VPH - Final 2

drraythe's version from 2016-04-24 14:56

Immunocompromised (IC) ppl & their pets CONT…

Question Answer
*What is the MAIN 1° mammalian reservoir & vector for zoonotic B. henselae? Who else might be able to carry it?CATS, however increasingly evident that dogs can be a source of human infxn w/ Bartonella spp [B. vinsonii]
How does Bartonella get spread among cats?FLEAS (Ctenocephalides felis, aka cat flea) primarily (bart simpson has fleas)
What is Bartonella like in cats?Theyre usually asymptomatic
Most common type of cat incriminated for infecting human w/ Bartonella are...Usually immature [<1 yr old] & asymptomatic
How does cat scratch dz present in humans?Lymphadenopathy. The classic lesion is a PAINFUL granulomatous inflammation of regional lymph nodes. Fever & malaise develops in some cases & headache, anorexia, Splenomegaly may also develop. (rollie scratched my lymphnodes & now they hurt & are grainy from his gross paws)
How would you go about Txing a cat for Bartonella?Tx of symptomatic cats is focused upon symptomatic & supportive care
If antimicrobial Tx is warranted, the drug of choice is azithromycin
Rigorous flea control essential for preventing reinfxn!!
What are the 2 best things you can do to prevent Bartonella?(1) Vector control = Flea control. Keep cats indoors to minimize exposure to fleas
(2) Hygienic practices = Avoid cat scratch/ bites, particularly from young cats. Wash/disinfect scratch/bites. Wash hands after handling cats
What are 3 things that The United States Public Health Service/Infectious dzs Society of America (USPHS/IDSA) reccs for ppl w/ HIV to avoid cat dz is...(1) Adopt a cat >1 year of age that is in good health
(2) Avoid rough play w/ cats, maintain flea control
(3) Wash any cat-associated wounds promptly & do not allow a cat to lick wounds or cuts
No evidence of benefit to cats or owners from doing what in regards to Bartonella?No evidence of benefit to cats or owners from culture or serologic testing of cats for Bartonella infxns
Most common Zoonotic virus w/ pet related infxns is?Lymphocytic Choriomenigitis Virus (LCM)
Main source of Lymphocytic Choriomenigitis Virus (LCM) infxn humans is?Rodent bites, excretions or secretions
How does Lymphocytic Choriomenigitis virus (LCM) present in normal people? IC people?Normal: Asymptomatic to flu-like
IC people: Teratogenic effects
**How is Toxoplasma gondii xmitted to humans? (3)(1) Most common way is undercooked meat/wild game UNDERCOOKED PORK MEAT containing cysts are the most important animal source
(2) Less commonly thru cats. Direct contact w/ cats themselves not likely source. Xmission of oocysts from cat feces-humans are a greater source of human infxn
(3) Mother-child - transplacental
(gondii didnt eat raw meat & he didn't like to eat cat shit either)
They say people should be careful cleaning cat litter pans...why & what details are there concerning this?People can get infected w/ oocysts through feco-oral xmission
NOTE: Oocysts need >24 hrs in the environment after being shed in cat feces to be infectious
How does Toxo affect normal people?Healthy persons can also acquire Toxoplasmosis but infxn becomes reactivated more commonly in the immunocompromised. Congenital Toxoplasmosis may cz abortion, neonatal death or fetal abnormalities
**How does Toxo affect IC people?They develop the CEREBRAL FORM (immunoCOMPETENT people don't) which czs a fatal encephalitis
If a HIV+ person tells you they have a cat & they have T. gondii Abs, what should you know?No correlation btwn cat ownership + sero-conversion for T. gondii antibodies in HIV-infected people
Owner of cat wants the cat “tested” to be sure the cat isn’t a risk for (owner) getting infected w/ T. gondii. Would some kind of testing of the cat be beneficial?If tested for antibodies (serology)... If do a fecal to test for shedding: Inconclusive if negative
**Will Preventing infxn of T. gondii in a pet cat prevent infxn in the human?Will NOT prevent human infxn … as most are infected by eating raw meat!!!
What are some ways to prevent feline infxn of T. gondii?Prevent feline infxn (no hunting, no raw meat), Clean litter box daily or have someone else do it (oocysts must be in environment for >24hr to become infective)
MOST IMPORTANT way to avoid infxn of T. gondii?Cook meat well done. Wash hands after contact w/ soil or raw meat
Which Giardia is most important spp w/ respect to human infxn?Giardia lamblia (smiling lamb faces)
*#1 cz of diarrhea in people w/ AIDS?Giardia
Which spp of Cryptosporidia is most important in human infxn?C. parvum in mammals, mainly calves
*How are humans infected w/ Giardia/Cryptosporidia?Ingestion of food or water contaminated by direct contact w/ shedding animals/humans or insect carriers or swallowing contaminated water while swimming
Are Giardia/cryptosporidium zoonotic?Usually no zoonotic component...There is no real need for a vertebrate reservoir host
**Who sheds the most oocytes of Giardia/Cryptosporidium?Immunosuppressed (IC) & young animals shed more oocysts
How does Giardia affect immunoCOMPENTENT people?Acute
Self-limiting diarrhea
Chronic diarrhea or as asymptomatic cyst shedding
Who are the 2 Types of individuals who are susceptible to infxn w/ Giardiasis?Young children & AIDS PTx
**How does Cryptosporidium affect immunocompromised people?Chronic Cryptosporidiosis → people who are HIV+ & then develop this now have AIDS. IT czs persistent diarrhea that can lead to death & there is no Tx
What are the risk factors on getting Giardia/Cryptosporidia (related to animals & otherwise?) (& preventative measures you can take?)Avoid DIRECT CONTACT w/ animals, so practice good hygiene around any animal!
Avoid direct contact w/ feces that may contain oocysts.
AVOID animals w/ diarrhea
Avoid very young or immunosuppressed animals
OTHER RISKS incld Contaminated water (containing oocysts) BOIL THE WATER
Which dermatophyte most commonly affects IC people?Microsporum canis
*Cryptococcus neoformans usually comes from where?Pigeon droppings
What should you know about Cryptococcus neoformans & IC people?Primarily a pathogen of the IC PTx & has qualified as an AIDS defining infxn. Czs CNS & cutaneous lesions
Which Cryptococcus affects normal ppl & which infects IC people?IC people = C. neoformans, yeast usually inhaled (the 1 we usually learn is the 1 that's the prob for IC people which is prolly why we've heard of it)
Normal people = C. gattii
Sporothrix schenkii is usually from where? How does it often infect humans?RESERVOIR IS THE ENVIRONMENT. However, a major source of infxn is cats
What are 2 Vx which might run a risk to IC people?Occasionally seen in IC person in contact w/ pet B. Bronchiseptica Vx & also potential w/ RB51 & contact w/ other Vet vxs or in vxd animals shedding the agent
What are 4 major guidelines for existing pets for IC owners?(1) Animals should not be fed raw meat or be allowed to drink from the toilets
(2) Recommend regular vet visits for early detection of infxns
(3) Let someone else handle animal waste
(4) Wash hands frequently & refrain from face & mouth contact w/ the animal
Guidelines for new pets → which age animals are preferred for IC owners?Older animals preferred. Young pups/kittens more prone to be carriers/infected w/ zoonotic agents
Guidelines for new pets → where should the IC person NOT get their pet from?Advise against pets from shelter environments
Guidelines for new pets → if they get their animal from a dealership, what should they avoid?Avoid Animal dealerships that mix animals from different sources. Higher Reported xmission of zoonoses via contact w/ imported animals here
Guidelines for new pets → before the new pet is introduced to the household, what should the IC person do?Animals should be examined by a vet pre-introduction to the PTx’s household
What are some GENERAL recommendations for IC people regarding pets? (3)(1) Do good hygiene around
(2) Keep pets healthy
(3) Avoid very young, IC or sick animals…& reptiles, amphibians

Emerging Zoonoses

Question Answer
What is an Emerging Zoonoses?A zoonosis that is: a dz newly recognized or newly evolved, or that has occurred previously but shows an ↑ in incidence or expansion in geographical, host or vector range
What are the most threatening emerging pathogens & why?RNA VIRUSES!! Bc of their unparalleled ability to adapt to new hosts & environments (no editing fxn so mutate all the time)
What are 5 viral emerging zoonoses?West Nile virus
Influenza viruses
Ebola virus
What are the 3 major global factors which lead to emergence?(1) Adaptation of infectious agent to new spp (spillover & accidental hosts. Also, crossing of the Species-Barrier)
(2) Environmental factors
(3) Host related factors
Explain what Spillover & Accidental hosts are & how it is a factor contributing to emergence. (Examples?)There is 1 reservoir host for the agent, but other spp. become infected but do not ‘maintain’ the agent. (ex: Hendra, SARS, MERS)
Explain what crossing of a species barrier is & contributes to emergence & what is an example?This is where an infectious agent establishes a complete cycle of xmission in a new species. An example is how Avian Influenza was in birds, but then mutated to be maintained & xmitted btwn people (species jumping)
What does Partial Crossing of the Species-Barrier mean? (Example?)This is where the initial reservoir host is still needed for the intermediate host to transmit to humans. An example would be how Hendra & Nipah can't be maintained in horses/pigs effectively enough to sustain xmission independently of bats. (concern is if complete crossing of spp. barrier may occur if mutations or other factors increased)
What are environmental factors which can contribute to emergence?Climate change affected by Host factors....such as global warming leading to more mosquito vectors
Host factors: what are some examples of how globalization & travel affect emergence?Intercontinental transport
Impact of trade & transport
Land use
Failure of public health systems
Climate change & global warming
Worldwide Failure of Public health systems can lead to things like...Inadequate surveillance & reporting
Inadequate implementation of control measures
Iatrogenic xmission of infectious dzs
Infection through transfusions & tranplants
What is the Role of the Veterinarian relating to emerging zoonoses?Education, as well as early detection & response. Report to the relevant authorities in YOUR COUNTRY
If you suspect you have an infectious & zoonotic emerging dz, what should you do FIRST?In all cases of infectious particularly zoonotic dzs, it is imperative that before collecting animal samples you report your suspicions to the relevant State or Federal authority.


Question Answer
What kinda viruses are flu viruses?RNA viruses in the Orthomyxoviridae family
What are the 3 genera of flu viruses (& who do they effect?)(1) Influenza A (humans, birds, horses, swine)
(2) Influenza B (humans & seals)
(3) Influenza C (humans, dogs & swine)
Birds are initial hosts to all Type _ Influenza virusesA
How would you describe the structure of an Influenza A virus?Enveloped virus & envelope contains 2 glycoproteins → Hemagglutinin protein (H), Neuraminidase protein (N). RNA core has 8 segments
Which type of flu has H & N proteins? Why do we care about these?Flu A. categorize subtypes based on these
How do new subtypes of flu A viruses occur?Due to REASSORTMENT, which is when more than 1 subtype of Flu A viruses infects a cell simultaneously & produce a new subtype
What are 2 different ways reassortment can occur?(1) Btwn Human Type A viruses & Animal Type A viruses
(2) RNA segments of each subtype reassort w/ each other producing a new subtype
New strains arise due to Antigenic ___Drift (small, gradual, minor changes that occur through point mutations in genes producing H+ N proteins)
Mechanism of Entry of Influenza virus into host cells is controlled by which antigen? How does it attach?H antigen, viral attachment to sialic acid receptors on host cells
Where do human flu viruses tend to 1st attach?To receptors on human trachea
Where do Avian Flu viruses tend to 1st attach?Receptors on intestinal & respiratory tract of waterfowl.
**Which animal has both receptor types of birds & humans?Swine, meaning they can get infected by both human & Avian Influenza viruses (acts as a mixing vessel)
Which viral antigen elicits host's Ab response?H (Hey Abs! Here!)
Release of virus from host cells is controlled by which viral antigen?N
H protein antigen does what?Mechanism of Entry of Influenza virus into host cells (HERRREEES VIREY!)
N protein antigen does what?Involved in release of virus from host cells (NEW viruses made in your cells, out & about!)
What benefit does the host making Abs to the N antigen have?Limits spread of infxns (bc N controls the release of it)
Who are the global, asymptomatic natural reservoir of Influenza A viruses from which novel viruses emerge to infect mammalian spp.?Wild Aquatic birds, notably waterfowl
Who is a "mixing vessel" for viral reassortment & why?PIGS, bc express both human & avian receptors on epithelial cells in trachea
Avian Influenza → Aquatic Avian reservoirs are wild birds of 2 Main Orders(1) Waterfowl of Order Anseriformes: ducks, geese, swan
(2) Order Charadriiformes: gulls, terns & shorebirds
What are the 2 subtypes of Avian Influenza, based on pathogenicity? Explain their pathogenicity(1) Influenza A (LPAI) subtypes cz no CS/low morbidity/mortality. Waterfowl & seabirds are the natural reservoir for all of these
(2) Highy pathogenic AI (HPAI) are the ones of concern bc of significant morbidity & mortality w/in infected poultry
*Any virus designated as ___ or ___ (which 2 antigenic proteins?) is of concern as these have the capability to convert from LPAI to HPAIH5 or H7
*If HPAI is detected in a country, who should be alerted?OIE alerted
How is Avian Flu xmitted/introduced into domestic poultry?Wild birds shed virus along migratory pathways & introduce virus through contact w/ domestic poultry. Usually via aerosol (Shed in saliva, nasal d/c & commonly via feces btwn birds in close contact). Can also be via Fomite xmission btwn poultry facilities from the movement of infected birds/humans/equipment/eggs
Describe LPAI dz in birdsWidespread & cz mild respiratory dz in poultry. Problems in turkeys: Canada, US
Describe HPAI dz in birdsSigns variable, depend on:
Genetics of the virus
Species of bird infected
Age of the bird.