Parasitología al día
versión impresa ISSN 0716-0720
COSTAMAGNA, SIXTO RAUL et al. FLUORESCENT STAINING WITH ACRIDINE ORANGE AND PAP SMEAR: VALIDATION TESTS OF BOTH TECNIQUES FOR THE DETECTION OF Trichomonas vaginalis. Parasitol. día [online]. 2000, vol.24, n.3-4, pp. 112-114. ISSN 0716-0720. http://dx.doi.org/10.4067/S0716-07202000000300008.
The present study examined the validity of PAP staining, as used for vaginal cytology, against fluorescent staining with acridine orange in order to determine the value of a negative result of Trichomonas vaginalis obtained by a PAP smear. We examined eighty vaginal-secretion samples from 18- to 45-year-old female patients of the Hospital Municipal of the city of Bahía Blanca, Province of Buenos Aires, Argentina. The samples were stained in parallel by the PAP smear technique and the fluorescent staining technique with acridine orange described by Fripp in 1975. The results of our validation tests demonstrated that, against fluorescent staining with acridine orange, the PAP smear has a 54.5% sensitivity for the detection of T. vaginalis for a 13.75% prevalence of disease among the females in the study with a 95% confidence level. In assays conducted "in parallel" for both stainings, the global value of the test was 93.8%, with a predictive negative value of 93.2%. We conclude that, although the PAP smear can detect T. vaginalis, its sensitivity is not high enough for the test to be used as the sole diagnostic means and the test must always be supplemented with fluorescent staining with acridine orange or another test of similar value. Otherwise, the diagnostic sensitivity would not be any higher than that of vaginal discharge exams in vitro.
Palabras clave : Trichomonosis; Trichomonas vaginalis; Acridine orange; Papanicolaou.