Thread by @IUIDfellowship

#idboardreview 30 goat farmer helped w/ goats birth 20d ago now presents w/ fever, rigors, severe retrobulbar headache, dyspnea, hepatitis. Dx? #medEd #idmedEd #IDtwitter

#coxiella burnetti (Q fever) manifest as a self-limited febrile illness, pneumonia, endocarditis, or hepatitis. There are many other less common manifestations, such as meningitis, encephalitis, and osteomyelitis. Infections are divided into acute and chronic forms.

#Qfever zoonosis usually acquired by inhalation or, much less commonly, by ingesting unpasteurized milk
Cattle, sheep, goats most common reservoirs
Infected parturient cats are important in spread in some areas
-extensive wildlife reservoir
-Windborne spread occur over 10 km

Pleomorphic gram-neg (structurally doesnt stain w Gram stain) coccobacillus
#Coxiella burnetii: only species in genus
Intracellular pathogen
Spore former
-acute infection leads to Ab against phase II Ag
chronic infections, such as endocarditis: IgG Ab against phase I Ag

Acute Qfever: 4 fold⬆️in titer b/w acute & convalescent samples
-Chronic #Qfever Dx clinical + IgG phase I titer equal to or >phase II & at least 1 : 1600
-Isolation of C. burnetii using shell vial technique in BSL 3 lab
-PCR on heart valve or joint fluid
FISH can id in tissue

Acute #Qfever: 10 days of doxycycline, a fluoroquinolone or a macrolide
Chronic Q fever: Doxycycline plus hydroxychloroquine until phase I IgG antibody decline to 1:800 or less

ajtmh.org/view/journals/… #coxiella

cdc.gov/qfever/stats/i… #coxiella