Rickettsia and related Flashcards
from Virginia
fever, HA, myalgias
multiple eschars on lower extremities, then
develops maculopapular rash on trunk spreading to extremities
3.3 > 14 < 149
LDH 1502 Tbil 2.4 ALT 195
How to Dx?
Rx?
Rickettsia Parkeri
similar to RMSF, EXCEPT IT HAS ESCHARS
Dx: PCR of eschar, or 4x increase in IgG (during illness, then 2-4 weeks later)
Rx: DOXY (Chloramphenicol preg)
from Virginia
fever, HA, myalgias
develops maculopapular rash on extremities spreading inward
3.3 > 14 < 149
LDH 1502 Tbil 2.4 ALT 195
How to Dx?
Rx?
Rickettsia Rickettsii/RMSF
NO ESCHARS (unlike Parkerii)
Dx: PCR/skin biopsy of lesions or 4x increase in IgG (during illness and 2-4 weeks later)
Rx: doxy (chloramphenicol pregnant)
58F returns from S. Africa with fevers, myalgias and scab on R-thigh.
What would her labs look like?
Rx?
African Tickbite Fever (Rickettsia Africae)
leukopenia, thrombocytopenia, elevated LFT’s
Rx: Doxy (chloramphenicol if pregnant)
55M from upstate NY with NHL receiving rituximab and requires multiple blood transfusions.
Pancytopenic with elevated Tbil and LDH.
How to Dx?
Rx?
Severely Ill?
Duration?
Babesiosis.
Dx: Ring forms in RBC on blood smear.
Rx: atovaquone and azithromycin (clinda+quinine alternative)
If severely ill: > 10% parasitemia benefit from exchange transfusion.
Duration: 6 weeks and at least 2 weeks after last positive smear.
Ascending Paralysis in a hiker from Seattle.
What does CSF look like?
Vector?
Treatment?
Tick Paralysis!
CSF is NORMAL
Dermacentor, amblyoma, Ixodes
Remove Tick!
Lyme Disease in Louisiana but no pathogen.
What is the syndrome?
What type of tick?
STARI
Amblyomma Americanum
Lone Star Tick
17M with conjunctivitis after squeezing a tick into his eye.
Rx?
Francisella tularensis conjunctivitis
Doxy/Gent/Streptomycin
Hiker from Nevada with fever, leukopenia and thrombocytopenia. No rash and illness is mild.
What physical exam finding?
What causes this?
Colorado Tick Bite Fever
splenomegaly
Virus
Patient presents with target lesion, fevers and cytopenias in Maryland.
What ELSE might he have?
So, this is lyme.
Anaplasma and Babesia
also trasmitted by Ixodes (as well as Borrelia miyamotoi and powassan virus)
When should you give single-dose doxy to prevent lyme disease?
- Attached tick identified as an adult or nymphal I. scapularis (black-legged) tick that transmits Lyme disease (also capable in Connecticut of transmitting Borrelia miyamotoi, human granulocytic anaplasmosis, Powassan virus and babesiosis)
- Tick is estimated to have been attached for ≥ 36 hours (based upon how engorged the tick appears)
- Antibiotic treatment can begin within 72 hours of tick removal
- The local rate of tick infection with B. burgdorferi is ≥ 20 percent (known to occur in parts of New England, parts of the mid-Atlantic states, and parts of Minnesota and Wisconsin)
- The person can take doxycycline (i.e., no contraindications such as pregnancy or breastfeeding)
How do you diagnose lyme arthritis?
Two tier serology with reflex IgG immunoblot
PCR of synovial fluid is specific, but not sensitive
treatment of lyme disease in pregnant patient?
amoxicillin
23M from west Africa presents with fevers, headaches and arthralgias x 4 months. Has soft posterior cervical lymph node.
Organism?
Dx?
Rx?
African Trypanosomiasis likely gambiense (Western, more chronic presentation)
Dx: Direct visualization in blood/csf
can get Ab test as well (POC - but not avail in us)
Rx: Melarsoprol
35M refugee from somalia has fevers, leukopenia and thrombocytopenia.
blood smear negative for malaria. But positive for something else.
What might happen if given PCN?
Borrelia recurrentis (spirochetes, seen on blood smear).
Louse-borne borrelia recurrentis which occur in poor hygiene areas (refugee camps)
If treat with PCN, can result in JH reaction (fevers and hypotension) - requires fluid and nsaids/steroids.
Tickborne relapsing fever cause fever:
Louse-borne relapsing fever causes fever:
1-3 days
3-6 days
What diseases can lice cause?
Epidemic Typhus (prowazekii)
Trench Fever (bartonella quintana)
Relapsing fever (borrelia recurrentis)
18M refugee from burundi presents with fevers, myalgias, cough and rash on trunk x 7 days - what is the vector?
Louse - this is epidemic typhus (prowazekii)
Which tick transmits tularemia and RMSF?
Dermacentor
east of the rock mountains and limited areas of pacific coast
what does this tick transmit? (3)
lyme
babesia
anaplasma
20M in homeless in NY presents with ‘tache noire’ and also papulovesicular rash.
What is this?
What vector?
Reservoir?
Treatment?
Rickettsial Pox (akari)
house mite vector
rodents reservoir
Doxy (chloram in pregnant)
Where is this found and what is the vector?
HME
SE/south central US
amblyomma americanum (lone star - STARI)
Morula
Where is this and what is the vector?
HGA
northeast/mid atlantic
Ixodes scapularis
what is recrudescent rickettsia prowazekii?
brill-zinsser disease
occurs in 15% of individuals with a history of primary epidemic typhus
remittent febrile course lasts about 7-10 days
ascending paralysis
wood tick and dog tick toxin
what is the feared adverse effect of chloramphenicol?
aplastic anemia
Geography of HME vs. HGA
Lethality of HME vs. HGA
HME is concentrated in southern belt, while HGA is is in the NORTH
HME has mortality rate 3% vs HGA 0.7%
23M dog trainer from south texas presents with fevers, myalgias.
dx?
Vector?
Treatment?
Murine (endemic) Typhus - serology
*Fleas from rodents and pets
usually self-limited, but give doxycycline as it can rarely cause severe illness
https://casereports.bmj.com/content/13/11/e239471
Fevers and mylagias 2 months after hunting swine
Brucella!
Very long incubation period. (vs. Q fever which is 2-4 weeks)
Micro and Clinical differences between epidemic and endemic typhus?
Epidemic: Prowazekii from Lice in refugees, crowded conditions and in US endemic in flying squirrels- can be LETHAL and recur (brill zinsser disease)
Endemic (murine): Typhi from fleas - endemic in US California, TX, Hawaii, mild disease with no recurrence
58M 3 days of fever/headache. Pulled tick off neck 3 days ago after fishing.
WBC 2.4, PLT 75, LFT’s normal
Improved, but then 2 days later recurred and has fatigue for several weeks
No response to Doxy
Dx?
Colorado Tick Fever Virus (CTFV) a coltivirus
RNA virus
CTFV, SRV in Idaho - Triphasix fever with headaches, myalgia and lethardy+ lekopenia and thrombocytopenia.
28F myalgia, cough, nausea, vomitting, f/c.
Macular rash on arms/thighs
cleaned out rat-infested garag
3.0>10< 98
Dx/Rx?
Murine/endemic typhis (R. typhi) from fleas
Doxy
Patient returns from Israel with eschar and MP rash including palms and soles
Mediterranean spotted fever (MSF), also known as boutonneuse fever (BF), is caused by Rickettsia conorii subspecies conorii (R conorii)
Doxy
fleas
rickettsia typhi (murine/endemic typhus)
yersinia pestis
flying squirrels
rickettsia prowasekii (epidemic typhus)
lice
bartonella quintana (trench fever)
borrelia recurrentis (louse-borne relapsing fever)
rickettsia prowazekii (epidemic typhus)
50M with fever, rigors, night sweats and headache - develops dry cough and maculopapular rash after returning from indonesia.
epidemic typhus (ricketssia prowazekii)
58M with ulcer on his knee from bug bite. Several weeks later develops lump in his groin.
Tularemia
Rx doxy, cipro, gent or streptomycin
Black Legged TIck (Ixodes)
Nyph Stage most disease transmission
Lyme, Anaplasma, Babesia, Miyamotoii, Powassan
how many meals to ticks have in their lives?
3
What is most common tick to bite in virginia?
Lone Star (Ambloymma americanum)
Ehrlichia and Tularemia
(in south, STARI, heartland virus, bourbon virus)
What tick transmits RMSF in virginia?
Dermacentor (Dog Tick)
also transmits Francisella
