VPH- Zoonoses Quiz Review 5

kelseyfmeyer's version from 2015-11-03 11:13

zoonotic chlamydial species (2)

Question Answer
can C. psittaci cause abortion in ppl?yes, occasionally
(what would be two ddx for C. psittaci?)Q fever, Tularemia
how do you diagnose C. psittaci in a bird?DIFFICULT TO DX, but consider in any recently purchased bird >lethargic + nonspecific illness. For Ante/Post mortem dx, often best to use a COMBINATION of tests, Serology + Antigen detection best. Not Culture [biohazard]. **must collect sample properly
what kinda serology result might indicate a C. psittaci infection?4 fold or more increase in in serologic titer in 2 samples obtained 2 wks apart. Use Indirect Fluorescent antibody [IFA] or complement fixation [CF]
how can you test for antigen of C. psittaci?ELISA & PCR, or Direct Fluorescent antibody [FA]
where do you want to take a sample from for C. psittaci if you are going to run an ELISA?want choanal (nasal) or cloacal swabs. If ante-mortem, choanal is better
what are the flaws of doing serology to dx C. psittaci?Need a rising titer to confirm, Can’t rule out if negative (too early infection to detect antibodies)
what are the flaws of doing ELISA to dx C. psittaci?Need choanal and cloacal swabs live bird. However, birds often only intermittantly shed. so you can't rule it out. Best if positive result AND clinical signs.
how do you treat C. psittaci in birds? humans? what should you know that the tx does?TETRACYCLINE for both. Note that Antibiotic treatment can suppress the antibody response in both humans and birds
is there a vx for birds for C psittaci?NO
what are three major reasons it's basically impossible to ERADICATE C. PSITTACI?(1) Large number of hosts, including free-ranging fowl (2) Immunity incomplete & short-lived in birds & mammals. No effective vaccine for control in birds (3) Infection in birds subclinical and shedding intermittent. >shedding greatest in young birds and precipitated by stress
what kinda PPE should you use when you might encounter C. psittaci?N95 respirators, protective clothing…gloves, goggles
what are the implimented infection controls for C. psittaci?(1) Isolation/quarantine (2) [PPE] for you, personnel; N95 respirators, protective clothing…gloves, goggles (3) At PM ,wet carcass > detergent+H20 to prevent aerosolisn (4) Clean cages, floors: EPA approved disinfectants
what should pet stores be doing to help reduce C. psittaci for themselves?(1) Maintain records of all bird sales, source of birds, cases (2) Advise purchase from breeder that screens/ or you conduct screen on the bird (3) Husbandry- design ventilation systems, disinfect cages
Control of Avian Chlamydiosis (AC) in birds---> what is the control method which has given the BEST results? (2 things)(1) Quarantine (2) Chemoprophylaxis with tetracyclines
Importation of birds into the U.S. is regulated by...?USDA-APHIS
why is there a 30 day quarantine of imported birds?NOT BECAUSE OF C. PSITTACI!! (its for exotic newcastle and such) because C. psittaci is already endemic to the us and 30d insufficient to eliminate C.psittaci infection
what happens with bids in the 30 day quarantine during importation? (what are they treated with, what is the rationale behind this, what does treatment do?)Birds are treated with chlortetracycline [CTC] (Chlamydia, Chlortetracycline) in their food during the 30 day quarantine (the 30 day quarantine is not for C psittaci tho), but the treatment is just to reduce chlamydial exposure to quarantine station employees who come into contact with imported psittacines! This will prevent shedding of the bacteria, but will not eliminate the infection
how long should tx be to eliminate infection in birds (C. psittaci)45 day treatment (chlortetracycline)--> so Importers advised to continue treatment for an additional 15 days after birds are released (since quarantine is only 30 days)
Why do current importation regulations do not prevent C. psittaci-infected birds from entering the U.S.? (4 things)(1) Treatment period with CTC not long enough (2) Birds may not ingest enough medicated feed/water (3) Stress of quarantine may lead to increased shedding resulting in more birds being infected (4) No control measure reqd after bird leaves quarantine
what is usually the first thing you're going to see if there is C. psittaci in an area?usually illness seen in the HUMAN before in the bird (birds asympatomatic usually)
Chlamydophila abortus is the agent for what? in who?Sheep/goats(cows)-- Agent of Enzootic ovine abortion.
can C. abortus cause abortion in HUMANS?yes
**********Zoonotic abortifacients in sheep/goats (6)(1) Coxiella burnetii (2) Chlamydophila abortus (3) Toxoplasma gondii (4) Campylobacter jejuni?? (5) B. melitensis ; B.abortus (6) Listeria
how is Chlamydophila abortus transmitted to humans?Aerosol (inhalation), In-utero transmission to fetus
how does a human infected with chlamydophila abortus present?Abortion +/- flu-like disease
how do sheep/goats present when they are infected with C. abortus?Sheep/goats usually only abort after initial infection and rarely abort a second time.
is there a C. abortus vx for animals? ppl?Inactivated vaccines [Canada/EU] available for sheep/goats (not humans)
what does the vx for C. abortus do? (for who?)FOR ANIMALS! may reduce abortions &neonatal mortality but do not prevent or eliminate infection from the flock.
what precautions should people take against C. abortus?Pregnant women should avoid being around sheep and goats during lambing and kidding.
Chlamydophila felis--> affects who? how does this dz present in humans?a cat dz. Humans, ESP CHILDREN, get conjunctivitis
are there vx of C. felis for animals? humans?vx for animals, not for humans
vx for C. felis is for who, and what does the vx do?CATS, Vaccines can markedly reduce the severity of clinical signs but do not prevent infection or shedding

Lyme and Ehrlichia

Question Answer
how do most dogs with lyme present?90% of dogs exposed do not show clinical signs (disease). There can be Acute onset polyarthropathy and accompanying pyrexia, though. MOST SERIOUS LONG-term DISEASES FROM LYME IS... Glomerular disease due to Ag/Ab complexes, and Cardiac & neurologic disease (rare)
are there vx for lyme for dogs?YES
is lyme dz re-portable? notifiable? in animals or people?REPORTABLE IN PEOPLE.
what is the MAINTENANCE HOST for Lyme? VECTOR?(NOTE: more detailed later about geographic location, but in general) HOST: infected wild animal spp. VECTOR: Density of Ixodidae ticks [hard ticks] (Little transovarian transmission occurs in ticks, although there is transtadial)
how do humans relate to the maintenance cycle of lyme?humans are an accidental host but NOT a dead end host!
describe how the vector for lyme can vary based on geographic location?(1) EAST COAST: Ixodes scapularis (the deer tick)- 25-50% of ticks infected. (2) WEST COAST: I. pacificus (the Western black-legged tick)- 1-5% of ticks infected
on the EAST COAST what are the main maintenance hosts?White-footed deer mice(principal reservoirs host) and deer
how do white-footed deer mice contribute to the maintenance cycle of lyme in the east?****CRUCIAL TO MAINTENANCE! because they remain spirochetemic but tolerant to infection. (can pass to uninfected ticks)
explain if/how/whats going on with ticks and how they can maintain lyme?NOT transovarian, but CAN have Transtadial transmission from larvae to nymph. So, Uninfected larval ticks feed on deermice--> become infected nymphal ticks--> Nymph infect other deermice and dogs/humans--> Infected mice source of infection > naïve larval ticks
how do white-tailed DEER play a role in the maintenance cycle of lyme?NOT INVOLVED IN LIFE CYCLE!! don't become spirochetemic enough to infect adult ticks. However, they are food to sustain the tick population, so that's something
explain the cycle for the WEST coat with lyme dz, and how it compares to the east coast cycleBOTH SPECIES OF TICKS are required for infection of humans. this is because the WOOD RAT and I. neotomae ticks maintain the dz in the area, but this tick RARELY Bites humans or dogs. Which means Uninfected, I. pacificus ticks, occasionally bite an infected woodrat and the tick then bites horses, dogs, humans (this is why there is Much lower infection rate in West Coast ticks)
How do humans get lyme dz?THEY GET BIT BY A TICK!!!! (east coast, Ixodes scapularis (the deer tick) and west coast, I. pacificus). USUALLY the bite is from a nymph. which must remain attached for 24 hrs or more to transmit the spirochete
**what is crucial for the transmission of the lyme spirochete from the tick bite?takes 24 hours to transmit!!! so IMPORTANT TO REMOVE TICK EARLY ON
is it possible for lyme to be transferred human to human?yes, rare, but transplacental and sexually transmitted possible
how does lyme dz usually present in humans?Presentation highly variable. Usually flu-like disease-- usually THREE BODY SYSTEMS AFFECTED: Cutaneous (erythema migrans), Neurological, Musculoskeletal (dz usually progresses in stages)
how can you dx dogs with lyme?DIFFICULT! hx of tick exposure helps, along with Clin signs of SHIFTING LAMENESS, pyrexia,swollen joints. If tx, there will be RAPID RESPONSE to antimicrobial therapy. Upon serology, a "significant" positive titer as evidence of exposure. Paired titres important for current infection. High antibody titers do occur in asymptomatic dogs!!!!! important to know infected animal may initially test seronegative.
how do you know if a dog was exposed to lyme? infected?exposure= elevated Ab titer. infected=PAIRED titers
what are some Common Currently used Diagnostic tests in dogs?PCR detection (not widely avail), SNAP tests, C6 Antibody Testing:Currently 2 commercially available tests for canine antibodies against the Lyme C6 peptide. NOTE: No blood test can confirm Lyme Disease in dogs!!!
what is meant by a C6 titer?C6 is a peptide on the lyme organism which you can form an Ab against. Can test for this Ab, look at a titer for it and can tell infection based on pre and post treatment measurements of it. (Quantitative C6 titer drops with a/biotic therapy).
how do we try to prevent confusion between Abs from vx and Abs from exposure?Traditional ELISA for antibody cannot distinguish:vaccine - induced antibodies from antibodies due to natural exposure. B.burgdorferi expresses several [OspA –C] Proteins but only when in the tick gut. These proteins used as vaccine antigens. However, Another outer membrane protein, C6 is only expressed by living B.burgdorferi+ is not used as a vaccine antigen. So use C6 as a way to tell if the dog was exposed/infected instead of just vx
if you test positive for C6 Abs, what does this mean?dog was EXPOSED/ infected, NOT FROM VX
how are dogs treated for Lyme?Dogs with acute Lyme arthritis respond rapidly to amoxicillin or tetracyclines (doxycycline)-(within 36hrs). Acute cases tx for 2 wks, chronic for 4wk. (Optimum period/dose not established by clinical trials)
what are you thinking if dogs with chronic arthritis doesnt respond to abx tx?may have immune-mediated polyarthropathy, & req. steroids
why is the lyme vx controversial?most dogs dont get dz and some questioning abotu effectiveness of dz.
what is the rare but most serious canine presentation of lyme?Screen for proteinuria, bc Lyme nephritis is severe
if you dx lyme, what else must you consider?coinfections, because of being tick bourne and they carry a lot of different dz agents
what is super important to stress to owners about lyme dz?Even in vaccinated dogs TICK CONTROL must be stressed to the owners since a very heavy B. burgdorferi burden may override vaccinal protection.
is there a vx for people against lyme? what should you know?not in development, but there are problems: poor demand, costly, Req. series of 3 vaccines/boosters to maintain titers, AND RISK OF AUTOIMMUNE ARTHRITIS
Prevention and control: Your role on educating clients on what for lyme? the importance of approved tick control [acaricides that kill ticks] in the environment, and tick repellents and EPA approved acaricides for pets. Vaccination alone or treatment alone is insufficient unless combined with vector control measures and advising owners on preventing tick exposure to them and their animals. Ticks carried by dogs [not dogs themselves], are the source and reservoir of infection to humans and it is important that owners are aware of the risks to human health posed by ticks that may carry multiple zoonotic agents.
what are the 4 species of zoonotic ehrlichia?Ehrlichia chaffeensis, Ehrlichia ewingii, Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila), E. canis(<--not really)
what are the 4 main tick born diseases in cats?Anaplasma phagocytophilum, Cytauxzoon felis, F. tularensis-zoonotic, Ehrlichia spp-little known (Bartonella spp.Ticks are also a possible vector)
what is the ehrlichia agent maintenance cycle like?Agents maintained within a tick – wild animal cycle
what are the biological vectors of ehrlichia/anaplasma sp? (3)Hard ticks (family Ixodidae) of Genera--> 3 sp: (1) Amblyomma spp (2) Dermacentor spp (3) Ixodes spp.**human diseases in the United States
E. chaffeensis-- main host?White-tailed deer (deer chaffed me last night)
E. ewingii-- main host?Deer mainly but Dogs? reservoir host in areas
A. phagocytophilum-- main host?Cervids & rodents reservoir hosts
what are the Accidental, dead-end Hosts for ehrlichia/anaplasma species, and how do they get infected?humans, dogs. Via tick bite.
what causes human monocytic ehrlichiosis?E chaffeensis (my deer one chaffed me)
what causes human ehrlichiosis?E. ewingii (dog one)
what causes human granulocytic ehrlichiosis?anaplasma phogocytophylum (horse one) (GA!!!)
how do you tx ehrlichia/anaplasma sp?The drug of choice for all forms of ehrlichiosis is doxycycline or other tetracyclines
is there dog-to human xmission of ehrlichia?While there are no reports of direct dog-to-human transmission of either E. ewingii or E.chaffeensis, identification of an infected pet would suggest the pet’s owner is at risk of exposure to infected ticks