Prevalence and Predictors of Syphilis in Female Sex Workers in Eastern China: Findings from Six Consecutive Cross-Sectional Surveys

Figures & data

Table 1 Demographics of Female Sex Workers (FSWs) in Six Consecutive Cross-Sectional Surveys

		All FSWs	High-Grade FSWs	Low-Grade FSWs
		n (%)	n (%)	n (%)
Venues	High-grade places	1307(52.66)
	Low-grade places	1175(47.34)
Age (years)	≦20	653(26.31)	343(26.24)	310(26.38)
	21~25	744(29.98)	487(37.26)	257(21.87)
	26~30	479(19.30)	268(20.5)	211(17.96)
	>30	606(24.42)	209(15.99)	397(33.79)
Marital status	Single	1029(41.46)	605(46.29)	424(36.09)
	Married	1156(46.58)	522(39.94)	634(53.96)
	Cohabiting	216(8.70)	135(10.33)	81(6.89)
	Divorced & widowed	81(3.26)	45(3.44)	36(3.06)
Education	Primary school or below	803(32.35)	340(26.01)	463(39.4)
	Junior school	1459(58.78)	808(61.82)	651(55.4)
	High school or above	220(8.86)	159(12.17)	61(5.19)
Receipt of free condoms	Yes	1086(43.76)	633(48.43)	453(38.55)
	No	1396(56.24)	674(51.57)	722(61.45)
Peer education	Yes	1890(76.15)	985(75.36)	905(77.02)
	No	592(23.85)	322(24.64)	270(22.98)
Risk behaviors	Yes	1177(47.42)	622(47.59)	555(47.23)
	No	1305(52.58)	685(52.41)	620(52.77)
Knowledge awareness	Yes	2230(89.85)	1150(87.99)	1080(91.91)
	No	252(10.15)	157(12.01)	95(8.09)
Syphilis	Positive	107(4.31)	41(3.14)	66(5.62)
	Negative	2375(95.69)	1266(96.86)	1109(94.38)

Table 2 Knowledge, Behavioral, Intervention and Serological Characteristics of Female Sex Workers in Six Consecutive Cross-Sectional Surveys

	2014(N=407)	2015(N=403)	2016(N=403)	2017(N=426)	2018(N=440)	2019(N=403)	p value*	p value for Trend **
	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)
Receipt of free condoms	189(46.44)	200(49.63)	219(54.34)	274(64.32)	288(65.45)	226(56.08)	<0.01	<0.01
Peer education	29(7.13)	84(20.84)	105(26.05)	89(20.89)	134(30.45)	151(37.47)	<0.01	<0.01
Knowledge awareness	334(82.06)	353(87.59)	370(91.81)	396(92.96)	417(94.77)	360(89.33)	<0.01	<0.01
Risk behaviors	178(43.73)	237(58.81)	222(55.09)	218(51.17)	251(57.05)	199(49.38)	<0.01	0.326
Syphilis	13(3.19)	15(3.72)	14(3.47)	27(6.34)	20(4.55)	18(4.47)	0.254	0.162

Notes: *By Chi-square test. **Linear-by-linear association analysis by Chi-square test.

Table 3 Comparison of Demographic and Behavioral Characteristics of Syphilis Positive and Syphilis Negative Female Sex Workers

		All FSWs		High-Grade FSWs		Low-Grade FSWs
		Syphilis Positive (N=107)	p value	Syphilis Positive (N=41)	p value	Syphilis Positive (N=66)	p value
		n(Prevalence %)		n(Prevalence %)		n(Prevalence %)
Age (years)	≦20	22(3.37)	0.059	8(2.33)	0.181	14(4.52)	0.711
	21~25	26(3.49)		12(2.46)		14(5.45)
	26~30	22(4.59)		10(3.73)		12(5.69)
	>30	37(6.11)		11(5.26)		26(6.55)
Marital status	Single	35(3.40)	0.002	16(2.64)	0.034	19(4.48)	0.025
	Married	58(5.02)		22(4.21)		36(5.68)
	Cohabiting	5(2.31)		0(0.00)		5(6.17)
	Divorced&widowed	9(11.11)		3(6.67)		6(16.67)
Education	Primary school or below	48(5.98)	0.011	18(5.29)	0.02	30(6.48)	0.584
	Junior school	54(3.70)		21(2.60)		33(5.07)
	High school or above	5(2.27)		2(1.26)		3(4.92)
Receipt of free condoms	Yes	36(3.31)	0.031	15(2.37)	0.123	21(4.64)	0.247
	No	71(5.09)		26(3.86)		45(6.23)
Peer education	Yes	75(3.97)	0.133	30(3.05)	0.741	45(4.97)	0.079
	No	32(5.41)		11(3.42)		21(7.78)
Risk behaviors	Yes	56(4.76)	0.298	20(3.22)	0.877	36(6.49)	0.221
	No	51(3.91)		21(3.07)		30(4.84)
Knowledge awareness	Yes	92(4.13)	0.176	34(2.96)	0.311	58(5.37)	0.216
	No	15(5.95)		7(4.46)		8(8.42)

Figure 1 Syphilis prevalence in female sex workers (FSWs) from 2014 to 2019.

Note: *Significant difference (p < 0.05) between high- and low-grade FSWs.

Table 4 Odds Ratios (OR) and 95 Confidence Intervals (CI) of Syphilis Among All Female Sex Workers (FSWs) and According to Location of Venues

Items		All FSWs		High-Grade FSWs		Low-Grade FSWs
		OR(95% CI)	p value	OR(95% CI)	p value	OR(95% CI)	p value
Venues	High-grade places	Ref		–		–
	Low-grade places	1.76(1.18–2.63)	0.006
Marital status	Single	0.29(0.13–0.62)	0.001	–		0.24(0.09–0.63)	0.004
	Married	0.4(0.19–0.84)	0.015			0.3(0.12–0.77)	0.012
	Cohabiting	0.2(0.06–0.61)	0.005			0.33(0.09–1.16)	0.084
	Divorced & widowed	Ref				Ref
Education	Primary school or below	–		4.39(1.01–19.15)	0.049	–
	Junior school			2.1(0.49–9.02)	0.321
	High school and above			Ref

Notes: The following potential risk factors were in the full model: venues, age, marital status, education, receipt of free condoms, peer education, knowledge awareness, risk behaviors. Odds ratios and 95 confidence intervals adjusted for the potential risk factors that were statistically significant in the three different logistic models.

Abbreviations: OR, odds ratio; CI, confidence interval.