Infectious Disease Flashcards
Types of Meningitis with lymphocytic predominance?
Cryptococcus, Lyme, viral, TB, RMSF
ABX - Treatment for pneumococcal meningitis?
Ceftrioxone and Vancomycin
When do you provide intrathecal antibiotics in meningitis?
Only when there is a piece of hardware (e.g., shunt)
In which bacterial meningitis has steroids been shown to decrease mortality?
pneumococcal meningitis
What meningitis? HIV with cd4 less < 100? What are the initial and most specific tests?
Cryptococcus Initial india ink most specific - cryptococcal antigen test
What is the treatment for cryptococcal menigitis?
Ampho and 5-FC followed by lifelong fluconazole unless t-cells go up
cyrptococcus ad mucomycosis - only 2 remaining uses of ampho.
treatment for lyme menigitis?
Ceftrioxone for severe meningitis 10-28 days, also recommended for lyme carditis with heart block
Doxycline may be used in early or mild
Doxycyclin, Amoxicillin or Cefuroxime for several weeks may be used.
TB Meningitis - is the protein high or low? how accurate is Acid fast stain?
most accurate test? Treatment?
Camper with rash (target), joint pain, facial palsy, head ache, LP shows lymphocytes - what is the most likely etiology? What is the treatment? What is the initial and or most specific test?
lyme,
V. What is the Empiric Antimicrobial Approach for Patients with Suspected Healthcare-Associated Ventriculitis and Meningitis?
V. What is the Empiric Antimicrobial Approach for Patients with Suspected Healthcare-Associated Ventriculitis and Meningitis?
Recommendations
Vancomycin plus an anti-pseudomonal beta-lactam (such as cefepime, ceftazidime, or meropenem) is recommended as empiric therapy for healthcare-associated ventriculitis and meningitis; the choice of empiric beta-lactam agent should be based on local in vitro susceptibility patterns
Man returns from Africa with abrupt fever, headache, chills severe bone & back pain. Decreased WBC and Platelets. Petichial Rash. What is the most likely diagnosis
Dengue Fever
A man without a spleen is bit by an Ixodes tick bite, hemolysis, fever, and shaking chills. RBC show ring forms. What is the likely organisim? what is the treatment?
Babesia
atovaquone and azithromycin
The two major antimicrobial regimens consist of atovaquone plus azithromycin or quinine plus clindamycin. These regimens are administered orally for 7 to 10 days [1,43]. Atovaquone plus azithromycin is preferred as this combination is better tolerated.
Long Island NY fever, chills, HA. T_ransaminaise High, WBC low, Platelet low. Tick bite_. Morulae in white cells. Most likely diagnosis and treatmet
Ehrlichia/Anaplasma phagocytophilia
A 51-year-old man with no significant past medical history presented with a five-day history of fever, malaise, and diffuse myalgias with no recollection of a tick bite. _He was found to have thrombocytopenia, elevated transaminase leve_ls, and renal insufficiency. Examination of the peripheral smear suggested the diagnosis of anaplasmosis. He was started on a course of doxycycline with eventual complete resolution of symptoms.
The peripheral smear (1000x, “feather edge”) shows morulae of
Hiv Patient with cats presents with increased AST/ALT. CT shows liver with cystic spactes filled with blood (pelios hepatitis). Biopsy silver stain/Warthin Starry Positive . What is the diagnosis? What is the organism?
Bartonella infections can cause serious morbidity and mortality in HIV-infected patients, particularly those with advanced immunosuppression.
This topic will address the epidemiology, microbiology, and clinical manifestations of Bartonella infections in HIV-infected patients. The diagnosis, treatment, and prevention of these infections are discussed elsewhere. (See “Diagnosis, treatment, and prevention of Bartonella infections in HIV-infected patients”.)
Other aspects of Bartonella infection are discussed separately. (See “Microbiology, epidemiology, clinical manifestations, and diagnosis of cat scratch disease” and “Endocarditis caused by Bartonella” and “South American bartonellosis: Oroya fever and verruga peruana”.)
MICROBIOLOGY — Although more than 20 distinct species of Bartonella have been isolated, only two Bartonella species cause a significant number of clinically relevant infections in individuals infected with the human immunodeficiency virus (HIV): Bartonella henselae and Bartonella quintana [1,2].
EPIDEMIOLOGY
Transmission — Patients with B. henselae infection usually have a history of cat exposures [3]. The transmission of Bartonella to humans most often results via a cat scratch involving the claw of a cat that is contaminated with Bartonella-infected flea feces. Cat fleas become infected with B. henselae after feeding on the cat. While on the cat, the fleas excrete feces that contain Bartonella. The cat’s claw becomes contaminated with flea feces when the cat scratches its skin in an area infested with fleas.
B. quintana infections predominantly occur in homeless persons with body lice. With B. quintana, it is believed that humans serve as the reservoir and body lice are the vectors.
UTD - SUMMARY AND RECOMMENDATIONS
●The diagnosis of bartonellosis can be made through histopathologic examination of biopsy tissue. Lesions are characterized by vascular proliferation and Warthin-Starry staining usually demonstrates numerous bacilli. (See ‘Diagnosis’ above.)
●Although isolation of this organism makes a definitive diagnosis, this is infrequently accomplished due to the fastidious nature of this organism. (See ‘Culture’ above.)
●Histopathologic findings in peliosis hepatis and splenitis typically consist of cystic blood-filled spaces and fibromyxoid stroma that contains a mixture of inflammatory cells and dilated capillaries. (See ‘Histopathology’ above.)
●Serologic testing is often used as supportive, but not definitive, evidence for infection. (See ‘Serology’ above.)
●Polymerase chain reaction testing plays an important role in the diagnosis of Bartonella because of the difficulty in isolating this organism from tissue samples. The PCR test generally can distinguish among the different Bartonella species. (See ‘Polymerase chain reaction’ above.)
●All HIV-infected individuals diagnosed with a Bartonella infection should receive antibiotic therapy. Although no randomized controlled trial data are available, observational studies suggest that patients generally respond well to prolonged courses of either erythromycin or doxycycline. (See ‘Therapy’ above.)
●For patients with bacteremia, we administer doxycycline (100 mg PO or IV twice daily) plus gentamicin (1 mg/kg IV every eight hours) [12]. The gentamicin is used only for the first 14 days. (See ‘Which therapy to use’ above.)
●Long-term suppressive therapy with a macrolide or doxycycline is recommended for patients with a history of relapse of Bartonella infection until the CD4 count has increased to >200 cells/microL for at least six months. (See ‘Suppressive therapy’above.)
●In patients who are not receiving antiretroviral therapy (ART), and who have central nervous system or ophthalmic disease, ART should be initiated two to four weeks after starting antimicrobial treatment for Bartonella. We do not delay initiation of ART in patients presenting with other manifestations of Bartonella. (See ‘When to initiate antiretroviral therapy’ above.)
●In patients with HIV infection we do not administer antimicrobial agents to prevent Bartonella infection. However, we provide counseling on how to decrease the risk of exposure. (See ‘Prevention’ above.)
Histopathology — Standard hematoxylin and eosin staining of bacillary angiomatosis (BA) lesions from any site characteristically shows lobular vascular proliferations composed of rounded vessels lined by variably protuberant plump endothelial cells (picture 1) [3]. In addition, clusters of neutrophils, neutrophilic debris, and lymphocytes are scattered throughout the lesions, especially around eosinophilic granular aggregates. Warthin-Starry silver staining of these aggregates reveals masses of small, dark-staining bacteria (picture 2). Electron microscopic examination, if performed, shows pleomorphic bacilli with a trilaminar wall (picture 3) [4].
Histopathologic findings in peliosis hepatis and splenitis typically consist of cystic blood-filled spaces and fibromyxoid stroma that contains a mixture of inflammatory cells, dilated capillaries, and granular purple material. Warthin-Starry staining of these lesions demonstrates findings similar to BA. (See “Peliosis hepatis”.)
