Nechama Peled

The contribution of smoking and exposure to tobacco smoke to Streptococcus pneumoniae and Haemophilus influenzae carriage in children and their mothers.

BACKGROUND Exposure to tobacco smoke is associated with higher risk of Streptococcus pneumoniae and Haemophilus influenzae infection. The aim of this study was to determine the influence of smoking and exposure to tobacco smoke on S. pneumoniae and H. influenzae carriage rates in children and their mothers. PATIENTS AND METHODS We performed a cross-sectional surveillance study of nasopharyngeal and oropharyngeal carriage of S. pneumoniae and H. influenzae in 208 children aged <60 months and their mothers. Smoking exposure and medical history were recorded. Carriage rates for children and their mothers in nasopharyngeal and oropharyngeal specimens were analyzed on the basis of smoking exposure. RESULTS The S. pneumoniae carriage rate was higher among children exposed to smoking than among nonexposed children (76% vs. 60%; P=.016). Exposed children more frequently carried S. pneumoniae serotypes included in the conjugate 7-valent vaccine, compared with nonexposed children (49% vs. 30% of all S. pneumoniae-positive nasopharyngeal cultures; P=.02). Carriage rates of S. pneumoniae were higher among mothers who smoked than among mothers exposed to smoking and among nonexposed mothers (32%, 15%, and 12%, respectively; P=.03). There were no differences in H. influenzae carriage rates between children and mothers from smoking and nonsmoking families. CONCLUSIONS Exposure to tobacco smoke increased S. pneumoniae carriage rates in general and for carriage of serotypes included in the conjugate 7-valent vaccine in particular in children. Smoking mothers had a higher S. pneumoniae carriage rate than did nonsmoking mothers. Smoking or exposure to smoking did not increase H. influenzae carriage rates in children and mothers.

Relative Importance of Nasopharyngeal versus Oropharyngeal Sampling for Isolation of Streptococcus pneumoniae and Haemophilus influenzae from Healthy and Sick Individuals Varies with Age

ABSTRACT Streptococcus pneumoniae and Haemophilus influenzae carriage is a useful index for measuring the emergence of resistance and outcome in vaccination trials. We performed a study to determine which sampling site, nasopharynx (NP) or oropharynx (OP), yields the highest rate of S. pneumoniae and H. influenzae isolation at different ages. Both NP and OP cultures were obtained from 216 children aged <60 months and their mothers. The total S. pneumoniae carriage rate was 68% among children and 15% among mothers (P < 0.001). Using NP alone for the isolation of S. pneumoniae would have missed 2, 2, and 42% and using OP alone would have missed 77, 66, and 45% of S. pneumoniae in children aged 0 to 23 months, 24 to 59 months, and mothers, respectively. Using NP cultures alone for H. influenzae would have missed 23, 24, and 81% of the isolates, respectively. The respective figures for H. influenzae isolation from OP alone are 38, 29, and 9%. In children, S. pneumoniae was carried mainly in the NP while H. influenzae was equally carried in the NP and OP. In mothers, S. pneumoniae was carried equally in the NP and OP while H. influenzae was carried significantly more often in the OP. In children, H. influenzae colonization increased during illness, mainly in the NP. Culturing only one site significantly reduced the recovery of H. influenzae at all ages. NP cultures for S. pneumoniae detected close to 100% of isolates in children but only 58% of isolates in mothers.

Epidemiological features of invasive Kingella kingae infections and respiratory carriage of the organism.

ABSTRACT The age, sex, and seasonal distributions of invasive Kingella kingae infections in southern Israel were examined and compared to the epidemiology of respiratory carriage of the organism. Medical records of all patients diagnosed between 1988 and 2002 were reviewed, and 2,044 oropharyngeal specimens were cultured on selective media during two periods (February to May and October to December) in 2001. Invasive infections significantly affected children (73 of 74 patients [98.6%] were younger than 4 years), 50 patients (67.8%) were males (P = 0.045), and 55 episodes (74.3%) occurred between July and December (P = 0.004). Carriage was higher in the 0- to 3-year-old group and decreased with increasing age (P for trend = 0.0008). Carriage rates were similar in both sexes and did not significantly differ between the February-to-May and October-to-December periods. The highest rate of carriage of K. kingae coincided with the age (less than 4 years) at which invasive infections were especially frequent. The peculiar sex and seasonal distributions of invasive disease, however, cannot be readily explained by the epidemiology of respiratory carriage. Viral infections and other yet-to-be-defined cofactors may play a role in the causation of invasive K. kingae infections.

Clinical significance and impact on mortality of extended-spectrum beta lactamase-producing Enterobacteriaceae isolates in nosocomial bacteremia.

During an 8-month period, 55 episodes of nosocomial bacteremia caused by Enterobacteriaceae species were identified in a tertiary medical center, of which 26 (47%) were caused by extended-spectrum beta lactamase (ESBL)-producing organisms. ESBL production was associated with resistance to aminoglycosides, fluoroquinolones, tetracycline and co-trimoxazole compared with non-ESBL-producing organisms (p < 0.01). By multivariate analysis, infection with ESBL-producing organisms was associated with previous antibiotic therapy and central venous catheter insertion and mortality was associated with heart failure, malignancy and a prolonged hospital stay. Nineteen (73%) patients infected with ESBL-producing organisms received adequate empirical antibiotic therapy and all 26 received adequate definitive therapy. The in-hospital mortality rate did not differ between patients infected with ESBL producers and those infected by non-ESBL-producing Enterobacteriaceae species [13/26 (50%) and 11/29 (38%), respectively] (p > 0.5).During an 8-month period, 55 episodes of nosocomial bacteremia caused by Enterobacteriaceae species were identified in a tertiary medical center, of which 26 (47%) were caused by extended-spectrum beta lactamase (ESBL)-producing organisms. ESBL production was associated with resistance to aminoglycosides, fluoroquinolones, tetracycline and co-trimoxazole compared with non-ESBL-producing organisms (p < 0.01). By multivariate analysis, infection with ESBL-producing organisms was associated with previous antibiotic therapy and central venous catheter insertion and mortality was associated with heart failure, malignancy and a prolonged hospital stay. Nineteen (73%) patients infected with ESBL-producing organisms received adequate empirical antibiotic therapy and all 26 received adequate definitive therapy. The in-hospital mortality rate did not differ between patients infected with ESBL producers and those infected by non-ESBL-producing Enterobacteriaceae species [13/26 (50%) and 11/29 (38%), respectively] (p > 0.5).

Community-Acquired Methicillin-Resistant Staphylococcus aureus in Institutionalized Adults with Developmental Disabilities

Methicillin-resistant Staphylococcus aureus (MRSA) has recently been reported to emerge in the community setting. We describe the investigation and control of a community-acquired outbreak of MRSA skin infections in a closed community of institutionalized adults with developmental disabilities. In a 9-month period in 1997, 20 (71%) of 28 residents had 73 infectious episodes. Of the cultures, 60% and 32% obtained from residents and personnel, respectively, grew S. aureus; 96% and 27% were MRSA. All isolates were genetically related by pulsed-field gel electrophoresis and belonged to a phage type not previously described in the region. No known risk factors for MRSA acquisition were found. However, 58 antibiotic courses had been administered to 16 residents during the preceding 9 months. Infection control measures, antibiotic restriction, and appropriate therapy resulted in successful termination of this outbreak. Selective antibiotic pressure may result in the emergence, persistence, and dissemination of MRSA strains, causing prolonged disease.

Exposure of Hospital Personnel to Brucella melitensis and Occurrence of Laboratory-acquired Disease in an Endemic Area

In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.In 1997, 7 cases of laboratory-acquired Brucella melitensis infections were detected among the hospital personnel of a medical centre serving an endemic area in southern Israel. Although the onset of symptoms in 6 of the 7 patients occurred during a 2-week period, suggesting a point source exposure, biotype analysis showed that the outbreak was caused by 3 different B. melitensis serovars, indicating multiple exposures. Review of the laboratory records showed that during 1997, the microorganism was recovered from 146 blood and synovial fluid cultures, and that during the 2 months in which the laboratory-acquired cases occurred (April and June), 53 of 530 positive aerobic blood culture bottles (10.0%) grew B. melitensis. The epidemiological investigation did not reveal the source of the outbreak, and no noticeable breaches in laboratory safety practices could be demonstrated. It is concluded that in areas endemic for brucellosis, hospital personnel are frequently exposed to Brucella microorganisms. Under these circumstances, significant morbidity may occur despite observance of recommended safety practices. Biotyping of Brucella isolates may contribute to the elucidation of complex epidemiological situations.

Hospital-acquired brevundimonas vesicularis septicaemia following open-heart surgery : Case report and literature review

Brevundimonas vesicularis (B. vesicularis) is a pseudomonad rarely encountered in human infection. A case of nosocomial septicaemia with this organism following open-heart surgery is presented, with a review of the literature. The isolate demonstrated resistance to ciprofloxacin and aztreonam, which has not yet been reported. Treatment with piperacillin/tazobactam resulted in full recovery. A review of the literature reveals that B. vesicularis is a virulent organism involved in serious infections such as central nervous system infection or bacteraemia, some of which are nosocomial. Meanwhile, empiric therapy for B. vesicularis infection should include a broad-spectrum antimicrobial agent until susceptibility results are known.Brevundimonas vesicularis (B. vesicularis) is a pseudomonad rarely encountered in human infection. A case of nosocomial septicaemia with this organism following open-heart surgery is presented, with a review of the literature. The isolate demonstrated resistance to ciprofloxacin and aztreonam, which has not yet been reported. Treatment with piperacillin/tazobactam resulted in full recovery. A review of the literature reveals that B. vesicularis is a virulent organism involved in serious infections such as central nervous system infection or bacteraemia, some of which are nosocomial. Meanwhile, empiric therapy for B. vesicularis infection should include a broad-spectrum antimicrobial agent until susceptibility results are known.

Nasopharyngeal versus oropharyngeal sampling for isolation of potential respiratory pathogens in adults

ABSTRACT The optimal methodology for the identification of colonization by potential respiratory pathogens (PRP) in adults is not well established. The objectives of the present study were to compare the sensitivities of sampling the nasopharynx and the oropharynx for identification of PRP colonization and to compare the sensitivities of samples from the nasopharynx by swab and by washing for the same purpose. The study included 500 participants with a mean age of 65.1 ± 17.8 years. Of these, 300 patients were hospitalized for acute febrile lower respiratory tract infection and 200 were controls. Each participant was sampled by oropharyngeal swab (OPS), nasopharyngeal swab (NPS), and nasopharyngeal washing (NPW). The samples were tested by conventional bacteriological methods to identify Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. OPS detected colonization by S. pneumoniae in 30% of the subjects compared with 89% by NPS and NPW (P < 0.000001). The corresponding rates for H. influenzae were 49% and 64%, respectively (no significant difference [NS]), and for M. catarrhalis were 72% and 46%, respectively (P < 0.0004). NPS identified 61% of the cases of colonization with S. pneumoniae, compared with 76% by NPW (NS). The corresponding rates for H. influenzae were 31% and 56%, respectively (P < 0.04), and for M. catarrhalis were 39% and 33%, respectively (NS). We conclude that the sensitivities of nasopharyngeal and oropharyngeal sampling for identification of PRP colonization in adults are different for each of the three bacteria in this category. The combined results of sampling from both sites are necessary to obtain a true picture of the rate of colonization. NPW is superior to NPS.

Antibiotic-Resistant Pneumococci Carried by Young Children Do Not Appear to Disseminate to Adult Members of a Closed Community

Although antibiotic-resistant pneumococci have been frequently detected among day care center (DCC) attendees, the transmission of these organisms to other members of the community has not been adequately studied. Nasopharyngeal cultures were obtained from 152 children and 244 adult members of a closed community (a kibbutz) in Israel. Serotyping, antibiogram, and pulsed-field gel electrophoresis were performed to determine the relatedness of isolated pneumococci. Twenty (30%) of the 66 isolates from children showed decreased susceptibility to penicillin and 9 isolates (14%) were resistant to > or =3 drugs. Of the 16 isolates from adults, 5 (31%) were intermediately resistant to trimethoprim-sulfamethoxazole. Resistant strains carried by DCC attendees were not isolated either from their parents or from other adult members of the community. Despite the high degree of interpersonal contact occurring in a closed community, resistant pneumococcal strains carried by DCC attendees do not appear to be easily transmitted to the adult population, which suggests the existence of an immunological barrier.

USE OF BACTEC 9240 BLOOD CULTURE SYSTEM FOR DETECTION OF BRUCELLA MELITENSIS IN SYNOVIAL FLUID

ABSTRACT Synovial fluid specimens aspirated from patients with arthritis were inoculated into an aerobic Peds Plus blood culture bottle and monitored by the BACTEC 9240 instrument for 4 weeks. A total of 1,072 synovial fluid cultures were processed, and 15 (0.14%) were positive for Brucella melitensis. A single culture, harboring 1.3 CFU of viable organisms per ml, was missed by the instrument. All 14 positive BACTEC cultures were detected within 3 to 7 days.