Human infection caused by penicillin-insensitive pneumococci

Pneumococcal vaccines for children and adults with bronchiectasis

BACKGROUND

Bronchiectasis is increasingly recognized as a major cause of respiratory morbidity especially in developing countries. Even in affluent countries, bronchiectasis is increasingly seen in some community subsections (e.g. Aboriginal communities) and occurs as a comorbidity and disease modifier in respiratory diseases such as chronic obstructive pulmonary disease (COPD). Respiratory exacerbations in people with bronchiectasis are associated with reduced quality of life, accelerated pulmonary decline, hospitalisation and even death. Conjugate pneumococcal vaccine is part of the routine infant immunisation schedule in many countries. Current recommendations for additional pneumococcal vaccination include children and adults with chronic suppurative disease.

OBJECTIVES

To evaluate the effectiveness of pneumococcal vaccine as routine management in children and adults with bronchiectasis in (a) reducing the severity and frequency of respiratory exacerbations and (b) pulmonary decline.

SEARCH STRATEGY

The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE and EMBASE databases were searched by the Cochrane Airways Group. Pharmaceutical manufacturers of pneumococcal vaccines were also contacted. The latest searches were performed in November 2008.

SELECTION CRITERIA

All randomised controlled trials that utilised pneumococcal vaccine on children and adults with bronchiectasis. All types of pneumococcal vaccines were included.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. No eligible trials were identified and thus no data was available for analysis. One small non-randomised controlled trial in children was reported.

MAIN RESULTS

One randomised controlled open label study in 167 adults with chronic lung disease (bronchiectasis and other diseases associated with bronchiectasis) compared 23-valent pneumococcal (PV) and influenza vaccine with influenza vaccine alone (control group). The study found a significant reduction in acute infective respiratory exacerbations in the PV group compared to the control group, OR=0.48 (95%CI 0.26, 0.88); number needed to treat to benefit = 6 (95%CI 4, 32) over 2-years. There was however no difference in episodes of pneumonia between groups and no data on pulmonary decline was available. In another study, a benefit in elimination of Strep. pneumoniae in the sputum was found in a non-randomised trial in children but no clinical effect was described.

AUTHORS' CONCLUSIONS

Current but limited evidence support the use of 23-valent pneumococcal vaccine as routine management in adults with bronchiectasis. Circumstantial evidence also support the use of routine 23-valent pneumococcal vaccination in children with bronchiectasis. Further randomised controlled trials examining the efficacy of this intervention using various vaccine types in different age groups are needed. There is no data on the efficacy of pneumococcal vaccine on pulmonary decline. With the lack of evidence in how often the vaccine should be given, it is recommended that health providers adhere to national guidelines.

Pneumococcal vaccines for children and adults with bronchiectasis

BACKGROUND

Bronchiectasis is increasingly recognized as a major cause of respiratory morbidity especially in developing countries. Even in affluent countries, bronchiectasis is increasingly seen in some community subsections (e.g. Aboriginal communities) and occurs as a comorbidity and disease modifier in respiratory diseases such as chronic obstructive pulmonary disease (COPD). Respiratory exacerbations in people with bronchiectasis is associated with reduced quality of life, accelerated pulmonary decline, hospitalisation and even death. Conjugate pneumococcal vaccine is part of the routine infant immunisation schedule in many countries. Current recommendations for additional pneumococcal vaccination include children and adults with chronic suppurative disease.

OBJECTIVES

To evaluate the effectiveness of pneumococcal vaccine as routine management in children and adults with bronchiectasis in (a) reducing the severity and frequency of respiratory exacerbations and (b) pulmonary decline.

SEARCH STRATEGY

The Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE and EMBASE databases were searched by the Cochrane Airways Group. Pharmaceutical manufacturers of pneumococcal vaccines were also contacted. The latest searches were performed in October 2006.

SELECTION CRITERIA

All randomised controlled trials that utilised pneumococcal vaccine on children and adults with bronchiectasis. All types of pneumococcal vaccines were included.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. No eligible trials were identified and thus no data was available for analysis. One small non-randomised controlled trial in children was reported.

MAIN RESULTS

No randomised controlled trials pertaining effectiveness of pneumococcal vaccine as routine management in children and adults with bronchiectasis were found. A benefit in elimination of Strep. pneumoniae in the sputum was found in a non-randomised trial in children but no clinical effect was described.

AUTHORS' CONCLUSIONS

At present, there is a lack of reliable evidence to support or refute the routine use of pneumococcal vaccine as routine management in children and adults with bronchiectasis. Randomised controlled trials examining the efficacy of this intervention using various vaccine types in different age groups are needed. Until further evidence is available, it is recommended that health providers adhere to national guidelines.

Impact of antibiotic resistance on chemotherapy for pneumococcal infections

Over the past three decades, penicillin-resistant pneumococci have emerged worldwide. In addition, penicillin-resistant strains have also decreased susceptibility to other beta-lactams (including cephalosporins) and these strains are often resistant to other antibiotic groups, making the treatment options much more difficult. Nevertheless, the present in vitro definitions of resistance to penicillin and cephalosporins in pneumococci could not be appropriated for all types of pneumococcal infections. Thus, current levels of resistance to penicillin and cephalosporin seem to have little, if any, clinical relevance in nonmeningeal infections (e.g., pneumonia or bacteremia). On the contrary, numerous clinical failures have been reported in patients with pneumococcal meningitis caused by strains with MICs > or = 0.12 microg/ml, and penicillin should never be used in pneumococcal meningitis except when the strain is known to be fully susceptible to this drug. Today, therapy for pneumococcal meningitis should mainly be selected on the basis of susceptibility to cephalosporins, and most patients may currently be treated with high-dose cefotaxime (+/-) vancomycin, depending on the levels of resistance in the patient's geographic area. In this review, we present a practical approach, based on current levels of antibiotic resistance, for treating the most prevalent pneumococcal infections. However, it should be emphasized that the most appropriate antibiotic therapy for infections caused by resistant pneumococci remains controversial, and comparative, randomized studies are urgently needed to clarify the best antibiotic therapy for these infections.

Meningitis caused by a penicillin- and chloramphenicol-resistant Streptococcus pneumoniae

We report here a case of a five-month-old infant with pneumococcal meningitis, which was both penicillin- and chloramphenicol-resistant, and the difficulties that arose, both in the laboratory diagnosis of the resistance and in the therapy of this infection.

Characteristics and antibiotic therapy of adult meningitis due to penicillin-resistant pneumococci

Of 66 episodes of pneumococcal meningitis seen in Bellvitge Hospital, Barcelona, Spain (January 1981 to June 1987), 15 (23 percent) were due to penicillin-resistant pneumococci [minimal inhibitory concentrations (MICs) of 0.1 to 4 micrograms/ml]. Fifty percent of these strains were also resistant to chloramphenicol. Most were sporadic community-acquired cases. Clinical characteristics were similar in both penicillin-resistant and penicillin-sensitive cases. Those cases with MICs of greater than 1 microgram/ml did not show a response to penicillin therapy. Of nine patients treated with cefotaxime (200 to 350 mg/kg per day) with penicillin G MICs of 0.1 to 4 micrograms/ml and cefotaxime MICs of less than or equal to 0.03 to 1 microgram/ml, seven recovered, one experienced a relapse after 14 days of therapy and the infection was cured with intravenous vancomycin, and one patient died with sterile cerebrospinal fluid. Thus, adults with meningitis due to penicillin-resistant pneumococci may be adequately treated with high doses (around 300 mg/kg per day) of intravenous cefotaxime if MICs of penicillin G are less than or equal to 4 micrograms/ml. Cases with higher resistance may require another antibiotic such as vancomycin.

Serotyping of Streptococcus pneumoniae by latex agglutination

A simple method is presented for serotyping Streptococcus pneumoniae which uses easily prepared sensitized polystyrene latex particles. The technique is simple, fast and reliable and can detect pneumococcal antigens in body fluids.

World-wide development of antibiotic resistance in pneumococci

Antibiotic-resistant pneumococci, especially penicillin-resistant strains, are being increasingly isolated. Pneumococci with intermediate penicillin-resistance (MIC 0.1-1.0 micrograms/ml) have been reported from many parts of the world over the past two decades, and highly resistant strains (penicillin MICs greater than or equal to 2 micrograms/ml) have also appeared. Infection may be acquired in the hospital or community, and nosocomial outbreaks may occur which require control measures to limit organism spread. Most infections occur in children with diminished host responses. Disease caused by pneumococci with intermediate penicillin-resistance may be treated with high doses of penicillin, but disease caused by highly resistant strains, especially meningitis, may require alternative therapy. Pneumococci resistant to sulfonamides, tetracyclines, erythromycin, lincomycin, clindamycin, chloramphenicol, aminoglycosides and rifampin have also appeared. Strains resistant to all the above-mentioned agents, including all beta-lactam antibiotics tested, have been reported from South Africa and Spain. Alternative therapy for resistant strains may include vancomycin, cefotaxime, cefoperazone, ceftriaxone and imipenem. Pneumococci isolated from sites suggestive of infection, especially blood and cerebrospinal fluid, should be routinely tested for penicillin-susceptibility.

Carriage of penicillin resistant pneumococci

A survey of 303 urban and 156 rural children showed nasopharyngeal carriage of relatively resistant Streptococcus pneumoniae organisms in 14.2% and 19.2% of children, respectively. These organisms have minimum inhibitory concentrations for penicillin in the range of 0.12-1 microgram/ml. An analysis of 40 relatively resistant S. pneumoniae strains showed resistance to co-trimoxazole in 47.5%, trimethoprim in 42.5%, fusidic acid in 20%, tetracycline in 2.5%, and rifampicin in 5%. All the strains were susceptible to chloramphenicol and vancomycin, while the minimum inhibitory concentrations of third generation cephalosporins and imipenem were comparable with or lower than those of penicillin. Eighty three per cent of the strains tested belonged to serogroups 6 and 19. These findings are discussed in relation to the poor clinical response to treatment with penicillin for relatively resistant S. pneumoniae meningitis, and the minimum inhibitory concentrations of alternate agents under review for treatment of systemic pneumococcal disease are presented.

Antimicrobial therapy of experimental meningitis caused by Streptococcus pneumoniae strains with different susceptibilities to penicillin

The pharmacokinetics and bacteriological efficacies of penicillin G, ceftriaxone, vancomycin, and imipenem were determined in rabbits with experimental meningitis caused by Streptococcus pneumoniae strains with different penicillin susceptibilities. Drug dosages were adjusted to attain peak concentrations in serum that were similar to those observed in infants and children. In animals infected with a penicillin-susceptible (MBC, 0.008 micrograms/ml) pneumococcus, penicillin G and ceftriaxone reduced the number of organisms in cerebrospinal fluid (CSF) by greater than or equal to 4.14 log10 CFU/ml after single doses and after 9-h continuous infusions. A single large dose (50 mg/kg) of penicillin G was comparatively ineffective (-2.15 log10 CFU/ml) against a relatively penicillin-resistant (MBC, 0.5 micrograms/ml) strain, whereas ceftriaxone therapy resulted in a 3.66- and 4.77-log10 CFU/ml reduction after single doses and 9-h continuous infusions, respectively. In animals in which meningitis was caused by a penicillin-resistant (MBC, 8.0 micrograms/ml) pneumococcus, a single dose of penicillin (50 or 150 mg/kg) or of ceftriaxone failed to lower the number of organisms in CSF. Vancomycin and imipenem reduced the counts in CSF by at least 2.19 and 4.10 log10 CFU/ml after single doses and 9-h infusions, respectively. In all experiments, a bactericidal titer of greater than or equal to 1:8 in CSF was necessary to achieve a maximal bacteriological effect.