Transmission of Escherichia coli O157:H7 in cattle is influenced by the level of environmental contamination.

A pen infection-transmission experiment was conducted to elucidate the role of pathogen strain and environmental contamination in transmission of Escherichia coli O157:H7 (ECO157) in cattle. Five steers were inoculated with a three-strain mixture of ECO157 and joined with five susceptible steers in each of two experimental replicates. Faecal and environmental samples were monitored for ECO157 presence over 30 days. One ECO157 strain did not spread. Transmission rates for the other two strains were estimated using a generalized linear model developed based on a modified 'Susceptible-Infectious-Susceptible' mathematical model. Transmission rates estimated for the two strains (0·11 and 0·14) were similar. However, the rates significantly (P = 0·0006) increased 1·5 times for every 1-unit increase in the level of environmental contamination measured as log10 c.f.u. Depending on the level of environmental contamination, the estimated basic reproduction numbers varied from <1 to 8. The findings indicate the importance of on-farm measures to reduce environmental contamination for ECO157 control in cattle that should be validated under field conditions.

Comparative trial of azithromycin and ciprofloxacin in the treatment of gonorrhea.

This single-blind (investigator) comparative study was designed to determine the efficacy and tolerability of 1 g of azithromycin vs 500 mg of ciprofloxacin both given as a single oral dose in patients with gonorrhea, who were constantly on the move. One hundred eight patients (59 men and 49 women) with clinically suspected gonococcal infection, confirmed by Gram-stain and culture, were enrolled. Data of 50 patients treated with azithromycin and 51 with ciprofloxacin were evaluable for efficacy and tolerability at the end of the study. After 2 weeks clinical and microbiological cure rates were 96.0% (48 out of 50) for the patients treated with azithromycin and 92.15% (47 out of 51) for the patients treated with ciprofloxacin (p > 0.05). Adverse reactions were reported in 5 patients treated with azithromycin and 6 with ciprofloxacin. In conclusion, 1 g azithromycin is at least as clinically and microbiologically effective and well tolerated as 500 mg of ciprofloxacin in the treatment of gonococcal infections. The drug is particularly useful for sailors and people constantly on the move.

Postcoital fixed drug eruption in a man sensitive to trimethoprim-sulphamethoxazole.

We describe a 34-year-old patient with a probable fixed drug eruption caused by trimethoprim-sulphamethoxazole, having developed the eruption after sexual intercourse with his wife, who was taking the drug. The patient was known to be allergic to trimethoprim-sulphamethoxazole by history, and the lesion then recurred at the same site when the drug was administered orally to his wife. To the best of our knowledge, this is the first report describing postcoital fixed drug eruption. Physicians should thus be aware of unusual and atypical forms of fixed drug eruption. Fixed drug eruption (FDE) is an unusual form of adverse drug reaction, in which one or more lesions appear in precisely the same place or places each time the precipitating drug is administered. The entity was first described by Bourns in 1889, but Brocq then coined the name some years later. FDE may occur anywhere on the skin or mucous membranes, but more frequently occurs on the genitalia and lips. Lesions are usually sharply demarcated patches which quickly become urticarial and sometimes vesicular in the centre. Itching or burning may also be present. Lesions generally leave prolonged postinflammatory hyperpigmentation. The exact pathogenesis of FDE has not been determined, but recent reports have underlined the importance of T lymphocytes, mast cells, keratinocytes and cytokines in the origin of the lesions. We now report a case of FDE apparently caused by trimethoprim-sulphamethoxazole in a male after intercourse with his wife, who was taking the drug. Such FDE, caused by contact with a drug seemingly present in the vaginal fluid, has not been previously described in the literature as far as we know.