biology and control of insects and rodents workshop vector...
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Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Vector-Borne Diseases of Public Health Importance
Rudy Bueno, Jr., Ph.D.
Director
Components in the Disease Transmission Cycle
PathogenAgent that is responsible for disease
VectorAn arthropod that transmits a pathogen
ReservoirSum total of all pathogen sources; maintenance host
Susceptible hostHost in which a pathogen can survive with manifestation of clinical symptoms usually
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Rodent Borne Diseases of Public Health Importance
Hantavirus: What is It?
Hantavirus is carried in the urine, saliva, or droppings of infected rodents such as deer miceHantavirus may result when the virus is breathed, swallowed, rubbed into the eyes, or touches broken skinThe chance of getting the hantavirus infection increases as contact with rodents or their nesting areas increasesYou cannot get the illness from another person, flies, or insectsCats and dogs do not get the virus
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 3
Hantavirus Epidemiology
Earliest known case, 1959Nearly all cases involve close interaction with rodentsEach hantavirus appears to be host specificDeer mouse is highly adaptable but generally not found in urban areasPeak season for hantavirus in U.S. is May through October
Possible Carriers of the Hantavirus
The deer mouse is the primary carrier4 to 9 inches long from head to tailColor from pale gray to reddish brownWhite fur on its belly, feet, and underside of tailPasses through holes as small as a shirt button
Deer Mouse
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Healthy Lungs
Diseased Lungs
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 5
Plague: What is It?
A flea transmitted disease caused by the bacteria, Yersenia pestisRodents are the primary carriers of plaguePredominately found in the Western states-AZ, NM, CO, CADomestic pets, especially cats, are very susceptible and can be fatal
McDowell et al. 1964.
Plague bacteria, Yersenia pestis
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 6
Flea Vector
Rock squirrel host, Spermophilus variegatus
Other rodentsPrairie DogsWoodratsChipmunksField mice
Three Forms of Plague
Bubonic plague-most common form; usually transmitted by a flea bite with characteristic swollen lymph nodesSepticemic plague-bacteria invades the blood stream causing toxic poisoning; difficult to diagnosePneumonic plague-bacteria invade the lung tissue; can be spread from person to person through air droplets; most dangerous form
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 7
Plague Symptomology
2-6 day incubation periodHigh feverLethargyLoss of appetiteSwollen lymph nodesAbdominal distressShortness of breathCoughing
Bubonic Plague
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 8
What is Tularemia?Bacterial pathogen, Francisella tularensis
Gram-negative coccobacillusRabbit fever, deer fly feverMaintained and amplified in nature
Vertebrate reservoirsArthropod vectors
Ticks, mosquitoes, deerflies, fleas, lice
100-200 cases annually in U.S.
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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McDowell et al. 1964.
Tularemia Cycle
Human TransmissionInfection from skinningArthropod bitesIngestion-rareInhalation-rare3-5 day incubation5-10% fatality with no treatment
<1% if treated
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 10
Plague/Tularemia SimilaritiesBacterialSymptomsSeasonalitySepticemic or pneumonicOverlapping geographic distributionTreatment
Plague/Tularemia Differences
VectorsTicks/deer flies-tularemiaFleas-plague
Primary susceptible hostRabbits-tularemiaRock squirrels-plague
Plague/Tularemia Differences
Susceptible domestic animalsDogs-tularemiaCats and possibly dogs-plague
Human involvementNot common-tularemiaMore Common-plague
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 11
Mosquito-Borne Diseases
Important Strains in the U.S.
Eastern Equine Encephalitis
Atlantic and Gulf Coast
LaCross EncephalitisMid-western & mid-Atlantic states
St. Louis EncephalitisVery commonFound nationwide
Western Equine Encephalitis
West of the Mississippi River to Pacific Coast
What is Encephalitis?A virus causing inflammation of and destruction of brain tissuePrimarily transmitted by mosquitoesSeasonal with peaks in midsummer to fallExhibit amplification cycles in susceptible hostsTransmission from year to year depends on overwintering mechanism
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 12
Vectors of West Nile Virus in Harris County, TX Cx. quinquefasciatus, the Southern House Mosquito
Aedes albopictus, the Asian Tiger Mosquito
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 13
WNV SymptomologyIncubation period, 5-15 daysMost people have no symptoms or have mild symptoms such as
fever, headache, and body-aches (flu-like symptoms), often with a skin rash and swollen lymph glands.
Severe symptoms includehigh fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, paralysis and in some cases death.
Geographical Information System: Tracking Diseases
Wk.24:6/11-6/15, 2002 (17)
Wks. 21-24:5/20-6/11,2003 (9)
Wks.Wks.22-24:6/3-6/18, 2004 (9)
Wks.6-24:2/12-6/15,2005 (14)
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Wks. 18-21:5/2-5/25,2006 (18)
Dengue and Yellow Fever: (Ae. aegypti) and Asian Tiger (Ae. albopictus) Mosquitoes
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Water storage container, backyard breeding habitat for Aedes aegypti.
Photo: WHO/TDR/Crump
Change in Distribution of Aedes aegypti in the Americas
PositiveEradicated/Died outStatus unknownIntercepted, not established
CDCCenters for Disease Control
and Prevention
PositiveEradicated/Died outStatus unknownIntercepted, not established
Aedes albopictus, in the United States, 1999
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 16
Symptoms of DengueCalled “breakbone fever”Severe headache, pain behind the eyes, backache, pain in the joints, severe rashIncubation period 5 – 6 days4 strains of dengue virusExposure to a second strain may result in dengue hemorrhagic fever
Severe Manifestation of Dengue Hemorrhagic Fever
(Photo: WHO/TDR/STI/Hatz)
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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Anopheles gambiae, Vector of Malaria
(Photo: WHO/TDR/Stammers)
Anopheles Breeding Site in Rice Paddy Fields, Thailand
(Photo: WHO/TDR/Crump)
Cleaning Weeds and Stagnant Water, Colombia
(Photo: WHO/TDR/Crump)
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
Page 18
Sleeping under insecticide treated bednet
Photos: WHO/TDR/Crump
Treating House with Pyrethroids, in Thailand
(Photo: WHO/TDR/Crump)
Biology and Control of Insects and Rodents WorkshopVector Borne Diseases of Public Health Importance
Copyrighted Material ~ All Rights ReservedCourse Materials for NEHA-CERT Course IRW0601
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The End: Questions?????
Links
http://www.dshs.state.tx.us/default.shtm
http://www.harriscountyhealth.com/
http://www.cdc.gov/page.do
http://www.who.int/en/
http://www.cabq.gov/
http://www.health.state.nm.us/