Sodium and urea excretion as determinants of urine output in autosomal dominant polycystic kidney disease patients on V2 receptor antagonists: impact of dietary intervention.

PURPOSE: Tolvaptan, a vasopressin V2 receptor antagonist, slows the decline in renal function in autosomal dominant polycystic kidney disease (ADPKD). However, it increases urine output such that patient adherence could be compromised. In a cohort of patients with ADPKD on tolvaptan, we aimed to identify the contribution of sodium and urea excretion rate to daily urine output, and to evaluate the effectiveness of dietary counseling on sodium and urea excretion rates. METHODS: Retrospective analysis of 30 ADPKD patients who underwent a single session of personalized dietary counseling to reduce sodium and protein intake before initiation of tolvaptan. Creatinine and 24-h urine were obtained regularly on treatment. Generalized estimation equations were used. RESULTS: Mean age and median eGFR were 44 ± 11 years and 52 (43-74) ml/min/1.73 m2. Tolvaptan increased diuresis from 2.5 to 5.2 l/day. After adjusting for the dose of tolvaptan, an increase in sodium and urea excretion rate by 50 mmol/day was associated with an estimated additional urine volume of 0.6 l/day (95% CI 0.4-0.8 l/day; P < 0.001) and 0.25 l/day (95% CI 0.11-0.39 l/day; P < 0.001), respectively. Dietary counseling resulted in a transient reduction of sodium excretion by 19 mmol/day during the first 4 months (P = 0.016) but resulted in a more sustained reduction in urea excretion by 69 mmol/day (P = 0.008). CONCLUSION: Both sodium and urea excretion rates contribute significantly to daily urine volume in patients treated with tolvaptan, and a single session of dietary counseling was transiently effective in reducing sodium intake but achieved a more sustained reduction in protein intake. Dietary counseling should be considered in the management of ADPKD patients treated by tolvaptan.

Escherichia coli O157:H7 outbreak linked to raw milk cheese in Quebec, Canada: use of exact probability calculation and casecase study approaches to foodborne outbreak investigation.

The analytical studies used to investigate foodborne outbreak are mostly case-control or retrospective cohort studies. However, these studies can be complex to perform and susceptible to biases. This article addresses basic principles of epidemiology, probability, and the use of case-case design to identify the source of an Escherichia coli O157:H7 outbreak linked to raw milk cheese consumption in Quebec, Canada; a small number of cases with the same pulsed-field gel electrophoresis (PFGE) profile were involved. Between 4 December 2008 and 15 January 2009, a cumulative total of 16 E. coli O157:H7 cases with the same PFGE profile were reported to Quebec public health authorities. Among the first six cases reported, three had consumed raw milk cheese from the same producer (cheese A). Raw milk cheese is consumed by about 2 % of the Quebec population. By using the exact probability calculation, it was found that a significantly higher proportion of E. coli O157:H7 cases (with the specific PFGE profile) than expected had consumed cheese A (P < 0.001). These computations were updated during the course of the investigation to include subsequent cases and gave the same results. A case-case study corroborated this result. This article considers alternative statistical and epidemiological approaches to investigate a foodborne outbreak-in particular with an exact probability calculation and case-case comparisons. This approach could offer a fast and inexpensive alternative to regular case-control studies to target public health actions, particularly during a foodborne outbreak.

A case of active tuberculosis in a cabin crew: the results of contact tracing.

INTRODUCTION: Transmission of communicable diseases on board aircraft is of considerable concern for passengers and aircrew. Previously published estimates of risk of tuberculosis (TB) transmission have been highly variable. Furthermore, very few studies have been published for active TB in aircrew. METHODS: The public health authorities advised the Medical Advisor of an airline that a cabin crewmember had been diagnosed with active TB. Contact tracing was done for the cabin crew who worked with the index case for more than 8 h. Cabin crewmembers were divided in two groups according to their exposure and had one tuberculin skin test (TST) more than 8 wk after the last exposure. Those with a TST > or = 5 mm have been recommended to have a QuantiFERON-TB Gold In-Tube (QFT) assay. RESULTS: Among the 56 identified contacts, 32 agreed to be evaluated, of whom 6 (19%) had a TST > or = 5 mm. Of those six, four underwent a QFT with one positive result. None had active TB. The percentages of positives in the two exposure groups were similar. All the positive contacts were born in Canada in the period when the childhood Bacille Calmette-Guérin (BCG) vaccination program was in effect. DISCUSSION: The same percentage of positives in the two exposure groups, the proportion of positive contacts below the expected rate in Canadians, and the high proportion of QFT negative among the TST positive contacts suggest that transmission of TB to the cabin crew is unlikely.

The delay in diagnosis of tuberculosis in the Monteregie region of Quebec, Canada.

INTRODUCTION: Despite being more prevalent in developing countries, tuberculosis (TB) remains an important health problem in Canada. Long diagnosis delays of respiratory tuberculosis are associated with adverse consequences for the patient but also for the community. From a public health perspective, identification of factors associated with long delays of diagnosis could help reduce these delays. OBJECTIVES: 1)To describe diagnosis delays of respiratory tuberculosis in Monteregie 2)To identify the characteristics of patients and factors associated with longer diagnosis delays 3)To identify consequences of these delays. METHODS: The study is descriptive and transversal. Data were obtained from notifiable diseases files of the Public Health Department of the Health and Social Services Agency of Monteregie. The diagnosis delay was calculated using the first symptomatic date and the date of diagnosis. For continued variable analyses, Student t tests and an ANOVA test were done. For categorical variables, Pearson's chi squared test and a Mann-Whitney test were done. RESULTS: The average delay of diagnosis for the 115 cases studied was 92.2 days (CI 80.6-103.8). Weight loss and/or non specific general malaise were associated with a longer diagnosis delay. No association was found between the diagnosis delay and possible consequences of longer delays. DISCUSSION AND CONCLUSION: Most patients had a diagnosis delay longer than two months. A larger study that would divide the total diagnosis delay into a patient delay and a suspicion delay (health care system delay) could permit a better identification of factors that favour long delays.

[Beauty and smoking: the utilization of public health programs in the prevention of tobacco use disorders]. / Beauté et tabagisme: l'utilisation des données probantes dans la prévention du tabagisme chez les jeunes.

Research in tobacco prevention is increasingly showing that anti-smoking campaigns aimed at youth work. However, not all interventions are effective, and some have had unintended harmful effects, even to the point of increasing tobacco use by youth. In this commentary, we discuss potentials risks associated with interventions poorly supported by the evidence, using the example of tobacco prevention campaigns that focus on the effects of smoking on beauty. We conclude with two points: 1) the importance of using strategies based on evidence, and 2) the importance of rigorous evaluation of innovative strategies.