Clinical features and analysis of the duration of colonisation during an outbreak of Salmonella braenderup gastroenteritis.

During an outbreak of acute Salmonella braenderup gastroenteritis we performed a standardised interview encompassing questions on clinical symptoms in 156 (127 adults and 29 children) of 215 identified patients. Sequential stool cultures were obtained for up to five months in these 156 cases. We restricted the analysis to the 122 patients with at least 3 or more available cultures. They were treated with a fluoroquinolone, trimethoprim-sulfamethoxazole, or not treated with antibiotics, according to the decision of the practitioners. For this reason, a randomised double blind study was not possible. Minimum inhibitory concentrations (MIC) of the prescribed drugs were measured for representative isolates before and after treatment. The most frequent symptoms were diarrhoea (98%) and abdominal pain (96%). Vomiting occurred in 43% of cases. Children were more severely ill. Seven weeks after acute gastroenteritis, stool cultures were still positive for salmonella in 71% of the 22 children and 30% of the 100 adults examined (p < 0.002). This rate decreased progressively in both groups to 5 and 3% respectively at 20 weeks (n.s.). Among adults, no significant difference in enteric carriage over time could be demonstrated between untreated patients and those treated with either a fluoroquinolone or trimethoprim-sulfamethoxazole. MIC for salmonella isolates remained unchanged after treatment. In a cohort of patients infected with a single strain of salmonella, fluoroquinolone therapy of acute gastroenteritis failed to influence the duration of enteric carriage, despite continuing susceptibility of the strain. In children, the rate of clearance of Salmonella braenderup from stool was statistically lower until the tenth week after the acute disease, but there was no further difference after 5 months.

Outbreak of Salmonella braenderup gastroenteritis due to contaminated meat pies: clinical and molecular epidemiology.

OBJECTIVES: To determine the epidemiologic, clinical and molecular characteristics of an outbreak of severe gastroenteritis due to the ingestion of meat pies highly contaminated with Salmonella braenderup. METHODS: In October 1993, we observed an outbreak of Salmonella braenderup gastroenteritis that occurred in the Lausanne area, Canton de Vaud, Switzerland. Cultures of suspected food products, of samples at the incriminated food factory and from workers, as well as a case-control study, were used to determine the source of the epidemics. Ribotyping of representative Salmonella braenderup strains was performed to define the molecular epidemiology. The clinical characteristics of this infection were determined by using a standardized interview performed during and 6 months after the outbreak in 156 of 215 identified patients. RESULTS: The outbreak resulted from the ingestion of pies, heavily contaminated (> 106 CFU/g) with a strain of Salmonella braenderup. The contamination was due to mishandling and recycling of jelly poured on top of the products. According to its ribotype and plasmid characteristics, this strain had not been isolated previously in Switzerland. Ten of the 24 workers of the incriminated food factory were shedding the epidemic strain in their stools, and one of them reported gastroenteritis 3 weeks before the beginning of the outbreak. The estimated attack rate in the exposed population was 7.5%. The median incubation time was 18 h. Among 127 adult patients studied, 98% had diarrhea, 95% abdominal pain, 74% fever > or = 38.5 degrees C, 69% nausea and 35% vomiting. One patient developed prosthetic valve endocarditis, and one reactive arthritis. Long-term complications were not identified, although 12 patients complained of irritable bowel syndrome and 24 of unusual asthenia lasting for more than 6 weeks after infection. Children had more severe signs and symptoms compared to adults, and six of 29 needed hospitalization. CONCLUSIONS: This study showed that ingestion of food highly contaminated with Salmonella braenderup resulted in severe but typical gastroenteritis and indicated mishandling of food during manufacture as the cause of this outbreak.

Absence of myelin basic protein in an improved purified duck embryo rabies vaccine.

The encephalitogenic potential of rabies vaccines prepared from nervous tissue is a result of the presence of myelin basic protein. Vaccines prepared from duck embryos are economical and efficient, but, occasionally, cases of allergic encephalomyelitis have been reported. An improved rabies vaccine has been developed that contains the classical Pitman Moore strain of rabies virus grown in embryonated duck eggs. This vaccine has been highly purified and enriched in immunologically effective rabies virus glycoprotein antigen. We have searched for the presence of myelin basic protein using sensitive radioimmunological and immunoblotting techniques. Whereas the classical duck embryo rabies vaccine contained small amounts of myelin basic protein, in the improved purified duck embryo rabies vaccine, none could be detected.

Amniotic fluid testosterone in prenatal sex determination.

Nonconjugated testosterone levels were measured by radioimmunoassay in samples of amniotic fluid from 60 normal pregnant women between 15 and 32 weeks of gestation. In the male fetuses, the mean +/- SEM amniotic fluid testosterone levels(328 +/- 25 pg/ml) were significantly higher (p less than 0,001) than the concentrations found in the female fetuses (121 +/- 9 pg/ml). The ranges were from 155 to 730 and from 46 to 240 pg/ml respectively, which shows an overlap area of the values between the sexes from 155 to 240 pg/ml. The results emphasize the potential interest of amniotic testosterone in the determination of fetal sex.

Humoral immunity conferred by the HDCS rabies vaccine Mérieux administered after exposure: 151 cases with and without specific immune globulin of human origin. Preliminary communication.

The results of the analysis of the neutralizing antibodies measured at days 30 and 90 after vaccination are described in brief. Different lots of Mérieux vaccine were used, of which two were checked separately for relative antigenic value by the Federal Public Health Service (CH). The lowest antigenic value (lot 0420 M) was 1.6 in relation to the standard NIH vaccine No.182. The inhibiting effect of immune globulin was shown to be significant with this lot, but not with the other, more powerful lots. The attention is drawn to isolated cases which did not present antibodies--or not a sufficient count--on days 30 or 90 according to the RFFI test.

Study on the binding of dihydrotestosterone, testosterone and oestradiol with sex hormone binding globulin.

Saturation studies on sex hormone binding globulin (SHBG) were performed with increasing levels of the three steroids: dihydrotestosterone (DHT), testosterone (T) and oestradiol (E2) in normal female sera. The curves obtained showed the clearly increasing SHBG affinity for E2, T and DHT, respectively. With T as saturating ligand, the mean values of SHBG binding capacity in normal and pathological sera, expressed as 10(-8) M SHBG were, for normal women, 5.87 +/- 0.2, for normal men, 3.69 +/- 0.1 and for hirsute women, 5.05 +/- 0.2. In hirsutism, SHBG levels were measured together with T and DHT levels. Hyperandrogenia was often better reflected by the T/SHBG ratio than by T levels alone. SHBG binding capacity, measured in pregnancy from the 7th to the 40th week, increased progressively as far as the 30th week. Values up to 5 times those of the mean value of the cycle were observed at the end of pregnancy. Variations in DHT, T and E2 binding as functions of SHBG concentrations, were also studied by adding a constant amount of each steroid to increasing SHBG concentrations in serum. DHT showed the greatest binding capacity, followed by T and then E2. Since the unbound fractions of T and DHT are believed to be biologically active, and since T and DHT are more sensitive than E2 to SHBG variations, the results obtained further support the hypothesis that SHBG plays an important role in the sex steroids balance.