Zoonotic Disease Of The Southwest Flashcards
Most common zoonotic disease investigated by AZ health departments
Rabies
Presence of zoonotic diseases in AZ exacerbated by (5)
-Diversity in wildlife species
- Disparities across communities
- Extreme climates
- Varying topography
- Close proximity to an international border
Where does tularemia occur (5)
North America
Europe
Former Soviet Union
China
Japan
What is the 3rd most common reported lab associated bacterial infection
Tularemia
Tularemia in AZ: location, reservoir/vector
Naturally in rabbits and rodents
Above 3,000 feet
Tularemia agent
Francisella tularensis = gram neg bacterium
Potential bioterrorism weapon
Tularemia epidemiology: incubation, period of communicability, susceptibility and resistance
1-14 days, average 3-5 days
NOT person to person —->flies can stay infective for 14 days, ticks stay infective throughout lifetime
All ages susceptible
Long term immunity following infection
Tularemia clinical diagnosis
Evidence/history of tick or deer fly bite, exposure to tissues of mammalian host infected
Fever, chills, headaches, diarrhea, muscles aches, joint pain, dry cough, progressive weakness
Without treatment, tularemia infection could progress to
Respiratory failure, shock, death
6 clinical forms of tularemia
Ulceroglandular
Glandular
Oculoglandular
Oropharyngeal
Pneumonic
Typhoidal
Most common clinical form of tularemia
Ulceroglandular
Ulceroglandular tularemia: cause, clinical signs
After tick or deer fly bite OR handling infected animal
Cutaneous ulcer with regional lymphadenopathy(swollen lymph nodes)
Glandular vs Ulceroglandular tularemia
Glandular = regional lymphadenopathy with NO ulcer
Ulceroglandular = with ulcer
Oculoglandular tularemia: cause, clinical sign
Bacteria enter eye when person is butchering infected animal and touches their eye
Conjunctivitis with preauricular lymphadenopathy
Oropharyngeal tularemia: cause, clinical signs
- From eating or drinking contaminated food or water
- Stomatitis, pharyngitis, tonsillitis and cervical lymphadenopathy
Most serious form of tularemia
Pneumonic
Pneumonic tularemia: cause, clinical signs
- From breathing dust or aerosols containing the organism or when other forms are left untreated and have hematogenous spread
-Primary pleuropulmonary disease
Typhoidal tularemia: clinical signs
Febrile illness without early localizing signs and symptoms
Type A vs Type B tularemia infections: difference in reservoirs
Type A = rabbits or ticks
Type B = hares and rodents
Where are type A tularemia strains localized
Western US
Tularemia mode of transmission (MANY)
- Bite of certain arthropods
- Inoculation of skin, conjunctival sac, or oropharyngeal mucosa with contaminated water, blood, or tissue while handling carcasses of infected animals
- Handling or ingesting insufficiently cooked meat of infected animal hosts
-Drinking contaminated water - Inhalation of dust from contaminated soil, grain, or hay
-Contaminated pelts and paws of animals
Tularemia treatment
Antibiotics = streptomycin, doxycycline, gentamicin
10-21 days
Most patients don’t completely recover
Where must tularemia be reported to (and time frame)
AZDA
Within 4 hours
Clinical samples used to test for tularemia
Ulcer scraping/swab
Lymph node biopsy
Tissue biopsy
Pharyngeal washes
Tularemia prevention
Note any change in behavior of pets
Inspect heard
Use dust masks when mowing
Use insect repellant with DEET
Wear long clothing
Remove attached ticks
Most severe disease caused by tick in US
Rocky Mountain spotted fever
What percent of RMSF cases are fatal
5-10
Is RMSF notifiable to CDC
YES
What state the most cases of RMSF
Arizona
RMFS: causative agent, mode of transmission (incubation period), how it causes disease
Rickettsia rickettsi = gran neg obligate intracellular parasite
Bite of infected tick
Usually 4-5 days
Invades endothelial cells of venules and capillaries —> replicates —> causes vasculitis
RMSF clinical signs
Fever (102 - 105)
Severe lethargy
Rash (but not in AZ)
In general what percent of RMSF cases develop rash
60
RMSF clinical signs in the LATE stage
Necrosis
Abdominal pain, vomiting
Signs of depression
Vestibular defects
Dyspnea
Myalgia
Most likely abnormal clinical finding for RMSF (3)
Hypoalbuminemia
Moderate leukocytosis
Thrombocytopenia
Clinical RMSF resembles infection with what
Eherlichia canis
Gold standard serologic test for RMSF
Indirect immunofluorescence assay with Ag
Other test for RMSF
PCR
Best antibiotic for RMSF treatment
Doxycycline
RMSF prevention in dogs
- Prevent tick attachment or promptly remove ticks
- Topical or systemic tick-control treatment such as permethrin, fipronil
- Seasonal tick and flea dips
- Impregnated collars containing amitraz or propoxur
Primary domestic reservoir for chagas
Dogs
How many people in Mexico, Central America and South America have chagas
8 million
Chagas: causative organism, mode of transmission, where only found
Trypanosoma cruzi = Protozoan parasite
To animals and people by insect vectors
Americas
Chagas aka
American trypanosomiasis
What insects in Arizona likely have chagas parasite
Kissing bugs
Chagas transmission to humans (5)
Vector borne
Congenital
Blood
Organ transplantation
Oral ingestion of contaminated foods
2 phases of chagas infection
Acute
Chronic
Acute chagas: timeline, clinical signs
First few weeks or months
Fever, fatigue, body aches, rash
Ramanas sign = swelling of eyelids
Chronic chagas: timeline, clinical signs
Decades to lifetime
Cardiac or GI complications
What percent of chronic chagas cases develop cardiac or GI complications
20-30
3 ways to diagnose chagas: acute vs chronic
PCR
Chronic = Serologic testing
Acute = find trypomastigotes in blood or CSF
Chagas treatment
Antiparasitic to kill parasite = benznidazole
Manage symptoms
Monitor heart
What is the only way to get drugs for chagas treatment in the United States and why
Through CDC
Not approved by FDA
Chagas in dogs: presentation
arrythmias
myocardial dysfunction
congestive hear failure
Risk factors for chagas in dogs
Living in or traveling to area with infected insect vectors
Dog kennels
High density areas attract kissing bugs
Chagas prevention
Vector control
Turn off outdoor lights
Clean up brush
House dogs inside
Use insecticides
Do traditional tick and flea repellants work on chagas
No
onchocerca lupi: causative organism, epidemiology
filarial nematode
adults embedded in ocular nodules and granulomatus masses of infected dogs
females release microfilaria found in skin of ears, nose, umbilical rregions
suspected vector = black fly
definitive host for onchocerca lupi
DOG
onchocerca lupi: clinical diagnosis
detectable via ophthalmic evaluation
detection of ocular nodules in sclera
histopath id of adult worms
onchocerca lupi treatment
surgical removal of worms
no evidence for treatment
