arthropod borne infectious disease
DESCRIPTION
Arthropod borne infectious disease. Arthropods that Transmit Disease. Ticks, mosquitoes, fleas and biting flies Transmission usually by biting or ingestion. Infections. Bacterial Ricketsia ricketsii , Borrelia burgdorferi , Yersinia pestis , Francisella tularensis Viral ( arboviruses ) - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/1.jpg)
Arthropod borne infectious disease
![Page 2: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/2.jpg)
Arthropods that Transmit Disease
• Ticks, mosquitoes, fleas and biting flies– Transmission usually by biting or ingestion
![Page 3: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/3.jpg)
Infections
• Bacterial– Ricketsia ricketsii, Borrelia burgdorferi, Yersinia
pestis, Francisella tularensis
• Viral (arboviruses)– Dengue, West Nile, Encephalitic viruses
• Parasites– Malaria, Dracunculiasis, tape worms
![Page 4: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/4.jpg)
Rocky Mountain Spotted Fever
• Caused by obligate intracellular bacterium Rickettsia rickettsii
• Tick borne disease
![Page 5: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/5.jpg)
![Page 6: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/6.jpg)
Fever, nausea, severe headaches, muscle pain and rash
![Page 7: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/7.jpg)
Rocky Mt. spotted fever
![Page 8: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/8.jpg)
Lyme Disease• Borrelia burgdorferi• Spirochete• Obligate Intracellular pathogen
![Page 9: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/9.jpg)
Borrelia burgdorferi
• 1.5Mbp• Strange genomic layout– Linear chromosome (900 kb)– Has over 20 circular AND linear plasmids
• Genome decay in obligate intracellular bacteria
• Loses many biosynthesis pathways (why make it if you can get it from the host)
![Page 10: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/10.jpg)
Epidemiology
• Transmitted by ticks (mainly deer ticks)– Most often by nymphal ticks
• Mammalian reservoirs: mice and deer
• Prevalent in northeast and midwest but spreading and increasing occurrence
![Page 11: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/11.jpg)
Lyme disease
![Page 12: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/12.jpg)
Lyme disease
![Page 13: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/13.jpg)
![Page 14: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/14.jpg)
Compare to life cycle
![Page 15: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/15.jpg)
![Page 16: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/16.jpg)
![Page 17: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/17.jpg)
Deer tick eating
![Page 18: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/18.jpg)
Lyme disease symptoms
1st stage: first few days erythema migrans (outwardly expanding rash)
Therefore gets a bullseye appearance. Not always occurs (most of the time though)
Flu-like symptoms too (fever, headache, muscle soreness, malaise)
Best treatable stage!
![Page 19: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/19.jpg)
Lyme disease rash
![Page 20: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/20.jpg)
![Page 21: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/21.jpg)
Lyme disease symptoms
• 2nd stage: Dissemination: days to weeks– spreads to bloodstream and may have bullseye
rash appear at other sites of the body
• Also pain in muscles joints and tendons, heart palpitations, strong headaches
![Page 22: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/22.jpg)
Lyme disease symptoms
• 3rd Stage: Persistent infections (months later)
• Brain, nerves, eyes, heart, joints
• Cognitive impairment, weakness, pain in joints (especially the knees), fatigue
• Can end up with permanent damage
![Page 23: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/23.jpg)
Transmission
• Bacteria normally live in gut epithelium of tick
• Must migrate to salivary glands to be secreted to host
![Page 24: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/24.jpg)
Vaccine LYMErix• Recombinant Outer surface
protien A (OspA)– Your body doesn’t make
antibodies to OspA normally– OspA only expressed in unfed
ticks, not in fed ticks or host
• Temperature is the trigger to stop OspA and start making OspC – other triggers for making
virulence proteins are pH and Fe starvation
![Page 25: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/25.jpg)
How the vaccine works
• Bacterial migration from midgut to salivary glands is inhibited when ticks feed on OspA (and also in OspC) immunized mice
• So immune serum appears to kill the bugs in the tick or prevent migration
![Page 26: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/26.jpg)
West Nile• +RNA Flavivirus • transmitted by mosquitoes that usually infects birds• Many human infections are avirulent
![Page 27: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/27.jpg)
West Nile
Severity of infections:– Avirulent
– Mild fever (West Nile Fever)
– Serious meningitis or encephalitis
![Page 28: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/28.jpg)
![Page 29: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/29.jpg)
Yersinia pestis
• Plague– Bubonic– Pneumonic– Septicemic
• Transmitted by fleas
![Page 30: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/30.jpg)
![Page 31: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/31.jpg)
Plague• Symptoms: Mostly
general– pain, fever, malaise,
headaches– Bubos
![Page 32: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/32.jpg)
Molecular mechanisms
• Plasmids and pathogenicity island – Specialized Type 3 Secretion system – Yop (Yersinia outer proteins) for evading immune
system
This includes preventing phagocytosis, adhesion, and inducing macrophage death
![Page 33: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/33.jpg)
Francisella tularensis
• Facultative intracellular pathogen causing tularemia or “rabbit fever”
• Often by ticks, also from mosquitoes and biting flies
![Page 34: Arthropod borne infectious disease](https://reader036.vdocuments.mx/reader036/viewer/2022062813/5681665f550346895dd9e608/html5/thumbnails/34.jpg)
Tularemia
• All feasible routes of infection
• Infects >250 species animals
• Infects all cell types tested