Trichomonads are flagellated, pear-shaped, motile organisms that are somewhat larger than leukocytes. These parasites can readily be seen microscopically moving briskly in a sample mixed on a slide with saline. Prompt inspection of vaginal secretions is advantageous because trichomonads slow with cooling. At times, T vaginalis may be found incidentally on a Pap test slide. Both of these microscopic slide tests have low diagnostic sensitivity that approximates only 60 percent (Krieger, 1988; Wiese, 2000). And, Pap tests can yield false-positive results. Thus, Pap test trichomonad indings warrant wet-prep microscopy or other diagnostic confirmation (American College of Obstetricians and Gynecologists, 2017 c). Of other tests, culture is expensive, lengthy, and sensitivities are 75 to 95 percent (Association of Public Health Laboratories, 2016; Huppert, 2007). Laboratory NAA T analysis of a vaginal, endocervical, or urine sample is available, is completed in minutes to hours, and ofers superior sensitivity of95 to 100 percent (Schwebke, 2011; Van Der Pol, 2014). Rapid POC testing is also available but may sacriice sensitivity for speed. The OSOi Trichomonas Rapid Test provides results in 10 minutes, is suitable for oice use, and has sensitivities of 88 to 98 percent (Herbst de Cortina, 2016).
Metronidazole, administered orally in a single 2-g dose, is efective in eradicating T vaginalis. For those with HIV infection, treatment instead with metronidazole 500 mg orally twice daily for 7 days improves eicacy. Because of the high rate of reinfection among women treated for trichomoniasis, retesting for T vaginalis is recommended for all sexually active women within 3 months following initial treatment (Workowski, 2015).
Metronidazole, an FDA category B drug, is not teratogenic or fetotoxic, but has displayed some tumorigenicity in animal stud ies (Briggs, 2015; Czeizel, 1998). For this reason, the manufac turer recommends against its use during the irst trimester (Pfizer, 2016). Fewer data are available for tinidazole, which is a category
C drug, and thus metronidazole is preferred. vletronidazole and tinidazole have similar chemical structures, and those allergic to metronidazole may also react to tinidazole. For allergic patients, metronidazole desensitization is efective, and one scheme is out lined in the study by Helms and coworkers (2008). With post partum breastfeeding, feeds are delayed for 24 hours following the mation. For tinidazole, the delay is 72 hours.
Perinatal transmission of trichomoniasis by direct contact in the birth canal is rare but may lead to neonatal respiratory or genital infection (Bruins, 2013; Trintis, 2010). Some studies have linked trichomonal infection with preterm birth. A few other studies implicate this infection with preterm premature rupture of membranes and small-for-gestational age newborns (Silver, 2014). However, treatment did not lower preterm birth rates in a randomized study by Klebanof and colleagues (2001). Also, in this study, but not one by Mann and coworkers (2009), treatment for trichomoniasis was associated instead with a higher preterm birth rate.