Term
|
Definition
| sign of meningeal inflammation= when the patient experiences pain if you are holding their thigh at a 90 degree angle to their body and then try to straighten their leg |
|
|
Term
| What idoes SMAC stand for? |
|
Definition
| sequential multi-analyzer for Chemistries/computer |
|
|
Term
| What is a normal CSF glucose? |
|
Definition
|
|
Term
| Why do you order CMPs on CSF for a patient if you suspect meningitis? |
|
Definition
|
|
Term
| What is teh WBC in a CSF with septic versus aseptic meningitis? |
|
Definition
bacterial= 100-1,000 cells/mL
viral= 50-200 cells/mL |
|
|
Term
| How do you test CSF for cryptococcal meningitis? |
|
Definition
| india ink or latex agglutination |
|
|
Term
| What is a cheap test to screen for malaria? |
|
Definition
| blood smear (thick smear for sensitivity and thin smear for better morphology) |
|
|
Term
| Describe the blood smear appearance of plasmodium falciparum. |
|
Definition
| banana shaped gametocytes, multiple ring forms, some applique |
|
|
Term
| 95% of all malaria deaths in US travelers is caused by... |
|
Definition
|
|
Term
| Name the rapid malaria diagnostic test. |
|
Definition
|
|
Term
| Which species can Binax NOW identify? |
|
Definition
| P. falciparum and P. vivax |
|
|
Term
| If a smear can't diagnose malaria, you can go on to... |
|
Definition
|
|
Term
| A tetrad within a RBC is pathognomonic for... |
|
Definition
|
|
Term
| What are the two significant species of babesia? |
|
Definition
| B. microtii and B. divergens |
|
|
Term
| How do people get babesiosis? |
|
Definition
| invertebrate vector: Ixodes tick that lives in the northeast and upper midwest; OR from blood transfusion-transmitted infections |
|
|
Term
| What is the vertebrate reservoir of babesiosis? |
|
Definition
| small mammals (white-footed mouse, rabbits), cattle, horses, dogs, etc. |
|
|
Term
| What is the incubation period for babesiosis? |
|
Definition
if transmitted by tick bite= 1 wk- 3 mths
if by blood transfusion= 17 days to 8 weeks |
|
|
Term
| Can mycobacterium respiratory infections be transmitted person to person? |
|
Definition
| mycobacterium tuberculosis is transmissible person-to-person but there are many other non-tuberculous mycobacteria (NTM) |
|
|
Term
| What does MOTT stand for? |
|
Definition
| mycobacteria other than tuberculosis (MOTT) |
|
|
Term
| How do patients get MOTT or NTM? |
|
Definition
| environmental exposure, not person-to-person |
|
|
Term
| How does MTB get down into the alveoli? |
|
Definition
|
|
Term
| What happens between the time someone get MTB and when they become PPD positive? |
|
Definition
| 1-3 weeks= mycobacteria multiply unrestricted in macrophages, which remain unactivated; lymphocytes infiltrate, express cytokines and IFN Macrophages activate and PPD becomes positive |
|
|
Term
| What type of immunity is needed against MTB? |
|
Definition
| intact cell mediated immunity/CD4 response |
|
|
Term
| T/F Most MTB infections are symptomatic. |
|
Definition
|
|
Term
| T/F MTB infections that cause symptoms rarely progress. |
|
Definition
|
|
Term
| What happens to the primary lesion or tubercle in the vast majority of TB? |
|
Definition
| primary lesion becomes fibrotic and calcifies |
|
|
Term
|
Definition
| a focus of granulomatous inflammation that calcifies and can be detected by CXR |
|
|
Term
|
Definition
| when there is a peripheral gohn focus plus hilar lymph nodes and they are both calcified on CXR |
|
|
Term
| Are there organisms in a calcified Gohn focus? |
|
Definition
| yes; there are often small numbers of MTB |
|
|
Term
| Where does reactivation tuberculosis most often occur? |
|
Definition
| usually apical upper lobes or superior segments of lower lobes |
|
|
Term
| How does TB spread throughout the body? |
|
Definition
|
|
Term
| Cavitary lesions left by tuberculosis can be colonized by what other microorganism? |
|
Definition
| fungus ball (mycetoma or aspergilloma) |
|
|
Term
| What is tuberculous lymphadenitis called? |
|
Definition
|
|
Term
| An individual who has been infected with TB but does not have active disease is said to have a ____. |
|
Definition
|
|
Term
| Are people with latent TB infection infectious to others? |
|
Definition
|
|
Term
| What should be done for patients with a latent TB infection? |
|
Definition
|
|
Term
| Name some different methods for testing for latent TB infection. |
|
Definition
| tuberculin skin testing, quantiFERON gold, elispot |
|
|
Term
| How long do you have before a TB skin test should be red? |
|
Definition
|
|
Term
| What is measured as a reaction to PPD? |
|
Definition
| palpable induration, NOT erythema |
|
|
Term
| What is a positive TB skin test? |
|
Definition
if no risk factors for TB= >15 mm
immigrant from endemic country, IVDA, prison/nursing home/hospital/laboratory, children over 5: >10mm
HIV, recent TB contact, CXR, immunosuppresed >5 mm |
|
|
Term
| Which patients is tuberculin skin testing unreliable? |
|
Definition
|
|
Term
| How is the quantiFERON Gold test performed? |
|
Definition
| patient's blood sampel is incubated for 16-24 hours with MTb-specific antigens; then the degree of cell-mediated immune reactivity (INF-gamma) is measured |
|
|
Term
| What are the advantages of using the QuantiFERON Gold? |
|
Definition
| detects latent infection, detects MTb infection in individuals who have recieved the BCG vaccine, no need to have PPD read |
|
|
Term
| What is the difference in the test tube of patients who are sensitized to TB versus those who are not? |
|
Definition
| if prior exposure, an antigen specific T-Cell will recognize the antigen presented by the APC and bind |
|
|
Term
| When working up a patient for active TB, which tests come back on the same day? |
|
Definition
| AFB smear and MTD nucleic acid amplification test (may not be sensitive enought on the first day) |
|
|
Term
| How is an AFB smear for active TB infection performed? |
|
Definition
| concentrated sputum, read using flourescence microscopy |
|
|
Term
| If you suspect a person has active TB, you must admit them to a... |
|
Definition
| negative pressure room and isolation |
|
|
Term
| What labs do you need to release a patient from isolation who is suspected of TB by proving that they do not in fact have TB? |
|
Definition
| 3 sputum spears (on seperate days) must be AFB-negative |
|
|
Term
| What allows mycobacteria to be "acid fast"? |
|
Definition
| cell walls have a very high lipid content due to presence of mycolic acids; these bind well to fuchsin (a red dye) in presence of carbolic acid ("phenol"), hence carbol-fuchsin stains; They then resist decoloration with ethanol and 3% HCL |
|
|
Term
| Describe the different stains for AFBs. |
|
Definition
Ziehl-Neelson= traditional, "hot" stain
Kinyoun= "cold"
Auramine-Rhodamine= flourochrome stain that is read with immunoflourescent scope and is very sensitive |
|
|
Term
| What is the most sensitive mycobacterial stain? |
|
Definition
|
|
Term
| What are some media on which mycobacteria can be cultured? |
|
Definition
| Lowen-stein Jensen (LJ) slants; or MIddlebrook 7H11 Agar |
|
|
Term
| What is Lowenstein-Jensen slant made out of? |
|
Definition
| coagulated whole eggs to solidify media; malachite green bacterial inhibitor |
|
|
Term
| What are the advantages to using Lowenstein-Jensen slants? |
|
Definition
| tubes are good for shipping (like to send off for drug susceptibility testing) |
|
|
Term
| What is middlebrook 7H11 agar made out of? |
|
Definition
| solid, agar-based medium (clear) |
|
|
Term
| What are the advanatages to using Middle brook 7H11 agar? |
|
Definition
| growth is faster than with egg-based media; easier to observe colony morphology with a microscope |
|
|
Term
| What is the gross description of MTb colonies? |
|
Definition
|
|
Term
| A smear of MTb grown in culture shows... |
|
Definition
|
|
Term
| What is the gold standard for MTb culture? |
|
Definition
| broth-based (liquid) culture |
|
|
Term
| What are the advantages to using liquid culture to culture MTb? |
|
Definition
| can culture sputum, blood, BM; used in automated systems |
|
|
Term
| What is the sensitivity and specificity of Gen-Probe MTD on smear positive respiratory specimens? |
|
Definition
senesitivity > 99%
specificity nearly 100% |
|
|
Term
| A patient who has a smear positive test for MTb but has a negative MTD has... |
|
Definition
| acid-fast bacilli infection but they are not mycobacterium tuberculosis; patient can come out of isolation |
|
|
Term
| What is the sensitivity and specificity of Gen-Probe MTD on smear-negative respiratory specimens? |
|
Definition
| sensitivity= 70-85%; specificity >99% |
|
|
Term
| What is probe amplification? |
|
Definition
| if the probe binds to the target, the probe is amplified |
|
|
Term
| Gen-Probe's AccuProbe identify what mycobacteria? |
|
Definition
| M. tuberculosis, MAC, M. kansasii, M. gordonae |
|
|
Term
| What specimens can you use Gen-Probe's AccuProbe on? |
|
Definition
| positive AFB culture (either plate or liquid broth); not from a direct smear |
|
|
Term
| What does HPLC stand for? |
|
Definition
| high-performance liquid chromatography |
|
|
Term
| How do you identify AFB via HPLC? |
|
Definition
| analysis of their mycolic acids; acid fast bacteria are saponified to remove their mycolic acids from the cell wall; mycolic acids are separated by acidification and extraction into chloroform; they are absorbed onto a reverse-phase colomn and detected with a flourescence spectrophotometer; different mycolic acid chromatographic patterns are charactersitic of the different spcies of mycobacteria |
|
|
Term
| Is biochemical testing used for identifying mycobacteria? |
|
Definition
| yes; historically it was the only method for identifying mycobactera and there is still some use fro biochemicals but they are relegated to reference labs when nothing else works |
|
|
Term
| Working with sputum for acid fast bacilli has a BSL of ____, while working with culture for acid fast bacilli has a BSL of ___. |
|
Definition
|
|
Term
| How long does it take for drug susceptiblity testing for MTb to come back? |
|
Definition
|
|
Term
| Name some standard drugs for treating MTb. |
|
Definition
| isoniazid, rifampin, pyrazinamide, ethambutol, and streptomycin |
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