Manifestations cliniques des infections à Chlamydia pneumoniae

Chlamydia pneumoniae is a newly described and ubiquitous bacterium. Most infections are asymptomatic as shown by a high worldwide séroprévalence (> 50% of cases). It is a common cause of acute respiratory infections, mainly pneumonia (> 50% of cases) and other acute respiratory tract infections (25% of acute bronchitis, < 5% of sinusitis, otitis and pharyngitis). About 10% of the community acquired pneumonia cases have been associated with Chlamydia pneumoniae infection. This incidence depends on a cyclic epidemiology with a high incidence for 2 to 3 years-followed by a low prevalence for 3 to 4 years. Most chlamydial infections are mild but occasionnaly severe with death especially in old people. Mostly acute infections are reccurent infections. The seroprevalence is higher in asthmatic patients, its role in acute exacerbation of chronic bronchitis is not definitely established. Extra-respiratory acute infections are less frequent, either fever alone, or cardiovascular diseases (acute myocarditis, pericarditis and endocarditis) or neurological (encephalitis, meningitis or Gudlain-Barré syndrome). In addition, seroepidemiology studies have shown an association with coronary artery disease, Chlamydia pneumoniae was detected in coronary atheroma by immunochemistry, polymerase chain reaction and by electron microscopy. Chlamydia pneumoniae may be involved in the atherosclerotc process. To define the clinical spectrum of infection requires precise laboratory diagnosis, the most efficient tests (PCR, direct immunofluorescence and culture) are done in specialized laboratories, serological tests are less reliable. Macrolides, cyclines and fluoroquinolones are the most potent antibiotics but with differences in vitro within and between these families of antibiotics. Bacteriological failures are described despite the in vitro activity. A lot of questions on clinical aspects, epidemiology and treatement are unanswered, we need more studies.     

Nontypeable Haemophilus influenzae (NTHi) epidemiology

While most systemic pediatric Haemophilus influenzae infections are caused by the type b strain (Hib), nontypeable H. influenzae: (NTHi) has been considered a respiratory tract pathogen common in local infection such as acute otitis media, acute pneumonia, secondary chronic respiratory disease and other otorhinolaryngologic infections. Recent findings show, however, that NTHi also causes invasive infections such as meningitis, bacteremia, and lower respiratory tract infections such as pneumonia. A review of NTHi epidemiology from the 1990s onward shows that NTHi causes significant morbidity in pediatric acute otitis media, sinusitis, conjunctivitis and lower respiratory diseases such as pneumonia in Japan. This summary also reviews the worldwide influence of Streptococcus pneumoniae and Hib vaccines on causative pathogens, and several studies about increasing incidence of invasive infections due to NTHi. This review also touches on the emergence of treatment- and drug-resistant H. influenzae, which are now major public health challenges. As a cause of bacterial pediatric infection, NTHi is an important target for prevention.     

Health-related quality of life of adults with upper respiratory tract infections

OBJECTIVE: To determine the impact that upper respiratory tract infections have on patients' physical, social, and emotional functioning, we measured the health-related quality of life (HRQL) of adults with upper respiratory tract infections. SETTING: Acute care clinic from November 2001 to February 2002. DESIGN: Prospectively administered survey. To measure HRQL, we used the Acute Form of the Short Form-36, version 2 (SF-36). For all 8 SF-36 subscales, we used norm-based scoring, in which the general U.S. population has a mean of 50. PATIENTS: Adults who had symptoms for fewer than 30 days completed the SF-36; and were diagnosed with nonspecific upper respiratory infection, viral syndrome, otitis media, sinusitis, nonstreptococcal pharyngitis, streptococcal pharyngitis, or acute bronchitis. MEASUREMENTS AND MAIN RESULTS: The sample of 318 patients was 63% female, 81% white, and had a mean age of 35 years. The primary diagnoses were nonspecific upper respiratory infection (42%), acute bronchitis (16%), sinusitis (12%), viral syndrome (9%), nonstreptococcal pharyngitis (8%), otitis media (7%), and streptococcal pharyngitis (6%). Patients had a mean general health subscale score of 50.9, which is not significantly different from the mean population value of 50 (P =.09). However, there were significant decrements in the remaining 7 subscales of the SF-36: physical functioning (45.5), role-physical (38.5), bodily pain (42.6), vitality (40.8), social functioning (37.8), role-emotional (46.8), and mental health (46.8; P <.0001 for all 7 subscales compared with normative values). Results were similar for the subset of patients with no comorbid illnesses (P <.001 for the same 7 subscales) and patients diagnosed with nonspecific upper respiratory infection (P <.001 for the same 7 subscales). These decrements were similar in magnitude, but somewhat different in subscale pattern, to those of adults with chronic lung disease, osteoarthritis, and depression. CONCLUSIONS: Physicians should remember that adults who seek care for upper respiratory tract infections have measurable, significant decrements in HRQL. For researchers, HRQL is an attractive, potential measure of outcome in future trials of established and novel therapies for upper respiratory tract infections.     

Upper respiratory tract infections in general practice: diagnosis,antibiotic prescribing,duration of symptoms and use of diagnostic tests

A diagnosis/antibiotic prescribing study was performed in 5 counties in Sweden for 1 week in November 2000. As part of this study, the characteristics and clinical management of patients with upper respiratory tract infections (n = 2899) in primary care were analyzed. Almost half of the patients were aged < 15 y and one-fifth of the patients consulted out of hours. Of all patients seeking primary care for upper respiratory tract infections, 56.0% were prescribed an antibiotic. Almost all patients who were given the diagnoses streptococcal tonsillitis, acute otitis media or acute sinusitis were prescribed antibiotics, compared to 10% of patients with common cold or acute pharyngitis. The most frequently prescribed antibiotic was penicillin V (79.2%) and this was even more pronounced out of hours, when the diagnoses otitis media and streptococcal tonsillitis were more frequently used. In patients with common cold and acute pharyngitis, the percentage who received antibiotics increased with increasing length of symptoms and increasing CRP levels. In patients with acute pharyngitis or streptococcal tonsillitis, antibiotics were prescribed less frequently provided streptococcal tests were performed. The management of patients with upper respiratory tract infections in general practice seems to be in good agreement with current Swedish guidelines. However, the study indicates some areas for improvement. The diagnosis of acute sinusitis seems to have been overestimated and used only to justify antibiotic treatment.     

肺炎衣原体急性呼吸道感染的临床研究

目的了解成人呼吸道感染患者急性肺炎衣原体感染的患病情况及临床特征。方法呼吸道感染住院患者１１０例，同时采集痰和咽拭子标本，应用聚合酶链反应（ＰＣＲ）检测肺炎衣原体ＤＮＡ，及采取静脉血检测肺炎衣原体ＩｇＧ和ＩｇＭ抗体。结果本组患者肺炎衣原体ＩｇＧ抗体的阳性率为７０％（７７／１１０），其中１７例（１６％）有肺炎衣原体近期感染的急性抗体，１２例（１１％）痰和（或）咽拭子肺炎衣原体ＰＣＲ检测结果阳性，联合应用两种方法的阳性率为２３％（２５／１１０）。肺炎衣原体急性感染以支气管哮喘急性发作、肺炎、慢性阻塞性肺疾病急性加重和急性支气管炎患者多见（分别为５７％、３５％、２６％和２５％），其临床表现无特征性。结论结果提示成人呼吸道感染患者肺炎衣原体急性感染的阳性率较高，提示肺炎衣原体是呼吸道感染的重要致病原，应引起临床的高度重视     

Antibiotic prescribing for patients with colds, upper respiratory tract infections, and bronchitis: A national study of hospital-based emergency departments

STUDY OBJECTIVE: Antibiotics are often used to treat viral upper respiratory tract infections, even though they are usually ineffective. However, frequent inappropriate antibiotic use contributes to the emergence of drug-resistant bacterial pathogens. This study used a national database to evaluate antibiotic use in treating upper respiratory tract infections in emergency departments. METHODS: Data were obtained from the 1996 National Hospital Ambulatory Medical Care Survey. Antibiotic prescribing rates were examined for colds, upper respiratory tract infections, and acute bronchitis. Patients with comorbid conditions or secondary diagnoses, such as chronic obstructive pulmonary disease, pneumonia, sinusitis, and HIV, were excluded. Bivariate and multivariate analyses were used to assess predictors of antibiotic use. RESULTS: Overall, there were an estimated 2.7 million ED visits for colds, upper respiratory tract infections, and bronchitis by children and adults in 1996. Antibiotics were prescribed for 24.2% (95% CI 18.9, 29.5) of patients with common colds and upper respiratory tract infections and for 42.2% (95% CI 35.2, 49.2) of patients with bronchitis. There were no significant associations between antibiotic use and patient race, sex, Hispanic ethnicity, geographic location, or source of payment. Antibiotics were prescribed less often by interns or residents than by staff or other physicians (odds ratio 0.43; 95% CI 0.19, 0.98), and patients younger than 18 years were less likely to receive antibiotics than adults (odds ratio 0.32; 95% CI 0.20, 0.52). Smokers were 4.3 (95% CI 2.2, 8.3) times more likely to receive antibiotics than nonsmokers. CONCLUSION: Antibiotics are commonly prescribed for ED patients with upper respiratory tract infections even though they are usually ineffective in otherwise healthy adults. Efforts should be made to reduce inappropriate antibiotic use for the sake of containing costs, preventing side effects, and limiting the spread of antibiotic resistance.     

PCR and serology were effective for identifying Chlamydophila pneumoniae in a lower respiratory infection outbreak among military recruits

During endemic infections, the sensitivity of diagnostic tests and rapid diagnosis of the respiratory tract pathogens is particularly important. Utilization of just one diagnostic technique, such as serological tests or polymerase chain reaction (PCR)-based detection methods, during outbreaks of lower respiratory tract infections (LRI) can result in some of the patients being missed. In this study we aimed to investigate the etiology of LRI in military recruits in Izmir, Turkey, among whom several pneumonia cases have been reported and 47 patients have been hospitalized. Nasopharyngeal swabs were used for PCR analysis of Chlamydophila pneumoniae, Mycoplasma pneumoniae and Legionella spp. Serum samples were collected in the acute and convalescent phase of infection for C. pneumoniae and M. pneumoniae. Thirty-nine patients were diagnosed with C. pneumoniae infection by PCR and/or serology. Diagnoses were established by PCR in the acute phase of infection in 40.4% of the group. Based on the results of these studies, PCR is a useful method for early detection and identification of C. pneumoniae-related LRI outbreaks. However, this technique is not sufficient to detect all positive cases per se. After effective therapy and introduction of appropriate infection control measures, the outbreak ceased without mortality. This is the first closed-community C. pneumoniae outbreak report from Turkey.     

Hyperamylasemia in acute exacerbation in patients with chronic respiratory failure

Serum amylase level was examined in 129 cases (225 episodes) of chronic respiratory failure at acute exacerbation, and in 59 cases (62 episodes) of pneumonia without respiratory failure as a control. Cases accompanying diseases, such as acute pancreatitis, parotiditis, ileus, and renal dysfunction, which were expected to develop hyperamylasemia were excluded. The 225 episodes were divided according to the cause of acute exacerbation into 4 groups: pneumonia, bronchitis, right heart failure without infection, and others (e.g. hemoptysis). Hyperamylasemia (greater than 400 S-U) was observed in groups of pneumonia (15/40 = 35.5%) and of bronchitis (12/95 = 12.6%) respectively, but not in those of right heart failure without infection (0/73 = 0%) and others (0/17 = 0%). As a result, hyperamylasemia was found only under conditions of inflammation of lung parenchyma and bronchi with acute exacerbation of respiratory failure. On the other hand no hyperamylasemia was observed in 62 episodes of only pneumonia without respiratory failure. It was concluded that both respiratory tract infection and acute respiratory failure are necessary factors for development of hyperamylasemia originating from lung or bronchi.     

Cytokine Responses in the Common Cold and Otitis Media

Cytokines are a group of diverse molecules that influence the function of every organ system. They are most well studied in their effects on the immune system and their integral role in mediating inflammation. The common cold and otitis media are two such disease states, and much has been learned about the various effects of cytokines in each disease. Most often the viruses isolated include rhinovirus (RV), respiratory syncytial virus (RSV), adenovirus, coronavirus, and picornavirus. Otitis media, sinusitis, bronchiolitis, pneumonia, and asthma exacerbation are commonly accepted as complications of viral upper respiratory tract infections. Furthermore, otitis media and upper respiratory infections are inextricably linked in that the majority (>70?%) of cases of acute otitis media occur as complications of the common cold. Cytokine polymorphisms have been associated with the severity of colds as well as the frequency of otitis media. This article attempts to update the reader on various studies that have recently been published regarding the role of cytokines in these two disease entities.     

Respiratory infections caused by Branhamella catarrhalis in 5 different hospitals

During 9 months (from January 1988 to September 1988), we experienced 82 patients (94 episodes) of respiratory infections with Branhamella catarrhalis in 5 different hospitals. There were 11 patients of acute bronchitis, 8 patients of pneumonia, 56 patients of chronic bronchitis (68 episodes), 3 patients of bronchiectasis, 3 patients of bronchial asthma with infection and chronic pulmonary emphysema in one patient. Ten cases of acute bronchitis and 3 cases of pneumonia had a recent history of common cold, with no underlying disease. There were 68 episodes of acute exacerbation of chronic bronchitis, the highest among 94 episodes of all respiratory infection. In chronic bronchitis the single pathogen B. catarrhalis was more than B. catarrhalis associated with other pathogens. H. influenza was associated with B. catarrhalis in in most cases of polymicrobial infection. beta-lactamase producing B. catarrhalis was 71% and oral penicillin was not effective in 8 cases of infection by beta-lactamase producing strains. These results show that B. catarrhalis is very important as a common pathogen of respiratory infection.     

Antibiotics and return visits for respiratory illness: a comparison of pooled versus hierarchical statistical methods

BACKGROUND: Antibiotic prescribing for respiratory illness has been associated with small reductions in return visits in an analysis of a large practice-based network. In this study, we apply hierarchical analytical methods that account for the clustering of patients by practices to identify whether antibiotic prescribing by primary care physicians reduces subsequent visits for 6 acute respiratory illnesses-upper respiratory infection, pharyngitis, bronchitis, otitis media, sinusitis, and cough. METHODS: The study data came from 318 family physicians and internists in 45 practices in the Practice Partner Research Network from January 1995 through December 1996, with 255,564 active patients. Patients treated with antibiotics were compared with those who were not on the frequency of revisit within the next 14 days. A simple pooling model and 3 hierarchical statistical models (fixed-effects, random-effects, and Bayesian) were used to compare the odds-ratios for return visits. RESULTS: Statistically significant results were found only for bronchitis and sinusitis by the hierarchical models, but the simple pooling model produced statistically significant results for all study conditions. CONCLUSION: We conclude that antibiotics may reduce return visits for patients with bronchitis and sinusitis, but not for patients with other respiratory illness (upper respiratory infection, pharyngitis, otitis media, or cough). Studies of large clinical databases should use methods of analysis that account for the grouping of patients by practice to avoid false positive associations (type I errors.)     

Bacteria isolated from chronic upper and lower respiratory tract infections and the associated therapeutic strategies--in paranasal sinusitis

Nasal sinusitis, tonsillitis, and pharyngolaryngitis typify upper respiratory tract infections, while bronchitis and pneumonia typify lower respiratory tract infections. Cases of paranasal sinusitis with severe suppuration are reportedly becoming less frequent, while those of chronic catarrhal paranasal sinusitis and edematous allergic paranasal sinusitis are becoming more so, The primary factor in paranasal sinusitis, a typical infectious disease encountered in otolaryngology, is bacterial infection. The main causative bacteria are Streptococcus pneumoniae, reported in 13.4% of cases, Haemophilus influenzae in 12.8% Moraxella catarrhalis in 5.5%, Staphylococcus aureus in 26.5%, Pseudomonas aeruginosa in 5.2%, and anaerobes. The incidence of strains resistant to antimicrobial agents has grown for S. pneumoniae, H. influenzae, and M. catarrhalis and decreased for S. aureus and P. aeruginosa. Acute exacerbation or severe suppuration in chronic paranasal sinusitis requires the administration of antimicrobial agents, with the same agent administered 2 weeks for maximal effect. First-line agents are AMPC/CVA, SBTPC, CDTR-PI, CFPN-PI, and GFLX for adults, with ASPC, SBPC, ACPC, CTRX, CMZ, FMOX, PAPM/BP, and MEPM injected in severe cases. Attention must be paid to strains that resist cephems and macrolides, such as PISP, PRSP, and BLNAR. In refractory chronic paranasal sinusitis, attention must also be paid to biofilms produced by S. aureus and P. aeruginosa. Suitable antimicrobial agents should be determined for treating of chronic paranasal sinusitis, in addition to the best procedure to ensure early recovery from inflammation, such as puncturing or irrigating the maxillary sinus, injecting a suitable agent, nebulization, and/or surgically widening the middle meatus.     

Serologically indicated pneumococcal respiratory infection in children.

Streptococcus pneumoniae infection was indicated serologically in 84 (19%) of 449 children hospitalized with middle or lower respiratory tract infection. Pneumococcal antigen was detected in acute serum in 28 patients, but in acute urine in only 2. An antibody response to type-specific capsular polysaccharides of S. pneumoniae was indicated in 27 patients and to a protein antigen, pneumolysin, in 25 patients, but to C-polysaccharide in only 10 patients. The observations mentioned above suggest that each serological test for pneumococcal etiology is insensitive, and to get an optimal result, a large panel of pneumococcal antigen and antibody assays must be used. Pneumococcal infection could be indicated serologically although no focus of infection, such as pneumonia or acute otitis media, or no laboratory evidence of bacterial infection as elevated values of C-reactive protein concentration, erythrocyte sedimentation rate or white blood cell count was present. Particularly antibody responses to pneumococcal pneumolysin were present in children without pneumonia or acute otitis media. Our results point out that no nonspecific parameter can be used for the selection of patients with probable pneumococcal etiology among children with respiratory tract infection. Concomitant viral infection, in most cases RSV infection, was present in a third of the children with pneumococcal infection. It is concluded that pneumococcal etiology should be actively sought for also in patients with viral respiratory infection, especially in young children with RSV infection.     

Patterns of antimicrobial use for respiratory tract infections in older residents of long-term care facilities

OBJECTIVES: To describe patterns of antimicrobial use for respiratory tract infections (RTIs) in older residents of long‐term care facilities (LTCFs). DESIGN: Data from a prospective, randomized, controlled study of the effect of vitamin E supplementation on RTIs conducted from April 1998 through August 2001 were analyzed. SETTING: Thirty‐three LTCFs in the greater Boston area. PARTICIPANTS: Six hundred seventeen subjects aged 65 and older residing in LTCFs. MEASUREMENTS: RTIs, categorized as acute bronchitis, pneumonia, common cold, influenza‐like illness, pharyngitis, and sinusitis, were studied for appropriateness of antimicrobial use, type of antibiotics used, and factors associated with their use. For cases in which drug treatment was administered, antibiotic use was rated as appropriate (when an effective drug was used), inappropriate (when a more‐effective drug was indicated), or unjustified (when use of any antimicrobial was not indicated). RESULTS: Of 752 documented episodes of RTI, overall treatment was appropriate in 79% of episodes, inappropriate in 2%, and unjustified in 19%. For acute bronchitis, treatment was appropriate in 35% and unjustified in 65% of cases. For pneumonia, treatment was appropriate in 87% of episodes. Of the most commonly used antimicrobials, macrolide use was unjustified in 43% of cases. No statistically significant differences in the patterns of antibiotic use were observed when stratified according to age, sex, race, or comorbid conditions, including diabetes mellitus, dementia, and chronic kidney disease. CONCLUSION: Antimicrobials were unjustifiably used for one‐fifth of RTIs and more than two‐thirds of cases of acute bronchitis, suggesting a need for programs to improve antibiotic prescribing at LTCFs.