Respiratory picornavirus infections in Korean children with lower respiratory tract infections

Recently, human rhinoviruses (RVs) and enteroviruses have been suggested as important etiological agents in young children with lower respiratory tract infections (LRTIs). We investigated the role of respiratory picornaviruses in hospitalized children with LRTI. A total of 233 nasopharyngeal samples were collected from hospitalized children with LRTIs from July 2004 to January 2006. All specimens were tested for the presence of human respiratory syncytial virus (hRSV), influenza virus A, influenza B, parainfluenzavirus, and adenovirus using direct immunofluorescent assay, and for human metapneumovirus (HMPV) by RT-PCR. Detection of RV was performed in nasopharyngeal samples by a RT-PCR assay that incorporated a BglI restriction enzyme digestion of the picornavirus RT-PCR amplicon, and detection of enterovirus was accomplished by hemi-nested RT-PCR using specific primers. Viral agents were detected in 70.4% (164/233) of the study population. The most frequently detected viruses were RV (64/233, 27.4%), hRSV (48/233, 20.6%), and enterovirus (43/233, 18.4%). Picornaviruses were detected as the sole viral agents in 27.0% (63/233) of children, whereas mixed viral infection was detected in 12.0%. These results suggest that picronavirus infection is an important etiological cause of LRTIs in Korean children.     

Viral lower respiratory tract infections in Filipino children

Viral causes of acute lower respiratory tract infection were studied prospectively between 15 June and 31 October 1984 in 312 Filipino children less than 5 years old living in periurban slums and middle-class housing. The cause was based on viral antigen detection, virus isolation, and antibody assays. There were 131 children (41.2%) who were admitted to the hospital, and 150 (47%) had an infiltrate on chest radiograph. A total of 198 viral infections were confirmed in 162 patients (51.9%), 42.3% with single viral infection and 9.6% with mixed (two or more) infection. The infections were measles (21.4%), influenza A (15.9%), parainfluenza types 1, 2, and 3 (8.8%), respiratory syncytial virus (7.1%), influenza B (5.8%), enteroviruses (5.1%), adenoviruses (3.9%), herpes simplex virus (1.6%), and cytomegalovirus (1.3%). Viral infections other than measles were seen in 39.7% of the cases. The presence of viral infection correlated with better nutritional status. Influenza A or B diagnosis was associated with mild forms of acute respiratory tract infection, measles and a preceding rash with severe disease.     

Detection of Mycoplasma pneumoniae in children with lower respiratory tract infections

Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) in children. We studied 75 children who had been hospitalized for community-acquired LRTIs for the detection of M. pneumoniae by serological analysis and polymerase chain reaction (PCR) to amplify a 277-base pair region of 16S rDNA gene of M. pneumoniae applied to throat swab specimens. Serological and/or PCR positive results diagnosed M. pneumoniae infection in 23 (30.7%) patients.     

Ultrastructural ciliary defects in children with recurrent infections of the lower respiratory tract

One hundred fifty-four children with recurrent or chronic infections of the lower respiratory tract compatible with the diagnosis of primary ciliary dyskinesia (PCD) were evaluated for the presence of ultrastructural ciliary abnormalities. Studies were performed on multiple samples of respiratory mucosa obtained by nasal and bronchial brushing. Twenty-eight children showed ultrastructural ciliary defects compatible with the diagnosis of PCD: Twenty-four presented dynein arm deficiency (either as isolated defect or in association with microtubular abnormalities), two had ciliary aplasia, and two showed microtubular abnormalities. Eleven patients with PCD had situs viscerum inversus, bronchiectasis, and chronic sinusitis (Kartagener's syndrome); one child with Kartagener's syndrome had normal ciliary structure. The appearance of respiratory symptoms within the first month of life, the colonization by Haemophilus influenzae, and a history of recurrent rhinitis and otitis were characteristically present in children with PCD. The clinical status of those patients who reached adolescence was, in our experience, remarkably good. An early diagnosis with adequate prevention and therapy of respiratory infections may have an important role in minimizing irreversible lung damage.     

Survey of Mycoplasma pneumoniae in Iranian children with acute lower respiratory tract infections

ObjectivesMycoplasma pneumoniae is an atypical pathogen, which is one of the major causes of lower respiratory tract infections (LRTIs) worldwide. This study was performed to determine the role of M. pneumoniae in acute LRTIs in children, who were referred to main pediatric hospitals in Shiraz, Iran, with the diagnosis of LRTI. Polymerase chain reaction method on a throat-swab specimen was utilized to detect M. pneumoniae.ResultsOne hundred patients with acute LRTIs were investigated in this study. There were 10 positive PCR for M. pneumoniae (10%), including 6 of 62 hospitalized patients and 4 of 38 outpatients. All patients with LRTIs due to M. pneumoniae had cough. Fever, flu like symptoms, dyspnea, pulmonary rales, wheezing, and conjunctivitis were other common signs and symptoms.ConclusionsThe percentage of cases with M. pneumoniae infection in our population is similar to the reported in other parts of Asia. Precise and early detection of pathogen and appropriate antibiotic therapy are the key points in management of patients with LRTIs.     

Mixed community-acquired lower respiratory tract infections

Although mixed infections are known to be clinically relevant in conditions such as nosocomial pneumonia and ventilator-related pneumonia, it is increasingly recognized that a substantial number of community-acquired lower respiratory tract infections may also be attributed to more than one pathogenic organism. A better definition of the true incidence of mixed infections in community-acquired lower respiratory tract infections is partly derived from recent advances in available diagnostic methods (eg, molecular biology). Two points still must be determined: whether the presence of a mixed infection is associated with altered outcomes and whether empirical antibiotic selection should be modified to account for potential polymicrobial infections.     

De-escalation in lower respiratory tract infections

PURPOSE OF REVIEW: The present article reviews recent data on the de-escalation of empirical antibiotic treatment on pneumonia, with special attention to newer strategies aimed at increasing adequacy and minimizing resistance emergence risks in ventilator-associated pneumonia. RECENT FINDINGS: A de-escalation strategy is feasible in a large proportion of patients with pneumonia, and at least two reports have associated de-escalation with a significantly better survival. Combined with other strategies, such as using biomarkers (e.g. C-reactive protein or procalcitonin), antibiotic heterogeneity, adherence to local microbiological flora, objective clinical criteria of non-response and of clinical ventilator-associated pneumonia resolution, they contribute to rationalizing and individualizing antimicrobial therapy. SUMMARY: A patient-based approach with prompt adequate empirical therapy, using broad-spectrum antibiotics based on reliable local microbiological data with streamlining as soon as microbiological data become available, allow outcomes to be improved and the emergence of resistance to be minimized.     

Biomarkers in lower respiratory tract infections

This review aims to provide physicians with an overview of the potential of biomarkers to complement existing clinical severity scores and in conjunction with clinical parameters to improve the diagnosis, risk-stratification and management of lower respiratory tract infections (LRTIs).The usefulness of biomarkers for diagnosing LRTIs is still unclear. However, the specificity of pneumonia diagnosis is high when high sensitivity C-reactive protein (CRP) and procalcitonin (PCT) are used.PCT, CRP and particularly pro-atrial natriuretic peptide (MR-proANP), pro-vasopressin (CT-proAVP) and proadrenomedullin (proADM) levels can reliably predict LRTIs mortality. These markers do not significantly improve the severity scores predictive values, confirming that biomarkers are meant to complement, rather than supersede, clinician’s judgment and validated severity scores.Biomarkers, and particularly PCT, are useful tools as antibiotic treatment duration indicators both in pneumonia and exacerbations of chronic obstructive pulmonary disease (COPD).Even if more data are required to fully appreciate the role of biomarkers in LRTIs management, there is emerging evidence that biomarkers have the potential to improve the daily clinical management of LRTIs.     

Antibody treatment of lower respiratory tract infections

Antibody treatment of lower respiratory infection has a long history of success and is receiving renewed interest. A variety of polyclonal and monoclonal preparations are clinically available. Although used primarily for infection prophylaxis, these agents have limited applications in the treatment of established infections. Immune serum was the first effective treatment for pneumococcal pneumonia. Although long-supplanted by the advent of antibiotics, passive immunotherapy for pneumococcal and other infections is being revisited in an era of increasing antibiotic resistance and growing numbers of immunocompromised individuals. Limited clinical evidence supports the use of immune globulins in the treatment of pertussis and severe streptococcal infection. Bone marrow transplant recipients with lower respiratory infections caused by cytomegalovirus or respiratory syncytial virus also may benefit by adjunctive treatment with immune globulins. Additional indications for antibody treatment of respiratory infection may develop with further investigation.     

Acute lower respiratory tract infections in patients with rheumatoid arthritis

OBJECTIVE: To determine whether drugs used in the treatment of rheumatoid arthritis (RA) contribute to the increased risk of respiratory infection or influence its outcome. METHODS: We identified all episodes of lower respiratory tract infection (LRTI) in our RA population over a 12 month period. A detailed drug history was recorded in each case, together with the clinical outcome. Premorbid illnesses and admission data were collected and analyzed to assess the influence of oral steroids and disease modifying antirheumatic drugs (DMARD) on outcome. RESULTS: The overall annual incidence of LRTI in patients with RA was 2.3% with a mortality rate of 22.5%. Demographic factors predicting LRTI included older age and male sex. Oral steroids and not taking DMARD were also associated with an increased risk of hospital admission with LRTI. Being male and having RA for over 10 years trended to the prediction of death as a result of infection. Taking DMARD was not associated with any adverse outcome. CONCLUSION: Respiratory infection is common in patients with RA and carries a high mortality. Oral steroids predispose to infection, while DMARD do not. Increasing age and male sex also predispose to respiratory tract infection.     

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.     

下呼吸道铜绿假单胞菌感染的耐药分析

目的研究我院呼吸内科近4年铜绿假单胞菌感染耐药状况。方法收集我院呼吸内科分离的下呼吸道病原菌中铜绿假单胞菌菌133株作体外药敏试验,对其结果进行分析。结果铜绿假单胞菌对二代头孢菌素及一些三代头孢菌素耐药率在65％以上,对哌拉西林／他唑巴坦敏感性较高。结论铜绿假单胞菌感染呈逐年上升趋势,且耐药率高,在应用抗菌药物治疗时应根据药敏结果和临床疗效选择用药,同时应注意加强病房消毒与细菌耐药监测。     

Identification of strains on recurrent Haemophilus influenzae infections in patients with chronic respiratory tract infections]

Nontypable Haemophilus influenzae is one of the most important pathogenic bacteria in respiratory tract infections. H. influenzae is most frequently associated with recurrent infections in chronic respiratory tract infections (CRTIs). It is known that H. influenzae often reemerges after the antibiotic treatment has been stopped. We analyzed serotype, biotype, and the OMP patterns of H. influenzae isolates from sputum of CRTIs patients to determine whether an exacerbation is caused by an identical H. influenzae strain, or by a new H. influenzae strain. One hundred eighty nine strains of H. influenzae were obtained from 124 exacerbation from 24 patients. The first and second isolates were identical in 23 out of 33 exacerbations (< or = 15-days interval between each exacerbation) and also in 22 out of 34 exacerbations (15 < days but < or = 30-days interval between each exacerbation). This is called early recurrence. In contrast, the first and second isolates were different in 28 out of 34 exacerbations (> 30-days interval between each exacerbation). This is called late recurrence. These results suggest that early recurrence and late recurrence of recurrent H. influenzae infections occur in a different mechanism.     

Role of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community-acquired lower respiratory tract infections.

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae, we studied 613 children aged 2-14 years who were hospitalized for community-acquired lower respiratory tract infections (LRTIs). The patients were enrolled in the study by 21 centers in different regions of Italy from May 1998 through April 1999. Paired serum samples were obtained on admission and after 4-6 weeks to assay the titers of M. pneumoniae and C. pneumoniae antibodies. Nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae were obtained on admission. Acute M. pneumoniae infections in 210 patients (34.3%) and acute C. pneumoniae infections in 87 (14.1%) were diagnosed. Fifteen of the 18 children with M. pneumoniae and/or C. pneumoniae infections whose treatments were considered clinical failures 4-6 weeks after enrollment had not been treated with macrolides. Our study confirms that M. pneumoniae and/or C. pneumoniae plays a significant role in community-acquired LRTIs in children of all ages and that such infections have a more complicated course when not treated with adequate antimicrobial agents.     

耐多药肺结核患者合并呼吸道感染的菌种分布及药敏分析

目的 了解耐多药肺结核患者合并呼吸道感染病原菌分布及耐药情况,指导临床合理用药。 方法 选取上海市肺科医院2007年1月-2009年12月住院耐多药肺结核合并呼吸道感染痰菌培养阳性病例127例及同期住院初治肺结核合并呼吸道感染痰菌培养阳性病例432例进行痰培养细菌鉴定及药敏试验,并进行分析。 结果 127例耐多药肺结核合并下呼吸道感染病例共分离出菌株151株,其中,以革兰阴性杆菌居首位,占67.5%,其次为真菌占30.5%,革兰阳性球菌占2%。与初治肺结核合并下呼吸道感染菌群比较,耐多药组肺炎克雷伯菌、大肠埃希菌、阴沟肠杆菌、不动杆菌等耐药程度较高的机会致病菌比率明显高于初治组,而较为常见、耐药程度较低的致病菌副流感嗜血杆菌则明显低于初治组,2组差异有统计学意义（P<0.05）。耐多药组真菌感染率(30.5%)高于初治肺结核组(20.6%)（P<0.05）,革兰阳性球菌感染比率低于初治肺结核组,2组差异有统计学意义（P<0.05）,混合感染率增高（P<0.05）。药敏显示革兰阴性杆菌对第三代以上头孢菌素、碳青霉烯类、喹诺酮类抗生素较敏感,细菌耐药程度增加,两组间比较有统计学意义（P<0.05）。革兰阳性球菌对青霉素、克林霉素耐药率高,对万古霉素较敏感。 结论 耐多药肺结核患者合并呼吸道感染病原菌以革兰阴性机会致病菌为主,且耐药现象严重,真菌混合感染增加。临床应重视细菌培养及药敏试验,减少不合理用药,积极治疗合并症,减少混合感染。     

Trends in bacterial pathogens of lower respiratory tract infections

OBJECTIVES: This study was conducted to determine the bacterial aetiology of lower respiratory tract infections in this environment as well as update the clinicians in the various antimicrobial alternatives available in the treatment. METHODS: Between September 2002 and February 2005, 157 bacterial pathogens from 556 patients with lower respiratory tract infections were isolated from sputum specimens, and subjected to susceptibility testing, using standard bacteriologic techniques. RESULTS: Out of the 556 cases, only 150 (27%) had an established bacterial aetiology. One pathogen was demonstrated in 143 (95.3%) patients and seven (4.7%) had mixed infections. The most prevalent single pathogen was Klebsiella pneumoniae (38%) while the most prevalent bacterial combination was Klebsiella and Pseudomonas species (2%). Isolates of Klebsiella pneumoniae were susceptible to ciprofloxacin, gentamicin and ceftriaxone. CONCLUSIONS: Bacteriological diagnosis and antibiotic resistance surveillance are indispensable in the effective management of lower respiratory tract infections.     

3种用药方案治疗下呼吸道感染的成本-效果分析

目的探讨3种不同治疗方案用于下呼吸道感染的经济效果。方法运用药物经济学成本-效果分析法对A组(左氧氟沙星口服)、B组(阿奇霉素口服)、C组(左氧氟沙星 阿奇霉素口服)进行回顾性分析评价。结果3种药物治疗方案成本分别为34.8元、56元、59.3元;细菌清除率分别为85.19%、80.77%、92.8%(P>0.05);痊愈率分别为65.6%、59.4%、75%(P>0.05);成本-效果比分别为(细菌清除率)0.41、0.69、0.64;(痊愈率)0.40、0.72、0.63;有效率分别为87.5%、78.125%、93.75%(P<0.05);3种方案治疗下呼吸道感染在痊愈率、细菌清除率上无显著差异,在有效率上有显著差异。结论综合考虑,C方案为较佳方案。