Remote sensing based identification of environmental risk factors associated with West Nile disease in horses in Camargue, France.

Geographic information system and remote sensing technologies were used to identify landscape features associated with risk of West Nile virus transmission as defined by the presence of confirmed horse cases. SPOT-4 images of Camargue area were used to generate a map of landscape categories of epidemic foci and the geographic information system was employed to determine the proportion of landscape components surrounding 10 horse case sites and 17 control sites. The spatio-temporal analysis of the cases outbreak gave the best results for a spatial window of 9 km and a temporal window of 18 days. Two clusters were identified (relative risk=3.35), both in the wet area of Camargue, near the town "Les Saintes Maries de la Mer". The first one was 4 km radius, the second 9 km. The relationships between the presence of cases and proportions of landscape categories were analyzed using generalized linear model. The best model indicated that rice fields and dry bushes, wet "sansouire" and open water were the major components of the landscape that were associated with the presence of West Nile virus cases.

Occupational injuries with captive lance-headed vipers (Bothrops moojeni): experience from a snake farm in Brazil.

We studied occupational injuries with captive lance-headed vipers (Bothrops moojeni) that occurred in a snake farm in south-eastern Brazil from February 1981 to May 1999. The risk of injury, taking into account 13 cases of snake-associated injuries (12 of them snake bites) was 2.73 per 10,000 person-days of work, and 3.51 per 100,000 venom extractions. Thirteen cases of injury occurred in seven workers, whereas 18 workers were never injured, suggesting that some individuals have a higher risk of injury than others perhaps due to lack of concentration or overconfidence. Eight episodes of occupational injuries occurring in four technicians, including a case of eye injury due to splashed venom during extraction, are reported. Assessment of whether envenoming occurred was facilitated by knowledge of the snake species and size, history of recent venom extraction and snake feeding, and examination of snake venom glands. Hypersensitivity reactions (anaphylaxis and serum sickness) to antivenom are a risk particularly to those workers who were bitten more than once and medicated previously. Antivenom therefore should not be administered to these individuals unless there is clear evidence that envenoming occurred or is likely to have occurred. Hypersensitivity to the venom is also a health concern for workers from snake farms.