No abstract

Infections and life-threatening complications due to verotoxin-producing Escherichia coli (VTEC) have been increasingly recognized as a public health problem in recent years. Through enhanced surveillance in Alberta, Canada, and in Scotland, 1,993 cases of VTEC infection and 115 cases of hemolytic-uremic syndrome (HUS) were detected in 1987-1991 in a combined population of more than 7.5 million; there were 24 deaths. The mean annual rates of VTEC infection were 12.1/100,000 and 2.0/100,000 for Alberta and Scotland, respectively. One case of HUS occurred for every 14 (Scotland) to 19 (Alberta) cases of VTEC infection. Rates of VTEC infection were highest among children < 5 years of age, while rates of resultant hospitalization were highest among the elderly. Male-to-female ratios for patients with VTEC infection varied with the age group. The incidence of this infection was highest in the summer: 64.0%-81.7% of cases occurred between May and September. Hamburger was the most common source reported. Unexplained geographic variation in prevalence was evident in both Alberta and Scotland. Most cases were sporadic, although several community and point-source outbreaks were identified in Scotland. HUS exhibited similar epidemiological patterns. Infections with VTEC impose a substantial preventable clinical and public health burden. Routine monitoring of these infections is considered worthwhile in order to elucidate their epidemiology and modes of transmission and ultimately to control them more effectively.

Lens changes and ocular disturbances have been reported in conjunction with the use of antipsychotic drugs. We estimated the incidence rate of a clinical diagnosis of cataract in patients with a psychotic disorder, schizophrenia, and compared it with the rate in the general population. Among the schizophrenic patients, we also examined the role of dose and duration of antipsychotic drugs on the risk of cataract development. We followed up two cohorts of patients 30-85 years of age who were included in the United Kingdom General Practice Research Database. Patients in one group had a diagnosis of schizophrenia (N = 4,209). The other group was an age- and sex-matched cohort of 10,000 patients sampled from the source population. The incidence of cataracts was 4.5 per 1,000 person-years among the general population and 3.5 in the schizophrenia population. Overall, antipsychotic drug use was not associated with the occurrence of cataracts. Nevertheless, among long-term users of chlorpromazine at daily doses of 300 mg or greater, and among users of prochlorperazine, the relative risks were 8.8 (95% confidence interval = 3.1-25.1) and 4.0 (95% confidence interval = 0.8-20.7), respectively. There is no indication that schizophrenia per se is associated with an increased risk of developing cataracts.

Quetiapine, a dibenzothiazepine derivative, is a atypical antipsychotic which has greater in vitro binding affinity for serotonin 5-HT2 receptors than for dopamine D2 receptors. Quetiapine effectively treats both the positive and the negative symptoms of schizophrenia and is also associated with an incidence of extrapyramidal symptoms no greater than placebo across the entire dose range. In addition, it does not cause persistent hyperprolactinaemia. Quetiapine is associated with high levels of patient acceptability and satisfaction, which may result from its combination of efficacy and relatively benign adverse effect profile. The drug is well tolerated and has a low propensity to cause adverse events both during acute and long term treatment in the adult populations. The adverse effect profile of quetiapine makes the drug advantageous for patient populations who are susceptible to the adverse effects of drugs. Indeed, preliminary data show quetiapine to be very well tolerated in the elderly. Overdoses of quetiapine of up to 20g have been reported; however, with appropriate management in an intensive care setting there have been no reported fatalities. Quetiapine is metabolised by the cytochrome P450 3A4 isoenzyme, and the dose may need to be adjusted if quetiapine is co-administered with drugs which affect the activity of this isoenzyme. Overall, quetiapine has a favourable risk-benefit profile that should make it a valuable first-line agent in the treatment of schizophrenia.