In January 2005, an epidemic of chikungunya fever broke out in the Comoro Islands and lasted until May 2005. In April, cases were also reported in Mayotte and Mauritius. On Réunion Island, the first cases were reported at the end of April. Surveillance of this epidemic required an adaptive system, which at first was based on active and retrospective case detection around the cases reported, then relied on a sentinel network when the incidence increased. Emerging and severe forms of infection were investigated. Death certificates were monitored. By April 2006, the surveillance estimate was 244,000 cases of chikungunya virus infection, including 123 severe cases and 41 of maternoneonatal transmission, with an overall attack rate of 35%. Chikungunya infection was mentioned on 203 death certificates and significant mortality was observed. This epidemic highlighted the need for a mutual strategy of providing information on arboviral diseases and their prevention and control between countries in the southwestern Indian Ocean.

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BackgroundSyndromic surveillance systems have been developed in recent years and are now increasingly used by stakeholders to quickly answer questions and make important decisions. It is therefore essential to evaluate the quality and utility of such systems. This study was designed to assess a syndromic surveillance system based on emergency departments' (ED) morbidity rates related to the health effects of heat waves. This study uses data collected during the 2006 heat wave in France.MethodsData recorded from 15 EDs in the Ile-de-France (Paris and surrounding area) from June to August, 2006, were transmitted daily via the Internet to the French Institute for Public Health Surveillance. Items collected included diagnosis (ICD10), outcome, and age. Several aspects of the system have been evaluated (data quality, cost, flexibility, stability, and performance). Periods of heat wave are considered the most suitable time to evaluate the system.ResultsData quality did not vary significantly during the period. Age, gender and outcome were completed in a comprehensive manner. Diagnoses were missing or uninformative for 37.5% of patients. Stability was recorded as being 99.49% for the period overall. The average cost per day over the study period was estimated to be €287. Diagnoses of hyperthermia, malaise, dehydration, hyponatremia were correlated with increased temperatures. Malaise was most sensitive in younger and elderly adults but also the less specific. However, overall syndrome groups were more sensitive with comparable specificity than individual diagnoses.ConclusionThis system satisfactorily detected the health impact of hot days (observed values were higher than expected on more than 90% of days on which a heat alert was issued). Our findings should reassure stakeholders about the reliability of health impact assessments during or following such an event. These evaluations are essential to establish the validity of the results of syndromic surveillance systems.

In order to evaluate the incidence and risk factors of infection by hepatitis C virus (HCV) among injecting drug users (IDUs), we conducted a prospective cohort study of HCV- and human immunodeficiency virus (HIV)-negative IDUs in the North and East of France. A total of 231 HCV and HIV IDUs who had injected drugs at least once in their lifetime were followed up every 3 months over a 12-month period. Serum anti-HCV and anti-HIV were tested at inclusion in the study and at the end of the follow-up. Data on injecting practices were collected at inclusion and at each visit. Of the 231 participants included, 165 (71.4%) underwent a final HCV and HIV serum test. The incidence was nil for HIV infection and 9/100 person-years (95% CI 4.6-13.4) for HCV infection. In a multivariable analysis, we found that syringe and cotton sharing were the only independent predictive factors of HCV seroconversion.

Over a 3-month period, ten children (aged 1-13 years) from a 15-km radius in southern Picardy developed typical D+ hemolytic uremic syndrome (HUS). Polymerase chain reaction, using two pairs of verocytotoxin 1-(VT1) and VT2-specific oligonucleotide primers and an internal control was used to detect VT genes directly from stools samples. VT2 gene was detected in seven of nine patients' stools and in 5 of 14 contacts' stool samples. A VT2-producing Escherichia coli (VTEC) O111 was isolated from five of nine children's stools and in 3 adults' stools of the 14 tested. A retrospective case-control study was performed which showed a higher rate of absence in school A, where the first four cases were detected, compared with a control school. The odds ratio for the whole school was 2.77 (confidence interval 1.46-5.26), and 15 (confidence interval 2.54-115.6) if only the nursery classes were considered. A culture of all food samples from households was always negative for VTEC. A retrospective cohort study performed in 89% of children attending school A showed no linkage between food or drink and gastroenteritis. These findings emphasize the potential for person-to-person transmission of VT2-producing E. coli O111, since the only salient risk factor was close contact.