Appendix C: STI Diagnostics
Rainbow Clinic for Abused Children, April 2020
Dr R Kularatne Department of Clinical Microbiology & Infectious Diseases WITS/NHLS October 2014
Laboratory Diagnosis of Sexually-Transmitted Infections (STIs) in Sexual Assault/Abuse of Children
The identification of sexually transmissible micro-organisms in children beyond the neonatal period suggests sexual abuse; however, the strength of association with child abuse varies by pathogen. Postnatally acquired gonorrhoea; syphilis; and non-transfusion, nonperinatally acquired HIV are usually diagnostic of sexual abuse. Rectal or genital infection with Chlamydia trachomatis among very young children might be the result of perinatally acquired infection and has, in some cases, persisted beyond infancy for as long as 2-3 years. Sexual abuse should be suspected when genital herpes is diagnosed. Anogenital warts, although suspicious for sexual abuse, have been diagnosed in children who have no other evidence of abuse. Bacterial vaginosis (BV) has been diagnosed in abused children, but its presence alone does not prove sexual abuse.
Implications of Common STIs in Children as Evidence of Sexual Abuse
| Syndrome | STI | Evidence for Sexual Abuse | Action |
| Anogenital discharge | Neisseria gonorrhoeae | Diagnostic | Report |
| Chlamydia trachomatis | Diagnostic (if unlikely to be perinatally acquired) | Report | |
| Trichomonas vaginalis | Highly suspicious | Report | |
| Bacterial vaginosis | Inconclusive | Medical follow-up | |
| Anogenital ulcers | Syphilis | Diagnostic | Report |
| Genital herpes | Suspicious | Report | |
| Anogenital warts | Condylomata accuminata | Suspicious | Report |
| HIV | HIV | Diagnostic (if unlikely to be vertically/perinatally or transfusion acquired | Report |
*Reports should be made to the agency mandated to receive reports of suspected child abuse
Laboratory Diagnosis of STIs in Child Sexual Abuse
Genital Discharge
Specimen Collection
- Boys: specimen collection from the urethra, anus +/- pharynx. For boys with a urethral discharge, a meatal specimen discharge is an adequate substitute for an intraurethral swab specimen. Alternatively, or additionally, a urine specimen could be collected.
- Girls: specimen collection from vagina and anus. Additionally, a urine specimen could be collected.
Laboratory Test Requests
- A cotton swab in Amies transport medium (medium contained within plastic sheath) should be sent for microscopy and culture/sensitivity (MC&S) to NHLS Helen Joseph Hospital, Microbiology. It should be transported at room temperature to the laboratory.
- A dry Dacron swab (metal shaft) and urine (if collected) should be sent for nucleic acid amplification testing (NAAT) to the NICD Centre for HIV & STIs. The swab should be placed in a sterile universal container, and a portion of the metal shaft cut so that the container can be closed tightly. It should be transported to the laboratory at 2°C to 30°C (i.e. at room temperature or on ice).
- Urine, if collected, should be transported in a sterile universal container to the NICD Centre for HIV & STIs at 2°C to 30°C (i.e. at room temperature or on ice).
The Laboratory Request Forms Should Specify
- Type of specimen (e.g. genital discharge; urine)
- Site of swab specimen (i.e. vaginal/ urethral/ pharyngeal/ anal)
- Indication for request (suspected child sexual abuse)
- Test request (i.e. MC&S or NAAT)
Tests Performed
- NHLS HJH Microbiology will report on the presence of the following:
- Microscopy: Trichomonas vaginalis, Bacterial Vaginosis, yeast, gram negative diplococci suggestive of Neisseria gonorrhoeae
- Culture: Neisseria gonorrhoeae, Candida species
- NICD Centre for HIV & STIs will perform the following assays:
- NAAT (Multiplex PCR) for Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis
- If multiplex PCR is positive, an additional confirmatory NAAT (e.g. APTIMA® assay) will be performed prior to reporting results.
Serology
Agents for which tests are available include Treponema pallidum (TPAT, RPR); HIV and Hepatitis B Virus (HBV). If initial exposure was recent, the infectious agents acquired through exposure might not result in positive results. A follow-up visit approximately 2 weeks after the most recent sexual exposure can include repeat physical examination and collection of additional specimens. Decisions regarding the agents for which to perform serological tests should be made on a case-by-case basis. If transmission of these agents is a concern but baseline tests are negative, repeat testing at 6 weeks, 3 months and 6 months after the last sexual exposure is recommended to allow time for antibodies to develop. Results of HBV testing (HBsAg) must be interpreted with caution as HBV can be transmitted non-sexually.
References
- 2010 STD Treatment Guidelines, CDC. http://www.cdc.gov/std/treatment/2010/sexual-assault.htm
- Standard Operating Protocols NHLS HJH Microbiology (MIC1732); NICD Centre for HIV & STIs (NIC0229; NIC0510; NIC0511)
Step by Step Guide to the Management of Child Abuse; Rainbow Clinic, RMMCH; Version: July 2023; Appendix C: STI Diagnostics