A high burden of asymptomatic genital tract infections undermines the syndromic management approach among adolescents and young adults in South Africa: implications for HIV prevention efforts

Table 4 Sex-stratified sensitivity analyses of syndromic screening for genital tract infections (GTIs) among sexually experienced, non-pregnant South African youth (aged 16–24 years) enrolled in the AYAZAZI study (n = 352)

Syndrome	Symptomatic	Laboratory test (gold standard)		Total	Sensitivity (%) [95% CI]	Specificity (%) [95% CI]	PPV (%) [95% CI]	NPV (%) [95% CI]
Syndrome	Symptomatic	Positive	Negative
Females (n = 198)
Vaginal discharge (VDS)^a	Yes	19	2	21	13.7	96.6	90.5	32.2
Vaginal discharge (VDS)^a	No	120	57	177	[8.4–20.5]	[88.2–99.6]	[69.6–98.8]	[25.4–39.6]
with cervical STIs as causative agents^b	Yes	7	14	21	11.7	89.9	33.3	70.1
with cervical STIs as causative agents^b	No	53	124	177	[4.8–22.6]	[83.6–94.3]	[14.6–57.0]	[62.7–76.7]
with vaginal STIs as causative agents^c	Yes	18	3	21	14.8	96.1	85.7	41.2
with vaginal STIs as causative agents^c	No	104	73	177	[9.0–22.3]	[88.9–99.2]	[63.7–97.0]	[33.9–48.9]
with only BV as a causative agent	Yes	14	7	21	13.3	92.5	66.7	48.6
with only BV as a causative agent	No	91	86	177	[7.5–21.4]	[85.1–96.9]	[43.0–85.4]	[41.0–56.2]
Lower abdominal pain (LAP)^d	Yes	4	9	13	7.0	93.4	30.8	70.6
Lower abdominal pain (LAP)^d	No	53	127	180	[1.9–17.0]	[87.8–97.0]	[9.1–61.4]	[63.3–77.1]
Males (n = 154)
Male urethritis (MUS)^e	Yes	0	1	1	0.0	99.3	0.0	89.5
Male urethritis (MUS)^e	No	16	137	153	[0–20.6]^g	[96.0–100.0]	[0–97.5]^g	[83.6–93.9]
Scrotal Swelling (SSW)^f	Yes	0	0	0	0.0	100.0	N/A	91.6
Scrotal Swelling (SSW)^f	No	13	141	154	[0–24.7]^g	[97.4–100.0]^g	[N/A]	[86.0–95.4]

Notes: GTIs included as the gold standard for VDS, LAP, MUS and SSW include (note: no sensitivity analysis was performed for GUD given testing via genital swabs and NAAT:
^aAny STI/GTI with VDS as a syndrome: N.gonorrhoeae, C.trachomatis, M.genitalium (cervical infection), T.vaginalis, BV, or C. albicans (vaginal infection);
^bAny cervical STI with VDS as a syndrome: N.gonorrhoeae, C.trachomatis, M.genitalium;
^cAny vaginal STI with VDS as a syndrome: T.vaginalis, BV, C. albicans;
^dAny STI/GTI with LAP as a syndrome: N.gonorrhoeae, C.trachomatis, M.genitalium
^eAny STI with MUS as syndrome: N.gonorrhoeae, C.trachomatis, M.genitalium, T.vaginalis;
^fAny STI with SSW as syndrome: N.gonorrhoeae, C.trachomatis;
^g1-sided 97.5% CI

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