacholine challenge test (PC20) showed a marked decrease of PC20 in asthmatic children; each was less than 5 mg/ml (mean value; 0.99 mg/ml). Family-allergy in at least one parent and wheeze were the two significant risk factors. Nevertheless, in 22 non-family-allergy children, the occurrence of asthma was also higher than general prevalence (18.2% vs 5.6%). Wheezing was evident in viral infections in infancy, but bacterial culture from sputum or throat swabs failed to find pathogenic bacteria. These results indicate that while the genetic factor may be important, viral infections may be more important because, even in non-family-allergy children, the occurrence of asthma was higher for infants infected in early infancy than the general prevalence for age-matched students.

Asthma↗
PubMed1982

Adhesion of type A Pasteurella mulocida to rabbit pharyngeal cells and its possible role in rabbit respiratory tract infections.

Pasteurella multocida serotype A was found in association with the mucosal epithelium of the nasopharynges of rabbits with respiratory tract infections. The bacteria specifically attached to squamous epithelial cells of the pharyngeal mucosa both in vivo and in vitro and to some tissue culture cell lines such as HeLa. All strains with serotype A capsules were adhesive. With the exception of one serotype D strain, strains with capsular serotypes B, D, and E were at least 10-fold less adhesive. Bacterial adhesiveness was much reduced after pronase digestion, heat treatment, and homogenization, but removal of the hyaluronic acid capsule increased adhesion. Electron microscopy revealed that fimbriae were produced by an adhesive pasteurella strain, but not by two nonadherent strains. The attachment of the former strain to pharyngeal and HeLa cells was inhibited by N-acetyl-D-glucosamine. Together, these findings suggest that this amino sugar may be a component of the receptor on both animal cell surfaces and that the fimbriae may be the adhesions. It is proposed that bacterial attachment has a role in colonization and infection of rabbit upper respiratory mucosae.

Adhesiveness↗
PubMed2005

Predictors of antibiotic prescription in respiratory tract infections by ambulatory care practitioners.

The use of antibiotics in viral respiratory infections (common cold, acute rhinosinusitis and acute bronchitis) promotes the emergence and spread of resistant bacteria. Studies have found that antibiotics are prescribed for 50-70% of respiratory tract infections, despite the fact that most of them have a viral etiology. The objective of the study was to determine predictors of antibiotic use in acute respiratory infections. It was conducted as a cross-sectional study on physicians' practices for antibiotic use. The subjects were internists and otolaryngologists of adult patients in an ambulatory setting in Buenos Aires. The instrument was a questionnaire with 20 clinical vignettes that included relevant variables for making decisions regarding antibiotic use in acute respiratory infections. The vignettes were constructed with a fractional factorial design with nine clinical variables. The absolute and relative weight of each clinical variable that predicted antibiotic use were calculated for each individual practitioner using multiple linear regression. The predictors with the greatest absolute weight in the decision to prescribe antibiotics were nasal discharge and cough (24% and 21% of total weight). The correlation between predictors and individual physician answers was high (r2 = 0.73). The mean probability and the rate of antibiotic prescription were both about 50%. Predictors of antibiotic use for acute respiratory infections among ambulatory physicians in this sample differ from internationally accepted guidelines. The likelihood of prescribing antibiotics for these illnesses is high. Wider implementation of management guidelines for acute respiratory infections could improve cost effective antibiotic use and decrease the development of antibiotic resistance.

Acute Disease↗
PubMed2001

Respiratory tract infections in cytomegalovirus-excreting and nonexcreting infants.

BACKGROUND: There is evidence of an immunosuppressive effect of cytomegalovirus (CMV), and CMV has been claimed to be a copathogen in respiratory tract infections (RTI). We therefore studied the significance of CMV viral load in infants with RTI, compared the frequency of infection with respiratory viruses and followed the course of RTI in CMV-excreting vs. nonexcreting infants. METHODS: We examined 201 infants consecutively admitted to the Department of Pediatrics for RTI. At admission nasopharyngeal aspirates, throat swabs and urine were examined for CMV, and nasopharyngeal aspirates were examined for respiratory viruses. RESULTS: In these patients 23.3% had CMV in the urine, 15.3% had CMV in the throat and 10.9% had CMV in the nasopharynx; 26.2% excreted CMV in at least one site. No relationship was found between CMV viral load and clinical symptoms. Infection with respiratory viruses was as common in infants excreting CMV as in nonexcreting infants. Symptoms and the course of infection were not different in the two groups except that CMV-excreting infants had a significantly higher frequency of rhonchi at admission (P = 0.007) and a tendency for longer duration of cough (P = 0.06). CONCLUSION: CMV viral load was not related to clinical symptoms. The frequency of infection with common respiratory viruses in infants was independent of CMV excretion. The course of infection was not more complicated in infants excreting CMV; however, a higher frequency of rhonchi was demonstrated in patients with CMV.

Child, Preschool↗
PubMed2001

The relationship between atopic status and IL-10 nasal lavage levels in the acute and persistent inflammatory response to upper respiratory tract infection.

We examined the influence of atopy on virus-induced airway inflammation by comparing the nasal response to naturally acquired upper respiratory tract infection in atopic and nonatopic subjects by measurement of cytokine, chemokine, and mediator levels in nasal lavage from 44 adults (23 atopic) taken during the acute and the convalescent phases of the common cold. Nasal aspirates were examined for the presence of upper respiratory viruses by RT-PCR. In atopic and nonatopic subjects there were increased levels of IL-1beta, IL-6, IL-8, TNF-alpha, RANTES, sICAM-1, MPO, ECP, IL-10, and IFN-gamma in nasal lavage during the acute compared with the convalescent phase (p < 0.001). During the acute phase histamine levels were significantly higher in the atopic than in the nonatopic subjects (p < 0.05), whereas IL-10 levels were significantly greater in the nonatopic than in the atopic subjects (p < 0.05). At convalescence levels of IL-1beta, IL-6, sICAM-1, ECP, RANTES and albumin were significantly higher in the atopic group (p < 0.05). An upper respiratory tract virus was found in 27 volunteers (61%) during the acute stage and in two volunteers (4%) at convalescence. We conclude that virus-induced inflammatory changes within the nose are more prolonged in atopic than in nonatopic subjects and that this is associated with reduced IL-10 levels in atopic compared with nonatopic subjects during the acute phase of upper respiratory tract infection.

Acute-Phase Proteins↗
PubMed2000

Vitamin A supplements and diarrheal and respiratory tract infections among children in Dar es Salaam, Tanzania.

OBJECTIVE: To determine the effect of vitamin A supplementation on the risk of diarrhea and of acute respiratory infection. DESIGN: Double-blind, randomized, placebo-controlled trial. SETTING: Dar-es-Salaam, Tanzania. SUBJECTS: Six hundred eighty-seven children, 6 to 60 months old, hospitalized with pneumonia, who received vitamin A or placebo at baseline and at 4 and 8 months after discharge from hospital. MAIN OUTCOME VARIABLES: Incidence and duration of episodes of diarrhea and respiratory tract infections during the year after discharge from the hospital. RESULTS: Relative to those receiving placebo, children receiving vitamin A had a significantly smaller risk of severe watery diarrhea (multivariate odds ratio = 0.56, 95% CI = 0.32-0.99, P =.04) but a higher risk of cough and rapid respiratory rate (multivariate odds ratio = 1.67, 95% CI = 1.17-2.36, P =.004). Vitamin A supplementation was also associated with increased risk of acute diarrhea among normally nourished children or children with stunted growth but was relatively protective among children with wasting disease (P value for interaction =.01). The apparently increased risk of respiratory tract infection was limited to children who were seronegative for human immunodeficiency virus (HIV) (P value for interaction =.07). CONCLUSIONS: Vitamin A supplements provide a low-cost intervention against morbidity in HIV-infected and undernourished children. Supplements may also have serious non-lethal adverse outcomes in well-nourished individuals. Whether these apparent detrimental effects of vitamin A are transient or long-term needs to be examined.

Child, Preschool↗
PubMed2001

Quantitative culture of bronchoalveolar lavage fluid in community-acquired lower respiratory tract infections.

To evaluate the diagnostic value of quantitative bacterial culture of bronchoalveolar lavage (BAL) fluid obtained by fibreoptic bronchoscopy, 67 consecutive immunocompetent adult patients admitted to hospital with community-acquired lower respiratory tract infections from September 1997 to May 1998 were investigated. Results were compared to the findings in eight healthy control persons investigated in February 1998. There was no difference between study patients and control persons when quantitative culture of total cumulative bacterial findings or bacteria categorized as members of the oropharyngeal normal flora were compared. The culture of normal flora in bronchial washings probably reflects contamination of the lower airways with secretions from upper arways by the fibreoptic procedure itself, as fractionated sampling showed a 10-fold reduct on in quantitative culture results when a primary bronchial washing was compared to a secondary sampling from the same bronchus in the control group. Twenty-four (36%) of 67 patients were cultured as positive in the study group while all control persons were cultured as negative for bacteria categorized as potential pathogens. With a threshold value for positive culture of 10(4) cfu ml(-1) the specificity of lavage culture of potential pathogenic bacteria in relation to actual lower airway infection was 100%. Therefore, quantitative bacterial culture of potential pathogenic bacteria in BAL fluid is very specific but only positive in about one-third of unselected immunocompetent adult patients with a lower respiratory tract infection.

Adult↗
PubMed1993

[Clinical studies on ceftriaxone in respiratory tract infections. CTRX Study Group].

We report that the results of clinical studies on ceftriaxone (CTRX) in respiratory tract infections (RTIs). Clinical efficacies and side effects of CTRX were as follows; 1. Clinical efficacies of CTRX in a total of 61 cases with RTIs were excellent in 11 cases, good in 23, fair in 11, poor in 12 and unknown in 4. Thus the overall clinical efficacy rate was 59.6%. In cases of patients with lung cancers, the efficacy rate was 42.9%. 2. Clinical efficacy rates with once daily dosage were 50.0% with a dose level of 1 g CTRX and 54.8% with that of 2 g CTRX. 3. Side effects were observed in 2 cases (3.1%) and laboratory abnormalities were observed in 1 case (1.6%). They were not serious, however. These data suggest that CTRX is one of the useful cephalosporins in treatment of RTIs.

Adult↗
PubMed1984

Asian multicenter trial of cefoperazone in respiratory tract infection.

The safety and clinical efficacy of cefoperazone were evaluated in a multicenter trial conducted at institutions in Japan, Korea, and Taiwan. Cefoperazone was given as the sole antibiotic for 481 respiratory tract infections in 476 patients. An overall satisfactory clinical response was achieved in 73.7% of patients. Cefoperazone was effective in 78.9% of cases of pneumonia, 81.1% of acute exacerbations of chronic bronchitis, and 69.4% of bronchiectasis with infection. A satisfactory bacteriological effect was obtained in 93.2% of cases in which Haemophilus influenzae was isolated, 70.2% of Klebsiella infections, and 84.6% of infections with Streptococcus pneumoniae. Although the eradication rate was only 38.6% in patients with Pseudomonas aeruginosa, the success rate increases to 59.1% if patients showing a decrease in the number of organisms are included. Cefoperazone was effective in 63.5% of the 148 cases that had failed to respond to treatment with other antibiotics. Adverse reactions occurred in 8.0% of patients and consisted primarily of rash, diarrhea, and fever. Cefoperazone appears to be an extremely useful injectable antibiotic for the treatment of respiratory tract infections in hospitalized patients.

Adolescent↗
PubMed2006

Guidelines for the use of antibiotics in acute upper respiratory tract infections.

To help physicians with the appropriate use of antibiotics in children and adults with upper respiratory tract infection, a multidisciplinary team evaluated existing guidelines and summarized key practice points. Acute otitis media in children should be diagnosed only if there is abrupt onset, signs of middle ear effusion, and symptoms of inflammation. A period of observation without immediate use of antibiotics is an option for certain children. In patients with sinus infection, acute bacterial rhinosinusitis should be diagnosed and treated with antibiotics only if symptoms have not improved after 10 days or have worsened after five to seven days. In patients with sore throat, a diagnosis of group A beta-hemolytic streptococcus pharyngitis generally requires confirmation with rapid antigen testing, although other guidelines allow for empiric therapy if a validated clinical rule suggests a high likelihood of infection. Acute bronchitis in otherwise healthy adults should not be treated with antibiotics; delayed prescriptions may help ease patient fears and simultaneously reduce inappropriate use of antibiotics.

Acute Disease↗
PubMed2006

Efficacy of N-acetyl-cysteine in combination with thiamphenicol in sequential (intramuscular/aerosol) therapy of upper respiratory tract infections even when sustained by bacterial biofilms.

A total of 102 patients with recurrent upper respiratory tract infections underwent microbiological exploration with appropriate sampling and direct biopsies of the infected sites. Therapy was then started and on day 1 each patient received two intramuscular injections of thiamphenicol glycinate acetylcysteinate (TGA). From day 2 to 10 sequential therapy with the same drug was continued employing TGA administered by aerosol. All putative etiologic agents recovered were susceptible to thiamphenicol and only 24 demonstrated the ability to produce in vitro biofilms. The organisms comprised 10 Staphylococcus aureus, 6 Streptococcus pyogenes, 4 Streptococcus pneumoniae and 3 Haemophilus influenzae. Of the 24 subjects in whom biofilms were demonstrated to be present in vivo by Scanning Electron Microscopy, clinical and bacteriological cure was obtained in 21 cases (87.5%) following sequential therapy with TGA. Failures were considered to be persistent signs and symptoms at day 15 after initiation of treatment and lack of eradication of 3 S. aureus strains, despite their in vitro susceptibility to thiamphenicol. Very few adverse events attributable to TGA were reported in this cohort of patients. In no case was discontinuation of treatment deemed necessary by the attending physician.

Acetylcysteine↗
PubMedDate not supplied

Mannan-binding lectin and RSV lower respiratory tract infection leading to hospitalization in children: a case-control study from Soweto, South Africa.

Respiratory syncytial virus (RSV) is the most important microbiological cause of lower respiratory tract infection (LRTI) in infants. Mannan-binding lectin (MBL) is believed to play a major protective role in the vulnerable period in infancy where the maternal antibodies have been catabolized, and the adaptive immune system has not yet matured. Mutations in the promoter region and in exon 1 of the gene-encoding MBL result in low serum levels of MBL. MBL deficiency is the most common immunodeficiency on the African Continent with frequencies of the variant alleles up to 0.29. We investigated whether MBL deficiency has an impact on the hospitalization for LRTI caused by RSV in infants from Soweto, South Africa. The cases were ethnic black Africans identified through surveillance for RSV-LRTI at Chris Hani Baragwanath Hospital, Soweto, and the controls were sampled from four immunization clinics in the area. Fifty-five cases and 113 age- and sex-matched controls were identified. Seventy-six per cent were under 6 months of age, and 42% (n = 23) were under 3 months of age. No association was found between low levels of MBL or carriage of variant alleles and LRTI caused by RSV, odds ratio (OR) 1.00 (CI 0.99-1.03) and OR 1.24 (0.73-2.12). We did not find support for the hypothesis that MBL deficiency leads to the hospitalization for LRTI caused by RSV.

Case-Control Studies↗
PubMed1997

Relevance of nucleic acid amplification techniques for diagnosis of respiratory tract infections in the clinical laboratory.

Clinical laboratories are increasingly receiving requests to perform nucleic acid amplification tests for the detection of a wide variety of infectious agents. In this paper, the efficiency of nucleic acid amplification techniques for the diagnosis of respiratory tract infections is reviewed. In general, these techniques should be applied only for the detection of microorganisms for which available diagnostic techniques are markedly insensitive or nonexistent or when turnaround times for existing tests (e.g., viral culture) are much longer than those expected with amplification. This is the case for rhinoviruses, coronaviruses, and hantaviruses causing a pulmonary syndrome, Bordetella pertussis, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Coxiella burnetii. For Legionella spp. and fungi, contamination originating from the environment is a limiting factor in interpretation of results, as is the difficulty in differentiating colonization and infection. Detection of these agents in urine or blood by amplification techniques remains to be evaluated. In the clinical setting, there is no need for molecular diagnostic tests for the diagnosis of Pneumocystis carinii. At present, amplification methods for Mycobacterium tuberculosis cannot replace the classical diagnostic techniques, due to their lack of sensitivity and the absence of specific internal controls for the detection of inhibitors of the reaction. Also, the results of interlaboratory comparisons are unsatisfactory. Furthermore, isolates are needed for susceptibility studies. Additional work remains to be done on sample preparation methods, comparison between different amplification methods, and analysis of results. The techniques can be useful for the rapid identification of M. tuberculosis in particular circumstances, as well as the rapid detection of most rifampin-resistant isolates. The introduction of diagnostic amplification techniques into a clinical laboratory implies a level of proficiency for excluding false-positive and false-negative results.

Bacterial Infections↗
PubMed1972

Are antibiotic drugs needed for the treatment of upper respiratory tract infections in infants?

Much confusion exists about the necessity of using antibiotic drugs to treat upper respiratory tract infections in children, especially infants. In this study the frequency of bacterial causes of such infections was studied in 4746 children under three years of age. Clinical evidence of infection was absent in half of these children and present in the others. There was no practical difference between the frequency of positive cultures from infected and non-infected children, suggesting that antibiotics were not required.

Age Factors↗
PubMed1996

[Comparative study on the efficacy of ritipenem acoxil and cefotiam hexetil in chronic lower respiratory tract infections by the double-blind method].

To objectively evaluate the efficacy, safety and usefulness of the newly developed penem oral antibiotic, ritipenem acoxil (RIPM-AC), against chronic lower respiratory tract infections, we conducted a multi-center double-blind comparative study using cefotiam hexetil (CTM-HE) as a control drug. RIPM-AC was orally administered at 200 mg, and CTM-HE at 400 mg, t.i.d. for 14 days, in principle. The results were as follows: The total number of patients enrolled in this trial was 202, of which 151 cases (RIPM-AC group: 75, CTM-HE group: 76) were evaluable for clinical efficacy. 1. The clinical efficacy rates (excellent+good) were 85.3% (64/75) in the RIPM-AC group and 80.3% (61/76) in the CTM-HE group. There was no significant difference between the two groups, hence the clinical equivalency of RIPM-AC to CTM-HE was demonstrated. 2. In the patients enrolled in the evaluation of clinical efficacy, the eradication rates of the causative organisms were 50.0% (13/26) in the RIPM-AC group and 75.0% (18/24) in the CTM-HE group, with no significant difference between the two groups. 3. Side effects were noted in 10 cases (11.0%) of the RIPM-AC group and 10 cases (10.9%) of the CTM-HE group. Abnormal laboratory test findings were observed in 8 cases(9.5%) of the RIPM-AC group and in 14 cases (16.7%) of the CTM-HE group. There were no significant differences between the two groups in the incidence of side effects and abnormal laboratory test findings. In the safety evaluation, RIPM-AC was judged to be safe in 73 cases (80.2%) and CTM-HE in 71 cases (77.2%), with no significant difference. 4. The usefulness rates (markedly useful+useful) were 79.5% (62/78) in the RIPM-AC group and 76.9% (60/78) in the CTM-HE group. There was no significant difference between the two groups. Since RIPM-AC showed clinical efficacy similar to those of CTM-HE and posed no particular safety problems, it is expected to be a useful antibiotic for the treatment of chronic lower respiratory tract infections.

Adult↗
PubMed1995

Comparison of the efficacy and safety of isepamicin and amikacin in the treatment of acute lower respiratory tract infections caused by gram-negative organisms.

In a prospective multicentre open trial, hospitalised adult patients with acute lower respiratory tract infections, mainly pneumonia or bronchitis, were randomised to receive either isepamicin 8 or 15 mg/kg once daily depending on the severity of the infection or amikacin 7.5 mg/kg twice daily. Patients with infections known to be caused by Pseudomonas aeruginosa were to be given concomitant treatment with ceftazidime. In the intent-to-treat population, i.e. patients who received at least one dose randomised treatment, a clinical cure or improvement at the end of treatment was seen in 112/125 (90%) isepamicin patients and 55/60 (92%) amikacin patients. The corresponding rates for patients with a primary diagnosis of pneumonia were 45/52 (87%) and 25/28 (89%). Cure/improvement rates for patients with P. aeruginosa as the causative pathogen (34 of whom also received ceftazidime) were 28/30 (93%) and 16/18 (89%), respectively. In the efficacy population (patients who had a valid pretreatment culture and who met other evaluability criteria), total elimination (documented or presumed if infection had resolved) of target pathogens occurred in 54/63 (86%) of isepamicin patients and 25/30 (83%) of amikacin patients. P. aeruginosa, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus were commonly isolated pathogens. Treatment-related adverse were mainly mild or moderate in severity and occurred in 10% of isepamicin patients and 13% of amikacin patients. Four patients (3 isepamicin and 1 amikacin) discontinued treatment because of severe adverse events and a further isepamicin patient withdrew because of a mild adverse event. Nephrotoxicity and ototoxicity occurred infrequently.

Adult↗