Cost-effective screening for Trichomoniasis. (Letters).

To the Editor: I read with interest a recent article in your journal, "Trichomonas vaginalis, HIV, and African Americans" (1), and I commend the authors' suggestion to implement screening and reporting of trichomoniasis for high-risk populations.

In the article, a cost-effective screening approach is mentioned, which includes culturing only for those women whose wet-mount tests are negative. In 1999, my colleagues and I reported on the validity of this method for diagnosing trichomoniasis in women (2). During our study, an additional vaginal swab was collected during the pelvic examination and placed into a glass tube. If the wet mount was negative, this swab was later added to a culture pouch for T. vaginalis. We found no statistically significant difference in the sensitivity of this method compared with that of adding swabs immediately to pouches at bedside. This method of delaying the second test until the results of the first test are known should be considered in screening women for trichomoniasis, especially in high-prevalence populations.

Jane R. Schwebke

University of Alabama at Birmingham, Birmingham, Alabama, USA

References

(1.) Sorvillo F, Smith L, Kerndt P, Ash L. Trichomonas vaginalis, HIV, and African Americans. Emerg Infect Dis 2001;7:927-32.

(2.) Schwebke JR, Venglarik MF, Morgan SC. Delayed versus immediate bedside inoculation of culture media for diagnosis of vaginal trichomonosis. J Clin Microbiol 1999;37:2369-70.

Reply to Dr. Schwebke

To the Editor: We welcome Dr. Schwebke's thoughtful comments about decreasing the cost of screening for Trichomonas vaginalis. Dr. Schwebke and her colleagues have demonstrated that storing a vaginal swab for 15-20 minutes in a glass tube at room temperature does not affect the viability of T. vaginalis or reduce the sensitivity of subsequent culture. This finding shows that vaginal swabs may be stored briefly while a wet-mount preparation is made and examined. If the wet mount is negative for T. vaginalis, the stored swab can then be processed for culture. If the wet mount is positive for T. vaginalis, no further culture of the specimen is needed, thereby reducing unnecessary costs. Given that the prevalence of this infection olden exceeds 20% in high-risk populations, this approach can reduce costs substantially without compromising the accuracy of the tests. Any method that reduces the cost of diagnosis will advance further screening for trichomoniasis and promote the ultimate goal of implementing intervention efforts.

Frank Sorvillo, * ([dagger]) Lisa Smith, * ([dagger]) and Peter Kerndt ([dagger])

* University of California at Los Angeles, Los Angeles, California, USA; and ([dagger]) Department of Health Services, Los Angeles County, Los Angeles, California, USA