Perceptions and Practices of Mass Bat Exposure Events in the Setting of Rabies Among U.S. Public Health Agencies

Current guidelines in the setting of exposures to potentially rabid bats established by the Advisory Committee on Immunization Practices (ACIP) address post‐exposure prophylaxis (PEP) administration in situations where a person may not be aware that a bite or direct contact has occurred and the bat is not available for diagnostic testing. These include instances when a bat is discovered in a room where a person awakens from sleep, is a child without an adult witness, has a mental disability or is intoxicated. The current ACIP guidelines, however, do not address PEP in the setting of multiple persons exposed to a bat or a bat colony, otherwise known as mass bat exposure (MBE) events. Due to a dearth of recommendations for response to these events, the reported reactions by public health agencies have varied widely. To address this perceived limitation, a survey of 45 state public health agencies was conducted to characterize prior experiences with MBE and practices to mitigate the public health risks. In general, most states (69% of the respondents) felt current ACIP guidelines were unclear in MBE scenarios. Thirty‐three of the 45 states reported prior experience with MBE, receiving an average of 16.9 MBE calls per year and an investment of 106.7 person‐hours annually on MBE investigations. PEP criteria, investigation methods and the experts recruited in MBE investigations varied between states. These dissimilarities could reflect differences in experience, scenario and resources. The lack of consistency in state responses to potential mass exposures to a highly fatal disease along with the large contingent of states dissatisfied with current ACIP guidance warrants the development of national guidelines in MBE settings.     

Recreational exposure to low concentrations of microcystins during an algal bloom in a small lake

We measured microcystins in blood from people at risk for swallowing water or inhaling spray while swimming, water skiing, jet skiing, or boating during an algal bloom. We monitored water samples from a small lake as a Microcystis aeruginosa bloom developed. We recruited 97 people planning recreational activities in that lake and seven others who volunteered to recreate in a nearby bloom-free lake. We conducted our field study within a week of finding a 10-μg/L microcystin concentration. We analyzed water, air, and human blood samples for water quality, potential human pathogens, algal taxonomy, and microcystin concentrations. We interviewed study participants for demographic and current health symptom information. Water samples were assayed for potential respiratory viruses (adenoviruses and enteroviruses), but none were detected. We did find low concentrations of Escherichia coli, indicating fecal contamination. We found low levels of microcystins (2 μg/L to 5 μg/L) in the water and (<0.1 ng/m³) in the aerosol samples. Blood levels of microcystins for all participants were below the limit of detection (0.147μg/L). Given this low exposure level, study participants reported no symptom increases following recreational exposure to microcystins. This is the first study to report that water-based recreational activities can expose people to very low concentrations of aerosol-borne microcystins; we recently conducted another field study to assess exposures to higher concentrations of these algal toxins.     

Toxicity of the aquaculture pesticide cypermethrin to planktonic marine copepods

The acute and sublethal toxicity of cypermethrin, the active ingredient in the sea lice treatment formulation Excis^®, to non‐target planktonic marine copepods was determined. The comparative sensitivities of three life stages (nauplii, copepodites, adults) of four common marine copepods (Acartia clausi, Pseudocalanus elongatus, Temora longicornis and Oithona similis) were assessed in 48‐h exposures, followed by a recovery period in toxicant‐free sea water. The cyclopoid copepod, O. similis, was most affected by cypermethrin, with EC₅₀ values ranging from 0.14 to 0.24 μg L^?1 for nauplii and adults respectively. With the exception of T. longicornis nauplii, the calanoid copepods (A. clausi, P. elongatus and T. longicornis) responded similarly to cypermethrin. Overall, 48‐h EC₅₀ values ranged from 0.12 μg L^?1 (T. longicornis nauplii) to >5 μg L^?1 (P. elongatus adults). For all species, nauplii and copepodite EC₅₀ values were lower than those of the adults. The primary toxic effect, immobilization, was generally irreversible. A sublethal test with adult A. clausi females, involving pulse exposures over 4 days measured a significant increase in egg production at the higher concentrations (1.58 and 5 μg L^?1). Concentrations causing acute toxicity to planktonic copepods were lower than the recommended sea lice treatment concentration of 5 μg L^?1 cypermethrin, indicating the potential for toxic effects in the field. However, acute toxicity values were higher than the Environmental Quality Standard of 0.016 μg L^?1 for dispersing treatment plumes, suggesting that cypermethrin released to the marine environment following sea lice treatments is unlikely to affect adversely planktonic copepods.     

A case–case study comparing the individual risk factors and symptomatology of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015, following implementation of the Ontario Investigation Tools

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S. Heidelberg and S. Typhimurium cases reported in Ontario in 2015, following implementation of the OIT. Multilevel logistic regression models were applied to assess associations between serotype and individual‐level demographic characteristics, exposures and symptoms for sporadic confirmed cases of S. Heidelberg and S. Typhimurium in Ontario in 2015. There were 476 sporadic cases of S. Typhimurium (n = 278) and S. Heidelberg (n = 198) reported in Ontario in 2015. There were significant associations between the odds of the isolate from a case being one of these serotypes, and travel, consumption of sprouts (any type), contact with reptiles and development of malaise, fever or bloody diarrhoea. The S. Typhimurium and S. Heidelberg cases differed in both symptom presentation and risk factors for illness. Case–case comparisons of Salmonella serotypes have some advantages over case–control studies in that these are less susceptible to selection and recall bias while allowing for rapid comparison of cases to identify potential high‐risk exposures that are unique to one of the serotypes when compared to the other. Comparing cases of two different Salmonella serotypes can help to highlight risk factors that may be uniquely associated with one serotype, or more strongly associated with one serotype compared to another. This information may be useful for understanding relative source attribution between common serotypes of Salmonella.     

Metal bioaccumulation and cellular fractionation in an epigeic earthworm (Lumbricus rubellus): The interactive influences of population exposure histories, site-specific geochemistry and mitochondrial genotype

Subcellular fractionation techniques were used to describe temporal changes (at intervals from T₀ to T₇₀ days) in the Pb, Zn and P partitioning profiles of Lumbricus rubellus populations from one calcareous (M_DH) and one acidic (M_CS) geographically isolated Pb/Zn-mine sites and one reference site (C_PF). M_DH and M_CS individuals were laboratory maintained on their native field soils; C_PF worms were exposed to both M_DH and M_CS soils. Site-specific differences in metal partitioning were found: notably, the putatively metal-adapted populations, M_DH and M_CS, preferentially partitioned higher proportions of their accumulated tissue metal burdens into insoluble CaPO₄-rich organelles compared with naive counterparts, C_PF. Thus, it is plausible that efficient metal immobilization is a phenotypic trait characterising metal tolerant ecotypes. Mitochondrial cytochrome oxidase II (COII) genotyping revealed that the populations indigenous to mine and reference soils belong to distinct genetic lineages, differentiated by ∼13%, with 7 haplotypes within the reference site lineage but fewer (3 and 4, respectively) in the lineage common to the two mine sites. Collectively, these observations raise the possibility that site-related genotype differences could influence the toxico-availability of metals and, thus, represent a potential confounding variable in field-based eco-toxicological assessments.     

Distribution of the Cinnabar moth Tyria jacobaeae L. at landscape scale: use of linear landscape structures in egg laying on larval hostplant exposures

The distribution of the xerothermophilous Cinnabar moth Tyria jacobaeae was studied in a low mountain region in western Germany between 1989 and 2001. T. jacobaeae started its immigration into the study area in 1989 and first established populations in climatically favoured habitats like abandoned quarries and train stations where the larval host plant, ragwort (Senecio jacobaea), occurs. Analysis of landscape features (altitude, morphology) reveals that T. jacobaeae then dispersed along valleys with roads to higher altitudes of the study area. Elevations of occupied sites increased between 1989 and 2001. In order to investigate whether dispersal is affected by linear structures like valleys or roads with gravelled verges, hostplant exposures were placed at a distance of 600 m to the next population of T. jacobaeae. The experiments suggest that egglaying predominantly took place on exposures in valleys with roads and sparsely plant-covered verges but can also occur along valleys lacking roads and suitable habitats. However, larvae were never recorded on Senecio exposures which were placed aside from valleys and roads.This revised version was published online in May 2005 with corrections to the Cover Date.     

变温对烟蚜茧蜂低温贮藏存活特性的影响

 【目的】明确变温对烟蚜茧蜂低温存活的影响,以及不同寄主僵蚜经低温贮藏后羽化率的差异,寻找烟蚜茧蜂在低温贮藏过程中的最适条件及寄主。【方法】以烟蚜和麦二叉蚜僵蚜为试验材料,经不同变温（4℃ 22 h/20℃ 2 h,4℃ 46 h/20℃ 2 h,4℃ 70 h/20℃ 2 h）处理后,比较烟蚜茧蜂羽化率、雄虫比和后足胫节长度的变化。【结果】经不同变温处理的僵蚜与恒定低温（4℃）处理相比,烟蚜茧蜂的羽化率有所提高,寄主为烟蚜的僵蚜羽化率经过4℃ 22 h/20℃ 2 h（T1）处理2周后最高,为78.33%;寄主为麦二叉蚜的僵蚜羽化率经过4℃ 46 h/20℃ 2 h（T2）处理1周后最高,为68.33%。雄虫比变化不显著,均在0.3—0.5。低温贮藏后,寄主为烟蚜的僵蚜羽化率略高于麦二叉蚜,且雄虫比和后代蜂雌雄蜂后足胫节长度差异不显著。【结论】变温处理后的烟蚜茧蜂羽化率高于恒定低温,且变温与恒低温贮藏后雄虫比例均比雌虫比例低。变温贮藏技术更适于烟蚜茧蜂的繁殖与释放。