Pilot study assessing the effectiveness of factory-treated, long-lasting permethrin-impregnated clothing for the prevention of tick bites during occupational tick exposure in highly infested military training areas, Germany.

The protective effectiveness of factory-based permethrin-impregnated polymer-coated battle dress uniforms (PTBDUs) against tick bites was evaluated at four military training areas in southwestern and central Germany where tick bite incidence is known to be high. Data were analyzed by comparing tick bite incidence using non-permethrin-treated BDUs (NTBDUs) during 2009 versus PTBDUs during 2010 and 2011, the first two years after their formal introduction for in-country use in the German Bundeswehr. During 2009, 262 individual tick bites were reported at the four training sites, resulting in a tick bite incidence of 8.8 % per exposed person when wearing NTBDUs only. In 2010 and 2011, one tick bite case occurred under field conditions each year that PTBDUs were worn, corresponding to a protective effectiveness of 99.6 and 98.6 %. These data imply an annual tick bite incidence of 0.035 and 0.078 % per exposed person, respectively. Between 2010 and 2011, a 0.8 % decline in the protective effectiveness of PTBDUs was observed. Five tick bite incidents occurred while wearing non-impregnated parkas over correctly worn PTBDUs. Ixodes ricinus ticks were collected by standard tick drags from 2009 to 2011, with high mean annual densities ranging from 28.9 to 106.5 ticks per 100 m(2), while single drags revealed tick densities between zero and 381 ticks per 100 m(2). Overall, 4596 I. ricinus ticks (54 ♂, 82 ♀, 1776 nymphs, and 2684 larvae) were collected, of which 128 (2.8 %; mean annual range, 0-10.1 %) were Borrelia burgdorferi s.l. positive. The Borrelia genospecies distribution was as follows: 112 (87.5 %) Borrelia afzelii, 10 (7.8 %) B. burgdorferi s.s., and 6 (4.7 %) Borrelia garinii. Neither the tick density means from 2009 to 2011 nor associated B. burgdorferi s.l. prevalences differed significantly among the military locations investigated. The documented tick bite reductions clearly demonstrate the powerful protective effectiveness of properly worn PTBDUs against tick bites. Nevertheless, all apparel worn over PTBDUs should also be impregnated with permethrin in order to prevent tick infestation and subsequent bites.

Human tick infestation pattern, tick-bite rate, and associated Borrelia burgdorferi s.l. infection risk during occupational tick exposure at the Seedorf military training area, northwestern Germany.

The human tick infestation pattern, tick bite rate, and associated Borrelia burgdorferi s.l.-infection risk were investigated during occupational tick exposure of military personnel at the Seedorf military training area, northwestern Germany, from January to December 2009. Borrelia burgdorferi s.l. seroconversion rates were monitored from April to September 2009. Continuous occupational health surveillance and education were established. Feeding ticks were mostly removed by medical personnel, transferred to 70% ethanol, identified, and tested for B. burgdorferi s.l. Pre- and post-exposure sera were screened for B. burgdorferi s.l. antibodies. A total of 710 feeding ticks was removed, 704 (99.2%) of which were I. ricinus, 5 were I. hexagonus (0.7%), and one was H. concinna (0.1%). Of the I. ricinus specimens, 63.9% were nymphs, 24.7% larvae, 10.9% adult females, and 0.5% adult males. The tick bite rate among occupationally exposed personnel was 42.2% from April to September 2009. Up to 18 simultaneously feeding ticks per person per exposure incident were detected. The mean number of attached ticks was 2.0±2.2 per person per exposure incident. Overall, 86.4% of all feeding ticks were removed from patients within less than 24h after attachment. Borrelia burgdorferi s.l. DNA could be detected in 3.5% of larval, 4.4% of nymphal, 13% of adult female, and 33.3% of adult male ticks, indicating a mean prevalence of 5.3%. Among the genospecies detected, B. afzelii accounted for 84%, B. burgdorferi s.s. for 11%, B. garinii for 3%, and B. spielmanii for 3%. The overall seroconversion rate in 566 personnel exposed from April to September was 1.7%, and 0.7% acquired clinical Lyme borreliosis. Experiences reported herein indicate the need to further improve personal protection measures, health education, and medical staff training in order to minimize exposure to ticks and optimize diagnosis of tick-borne diseases.

Electrodermal and phasic heart rate responses in the Guilty Actions Test: comparing guilty examinees to informed and uninformed innocents.

The present mock-crime study concentrated on the validity of the Guilty Actions Test (GAT) and the role of the orienting response (OR) for differential autonomic responding. N=105 female subjects were assigned to one of three groups: a guilty group, members of which committed a mock-theft; an innocent-aware group, members of which witnessed the theft; and an innocent-unaware group. A GAT consisting of ten question sets was administered while measuring electrodermal and heart rate (HR) responses. For informed participants (guilty and innocent-aware), relevant items were accompanied by larger skin conductance responses and heart rate decelerations whereas irrelevant items elicited HR accelerations. Uninformed participants showed a non-systematic response pattern. The differential electrodermal responses of informed participants declined across the test. With respect to the HR data, however, no habituation was observed. Findings suggest that GAT results could not exclusively be interpreted by referring to the OR.