Epidemiology of sexually transmitted infections in suspected child victims of sexual assault. Rebecca G Girardet, Sheela Lahoti, Laurie A Howard et al. Pediatrics 2009;124:79-86. (from Houston TX, Atlanta GA, Harrisburg PA and Brooklyn NY)
Review from Winter 2010 issue
The objectives of this article were to describe the epidemiology of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Treponema pallidum, human immunodeficiency virus (HIV), and Herpes simplex virus type 2 (HSV) infection in children who are sexually abused. Culture, serology, or nucleic acid amplification tests were used.
This is a multicenter study from the Centers for Disease Control and Prevention (CDC) of tertiary referral centers in four states — Texas, Georgia, Pennsylvania, and New York — where data were collected on children evaluated for suspected sexual abuse from January 2000 to September 2004. Boys and girls ages 0-13 were eligible if they met criteria that suggested they were at risk for a sexually transmitted infection (STI) according to the AAP 2005 guidelines. These criteria included those who had a complaint or suspicion of genital-genital or genital-anal contact; those with anogenital trauma or other findings suggestive of sexual contact; those who lived in households with other children with an STI; or those whose perpetrators were known to have an STI. All children with one or more risk factors were tested by a variety of methods.
Positive cultures for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) were confirmed by standard methods. Positive nucleic acid amplication tests (NAATs) for NG and CT were confirmed by a second NAAT, and polymerase chain reaction tests (PCR), as well as by additional genotypying at the CDC. For children who underwent venipuncture, additional serum was collected for HSV type specific immunodot enzyme assay of antibody (IgG). Non treponemal serologic tests for syphilis and HIV were performed. Wet mounts for Trichomonas vaginalis were done only when there was a vaginal discharge. When other suspicious lesions were present, cultures for HSV-2 or other genital ulcer disease pathogens was performed. The children’s genital findings were categorized according the Adams 1992 guidelines.
Of the 537 children analyzed for this study, 257 provided a “clear, credible, and detailed” description of molestation. Other children were examined because of a report made by another person, the presence of a vaginal discharge or other physical abnormality, and/or other significant concerns for STI.
Those who tested positive for one or more STI were 40 of 485 girls (8.2%). None of the 51 boys in the study tested positive for one or more STI. C. trachomatis was found in 15 girls; in eight of those it was found in a confirmed NAAT alone. There were two children who had culture and NAAT negative results from vaginal specimens but who had positive C. trachomatis anal cultures. One of these two girls was negative for all other STIs but the other was positive by culture and NAAT for vaginal and anal gonorrhea.
N . gonorrhoeae was detected in 16 girls (3.3%), four of whom were diagnosed by NAAT alone. All those with a positive vaginal culture for N. gonorrhoeae were also positive by NAAT. Seven girls (1.4%) had a positive culture and/or NAAT for both C. trachomatis and N. gonorrhoeae. Girls with a NAAT positive only for C. trachomatis were older than girls positive for only N. gonorrhoeae on NAAT alone. Only one child had a positive confirmed serologic test for syphilis and no child was positive for HIV. Twelve children had genital ulcers and five were positive for HSV-2 by culture. Serology for type-specific HSV antibody was present in 285 children. HSV-1 was detected in 129 and HSV-2 in seven. Only one of the children with positive culture on serology had a positive serology. No child with HSV-2 was also positive for C. trachomatis. Eighty-five girls had a wet mount for T. vaginalis, with five of those positive. Of all 40 children who tested positive for more than one STI, seven were confirmed only by NAAT.
Interestingly, there were geographic differences in prevalence, with the Atlanta site having a 7.8% prevalence of N. gonorrhoeae compared to the Texas site (1.7%). The study also evaluated previous maternal infection with either C. Trachomatis or N. gonorrhoeae. Mothers of six children, four of whom were older than three years, reported previous infection. In two children with N. gonorrhoeae, there was no history of maternal infection. No child with HSV-2 had a maternal history of HSV-2.
Thirty-three children had definite evidence of penetrating genital trauma based upon the 1992 classification. There was variability amongst the sites of the numbers of children with different categories of genital findings — normal, nonspecific, suspicious, suggestive, or clear evidence. Vaginal discharge, considered nonspecific, was reported in 53 girls, 10 with C. trachomatis, with four of those positive by culture and six by NAAT. For those with a discharge who were positive, eleven were by culture and 13 were by NAAT. Three with discharge had T. vaginalis on wet mount. Girls with a discharge were more likely to test positive for an STI. Eight girls who were positive for C. trachomatis and two who were positive for N. gonorrhoeae did not have a vaginal discharge, however.
The authors emphasized in the discussion that the prevalence of STI is low in children being evaluated for suspected sexual abuse, even when using highly sensitive detection methods. NAATs increased the detection of C. trachomatis two-fold and N. gonorrhoeae by about 1%. Because of the low prevalence of STIs, any positive NAAT should be confirmed by culture or another NAAT, according to the authors. No cases of pharyngeal gonorrhea and no boy with an STI was detected. The authors point out that decreasing rates of STIs in adults reflect the low prevalence in children. Most cases of gonorrhea occurred in children with nonspecific or normal findings. Males may not have been detected due the reliance on NAATs and due to the fact that fewer had rectal cultures.
Reviewed by Lori Frasier M.D.
One significant weakness of this study was the use of the 1992 Adams classification, with the variability between centers’ classification of “abnormal” findings probably reflecting its use rather than the use of a more current classification system. The development of a common classification system amongst the four sites would have made these data more valuable. That, however, was not the point of the study.
A take-home message from this study, which was not particularly well emphasized, was that NAATs could be used exclusively for genital sites if positives are confirmed with a second NAAT, using a different amplification method or targeting a different sequence. This is especially helpful in the case of C. trachomatis where cultures are increasingly difficult to obtain. The study reaffirms the importance of using guidelines in determining whom to test and at what sites, while understanding that only a few children will be positive for an STI without any physical indicators or symptoms of discharge.
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