Use of anticoagulant rodenticides by pest management professionals in Massachusetts, USA.

Secondary exposure to chemical rodenticides, specifically second-generation anticoagulant rodenticides (SGARs), poses a threat to non-target wildlife including birds of prey. Federal regulations in the United States currently limit homeowner access to SGARs as a way of minimizing this threat. With legal access to SGARs, pest management professionals (PMPs) represent a potential linkage to non-target exposure. There is limited research focused on rodent control practices, chemical rodenticide preferences, level of concern and awareness, or opinions on rodenticide regulations as they relate to PMPs. An online survey was sent to PMP companies across Massachusetts, USA, between October and November 2015. Thirty-five responses were obtained, a 20 % response rate. The preferred rodent control method among responding PMP companies was chemical rodenticides, specifically the SGAR bromadiolone. Respondents varied in their level of concern regarding the impact of chemical rodenticides on non-target species and showed a low level of awareness regarding SGAR potency and half-life. All responding companies reported using integrated pest management (IPM) strategies, with nearly all utilizing chemical rodenticides at some point. Enhanced education focused on SGAR potency, bioaccumulation potential, exposure routes, and negative impacts on non-target wildlife may improve efforts made by PMPs to minimize risk to wildlife and decrease dependence on chemical rodenticide use. Future studies evaluating use of anticoagulant rodenticide (ARs) by PMPs and the association with AR residues found in non-target wildlife is necessary to determine if current EPA regulations need to be modified to effectively reduce the risk of SGARs to non-target wildlife.

Protective practices against zoonotic infections among rural and slum communities from South Central Chile.

BACKGROUND: Despite well-recognized recommendations to reduce human exposure to zoonotic pathogens, the use of personal and herd-level protective practices is inconsistent in communities where human interactions with animals are common. This study assessed household-level participation in rodent- (extermination, proper food storage, trash disposal), occupational- (preventive veterinary care, boot-wearing, glove-wearing), and garden-associated (restricting animal access, boot-wearing, glove-wearing) protective practices in farms, villages, and slums in the Los Rios region, Chile, where zoonotic pathogens are endemic. METHODS: Questionnaires administered at 422 households across 12 communities recorded household-level socio-demographic characteristics and participation in nine protective practices. Household inclusion in the analysis of occupational practices required having livestock and a household member with occupational exposure to livestock (n = 127), and inclusion in analysis of garden practices required having a garden and at least one animal (n = 233). The proportion of households participating in each protective practice was compared across community types through chi-square analyses. Mixed effects logistic regression assessed household-level associations between socio-demographic characteristics and participation in each protective practice. RESULTS: Most households (95.3 %) reported participation in rodent control, and a positive association between the number of rodent signs in a household and rodent extermination was observed (OR: 1.75, 95 % CI: 1.41, 2.16). Occupational protective practices were reported in 61.8 % of eligible households; household size (OR: 1.63, 95 % CI: 1.17, 5.84) and having children (OR: 0.22, 95 % CI: 0.06, 0.78) were associated with preventive veterinary care. Among eligible households, 73.8 % engaged in protective practices when gardening, and species diversity was positively associated with wearing boots (OR: 1.27, 95 % CI: 1.03, 1.56). Household-level participation in all three protective practices within any exposure category was limited (<10.4 %) and participation in any individual protective practice varied considerably within and across community types. CONCLUSIONS: The levels of participation in protective practices reported in this study are consistent with descriptions in the literature of imperfect use of methods that reduce human exposure to zoonotic pathogens. The wide differences across communities in the proportion of households participating in protective practices against human exposure to zoonotic pathogens, suggests that future research should identify community-level characteristics that influence household participation in such practices.

[Monitoring populations of rodent reservoirs of zoonotic diseases. Projects, aims and results]. / Monitoring von gesundheitsgefährdenden Nagetieren. Projekte, Ziele und Ergebnisse.

Rodents can harbor and transmit pathogens that can cause severe disease in humans, companion animals and livestock. Such zoonotic pathogens comprise more than two thirds of the currently known human pathogens. The epidemiology of some zoonotic pathogens, such as hantaviruses, can be linked to the population dynamics of the rodent host. In this case, during an outbreak of the rodent host population many human infections may occur. In other rodent-borne zoonotic diseases such phenomena are not known and in many cases the rodent host specificity of a given pathogen is unclear. The monitoring of relevant rodent populations and of the rodent-borne zoonotic pathogens is essential to (1) understand the distribution and epidemiology of pathogens and (2) develop forecasting tools to predict outbreaks of zoonoses. Presently, there are no systematic long-term monitoring programs in place for zoonoses in Germany. Rodent monitoring activities are largely restricted to the plant protection sector, such as for the common vole (Microtus arvalis) and forest-damaging rodents. However, during the last 10-15 years a number of specific research projects have been initiated and run for a few years and Norway rat (Rattus norvegicus) monitoring has been implemented in Hamburg and Lower Saxony. Based on close cooperation of federal and state authorities and research institutions these efforts could be utilized to gain information about the distribution and importance of rodent-borne zoonoses. Nevertheless, for the integration of rodent population dynamics and zoonotic disease patterns and especially for developing predictive models, long-term monitoring is urgently required. To establish a systematic long-term monitoring program, existing networks and cooperation need to be used, additional collaborators (e.g., pest control operators) should be included and synergetic effects of different scientific fields should be utilized.

Temporal distribution and weather correlates of Norway rat (Rattus norvegicus) infestations in the city of Madrid, Spain.

Urban Norway rats are challenging pests, posing significant health and economic threats. Implementing ecologically based integrated rodent management (EBIRM) programmes relies primarily on the understanding of ecological relationships between rodents and their environments, with emphasis on the processes influencing rodent populations in the target ecosystem. We investigated the temporal distribution of urban Norway rat infestations in Madrid, Spain, and tested for the association of such infestations with temperature, relative humidity and precipitation by fitting a multivariate Poisson generalized linear model to a 3-year (2006-2008) daily time series of 4,689 Norway rat sightings. Norway rat infestations showed a marked seasonality, peaking in the summer. Most Norway rat sightings were reported on Mondays. Minimum temperature and relative humidity were positively associated with Norway rat infestation, whereas the association with precipitation was negative. The time series was adequately explained by the model. We identified previously unrecognized time periods that are more prone to Norway rat infestation than others and generated hypotheses about the association between weather, human outdoor activity, resource availability, rodent activity and population size. This provided local authorities engaged in preserving urban ecosystem health with basic research information to predict future rodent outbreaks and support the implementation of EBIRM programmes in urban areas.

Assessing spatial variation and overall density of aerially broadcast toxic bait during a rat eradication on Palmyra Atoll.

Baits containing brodifacoum rodenticide were aerially applied to eradicate invasive black rats from Palmyra Atoll, an important biodiversity center. Bait application must be sufficient to be effective, while minimizing environmental hazards by not exceeding designated label rates, prompting our bait density assessments for two aerial drops. With few physical or human resources on this remote, uninhabited atoll, assessments were particularly challenging, requiring observations within 30 min of aerial application to avoid bait loss to rats, crabs, or elements. We estimated bait density using quadrat sampling within 13 terrestrial sampling areas. We also sampled 10 tidal flat areas to assess inadvertent bait scatter into marine aquatic environments. Of particular value for challenging sampling circumstances, our quadrats had to be lightweight and durable, which we addressed by using widely available PVC hoops ("Hula Hoops"), the size of which was ideal for sampling purposes. At 77.5 and 78.7 kg/ha, overall bait densities were very near to the target densities of 80 and 75 kg/ha, respectively. However, considerable variability in bait densities existed among sampled areas, 8.6-178.2 and 31.4-129.5 kg/ha for the respective drops, respectively. Environmental, human, and equipment factors likely accounted for this variability. Tidal flat sampling revealed variable bait scatter into aquatic environments, from 0-46.3 kg/ha across the two drops. No differences were found in average bait densities among 1-, 4-, and 7-m distances from high tide lines. Our methods might broadly assist bait density (and other) surveys under challenging circumstances.

Comparison of population estimators and indices for monitoring house mice in sorghum crops.

House mice (Mus musculus domesticus Schwarz & Schwarz, 1943) are monitored in Australia and China to track changes in mouse population densities and forecast their potential damage to cereal crops. The present study compared population indices based on the number of different mice caught and overall trap success from live-trapping with an oil card index (OC) and a tracking index (T) for monitoring mice in sorghum crops immediately before crop maturation. T was measured as the percentage of track board covered with mouse footprints night(-1), and OC as the percentage of card removed by mice night(-1). The reliability of these abundance indices was quantified by Pearson correlation coefficient with the trappable population size (Ñ), which was estimated by capture-recapture over eight consecutive nights on 175 × 5 trapping grids, in sorghum crops on two properties on the Darling Downs, Queensland. Because of differences among individual mice in capture probability, Model M(h) of program MARK was used to account for such heterogeneity and to estimate the size of each mouse population. The number of individual animals caught was more strongly correlated with Ñ than trap success and, therefore, might be a more reliable index; the data suggest that three trapping occasions provide optimal precision for this index. T correlated significantly with Ñ only at sites where the canopy of sorghum plants was closed, and its use should, therefore, be restricted to this habitat. OC did not correlate with Ñ because none or very little of the cards was eaten at low to moderate mouse densities. T and the number of animals caught over three trapping nights are recommended for monitoring mice in sorghum crops immediately prior to crop maturation.

[Rodent control: review of rodenticides registered in the field of environmental health in Spain]. / El control de los roedores: revisión de los rodenticidas registrados en el ámbito de la sanidad ambiental en España.

The use of what are known as "rodenticides", defined as biocides used for rodent control, is currently required. In the recent transposition of the Biocide Directive by way of Royal Decree 1054/2002, rodenticides are included under Main Group 3, Product Type 14. The current status of rodenticides in the Official Pesticide Registry is analyzed. This study has been conducted based on the data in the database of the Spain's Official Registry of Pesticides for Use in Public Health for rodenticides (technical and formulated active ingredients). Nine (9) of the technical active ingredients registered are anticoagulants, one (1) has a sedative effect and one (1) causes hypercalcemia. A total of 412 of the 416 formulated rodenticides include some anticoagulant (87.4% are coumarin derivatives, while 12.6% are indandione derivatives). A total 94.2% of these products are formulated as solids and are classified as slightly or moderately hazardous. Aspects such as effectiveness on the different species or the type of effect are not required. Based on the analysis conducted, the one outstanding aspect revealed is large number of formulated rodenticides registered in Spain in comparison to other countries. One of the major consequences which may be anticipated from the transposition of EC Directive 98/9/EC, is the reduction in the number and type of rodenticides which are registered and a greater degree of accuracy as to their effectiveness, the type of effect, the composition (baiting) and the type of formulation.

An index technique to monitor broadcast calibration and bait pick up, plus rodent and avian sign under arid conditions.

As part of product-performance and wildlife-hazards studies of 2% zinc phosphide (Zn3P2) steam-rolled-oat baits (11.2 kg ha-1) to reduce vole populations (Microtus spp) in alfalfa (Medicago sativa), we used randomly located, brushed-dirt plots (eight approximately 930-cm2 plots per 0.2-ha enclosure) to monitor bait-broadcast and -removal patterns, as well as to index vole and avian sign. Research was conducted in 18 x 0.2-ha enclosures containing 2.5-year-old stands of alfalfa; a 2-day pre-bait (placebo baits broadcast in all enclosures) period followed by a 14-day test-bait period (placebo and 2% Zn3P2 baits in nine enclosures each) characterized the bait exposures. Baits were broadcast manually by two certified pesticide applicators (CPAs) using Spyker Model-75 spreaders. Baits that fell onto plots were counted < 30 min later to assess the uniformity of bait distribution. The main statistical design was a 2 (placebo or Zn3P2 baits) x 3 (vole-only, vole-pheasant, vole-quail exposures) x 14 (days) factorial, with days considered repeated measurements. In the six vole-only enclosures, baits were removed from the brushed-dirt plots and replaced with four 0% or 2% Zn3P2 baits (one per 232.6-cm2 quadrant; 32 per enclosure); these 'placed' baits were then monitored daily for removal, while the surfaces of all plots were monitored daily for the presence:absence of animal/bird sign. Key results were: (a) 3.51 (+/- 2.66) and 3.39 (+/- 3.52) mean (+/- SD) baits were found on plots after pre-bait and test-bait broadcasts, respectively--less than the predicted 4.52 particles per 930-cm2 plot; (b) baits 'placed' on plots in placebo-baited enclosures were removed earlier than those in Zn3P2-baited enclosures--data in agreement with observed vole mortality; and (c) species x bait interactions occurred for both the vole- and pheasant-sign counts, but not quail-sign counts--data also indirectly confirming Zn3P2-induced mortality effects on voles and pheasants. This technique has utility for a variety of wildlife biology and chemical registration studies; although limited to arid conditions, the technique affords useful indices of broadcast calibration, bait pick-up, as well as target and non-target species mortality.

[The efficacy of Salmocumarín rodenticide in livestock-raising and urban sites]. / Efectividad del rodenticida Salmocumarín en objetivos pecuarios y urbano.

The activity in burrows at four different sites was calculated, and it went from 80 to 98% during pretreatment. For the first time in our country, average values of days/deaths of synanthropic rodents in natural conditions were obtained, and the reached values were between 16.50 and 19.06 after applying the biorodenticide. In the statistical analysis, a significant difference was found in the set of objectives related with days/deaths averages (H = 8.60*; p < 0.05). Moreover, no significant differences were found in percentages of residual activity in burrows (G = 8,27; p < 0.05). Results obtained show that Salmocumarín biorodenticide is much more effective in places where great populations of this species of cosmopolitan rodents exist.