5 - Parasitic Diseases Flashcards
1
Q
Rocky mountain spotted fever parasite
A
Ixodid tick
2
Q
Rocky mountain spotted fever epidemiology
A
- More common in children, young adults who venture outdoors
- Males more likely than females
- Transmitted by ixodid tick bite
3
Q
Rocky mountain spotted fever patient presentation
A
- 3-14 days after tick bite
- Sudden onset of headache, fever, then chills, myalgias, arthralgias; rash appears anywhere from day 1 to day 6
- Rash characteristically begins on wrists, forearms and ankles, then spreads to arms, thighs and trunk, and finally face. 13% of cases have NO rash
4
Q
Rocky mountain spotted fever diagnosis
A
- Immunofluorescent antibody to anti-rickettsii antibodies
- Direct immunofluorescence of antigen within endothelial cells
5
Q
Rocky mountain spotted fever treatment
A
- Doxycycline 200 mg/day PO or IV in two divided doses
- Chloramphenicol 50-75 mg/kg/day in four divided doses
6
Q
Flea bite parasite
A
Ctenocephalides canis
- Dog flea (Ctenocephalides canis)
- Ectoparasite (a parasite, such as a flea, that lives on the outside of its host)
7
Q
Flea bite signs and symptoms
A
- Papular pruritic urticaria occurs at bite site, found on knees, legs of children
- May be in various stages of crusting if re-exposure occurs
- Self-limiting disease, secondary infections are very unlikely in humans
8
Q
Flea bite treatmetn
A
- Topical antihistamine
9
Q
Bed bug parasite
A
Cimex lectularius
- Reside in cracks in floors and walls, in bedding, and in furniture
- They usually feed only once a week, and less often in cold weather
- Can travel long distances in search of a human host, and can survive for 6-12 months without feeding
10
Q
Bed bug signs and symptoms
A
- Bites occur on exposed sites on the face, neck, arms and hands with several lesions in a row
- Nocturnal feedings produce a linear arrangement of papular urticaria
- Self-limiting disease, typically does not lead to an infectious disease
11
Q
Bed bug treatment
A
- Hydrocortisone cream or antihistamine
12
Q
Houseflies parasite
A
Musca domesticus Linnaeus
- Main problem is esthetic, primarily a nuisance, but can be a disease carrier
13
Q
Head lice parasite
A
Pediculus humanus capitus
14
Q
Head lice diagnosis
A
- Diagnose by discovery of live adult lice or nits with viable louse inside; most commonly at hairline of temple, post-auricular areas and occiput
15
Q
Head lice treatment
A
- Treat with malathion (Ovide) in children
- Lindane (Kwell), Nix, RID, or ivermectin, may require retreatment in 7-14 days
16
Q
Body lice parasite
A
Pediculus humanus corporis
- Live in seams of clothing, venture to human host only to feed
17
Q
Body lice treatment
A
- “Cure” by improved hygiene
- At times application of pyrethrin (medication which paralyzes and kills the lice and eggs) or malathion (kills lice and some eggs)may be warranted
18
Q
Pubic lice parasite
A
Pediculus pubis (pubic lice, “crabs”)
19
Q
Pubic lice transmission
A
- Transmitted by close physical contact; sharing towels
20
Q
Pubic lice signs and symptoms
A
- Pruritis most common symptom followed by excoriations and possible inguinal lymphadenopathy
21
Q
Pubic lice treatment
A
- Treat with same regimen as for head lice; may require retreatment. Many patients closely crop off pubic hair to remove dead nits
22
Q
Scabies parasite
A
Sarcoptes scabiei
23
Q
Scabies pateint presentation
A
- Very highly contagious parasitic infection, multiply only on human skin
- Mites can remain alive for 2-3 days in clothing or in bedding
- It can take up to 3 weeks for a person to become symptomatic once exposed
- Areas affected in order of prevalence: interdigital webs of hands, wrists, shaft of penis, antecubital crease, feet, genitalia, buttocks, axillae
24
Q
Scabies diagnosis
A
- Diagnose by finding a burrow, place a drop of mineral oil over the burrow, and the area is scraped/cut off with a #15 scalpel blade and inspected via microscopy
25
Scabies treatment
- Treat with permethrin
| - Next choice is lindane (due to increased resistance, risk of seizures)
26
Cutaneous larva migrans parasite
Ancyclostoma brazillense
27
Cutaneous larva migrans general
- Represents any cutaneous lesion from migration of nematode parasites
- Most common in US --> Ancyclostoma braziliense (dog/cat hook worm larvae)
28
Cutaenous larva migrans life cycle
- Ova of hookworms are deposited in sand and soil in warm, shady areas, hatching into larvae that penetrate human skin
- Larvae migrate up to several centimeters a day between the stratum germinativum and stratum corneum, larvae die days to months later
29
Cutaneous larva migrans clinical presentation
- Lesion is a serpiginous, raised, tunnel-like line of erythema (path of migration)
- Self-limiting illness since humans are “dead-end” hosts
30
Cutaneous larva migrans treatmetn
- If treatment is desired, thiabendazole, ivermectin or albendazole topically
31
Seabather's eruption parasite
Larvae of thimble jellyfish, sea anemone
32
Seabathers eruption clinical presentation
- Papulo-vesicular rash occurring only in regions covered by swimwear
- Florida and Caribbean Due to larvae of the thimble jellyfish
- Long Island, NY Due to larvae of sea anemone
- Lesions present for 1-2 weeks
33
Seabather's eruption treatmen
- Topical steroid cream to reduce inflammation
34
Leishmaniasis parasite
LeishmaniaI
- Parasitic infection caused by many species of the protozoa Leishmania
- 4 syndromes Cutaneous, mucocutaneous, diffuse cutaneous, visceral
35
Leishmaniasis clinical presentation
- Primary lesions occur as a papule at the site of a sandfly bite
- Papules enlarge over several weeks and become a dusky red-purple color
- Eventually the lesion ulcerates, stops peripheral extension after 2 months, and eventually the nodule heals with a depressed scar after 3-6 months
36
Leishmaniasis diagnosis
- Diagnose by finding amastigotes (non-flagellate form) on smear or in skin biopsy or pro-mastigotes on culture of wound aspirate
37
Leishmaniasis treatment
- Treat with Pentostam (drug used for protozoal infections)
| - Administration Intra-lesion, IV, IM
38
Lyme borrelliosis parasite
Borrelia Burgdorferi
39
Lyme borrelliosis general
- Multi-system disease caused by the spirochete Borrelia Burgdorferi, transmitted to humans by the bite of an infected ixodid tick
- Transmission usually occurs after prolonged attachment/feeding (18+ hrs.)
40
Lyme borrelliosis disease stages
Stage 1 = Erythema migrans
o Expanding annular lesion w/ red border and partially clearing center
Stage 2 = Disseminated infection
o Fever, chills, myalgia, headache, weakness, photophobia, meningitis, carditis with heart block
Stage 3 = Persistent infection
o Fever, lymphadenopathy, arthritis, encephalopathy, polyneuropathy
41
Lyme borrelliosis diagnosis
- Diagnose by enzyme immunoassay or immunofluorescent assay followed by a Western immunoblot; or by culture from a lesional skin biopsy
42
Lyme borrelliosis treatmetn
- Treat with doxycycline 100 mg bid for 10 days in acute stage (if patient is under 12, treat with amoxicillin)
- Treat for 20-30 days if stage 2
- Treat for up to 60 days if stage 3
43
Lyme borrelliosis immunizations
- Immunization for prophylaxis was available with LYMErix
| - Was taken off market due to lack of use
44
Bot fly transmision
- Transmission is through the laying of eggs on the human host or an intermediary vector (fly, mosquito, etc.)
45
Bot fly symptoms
- Firm nodule, typically is painful
| - May exude purulence and can experience movement in the tissue.
