ID Exam 2: Zoonotics Flashcards
Bartonella Henselase
Gram negative
Silver stain
Cat scratch fever (painful axillary lymphadenopathy - immunocompetent)
Bacillary angiomatosis (raised red vascular lesions - immunocompromised – HIV)
BA: doxy
CSF or BA: macrolides
Brucella
Gram negative Barn animals = reservoir, unpasteurized dairy Facultative intracellular (open gate) Undulating fever Hepatosplenomegaly (RE system infection) Osteomyelitis Tx: doxy, rifampin
Francisella tularensis
Gram negative coccobacilli
Facultative intracellular (open gate), need cystiene
Phase variation
Genotypes: A1 (eastern US), A1b = fatal cases
Rabbits are main reservoir (dermacenter ticks can transmit)
Can be aerosolized (report to CDC)
NO person to person spread
Path: ulcer, lymph spread, RE system, caseating granuloma
Tx: AG
Pasteurella Multocida
Cats and dogs
Osteomyelitis, nec fas
Catalase positive, oxidase positive, encapsulated
SGA, bipolar staining (safety pin staining)
Tx: PCN
Rickettsial diseases
Poor gram staining (neg), coccibacillary Stain with Giemsa Obligate intracellular -> needs NAD+ and CoA (small genome, no LPS or aminoglycan, acquire cholesterol from host) Transmission via arthropods Targets endothelial cells (blood vessels) Weil-Felix medium HA, fever, vasculitis Tx: doxy
Rickettsia rickettsii
Dermacentor tick
Palms and sole rash, spread centrally (2-14d incubation)
HA, fever, myalgias, vasculitis
Rickettsia prowzekii
Spread by louse
Rash start centrally, spread out, spares palms/soles
Myalgias, PNA, encephalitis/coma
Modes of transmission
Cutaneous contact (bites)
Arthropod vector
Inhale
Ingest
Types of plague
Bubonic: LNA, 60-90% mortality
Septicemic: Multiorgan invasion, little evidence of dz, death in 24 hours (probably ingestion for route)
Pneumonic: Lung infection, highly infectious, 100% mortality
Virulence factors of yersinia
Plasmid encoded: VW antigens, T3SS, coagulase/fibrinogen
Chr encoded: Fe acquisition, attachement/invasion, endotoxin
Francisella tularensis presentations/types
Glandular Oculoglandular Pharyngeal Typhoidal Pulmonary
Erythemia chronicum migrans
Bulls eye rash
Detects collagen and migrates along bundles
Erythemia chronicum migrans
Bulls eye rash
Detects collagen and migrates along bundles
Rickettsia typhi
Flea transmission, endemic responsible
epidemic = lice
Rickettsia typhi
Flea transmission, endemic responsible
epidemic = lice
Scrub typhus rickettsia group
Rash often missing, eschar present
Chiggers
Ehrlichia and Anaplasmosis
Obligate intracellular Infect phagocytic cells Multiply inside vaccules (mulberry inclusions) Fever, HA, malase, WITHOUT rash Elevated liver enzymes Leukopenia, thrombocytopenia Ehr = monocytes, tetra Ana = granulocytes, doxy
Viral zoonotic transmission
Animals to humans (no human to human): rabies, sin nombre, west nile
Animals to humans (some human to human): ebola, marburg, nipah, monkeypox
Animals to humans (and human to human): flu, SARS, HIV, yellow, dengue, zika, chikungunya
Rabies virus (rhabdovirus)
Do not need to be reported, underreported
Immunization and PEP (rabies Ig)
Bullet shaped, non-seg
Each host harbors unique variant
Rabies: two forms
Furious (encephalitic): Difficultly swallowing, hydrophobia, hypersalivation, halliucination, CNS death
Paralytic form: Lack of furious features, quadraplegia, multiple organ failure, death
Rabies PEP
Soapy water
Human rabies Ig: area of wound
Vaccine: different site (day 0,3,7,14)
Hantavirus
3 segments, -RNA
Aerosolized rat urine, host doesn’t show dz
Hemorrhagic fever with renal syndrome
Hantavirus pulmonary syndrome
Hantavirus pulmonary syndrome
Prodrome: Fever, chills, myalgia
Severe leg/back pain
NO COUGH
Low platelet, neutrophilia, elevated LDH and AST
Ebola vaccine
Tested during recent outbreak
Immediate vaccination group = 100% protection
Rhabdovirus with ebola glycoprotein
Long term consequences ebola
People do recover but can develop eye/joint problems
Ebola can persist in eye, semen, amniotic fluid, CNS
Humans as host for arborviruses
Usually dead end hosts: west nile, St. Louis, eastern/northern/venusalia/japanese
Exceptions (human-mosquito-human transmission): Dengue Yellow Zika Chikungunya
Virus must replicate in mosquito, eventually in salivary gland and transmitted at next bite
Arborviruses outcomes
Usually asx. (except chikungunya) Febrile illness - most mild Neuro dz MSK dz Hemorrhagic fever (loss of platelet fxn) Congenital dz (Zika)
3 classes of arborviruses
Bunyaviridae
Flaviviridae
Togaviridae
Dengue serotypes and syndromes
Serotypes 1-4 (all emerged separately)
Human-mosquito-human cycle maintains
Fever: acute, febrile, HA, pain, rash
Hemorrhagic fever, shock: thrombocytopenia, capillary leakage, liver damage
Risk factor: second infection with DIFFERENT serotype -> more likely to get DHF/DSS disease
Antibody mediate enhancement of infection
Hypothesis for dengue severe infection
Subacute, non-neutralizing abx bind but don’t neutralize disease
Larger, more severe immune response
Can be mediated by maternal antibodies as well
Complications of dengue vaccine
Dengavaxia
Need to protect against all 4 serotypes
Concern about waning immunity enhancing disease
Current working vaccine uses yellow fever vaccine and replaces with dengue proteins
Undergoing long term safety analysis
Seronegative at vaccination may be at high risk for hospitalization
Chikungunya virus
Togavirus
Joint/muscle pain, progression to chronic MSK pain
Zika virus: congenital syndrome
Most severe if 1st trimester
Sexually transmissible??
Microcephaly but also:
CNS injury, growth restriction, ocular abnormalities, placental insufficency
Epidemologic features of arborviruses in US: age groups
Neuroinvasive charateristics:
WNV: elderly (July-Sept), bird host
St. Louis: elderly
La Crosse: young
