How adequate is adequate for the collection of endocervical specimens for Chlamydia trachomatis testing?

BACKGROUND: Endocervical specimen adequacy has been assessed by subjective criteria that are based on arbitrarily chosen thresholds for the presence of target cells observed on microscopic slide examinations. GOAL OF THIS STUDY: To assess the relationship of chlamydia test positivity to specimen adequacy with the use of a semi-quantitative cytologic staining method for assessing endocervical specimen collection cellularity. STUDY DESIGN: Endocervical specimens for chlamydia testing (PACE 2, GenProbe, San Diego, CA) and for a slide cytologic examination (n = 3,500) were collected in parallel. A semi-quantitative cytologic examination to determine a specimen adequacy (SA) score was performed for every chlamydia-positive result (n = 163) and approximately every fifth negative result (n = 626). The Chi-square test for linear trends was used to assess the relationship between SA scores and chlamydia positivity. The median SA scores for chlamydia-positive and negative slides were compared. RESULTS: The median SA scores for chlamydia-positive and -negative slides were 27 and 20, respectively (P < 0.001). Chlamydia positivity rates increased with increasing specimen adequacy scores (0-9, 2.7%; 10-19, 15.1%; 20-29, 24.8%; and 30-45, 31.3%; Chi-square for linear trend: P < 0.001). CONCLUSION: These results demonstrate a linear relationship between the numbers of cells observed on an endocervical smear and chlamydia positivity rather than the threshold concept in practice. The semiquantitative cytologic technique offers an objective method for further evaluating specimen adequacy for Chlamydia trachomatis testing.

Vitamin A levels of blood in collared peccaries (Tayassu tajacu) from south Texas.

Serum vitamin A concentrations were determined for 24 adult female collared peccaries from 1 captive and 2 wild populations during the period 30 January-15 March, 1983. Normal serum vitamin A concentrations of well-fed captive peccaries (mean = 39.0 micrograms/dl) were slightly higher than the reported range of values for domestic swine. Mean vitamin A concentrations of blood serum did not differ among the captive and 2 wild populations. However, a few individuals from the wild populations had low serum levels of vitamin A which suggested a possible vitamin A deficiency for these females.