A case of autochthonous Plasmodium vivax malaria, Corsica, August 2006

A case of Plasmodium vivax malaria was diagnosed in Corsica in summer 2006. This is the first case of autochthonous transmission of malaria to be reported in Corsica since 1972. Corsica is a well-known malaria endemic region characterised, for several years now by an anophelism situation without malaria disease, due to the presence of An. labranchiae and An. saccharovi able to transmit P. vivax. The occurring sequence of malaria signs in an imported case on 9 July and in an autochthonous case on 5 August, both in Porto, implies a transmission by local Anopheles. This suspicion is reinforced by the results of entomological investigations. However, from June to September 2006, no other P. vivax malaria case and no other autochthonous case were detected in Corsica. Therefore, it seems that no permanent malaria transmission occurs in this island. Mosquito eradication actions and anti-vectorial measures have been reinforced as well as individual prevention measures against imported diseases while travelling in tropical countries. Obviously, detection of one exceptional autochthonous transmission of one malaria case in Corsica does not justify proposing malaria protection to tourists.     

Effects of sublethal doses of fipronil on the behavior of the honeybee (Apis mellifera)

Fipronil is a phenylpyrazole insecticide introduced for pest control, but it can also affect non-target insects such as honeybees. In insects, fipronil is known to block GABA receptors and to inhibit ionotropic glutamate-gated chloride channels, but the behavioral effects of low doses are not yet fully understood. We have studied the effect of sublethal doses of fipronil on the behavior of the honeybee (Apis mellifera) under controlled laboratory conditions. The drug was either administered orally or applied topically on the thorax. A significant reduction of sucrose sensitivity was observed for the dose of 1 ng/bee 1 h after a thoracic application. No significant effect on sucrose sensitivity was obtained with acute oral treatment. A lower dose of fipronil (0.5 ng/bee applied topically) impaired the olfactory learning of the honeybees. By contrast, locomotor activity was not affected. Our results suggest a particular vulnerability of the olfactory memory processes and sucrose perception to sublethal doses of fipronil in the honeybee.     

The prevalence of reported asthma is independent of exposure in house dust mite-sensitized children.

In areas with low house dust mite (HDM) allergen exposure, both mite sensitization and asthma prevalence are low. In most other areas, HDM allergen exposure is higher than the threshold for sensitization. In this setting, is HDM allergen exposure a factor which is causally related to the development of asthma in HDM-sensitive individuals? To answer this question, the cumulative prevalence of asthma was evaluated in a group of 157 schoolchildren, aged 10 and 11 yrs, who were allergic to HDM allergen, and compared it with HDM allergen exposure and atopic status, using univariate and multivariate analysis. HDM allergen levels were measured in mattress dust using an enzyme-linked immunosorbent assay (ELISA) method. Of mattress dust samples, 94% had an HDM allergen level >2 microg x g dust(-1). Atopy was evaluated by means of skin prick tests using five common allergens. Among the predictive variables studied by means of univariate analysis, only the number of positive skin tests and male sex correlated with asthma prevalence, but not HDM allergen exposure. Logistic regression analysis also demonstrated that the number of positive skin tests correlated with asthma prevalence (odds ratio (OR)=1.38, p=0.05), whereas the OR for HDM allergen exposure was 1.0. This survey suggests that, in a geographical area with high HDM allergen exposure, asthma prevalence is not linked with HDM allergen levels.     

Outbreak of Typhoid Fever on the French Riviera

 A case-control study was conducted to establish the source of a community outbreak of typhoid fever in Utelle, France, a village located in the Alpes-Maritimes district of the French Riviera. Thirteen confirmed cases of typhoid fever and 41 confirmed community controls were included in the study. Cases and controls did not differ regarding ingestion of water. Multivariate logistic regression analysis identified consumption of pork meats during a village festival as the only statistically significant risk factor for typhoid fever after adjusting for age and sex (odds ratio, 76.0; 95% confidence interval, 3.5–1660). Assessment of food-handling procedures at the inn where the food had been prepared showed that the refrigeration and cooking facilities were inadequate to maintain a proper sanitary environment during the preparation of a meal for 350 people. Although the exact cause of the epidemic could not be confirmed, food contaminated by a chronic typhi carrier is the most plausible hypothesis.     

Capture–Recapture Method for Estimating Annual Incidence of Imported Dengue,France, 2007–2010

Imported dengue cases pose the public health risk for local circulation in European areas, especially southeast France, where the Aedes mosquito is established. Using a capture–recapture method with Chao’s estimator, we estimated the annual incidence of dengue fever and the completeness of existing mandatory notification and laboratory network surveillance systems. During 2007–2010, >8,300 cases with laboratory evidence of recent dengue infection were diagnosed. Of these cases, 4,500 occurred in 2010, coinciding with intense epidemics in the French West Indies. Over this 4-year period, 327 cases occurred in southeast France during the vector activity period. Of these, 234 cases occurred in 2010, most of them potentially viremic. Completeness of the mandatory notification and laboratory network systems were ≈10% and 40%, respectively, but higher in southeast areas during May–November (32% and 69%, respectively). Dengue surveillance systems in France provide complementary information that is essential to the implementation of control measures.