ENTOMOLOGIC INDEX FOR HUMAN RISK OF LYME-DISEASE

An entomologic index based on density estimates of Lyme disease spiroc hete-infected nymphal deer ticks (Ixodes scapularis) was developed to assess human risk of Lyme disease. The authors used a standardized pro tocol to determine tick density and infection in numerous forested sit es in six Rhode Island towns. An entomologic risk index calculated for each town was compared with the number of human Lyme disease cases re ported to the Rhode Island State Health Department for the same year. A strong positive relation between entomologic risk index and the Lyme disease case rate for each town suggested that the entomologic index was predictive of Lyme disease risk.