A Taxonomic Checklist of the Mosquitoes of Montana With Notes On New Geographic Distributions.

An updated checklist of 50 species of mosquitoes found in Montana is presented and includes 2 new records (Aedes niphadopsis and Anopheles walkeri) that can be added to the 2005 state list by Darsie and Ward. The results of a statewide mosquito surveillance program, conducted annually from 2004 to 2015, facilitated the establishment of an abundance rating of the species in the state and expanded the known geographic range for Coquillettidia perturbans, Ae. nigromaculis, and Culiseta minnesotae.

Antimicrobial stewardship in a community hospital: attacking the more difficult problems.

BACKGROUND: Antibiotic stewardship has been proposed as an important way to reduce or prevent antibiotic resistance. In 2001, a community hospital implemented an antimicrobial management program. It was successful in reducing antimicrobial utilization and expenditure. In 2011, with the implementation of a data-mining tool, the program was expanded and its focus transitioned from control of antimicrobial use to guiding judicious antimicrobial prescribing. OBJECTIVE: To test the hypothesis that adding a data-mining tool to an existing antimicrobial stewardship program will further increase appropriate use of antimicrobials. DESIGN: Interventional study with historical comparison. METHODS: Rules and alerts were built into the data-mining tool to aid in identifying inappropriate antibiotic utilization. Decentralized pharmacists acted on alerts for intravenous (IV) to oral conversion, perioperative antibiotic duration, and restricted antimicrobials. An Infectious Diseases (ID) Pharmacist and ID Physician/Hospital Epidemiologist focused on all other identified alert types such as antibiotic de-escalation, bug-drug mismatch, and double coverage. Electronic chart notes and phone calls to physicians were utilized to make recommendations. RESULTS: During 2012, 2,003 antimicrobial interventions were made with a 90% acceptance rate. Targeted broad-spectrum antimicrobial use decreased by 15% in 2012 compared to 2010, which represented cost savings of $1,621,730. There were no statistically significant changes in antimicrobial resistance, and no adverse patient outcomes were noted. CONCLUSIONS: The addition of a data-mining tool to an antimicrobial stewardship program can further decrease inappropriate use of antimicrobials, provide a greater reduction in overall antimicrobial use, and provide increased cost savings without negatively affecting patient outcomes.

Monitoring sheep and Culicoides midges in Montana for evidence of Bunyamwera serogroup virus infection.

INTRODUCTION: A serological and entomological investigation was performed to monitor for potential Bunyamwera (BUN) serogroup virus activity in Montana. RESULTS: To facilitate the serological investigation, sera were collected from 104 sheep in 2013 and 2014 and assayed by plaque reduction neutralization test using all six BUN serogroup viruses known to occur in the United States: Cache Valley virus (CVV), Lokern virus (LOKV), Main Drain virus (MDV), Northway virus, Potosi virus and Tensaw virus. BUN serogroup virus-specific antibodies were detected in 41 (39%) sheep. Of these, three were seropositive for MDV, one was seropositive for CVV, one was seropositive for LOKV and 36 had antibodies to an undetermined BUN serogroup virus. Additionally, 30,606 Culicoides sonorensis were collected in 2013 using Centers for Disease Control and Prevention (CDC) light traps and assayed for cytopathic virus by virus isolation in African Green Monkey kidney (Vero) cells. All midges were negative. Almost one-third of the midges were further tested by reverse transcription-polymerase chain reaction using BUN serogroup virus-reactive primers and all were negative. CONCLUSIONS: We provide evidence of BUN serogroup virus infection in sheep but not C. sonorensis in Montana in 2013-2014. This study also provides the first evidence of CVV, MDV and LOKV activity in Montana.

Evaluation of methods for collecting blood-engorged mosquitoes from habitats within a wildlife refuge.

Mortality of American white pelican (Pelecanus erythrorhynchos) chicks attributed to West Nile virus (WNV) prompted field studies on the bionomics of mosquitoes on a wildlife refuge in northern Montana. One component of these studies was to identify blood meal sources for Culex tarsalis, the primary vector of WNV in the region, and the potential bridge vectors Aedes vexans and Culiseta inornata. To accomplish this, 3 methods were evaluated to collect bloodfed mosquitoes: a gasoline powered aspirator, CO2-baited light traps, and fiber pots in shelterbelts consisting of stands of deciduous trees and shrubs and marshes along the lake edge. Fiber pots were also deployed in open fields of prairie grasses. Overall, fiber pots were the most efficient method for collecting engorged Cx. tarsalis and Cs. inornata, largely due to shorter sampling and processing times. Aedes vexans was not collected in fiber pots but was more abundant in aspiration samples than the other 2 species. The optimal location for collecting Cx. tarsalis was dependent on trapping method. Aspirations and fiber pot placements collected more Cx. tarsalis in shelterbelts, while CO2-baited light traps collected more Cx. tarsalis in the marsh habitat. Sixteen avian and 4 mammalian hosts were identified from bloodfed Cx. tarsalis with 46 blood meals derived from birds and 49 from mammals. Aedes vexans and Cs. inornata fed predominantly on white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus), respectively. Humans were identified as hosts in 33% of engorged Cx. tarsalis, 4% of engorged Ae. vexans, and 18% of engorged Cs. inornata.

Using undergraduate researchers to build vector and West Nile virus surveillance capacity.

Vector surveillance for infectious diseases is labor intensive and constantly threatened by budget decisions. We report on outcomes of an undergraduate research experience designed to build surveillance capacity for West Nile Virus (WNV) in Montana (USA). Students maintained weekly trapping stations for mosquitoes and implemented assays to test for WNV in pools of Culex tarsalis. Test results were verified in a partnership with the state health laboratory and disseminated to the ArboNET Surveillance System. Combined with prior surveillance data, Cx. tarsalis accounted for 12% of mosquitoes with a mean capture rate of 74 (±SD = 118) Cx. tarsalis females per trap and a minimum infection rate of 0.3 infected mosquitoes per 1000 individuals. However, capture and infection rates varied greatly across years and locations. Infection rate, but not capture rate, was positively associated with the number of WNV human cases (Spearman's rho = 0.94, p < 0.001). In most years, detection of the first positive mosquito pool occurred at least a week prior to the first reported human case. We suggest that undergraduate research can increase vector surveillance capacity while providing effective learning opportunities for students.

Stable fly phenology in a mixed agricultural--wildlife ecosystem in northeast Montana.

The stable fly, Stomoxys calcitrans (L.), is a cosmopolitan species of blood-feeding Muscidae and an important pest of cattle. Although the cattle industry is the largest commodity in Montana, no research has been conducted on the abundance, distribution, or impact of stable flies in the state. Observations of stable flies attacking West Nile virus (family Flaviviridae, genus Flavivirus, WNV) -infected pelicans on a refuge in close proximity to pastured and confined cattle provided an opportunity to describe stable fly phenology in a mixed agricultural-wildlife ecosystem. Coroplast cards used to monitor and compare adult populations in three habitats (peninsula, pasture, confinement lot) located within 1.5-4.5 km of each other revealed that temporal dynamics differed by site. Adult abundance was generally lowest at the confinement lot, the only location where larval development was identified. Stable flies were collected on all traps placed in pasture, with traps adjacent to pastured cattle consistently collecting the most. Adults also were collected on the peninsula supporting the pelicans' nesting site, but whether the potential hosts or physical landscape served as an attractant is unclear. At all three sites, data indicated that overwintering was not successful and that a transition occurred from early season immigrating adults that used suitable local larval development substrates to subsequent autochthonous populations.

Reproductive potential of stable flies (Diptera: Muscidae) fed cattle, chicken, or horse blood.

Reproductive potential was assessed for stable fly cohorts fed cattle, chicken, or horse blood. Flies provided chicken blood oviposited 20% more eggs per day than did those fed cattle or horse blood. However, flies provided cattle or horse blood were fecund 50% longer. When both egg viability and number of eggs produced were considered, lifetime reproductive potential was almost twice as high for flies fed cattle or chicken blood than for flies fed horse blood. Maternal investment, which took egg production and volume into account, was higher in cohorts fed cattle blood (70 mm3) when compared with the other treatments (chicken = 54 mm3, horse = 55 mm3). This is the first report of stable flies producing viable eggs after feeding on bird blood. Results from this study in addition to field observations indicate that stable fly interactions with birds may be limited to relatively low risk scenarios.