MRSA: rare in the vagina.

STUDY OBJECTIVE: To determine the prevalence of vaginal Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in sexually active adolescent women. DESIGN: A prospective surveillance study. PARTICIPANTS: Patients included 315 sexually active young women (ages 13-24) undergoing routine pelvic examination and wet mount testing in an urban teen health center. MAIN OUTCOME MEASURES: Prevalence of vaginal S. aureus and MRSA. RESULTS: S. aureus was present in 16 samples for a point estimate of 5.1% (95% CI: 2.6%-7.5%). MRSA was detected in two samples, giving a vaginal prevalence estimate of 0.6% (95% CI: 0.0% -1.5%). No differences were detected in the prevalence of S. aureus by age or race, although no cases of S. aureus were observed in those under age 15. CONCLUSION: The prevalence of MRSA in a sample of sexually active adolescents was as rare as reported in other populations. It is unlikely that vaginal MRSA is a reservoir for community acquired infections.

Photoperiodic regulation of the orexigenic effects of ghrelin in Siberian hamsters.

Animals living in temperate climates with predictable seasonal changes in food availability may use seasonal information to engage different metabolic strategies. Siberian hamsters decrease costs of thermoregulation during winter by reducing food intake and body mass in response to decreasing or short-day lengths (SD). These experiments examined whether SD reduction in food intake in hamsters is driven, at least in part, by altered behavioral responses to ghrelin, a gut-derived orexigenic peptide which induces food intake via NPY-dependent mechanisms. Relative to hamsters housed in long-day (LD) photoperiods, SD hamsters consumed less food in response to i.p. treatment with ghrelin across a range of doses from 0.03 to 3 mg/kg. To determine whether changes in photoperiod alter behavioral responses to ghrelin-induced activation of NPY neurons, c-Fos and NPY expression were quantified in the arcuate nucleus (ARC) via double-label fluorescent immunocytochemistry following i.p. treatment with 0.3 mg/kg ghrelin or saline. Ghrelin induced c-Fos immunoreactivity (-ir) in a greater proportion of NPY-ir neurons of LD relative to SD hamsters. In addition, following ghrelin treatment, a greater proportion of ARC c-Fos-ir neurons were identifiable as NPY-ir in LD relative to SD hamsters. Changes in day length markedly alter the behavioral response to ghrelin. The data also identify photoperiod-induced changes in the ability of ghrelin to activate ARC NPY neurons as a possible mechanism by which changes in day length alter food intake.

Stepwise diagnosis of Trichomonas vaginalis infection in adolescent women.

The objective of this study was to examine the effects of clinical factors and of the type and timing of a secondary test in improving the sensitivity of Trichomonas vaginalis detection in young women over that of a wet mount alone. For this purpose, sexually active adolescent women (n = 345) were recruited from a hospital teen clinic or emergency department. Following an interview and a pelvic exam, four primary T. vaginalis tests (wet mount, culture, a rapid test, and a nucleic acid amplification test [NAAT]) were performed on vaginal swabs. If the wet-mount result was negative, two secondary tests (culture and a rapid test) were performed on the used wet-mount swab and saline. A positive result by any of the four primary tests was considered a true T. vaginalis-positive result. The prevalence of T. vaginalis was 18.8% overall and 8.8% in the 307 wet-mount-negative women. There was 100% concordance between primary and secondary rapid tests. Secondary culture was 80% sensitive compared to primary culture. The likelihood of a positive rapid test increased with increasing time between specimen collection and testing. A wet mount followed by a rapid test was the most sensitive strategy using two tests (86.4%; confidence interval [CI], 75.3 to 93.4%). Limiting secondary testing to those with multiple partners resulted in a lower sensitivity (73.9%; CI, 61.5 to 84%) that was not significantly better than that of the wet mount alone (58.5%; CI, 45.6 to 70.6%). We conclude that a rapid test can be delayed or performed on a used swab with no loss of sensitivity. Until a NAAT for T. vaginalis is commercially available, a stepwise approach using an additional rapid test for wet-mount-negative women is recommended for adolescent women regardless of clinical factors.