An epidemic of pertussis among elderly people in a religious institution in The Netherlands.

An epidemic of pertussis is described among elderly people in a religious institution in the Netherlands in 1992. Subjects were evaluated for their vaccination status and for history and presence of respiratory symptoms. Specimens were collected for culture, polymerase chain reaction, and serological evaluation. None of the 75 residents and 19 of 24 nonresident personnel had been vaccinated against pertussis. The overall attack rate of clinical pertussis, defined as persistent cough lasting at least 2 weeks, was 49%. In five subjects with clinical pertussis, either culture or polymerase chain reaction or both were positive for Bordetella pertussis. A significant (at least 4-fold) change in specific antibody titre was observed in 85% (41/48) and 20% (10/49) of subjects with and without clinical pertussis, respectively (P < 0.0001, chi-square 41.1). The attack rate of laboratory-confirmed pertussis was 42% (41/98). This rate was 5% (1/19), 20% (1/5), and 53% (39/74) in vaccinated personnel, nonvaccinated personnel, and nonvaccinated residents, respectively (not significant). Among residents aged between 55-74 years and 75-94 years, the attack rates were 47% (17/36) and 58% (22/38), respectively (relative risk=0.8; 95% confidence interval 0.5-1.3). Four of 75 residents (5%) died from intracranial bleeding, while they were symptomatic for pertussis. It is concluded that the attack rate of pertussis was high among nonvaccinated elderly and that pertussis tended to increase with age. There may be a considerable risk of mortality from pertussis in this population. Physicians should be alert to the diagnosis of pertussis in the elderly with nocturnal and prolonged periods of coughing.

[An epidemic of Salmonella typhimurium associated with traditional salted, smoked, and dried ham]. / Een Salmonella-typhimurium-epidemie in verband gebracht met ambachtelijk gezouten, gerookte en gedroogde varkensham.

OBJECTIVE: To discover the cause of an outbreak of gastroenteritis after a family party. DESIGN: Retrospective cohort study. METHODS: All 109 party-goers were asked to complete a written questionnaire about consumed food products and demographic and clinical variables and to hand in a faeces sample. The data were collected at the Public Health Institute Midden-Limburg, the Netherlands. Faeces and the remaining food products were examined microbiologically. The attack rates and the incidence rates of positive faeces culture among consumers and non-consumers of specific food products were calculated as well as the corresponding relative risks (RR) with 95% confidence intervals (95% CI). RESULTS: The overall attack rate was 35%. Salmonella typhimurium phage type 20 was found in 'Coburger ham' and statistically significantly more frequently in faeces of ill compared with non-ill party-goers (RR: 6.4; 95% CI: 2.5-16.1). Twenty-eight different food products were served. Consumption of 'Coburger ham' only, was statistically significantly related to a positive faeces culture (RR: 4.1; 95% CI: 2.0-8.5). Only consumption of 'Coburger ham' and of 'bone ham' was statistically significantly related to being ill (RR: 2.4; 95% CI: 1.5-4.0 and RR: 1.4; 95% CI: 1.1-1.9, respectively). 'Coburger ham' and 'bone ham' originated from the same batch of raw meat and were prepared in the same manner in the same salt bath. The shorter duration of salting and drying of 'Coburger ham' compared with 'bone ham' corresponded with a higher relative risk of becoming ill. CONCLUSION: Consumption of 'bone ham' and 'Coburger ham' infected with S. typhimurium phage type 20 caused the outbreak. Traditional salting, drying and smoking of raw pork meat was not antimicrobiologically effective against S. typhimurium. Investigation of the antimicrobiological effect of the traditional preparation of meat and the importance of Good Manufacturing Practices and quality control in all stages of production of pork meat, according to the principles of Hazard Analysis and Critical Control Points, is advised.

Treating acute urinary tract infections. An RCT of 3-day versus 7-day norfloxacin.

A randomized, controlled trial was carried out to compare two courses of treatment in women with acute urinary tract infection in general practice. The 3-day course of treatment was found to be as effective as, and cheaper than, the 7-day therapy.

The reproducibility of urinalysis using multiple reagent test strips.

Ninety urine samples were examined twice by 3 "observers" (two persons, using only visual observation, and one person using a spectrophotometric analyser) using multiple reagent teststrips. To determine reproducibility, inter- and intra-observer agreement were calculated and expressed as Cohen's kappa and as weighted kappa. The results show negligible intra-observer differences between the visual and spectrophotometric observation. The lack of agreement between inter- and intra-observer urinalysis results, using multiple reagent test strips was disappointing, considering the simplicity of the test procedure. Further improvement of reproducibility, e.g. by enhancing the discoloration of the test pads, is necessary. Reproducibility is not improved by using a spectrophotometric analyser instead of visual reading of the test strips.

[Bavaroise and an epidemic of Salmonella enteritidis]. / Bavaroise en een epidemie van Salmonella enteritidis.

In the literature an association is made between the increasing prevalence of Salmonella enteritidis in poultry products and in the isolates of patients with gastroenteritis, without sufficient evidence of a causal relationship between the increasing prevalences. A microbiological and epidemiological analysis of a food poisoning incident among 239 visitors of a restaurant by way of food specific attack rates and food specific infection rates revealed an epidemic of 70 cases of S. enteritidis enteritis. The analysis supports the causal relationship with the consumption of an infected, unhygienically prepared egg product, in this case bavaroise.

Different lengths of treatment with co-trimoxazole for acute uncomplicated urinary tract infections in women.

STUDY OBJECTIVE: To compare three days' and seven days' treatment with co-trimoxazole in women with acute dysuria, strangury, and urinary frequency or urgency. DESIGN: Randomised double blind placebo controlled trial. SETTING: General practices in the south east of The Netherlands. PATIENTS: 327 Non-pregnant female patients aged 12 to 65. INTERVENTION: 161 Women were allocated to three days' treatment (co-trimoxazole 960 mg twice a day), and 166 women were allocated to seven days' treatment (co-trimoxazole 960 mg twice a day). MAIN OUTCOME MEASURE: Resolution of symptoms at one, two, and six weeks. RESULTS: The rates for resolution of symptoms were not significantly different between the two groups. Cumulative rates of recurrence after three days' and seven days' treatment were 31/139 (22%) and 23/151 (15%) respectively six weeks after entry (p = 0.16). Adverse effects occurred in a quarter of women given three days' treatment compared with a third of women receiving seven days' treatment (p = 0.29). In only two patients did adverse effects necessitate stopping treatment. CONCLUSIONS: Three days of co-trimoxazole seems to be as effective as a seven days' course for treating acute urinary tract infection in non-pregnant women.

Inducing capacity and selection of resistant variants of cefpirome (HR 810) in comparison with other beta-lactam compounds.

The inducing capacity of cefpirome (HR 810) and the ability of the compound to select for stable derepressed mutants was determined and compared with those of cefodizime (HR 221), cefotaxime, ceftazidime and cefamandol. Variations in both characteristics between and within species was observed. Overall, cefodizime showed the lowest, cefamandol the highest inducing capacity. Antibiotic resistant variants were isolated from all strains tested at a frequency of around 10(-9). A stable increased enzyme production was found in Pseudomonas aeruginosa after exposure to ceftazidime as well as in the resistant mutants from Enterobacter cloacae after selection with cefpirome, ceftazidime, cefotaxime and cefamandol. In the other resistant mutants the resistance was probably due to changes in permeability. All resistant variants remained relatively susceptible to cefpirome.

A regional survey of the resistance to beta-lactam antibiotics in clinical isolates of (facultative) aerobic micro-organisms.

From 1980 to 1986 a regional survey was performed to investigate the susceptibility of beta-lactam antibiotics in clinical isolates of Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa in 6 hospitals located in the southern part of the Netherlands. Each year 300 to 400 strains were tested. The susceptibility to representatives of the older and the newer beta-lactam antibiotics was determined by a microbroth dilution assay using an inoculum size of 10(5) colony forming units (CFU)/ml in ISO-Sensitest broth (Oxoid). No significant differences in antibiotic sensitivity of the micro-organisms from the different hospitals were found. There was no evidence for an increase in antibiotic resistance of the strains during the sampling period. In contrast, there was a general tendency to an increase in antibiotic sensitivity.

In vitro activity of ampicillin alone and in combination with different concentrations of 6 beta-bromopenicillanic acid, clavulanic acid and mecillinam.

The antibacterial activity of ampicillin against Enterobacteriaceae strongly increased when combined with 6 beta-bromopenicillanic acid (BPA) or clavulanic acid (CA). In vitro, the combination ampicillin: BPA in the ratio 1:1 proved to be the most effective one. The antibacterial activity of mecillinam against Enterobacteriaceae was strongly potentiated by the addition of ampicillin. The combination mecillinam:ampicillin in the ratio 4:5 showed an antibacterial activity comparable to that of new beta-lactam compounds such as cefotaxime and ceftazidime.

In vitro evaluation of Ro 23-6240, a new fluorinated 4-quinolone.

The in vitro antibacterial activity of Ro 23-6240 was assessed and compared with those of ciprofloxacin and beta-lactam antibiotics including several oral compounds against members of the family Enterobacteriaceae (n = 130) and Pseudomonas spp. (n = 31). In general, Ro 23-6240 was 2 dilution steps less active than ciprofloxacin. For the Pseudomonas spp. the MICs for 90% inhibition were 2 and 0.5 mg/1 for Ro 23-6240 and ciprofloxacin, respectively. For the other species tested, the MIC90 values for Ro 23-6240 ranged from 0.031 to 1 mg/1 and for ciprofloxacin from 0.016 to 0.25 mg/1. Spontaneous Ro 23-6240-resistant mutants were only isolated from Enterobacter cloacae with a frequency similar to that of ciprofloxacin (4.8 X 10(-8) and 2.4 X 10(-8), respectively). No resistant mutants were isolated from Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae and Pseudomonas aeruginosa at concentrations of 4 and 8 times the MIC of Ro 23-6240 or ciprofloxacin (frequency less than 10(-9).

In-vitro evaluation of carumonam (Ro 17-2301).

The in-vitro antibacterial activity of carumonam (Ro 17-2301) was assessed and compared with those of aztreonam and other beta-lactam antibiotics. Carumonam was highly active against the Enterobacteriaceae and Pseudomonas strains resistant to ampicillin (MIC greater than or equal to 256 mg/l) and carbenicillin (MIC greater than or equal to 64 mg/l), respectively. The MICs of carumonam for 90% of the strains ranged between 0.25 mg/l for Klebsiella spp. to 32 mg/l for Pseudomonas spp. The antibacterial activity was minimally altered by changes of medium or inoculum size. Carumonam was resistant to hydrolysis by the plasmid-mediated and chromosomal beta-lactamases tested. Also in the microbiological assay no inactivation was observed. Carumonam was an effective inhibitor of the SHV enzyme and the chromosomal beta-lactamases tested. Against the other plasmid-mediated enzymes carumonam was not an effective inhibitor.

Analysis of the relationship between ampicillin resistance and beta-lactamase production in Branhamella catarrhalis.

23 strains of Branhamella catarrhalis, mainly isolated from patients with acute exacerbations of chronic bronchitis, were studied. The strains were selected on the basis of a positive beta-lactamase reaction using the cefinase disc or the nitrocefin method. No bands were visible by isoelectric focusing of the crude enzyme extracts of strains showing a weak positive reaction with the cefinase method. In the 15 remaining strains, at least 6 different isoelectric focusing patterns could be detected. Four strains showed a pattern similar to that of the Ravasio strain, the most common type in a previous study. The most prevalent type in this study, present in 5 strains, demonstrated an isoelectric focusing pattern quite different from those described so far: a main band at pI 5.28 and 2 minor bands at pI 5.71 and 6.37. Two beta-lactamase-positive, but ampicillin-sensitive strains (MIC = 0.064 mg/L) showed different isoelectric focusing patterns, pI = 4.93 and 5.43, respectively, but similar substrate profiles.

Sch 34343, in-vitro antibacterial activity and beta-lactamase stability.

The in-vitro activity of Sch 34343, a derivative of Sch 29482, was assessed and compared with that of other beta-lactam antibiotics. Nearly all Enterobacteriaceae, including ampicillin-resistant strains (MIC greater than or equal to 256 mg/l) were inhibited at concentrations ranging from 0.125-8 mg/l. The geometric mean MIC values varied from 0.25 mg/l to 2.4 mg/l for Klebsiella and Serratia spp., respectively. Sch 34343 did not inhibit Pseudomonas aeruginosa. The antibacterial activity was minimally altered by changes of medium or inoculum size. The results suggest high stability against plasmid- and chromosomally-mediated beta-lactamases. However, crude extracts of four Pseudomonas strains did hydrolyse Sch 34343. In addition to the high antibacterial activity and the beta-lactamase stability, Sch 34343 markedly inhibited most plasmid- and chromosomally-mediated beta-lactamases, with the exception of PSE-1 and PSE-4.

Comparison of different tobramycin assays.

Three commercial available tobramycin assays, the fluorescent immunoassay (AMES), the Diagnostic Products Corp. radioimmunoassay, and the Nuclear Medical System radioimmunoassay, were compared with the microbiological assay and the chemical assay involving high-performance liquid chromatography. The results obtained with each assay were evaluated in terms of usefulness, reproducibility, and cost-effectiveness.