D. Van Cauteren

Burden of acute gastroenteritis and healthcare-seeking behaviour in France: a population-based study.

In France surveillance underestimates the true burden of acute gastroenteritis (AG). We conducted a population-based, retrospective cross-sectional telephone survey between May 2009 and April 2010 in order to obtain more accurate estimates of the incidence and the burden of AG and to describe healthcare-seeking behaviour for AG. Of the 10 080 persons included in the survey, 260 respondents reported 263 episodes of AG. The incidence rate of AG was estimated at 0·33 cases/person-year (95% CI 0·28-0·37). It was highest in children aged <5 years and declined with age. Thirty-three percent (95% CI 27-40) of the AG cases consulted a physician and 76% (95% CI 70-82) used medication. Our results indicate that there are more than 21 million episodes of AG each year in France. These results allow a more accurate interpretation of the data derived from existing AG surveillance systems.

Estimating the burden of mucormycosis infections in France (2005–2007) through a capture-recapture method on laboratory and administrative data

BACKGROUND Mucormycoses are rare but severe fungal infections whose incidence is increasing, particularly in immunosuppressed and diabetic patients. Following a retrospective study on the characteristics and outcomes of cases who were identified through two sources of information, we carried out a capture-recapture method to estimate the actual burden of the disease in France, 2005-2007. METHODS An administrative dataset from the national hospital discharge system and a laboratory dataset from the National Reference Centre for Mycoses and Antifungals were combined to identify patients from 2005 to 2007. We applied capture-recapture equations to estimate the number of cases missed by both sources and to assess the advantages of each dataset, especially in terms of sensitivity. RESULTS There were 94 mucormycosis cases included in the study: 30 and 31 in each respective source and 33 common to both. Capture-recapture showed that 28 cases were missed (expected total: 122 cases, CI95: 102-142). Each dataset had a sensitivity value below 53%. The merged set yielded a 77% sensitivity (66%-92%). CONCLUSION This study highlights the importance of combining available sources when analysing rare infectious diseases. The proportion of 23% missed cases might seem acceptable given the scarcity of the disease, for which further knowledge is needed. However this proportion could decrease in the future, through the sensitization of clinicians, pathologists and mycologists together with the improving quality of discharge datasets.

Description of two waterborne disease outbreaks in France: a comparative study with data from cohort studies and from health administrative databases

Waterborne disease outbreaks (WBDO) of acute gastrointestinal illness (AGI) are a public health concern in France. Their occurrence is probably underestimated due to the lack of a specific surveillance system. The French health insurance database provides an interesting opportunity to improve the detection of these events. A specific algorithm to identify AGI cases from drug payment reimbursement data in the health insurance database has been previously developed. The purpose of our comparative study was to retrospectively assess the ability of the health insurance data to describe WBDO. Data from the health insurance database was compared with the data from cohort studies conducted in two WBDO in 2010 and 2012. The temporal distribution of cases, the day of the peak and the duration of the epidemic, as measured using the health insurance data, were similar to the data from one of the two cohort studies. However, health insurance data accounted for 54 cases compared to the estimated 252 cases accounted for in the cohort study. The accuracy of using health insurance data to describe WBDO depends on the medical consultation rate in the impacted population. As this is never the case, data analysis underestimates the total number of AGI cases. However this data source can be considered for the development of a detection system of a WBDO in France, given its ability to describe an epidemic signal.

Physician practices in requesting stool samples for patients with acute gastroenteritis, France, August 2013–July 2014

A better understanding of physician practices in requesting stool samples for patients with acute gastroenteritis (AG) is needed to more accurately interpret laboratory-based surveillance data. A survey was conducted in General Practitioners (GPs) between August 2013 and July 2014 to estimate the proportion of stool samples requested for patients with AG and to identify factors associated with GP requests for a stool sample. National health insurance (NHI) data together with surveillance data from a French Sentinel GP network were also used to estimate the proportion of stool samples requested. This proportion was estimated at 4·3% in the GP survey and 9·1% (95% confidence interval 8·7-9·6) using NHI data. Multivariate analysis indicated that the ratio of stool samples requested was almost five times higher in patients with bloody diarrhoea and 10-20 times higher in patients with a long duration of illness before consultation. Laboratory-based surveillance data underestimates the actual burden of disease as fewer than one in 10 AG cases consulting their GP will be requested to submit a stool sample for laboratory testing. This underestimation varies by pathogen as stool samples are more frequently requested for severe illness.