Investigations
1st investigations to order
forensic specimens
Test
Forensic specimens that can be used to identify the perpetrator include blood, hair strands and combings, fingernail, pharyngeal, genital, and anal swabs, and clothing and bedding from the time of offence.
A forensic examination should be strongly considered for any child, adolescent, or adult, and undertaken as soon as practicable. The recommended timing of the examination depends on the sample type and local jurisdictions; paediatricians should familiarise themselves with their relevant policy. Most protocols recommend that forensic evidence should be collected if less than 72 hours have passed since the assault, but some are as late as 168 hours.[34][38][49]
Result
specimens may identify the perpetrator
testing for Neisseria gonorrhoeae
Test
Culture and nucleic acid amplification test (NAAT) are recommended for detecting genitourinary infection with N gonorrhoeae in adults and adolescents.[47] NAATs are sensitive and less invasive and they can be carried out on a self-taken vulvovaginal swab or a first-catch urine specimen.
Although evidence of the use of NAATs in children is limited, they can be used to test for N gonorrhoeae from vaginal and urine specimens in children.[47][48] Confirmation of positive NAAT results should be undertaken using a different NAAT.[48] Culture can be used to test urogenital and extragenital sites for children.[47]
Result
positive in gonorrhoea infection
testing for Chlamydia trachomatis
Test
Nucleic acid amplification tests (NAATs) for C trachomatis are the most sensitive tests for vaginal, cervical, or urethral specimens, and are the test of choice for adults, adolescents, and children.[47][48] NAATs are the most sensitive tests for these specimens and can be carried out on a self-taken vulvovaginal swab or a first-catch urine specimen
A positive result is diagnostic of sexual contact if perinatal transmission is excluded.
Result
positive in chlamydia infection
serological tests for syphilis
Test
A positive result is diagnostic of sexual contact if perinatal transmission is excluded.
Result
positive in syphilis
serological tests for hepatitis B
Test
For children and adolescents in countries with universal vaccination for hepatitis B, testing for hepatitis B antibodies is usually not required. In countries without universal vaccination, or if there is no record of hepatitis B vaccination, a test for hepatitis antibodies is required to determine the need for hepatitis B immunoglobulin or vaccine.
Result
positive HBsAG
HIV serology
Test
A positive result is diagnostic of sexual contact if perinatal and percutaneous transmission are excluded. Percutaneous exposure may occur from blood transfusion, medical or surgical procedures, or injecting drug use.
A baby born to a mother with HIV may be HIV antibody positive until 12 to 18 months following birth, owing to passive transmission of maternal antibodies across the placenta.
Result
positive in HIV infection
urine beta human chorionic gonadotrophin
Test
A positive result in a pregnant adolescent female indicates sexual contact.
Result
positive in pregnancy
testing for trichomonas
Test
A positive result is diagnostic of sexual contact.
Result
positive in trichomoniasis
anogenital culture: herpes simplex virus polymerase chain reaction (PCR)
Test
A positive result is suggestive of sexual contact.
Result
positive in herpes simplex virus infection
LFT
Test
LFTs should be obtained at baseline and during prophylactic therapy, as prophylaxis medications have significant adverse effects and can affect liver function.
Result
normal prior to commencing HIV post-exposure prophylaxis
creatinine
Test
Tests of renal function should be obtained at baseline and during prophylactic therapy, as prophylaxis medications have significant adverse effects and can affect renal function.
Result
normal prior to commencing HIV post-exposure prophylaxis
urea
Test
Tests of renal function should be obtained at baseline and during prophylactic therapy, as prophylaxis medications have significant adverse effects and can affect renal function.
Result
normal prior to commencing HIV post-exposure prophylaxis
FBC
Test
Tests of haematological parameters should be obtained at baseline and during prophylactic therapy, as prophylaxis medications have significant adverse effects and can affect parameters of the FBC.
Result
normal prior to commencing HIV post-exposure prophylaxis
Investigations to consider
HIV confirmatory test
Test
A confirmatory test on a separate blood sample should be carried out on all individuals for whom initial HIV tests are positive. A positive result confirms infection and is diagnostic of sexual contact if perinatal and percutaneous transmission are excluded.
Result
positive in HIV infection
HIV RNA PCR
Test
Positive result confirms infection and is diagnostic of sexual contact if perinatal and percutaneous transmission are excluded.
Result
positive in HIV infection
Treponema pallidum haemagglutination assay for syphilis
Test
A positive result confirms infection and is diagnostic of sexual contact if perinatal transmission is excluded.
Result
positive in syphilis
serum rapid plasma reagin for syphilis
Test
A positive result indicates infection and, if supported by a confirmatory test, is diagnostic of sexual contact if perinatal transmission is excluded.
False positive results can occur: for example, in pregnancy or autoimmune disease.
Result
positive in syphilis
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