Trichomonas vaginalis prevalence, incidence, risk factors and antibiotic-resistance in an adolescent population.
OBJECTIVE
To determine the prevalence and incidence of trichomoniasis, risk factors for infection, and the prevalence of metronidazole and tinidazole-resistant Trichomonas vaginalis (T. vaginalis) in female adolescents.


METHODS
Nonpregnant, HIV-seronegative, sexually active females (13-19 years) visiting an inner city public primary care clinic were tested for T. vaginalis by wet mount and culture, and interviewed about risk-taking behavior every 6 months. Infected patients were treated with a 2 g oral dose of metronidazole. Isolates from positive T. vaginalis cultures were tested for in vitro resistance to metronidazole and tinidazole.


RESULTS
Among 467 study participants, 67 (14.4%; 95% confidence interval, 11.3-17.5) were diagnosed with trichomoniasis at first T. vaginalis culture. Significant risk factors for T. vaginalis infection were having an older sex partner and concurrent Neisseria gonorrhoeae infection. The incidence was 22.1 cases per 100 person-years. Among 42 participants who had a prevalent infection and returned for followup, 13 (31.0%) had at least 1 more episode of trichomoniasis. Resistance testing was completed for 78 isolates: 37 at first visit and 41 during follow-up. One (2.7%; 95% confidence interval, 0.07-14.2) of the 37 first-visit isolates was moderately resistant to metronidazole (minimal lethal concentration = 200 microg/mL). Of the 41 follow-up visit isolates, 1 was moderately resistant to metronidazole and 2 had borderline resistance (minimal lethal concentration = 50 microg/mL). The prevalence of tinidazole resistance was 0% (0.0%-9.5%).


CONCLUSIONS
The study population had high prevalence and incidence of trichomoniasis. The prevalence of antibiotic-resistant T. vaginalis among female adolescents was low.
Krashin
Jamie W
JW
Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Koumans
Emilia H
EH
Bradshaw-Sydnor
Ayanna C
AC
Braxton
Jim R
JR
Evan Secor
W
W
Sawyer
Mary K
MK
Markowitz
Lauri E
LE
D000293:Adolescent; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D004351:Drug Resistance; D005260:Female; D006801:Humans; D015994:Incidence; D008795:Metronidazole / Q000494:pharmacology; D021261:Parasitic Sensitivity Tests; D015995:Prevalence; D011739:Pyrimethamine / Q000494:pharmacology; D012307:Risk Factors; D012747:Sexual Partners; D014245:Trichomonas Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology; D014247:Trichomonas Vaginitis / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology; D014246:Trichomonas vaginalis / Q000187:drug effects* / Q000302:isolation & purification; D055815:Young Adult
D000981:Antiprotozoal Agents; D008795:Metronidazole; D011739:Pyrimethamine