Publications by authors named "Seth Britch"

Mortality caused by passive resin transfluthrin diffusers (∼5 mg AI per 24 h release rate) suspended in small 2-person tents was measured for colony-reared sentinel pyrethroid susceptible and female mosquitoes, as well as a pyrethroid-resistant strain of , in a USA military field camp scenario. Mortality effects were investigated for impact by factors such as sentinel cage location (inside tent, tent doorway and outside tent), exposure time (15, 30, 45 and 60 min), and environmental temperature (°C), all of which were examined over an 8-week period. Analyses determined there was a significant interaction between mosquito strain and transfluthrin susceptibility, with the two susceptible strains experiencing significantly greater mean mortality than the resistant strain.

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Recent experiments suggest spatial repellents may significantly reduce biting pressure from host-seeking riceland mosquitoes, such as Anopheles quadrimaculatus, in a warm-humid open-field habitat. However, little is known regarding efficacy of these formulations in partially enclosed spaces where US military personnel may be sheltered or concealed in an operational environment. In this study we investigated the capability of 3 spatial repellents-metofluthrin, linalool, and d-cis/trans allethrin-to reduce mosquito incursion into small open-top enclosures of US military camouflage netting.

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The control of such human diseases as dengue, Zika, and chikungunya relies on the control of their vector, the Aedes aegypti mosquito, because there is no prevention. Control of mosquito vectors can rely on chemicals applied to the immature and adult stages, which can contribute to the mortality of non-targets and more importantly, lead to insecticide resistance in the vector. The sterile insect technique (SIT) is a method of controlling populations of pests through the release of sterilized adult males that mate with wild females to produce non-viable offspring.

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Aedes aegypti is a prominent disease vector that is difficult to control through traditional integrated vector management due to its cryptic peridomestic immature-stage habitat and adult resting behavior, increasing resistance to pesticide formulations approved by the US Environmental Protection Agency, escalating deregistration of approved pesticides, and slow development of new effective chemical control measures. One novel method to control Ae. aegypti is the sterile insect technique (SIT) that leverages the mass release of irradiated (sterilized) males to overwhelm mate choice of natural populations of females.

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Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic arbovirus with important livestock and human health, and economic consequences across Africa and the Arabian Peninsula. Climate and vegetation monitoring guide RVFV forecasting models and early warning systems; however, these approaches make monthly predictions and a need exists to predict primary vector abundances at finer temporal scales. In Kenya, an important primary RVFV vector is the mosquito Aedes mcintoshi.

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United States military troops in the field are exposed to the environment and are thus at high risk for transmission of arboviruses, and degradation of mission from continual harassment from insects. Passive vector control, such as application of residual insecticides to US military materials common in the field such as tents and camouflage netting, has been shown to be effective and can contribute to a successful integrated vector management (IVM) plan in the field to reduce this risk. However, other common US military field materials have not been evaluated with residual pesticides.

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United States military personnel deployed in austere hot-arid, temperate, and tropical conditions in remote locations worldwide rely on the Department of Defense (DoD) Pest Management System measures such as application of pesticide residual and ultra-low-volume or thermal fog treatments for protection from routine exposure to nuisance and disease-vector insects. Timed pesticide misting systems originally developed for residential outdoor use show promise as potential enhancements to standard DoD Pest Management System measures, in particular to protect perimeters surrounding US military field encampments. To investigate the capabilities of misting systems in remote locations in diverse environments, this technical engineering report describes the development of 2 key modifications to a commercial residential misting system to enable us to operate the system away from a standard power grid, and to safely operate the system with small volumes of a variety of pesticide misting formulations.

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Efficacy of public health pesticides targeting nuisance and disease-vector insects such as mosquitoes, sand flies, and filth-breeding flies is not uniform across ecological zones. To best protect public and veterinary health from these insects, the environmental limitations of pesticides need to be investigated to inform effective use of the most appropriate pesticide formulations and techniques. We have developed a research program to evaluate combinations of pesticides, pesticide application equipment, and application techniques in hot-arid desert, hot-humid tropical, warm and cool temperate, and urban locations to derive pesticide use guidelines specific to target insect and environment.

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Rift Valley fever (RVF) is a zoonotic disease, that causes significant morbidity and mortality among ungulate livestock and humans in endemic regions. In East Africa, the causative agent of the disease is Rift Valley fever virus (RVFV) which is primarily transmitted by multiple mosquito species in Aedes and Mansonia genera during both epizootic and enzootic periods in a complex transmission cycle largely driven by environmental and climatic factors. However, recent RVFV activity in Uganda demonstrated the capability of the virus to spread into new regions through livestock movements, and underscored the need to develop effective mitigation strategies to reduce transmission and prevent spread among cattle populations.

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Interannual climate variability patterns associated with the El Niño-Southern Oscillation phenomenon result in climate and environmental anomaly conditions in specific regions worldwide that directly favor outbreaks and/or amplification of variety of diseases of public health concern including chikungunya, hantavirus, Rift Valley fever, cholera, plague, and Zika. We analyzed patterns of some disease outbreaks during the strong 2015-2016 El Niño event in relation to climate anomalies derived from satellite measurements. Disease outbreaks in multiple El Niño-connected regions worldwide (including Southeast Asia, Tanzania, western US, and Brazil) followed shifts in rainfall, temperature, and vegetation in which both drought and flooding occurred in excess (14-81% precipitation departures from normal).

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Preemptive treatment of dry habitats with an ultra-low volume (ULV) residual larvicide may be effective in an integrated vector management program to control populations of container-inhabiting mosquitoes, key vectors of Zika, dengue, and chikungunya viruses. We exposed dry, artificial containers placed in exposed and protected locations to Natular 2EC (spinosad) larvicide applied with a truck-mounted ULV sprayer in a simulated urban setting in North Florida, and later introduced water and or larvae to conduct bioassays. Up to 50% mortality was observed in bioassays, indicating further analysis of spinosad as a residual treatment application.

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We investigated the efficacy of a liquid larvicide, Natular 2EC® (spinosad), applied with ultra-low volume sprayer as a residual application during the dry season in southeastern Thailand against 4 medically important species-, , , and . We found that this larvicide could be applied as a residual to dry areas known to collect water and potentially still be effective after rains or irrigation, which could increase the flexibility and efficiency of an integrated vector management program targeting these species. This investigation also demonstrated, for the 1st time, efficacy of spinosad against and .

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The invasive is an important disease vector increasing in frequency in hot-arid regions of the USA such as the Southwest. Within hot-arid surroundings this mosquito may be confined to peridomestic locations that tend to be cooler and humid, such as in lush, irrigated ornamental vegetation surrounding homes. However, to reach these habitat refugia, ultra-low volume (ULV) applications of insecticides targeting this mosquito must retain efficacy after being sprayed from the air or street where hot-arid conditions are prevalent.

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We conducted aerial fixed wing ultra low volume (ULV) spray trials with naled to investigate penetration of exposed and simulated cryptic habitat within opened buildings, partially sealed buildings, and outdoor locations targeting sentinel adult Aedes aegypti mosquitoes in north central Florida. Mortality was observed in open and closed buildings and outdoors, even in mosquitoes placed in cryptic habitats. Observations on the impact of building type, mosquito exposure method such as placement in cryptic habitat, and spray nozzle size on mosquito mortality are described and analyzed.

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Emerging technology designed to kill mosquito larvae with sound waves may present a nonchemical and nonbiological alternative to reduce larval populations of key medically important mosquito species such as Aedes aegypti in containers or catchments of water. These devices could benefit integrated vector management programs facing public resistance to the use of chemical or biological larvicides in stored drinking water. In this study we investigate the efficacy of a Larvasonic SD-Mini Acoustic Larvicide device in reducing larval populations of Ae.

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Mosquito surveillance in remote areas with limited access to canisters of CO or dry ice will benefit from an effective alternative CO source, such as the natural production of CO from yeast fermentation. In this study, we investigate differences in mosquito capture rates from the Centers for Disease Control and Prevention (CDC) light traps baited with dry ice compared with traps baited with yeast fermentation of several carbohydrate sources over 23 trap-nights. Results demonstrated the ability of yeast-generated CO to effectively attract mosquitoes to a CDC trap, regardless of carbohydrate source.

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Rift Valley fever (RVF) is a zoonotic disease endemic in sub-Saharan Africa with periodic outbreaks in human and animal populations. Mosquitoes are the primary disease vectors; however, Rift Valley fever virus (RVFV) can also spread by direct contact with infected tissues. The transmission cycle is complex, involving humans, livestock, and multiple species of mosquitoes.

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Rift Valley fever (RVF), an emerging mosquito-borne zoonotic infectious viral disease caused by the RVF virus (RVFV) (Bunyaviridae: Phlebovirus), presents significant threats to global public health and agriculture in Africa and the Middle East. RVFV is listed as a select agent with significant potential for international spread and use in bioterrorism. RVFV has caused large, devastating periodic epizootics and epidemics in Africa over the past ∼60 years, with severe economic and nutritional impacts on humans from illness and livestock loss.

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Filth fly control measures may be optimized with a better understanding of fly population dynamics measured throughout the day. We describe the modification of a commercial motorized sequential mosquito trap to accept liquid odorous bait and leverage a classic inverted-cone design to passively confine flies in 8 modified collection bottles corresponding to 8 intervals. Efficacy trials in a hot-arid desert environment indicate no significant difference (P  =  0.

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Rift Valley fever virus (RVFV) continues to pose a threat to much of the world. Unlike many arboviruses, numerous mosquito species have been associated with RVFV in nature, and many species have been demonstrated as competent vectors in the laboratory. In this study, we evaluated two field-collected Psorophora species, Psorophora columbiae (Dyar and Knab) and Psorophora ciliata (F.

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Multiple trials were conducted from 2006 to 2014 in an attempt to validate aerial spray efficacy at altitudes conducive to night spray operations using night vision goggles (NVGs). Higher altitude application of pesticide (more than 400 ft (121.9 m) above ground level (AGL)) suggested that effective vector control might be possible under ideal meteorological conditions.

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Phlebotomine sand flies are blood-feeding insects that transmit Leishmania parasites that cause various forms of cutaneous and visceral leishmaniasis and sand fly fever viruses (Phlebovirus; Bunyaviridae) in humans. Sand flies pose a significant threat to US military personnel deployed to Leishmania-endemic and sand fly fever endemic regions which include Europe, the Mediterranean basin, Middle East, Central Asia, Southwest Asia, and Africa. A research project supported by the Department of Defense Deployed Warfighter Protection Program was initiated to evaluate the susceptibility of 2 Old World sand fly species, Phlebotomus papatasi and P duboscqi, to a number of commonly used pyrethroid and organophosphate insecticides.

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Egypt is affected by serious human and animal mosquito-borne diseases such as Rift Valley fever (RVF). We investigated how potential RVF virus mosquito vector populations are affected by environmental conditions in the Nile Delta region of Egypt by collecting mosquitoes and environmental data from 3 key governorates before and after 2012 seasonal flooding. We found that environmental effects varied among species, life stages, pre- and postflood groupings, and geographic populations of the same species, and that mosquito community composition could change after flooding.

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This study was conducted to determine the efficacy of truck-mounted ultra-low volume applications of pyriproxyfen against Aedes aegypti larvae in artificial water containers and wild adult Ae. albopictus populations in an urban setting. The study was conducted over a 3.

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