CC Sept 2015 Syphilis testing

echoecho's version from 2015-10-19 03:25


Question Answer
Caused by what?Treponema pallidum
In 2013, there were how many cases reported in the US?56,000
1/3 of the 56,000 cases were what type of cases?primary or secondary
The epidemiology of syphilis has shifted from heterosexual men and women of racial and ethnic minority groups in the 1990s to what group?MSM (younger men who have sex with men) who accounted for 3/4 of all new infections in 2013
What two ethnic groups are disproportionately affected?Hispanic and AA
Rates of syphilis in what type of facilities for men and women have increased considerably?correctional
Has congenital syphilis also shown a dramatic rise over the past few years?yes
Screening for syphilis is usually done with non-treponemal tests, name these?VDRL or RPR
Both VDRL and RPR tests detect antibodies to ______ in the blood. These tests become positive _____ weeks after a primary infection so they may be negative very early in the course of the disease?cardiolipin; 3
What conditions can cause a false positive RPR or VDRL?autoimmune disorders, increased age, cirrhosis, malaria, IV drug use
*** Nontreponemal testing alone is ______ (sufficient vs. insufficient) to make the dx of syphilis?insufficient
Why should one always use the same nontreponemal test (RPR or VDRL)?because the titers used in the VDRL and RPR are scaled differently
List the confirmatory treponemal testing for patients with a positive VDRL or RPR?1) FTA-ABS (fluorescent treponemal antibody absorption) test OR 2) TP-PA (Treponema pallidum passive particle agglutination test)
The FTA-ABS and TP-PA test have high ______ (specificity vs. sensitivity) and a low false positive rate for syphilis and become positive earlier int he course of the disease than nontreponemal tests?specificity
Once a treponemal test has become positive, the majority of pts continue to have positive tests even after treatment, true or false?true
What test is done to detect T. pallidum in the exudates of lesions or in tissues and considered the definitive method of diagnosisng patients early in the course.?darkfield microscopy
Why is it difficult to get patients to do a darkfield microscopy?many patients are unaware of a primary infection due to the small siz ena dasymptomatic nature of an early lesion (chancre)
What % of patients are diagnosed with syphilis in the primary stage?30-40%
Once a dx of syphilis is made, what test should be done (if not previously obtained) to establish what?nontreponemal test; baseline titer
What other test is also recommended since co-infection is common?HIV
After treatment, the nontreponemal test titer should decrease by a factor of ____ over the next _________ to _________ months?4; 3-6 months
This decline may be slower in patients who have what?previously been infection with syphilis
Titers should be drawn at ___ months and again at ___ months?6 ; 12
Patients who develop s/s of syphilis or who have a ___ fold increase in the nontreponemal titer measured at the time of rx should be considered to have failed treatment or been reinfected?4
What is recommended if patient failed treatment or been reinfected? retreatment and retesting for HIV
If titers do not decrease as expected but there is no clinical evidence of recurrent disease, the optimal course of treatment is?unclear
Up to 15% of patients treated appropriately for syphilis do not have the expected decrease in titers at 1 year, termed what?"serofast"
Serologic conversion is likely to be slower in individuals with what?1) higher baseline titers 2) prior treated episodes of infection 3) HIV coinfection
As long as there is no persistence of symptoms and some evidence of serologic improvement is confirmed, then continued close monitoring is appropriate for up to ____ months in those pts where good follow-up is assured?36
Retreatment should be considered in what patients?whom follow-up is unlikely or uncertain and also retested for HIV
What testing is useful in the dx of neurosyphilis?CSF testing with VDRL,FTA-ABS, and newer assays like B cell chemoattractan chemokine (CXC motif)
Is syphilis a reportable disease in all 50 states?yes
*** The USPSTF recommends screening all men and women at increased risk of infection such as what?1) MSM 2) commercial sex workers 3) persons who exchange sex for drugs 4) those in adult correctional facilities
Is it recommended to screen asymptomatic men and women not at increased risk?no
The USPSTF also recommends that all women who are ______ should be screened for syphilis at their first visit?pregnant
*** Summary: screening is usually done with a _______ test and confirmed by a _____ test?nontreponemal; treponemal
*** Summary: List 5 causes of false-positive nontreponemal test?1) autoimmune disorders 2) increased age 3) cirrhosis 4) malaria 5) IV use
*** Summary: There should be a ____ fold decrease in the nontreponemal titer following treatment?4
*** Summary: ________ testing (treponemal vs. nontreponemal) is used to determine reinfection?nontreponemal