Practical Applications for Managing Biological Risks Vector Transmission

Practical Applications for Managing Biological Risks Vector Transmission Dairy Producers Center for Food Security and Public Health Iowa State University 2006

Biological Risk Management (BRM) • Overall process of awareness education, evaluation, and management • Designed to improve infection/disease control – Foreign and domestic diseases • Provide tools to minimize risk Center for Food Security and Public Health Iowa State University 2006

Biological Risk Management (BRM) • Disease risk cannot be totally eliminated – Animal, its environment – Decrease exposure – Infectious agent interactions • Minimize threat to animals and humans • No one-size-fits-all answer Center for Food Security and Public Health Iowa State University 2006

Routes of Transmission • Spread of disease agents – Animal animal human • Different modes of transmission – Aerosol – Direct contact – Fomite – Oral – Vector-borne – Zoonotic Center for Food Security and Public Health Iowa State University 2006

Vector Transmission • Insect • Acquires pathogen from one animal • Transmits to another animal – Biological vectors • Midges, ticks, mosquitoes – Mechanical vectors • Flies Center for Food Security and Public Health Iowa State University 2006

Selected Diseases Spread by Vectors Foreign diseases • Akabane • Bluetongue • Heartwater • Lumpy skin disease • Rift Valley fever Present in U. S. • Anaplasmosis • Anthrax • Contagious mastitis • Pink eye (Moraxella bovis) • Vesicular stomatitis Center for Food Security and Public Health Iowa State University 2006

Routes of Transmission • Apply to all infectious agents • Animal must be exposed to develop disease • Understand different routes of transmission = Gain control • Risk areas must be identified – Design protocols to minimize exposure Center for Food Security and Public Health Iowa State University 2006

Disease Transmission • Animals may not exhibit obvious clinical signs of disease • Awareness of all routes of transmission is essential – Develop strategy to minimize disease risk for livestock operation Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps Overview • Farm perimeter • Animal identification • Animal health • Sick/dead animals • Isolation/quarantine • Supply handling • Neonatal management Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Limit contact with animals – Neighbor’s livestock – Wildlife, birds – Roaming cats, dogs • Maintain fences • Establish biosecurity protocols for delivery vehicles, personnel • Lock gates Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Identify individual animals • Important for: – Communicating health status – Treatment needs – Location on farm – Record keeping Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Keep health records on every animal • Review vaccination and treatment programs – Annually, bi-annually – Protocol versus actual • Investigate unusual signs, unresponsive cases – Neurologic, downers, sudden death Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Train farm personnel to report sick animals – Inspect animals daily – Clean equipment, boots, clothing • Euthanize terminally ill animals promptly and appropriately – Removed or rendered • Perform necropsy on animals that died from unknown causes Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Isolate ill animals immediately – No shared ventilation, direct contact with other animals • Quarantine newly introduced animals – New purchases, returning animals • Time determined with veterinarian • Test for key diseases before placing with rest of herd Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Store non-refrigerated vaccines and antibiotics out of sunlight as it can deactivate them • Monitor refrigeration temperature monthly – Ideal temp 36 -46 o. F • Restrict access to medication to only properly trained personnel Center for Food Security and Public Health Iowa State University 2006

General Prevention Steps • Ensure adequate ingestion of diseasefree colostrum in first 6 hours of life • Prevent contact with older animals, contaminated environments Center for Food Security and Public Health Iowa State University 2006

Vector Control Center for Food Security and Public Health Iowa State University 2006

Vector Control • Source reduction – Flies, midges, mosquitoes • Control adults – Flies, mosquitoes • Minimize animal interaction – Ticks, midges • Treatment protocols Center for Food Security and Public Health Iowa State University 2006

Source Reduction • Flies – 4 life stages • Egg, larva, pupa, adult • Cycle as short as 10 days in warm weather – Lay eggs in organic matter • Manure, feed, wet bedding • Disturb weekly to prevent development – Clean up spilled feed, feed bunks Center for Food Security and Public Health Iowa State University 2006

Source Reduction • Fly larvicides – Feed additives • All animals on farm, 3 weeks prior to season – Parasitic wasps feed on fly pupa – Predatory mites, beetles feed on larva • Adulticides – Knockdowns for high concentrations – Residuals for barn walls, ceilings – Baits, fly traps in conjunction with other methods Center for Food Security and Public Health Iowa State University 2006

Control Adult Flies • Target key areas on farm – Milking parlor, calf hutches – Barns – Animals Center for Food Security and Public Health Iowa State University 2006

Disease Transmission • Flies can spread: – Contagious mastitis – Dermatophilus (rain rot) – Grubs – Lumpy skin disease – Pink eye (Moraxella bovis) – Screwworm Center for Food Security and Public Health Iowa State University 2006

Source Reduction • Biting midges – Lay eggs in decaying vegetation, wet soil, mud – Larvae need moisture, organic matter – Adults fly 1 -2 miles from source – Manage settling ponds, stagnant water Center for Food Security and Public Health Iowa State University 2006

Disease Transmission • Biting midges can spread: – Bluetongue virus Center for Food Security and Public Health Iowa State University 2006

Source Reduction • Mosquitoes – Lay single eggs in damp soil – Lay eggs on water surface • Larvae, pupae live upside down in water; – Breathe via siphon, trumpet at water surface – Larvae need organic matter for development Larva Center for Food Security and Public Health Iowa State University 2006

Disease Transmission • Mosquitoes can spread: – West Nile virus – Rift Valley fever – Lumpy skin disease – Vesicular stomatitis Center for Food Security and Public Health Iowa State University 2006

Source Reduction • Eliminate mosquito larval habitats • Fill tree holes • Empty containers that hold water weekly • Circulate lagoons, water tanks • Drill holes in or use half tires for silage piles Center for Food Security and Public Health Iowa State University 2006

Mosquito Larvicides • Use when source reduction and biological control not feasible • More effective and target-specific • Less controversial than adulticides • Applied to smaller geographic areas – Larvae concentrate in specific locations Center for Food Security and Public Health Iowa State University 2006

Control Adult Mosquitoes • Insecticides/adulticides • Less efficient than source reduction • Require multiple applications • Require proper environmental conditions – Light wind, no rain • Small droplets to contact adults Center for Food Security and Public Health Iowa State University 2006

Minimize Animal Interaction • Ticks – Mow pastures – Acaricides • Midges – No effective animal treatment – Increase distance from source – Confine animals Center for Food Security and Public Health Iowa State University 2006

Disease Transmission • Ticks can spread: – Anaplasmosis – Babesiosis – Dermatophilus (rain rot) – Heartwater – Q fever Center for Food Security and Public Health Iowa State University 2006

Summary • Vector borne transmission occurs everyday on farms – Mastitis, pink eye, anaplasmosis • Foreign animal diseases can also be spread via vectors – Rift Valley Fever, heartwater • Prevention steps as described here can help minimize your risk Center for Food Security and Public Health Iowa State University 2006

Key Learning Objectives • Biological risk management is important • All diseases are transmitted by a few common routes • Disease risk can be managed • Awareness education is essential • You play a critical role! Center for Food Security and Public Health Iowa State University 2006

Questions? www. cfsph. iastate. edu/BRM brm@iastate. edu 515 -294 -7189 CFSPH Iowa State University, College of Veterinary Medicine Ames, IA 50011 Center for Food Security and Public Health Iowa State University 2006

Acknowledgments Development of this presentation was funded by a grant from the USDA Risk Management Agency to the Center for Food Security and Public Health at Iowa State University. Center for Food Security and Public Health Iowa State University 2006

Acknowledgments Author: Danelle Bickett-Weddle, DVM, MPH Reviewer: James Roth, DVM, Ph. D Center for Food Security and Public Health Iowa State University 2006