Sociodemographic characteristics
A total of 1,207 participants were recruited in this survey and included in the analysis. The mean age was 30.7 ± 6.8 years. The majority of the participants were between 25 and 30 years old (30.6%, 369/1207), married (63.1%, 762/1207), had a monthly income between $500-$1000 (56.8%, 686/1207) and worked in the current location over one year (61.2%,738/1207). Almost three-fourths (77.6%, 936/2107) of participants' household registrations were in other provinces. (Table 1 )
Table 1
Social demographic and sexual behavioral characteristics of participants among FSW in Southern China, 2018 (N = 1207)
Characteristics
|
Gonorrhea testing in the past twelve months n (%)
|
Chlamydia testing
in the past twelve months n (%)
|
Total
|
No
(n = 1117)
|
Yes
(n = 90)
|
P
|
No
(n = 1082)
|
Yes
(n = 125)
|
P
|
Age(years)
|
|
|
< 0.001
|
|
|
< 0.001
|
|
18–25
|
182(16.3)
|
19(21.1)
|
|
177(16.4)
|
24(19.2)
|
|
201(16.7)
|
26–29
|
356(31.9)
|
13(14.4)
|
|
345(31.9)
|
24(19.2)
|
|
369(30.6)
|
30–34
|
299(26.8)
|
15(16.7)
|
|
292(27)
|
22(17.6)
|
|
314(26.0)
|
≥ 35
|
280(25.1)
|
43(47.8)
|
|
268(24.8)
|
55(44.0)
|
|
323(26.7)
|
Workplace
|
|
|
0.040
|
|
|
0.003
|
|
Middle tier
|
128(11.5)
|
4(4.4)
|
|
128(11.8)
|
4(3.2)
|
|
132(10.9)
|
Low tier
|
989(88.5)
|
86(95.6)
|
|
954(88.2)
|
121(96.8)
|
|
1075(89.1)
|
Ethnicity
|
|
|
0.002
|
|
|
0.004
|
|
Han
|
1011(90.5)
|
72(80.0)
|
|
980(90.6)
|
103(82.4)
|
|
1083(89.7)
|
Non-Han
|
106(9.5)
|
18(20.0)
|
|
102(9.4)
|
22(17.6)
|
|
124(10.3)
|
Marital status
|
|
|
< 0.001
|
|
|
0.004
|
|
Not married
|
315(28.2)
|
26(28.9)
|
|
303(28)
|
38(30.4)
|
|
341(28.3)
|
Married
|
717(64.2)
|
45(50.0)
|
|
700(64.7)
|
62(49.6)
|
|
762(63.2)
|
Divorced or widowed
|
84(7.5)
|
19(21.1)
|
|
78(7.2)
|
25(20.0)
|
|
103(8.5)
|
Household registration
|
|
0.071
|
|
|
< 0.001
|
|
Local city
|
75(6.7)
|
11(12.2)
|
|
67(6.2)
|
19(15.2)
|
|
86(7.1)
|
Other cities in this province
|
168(15.0)
|
17(18.9)
|
|
153(14.1)
|
32(25.6)
|
|
185(15.3)
|
Other provinces
|
874(78.2)
|
62(68.9)
|
|
862(79.7)
|
74(59.2)
|
|
936(77.6)
|
Monthly income (USD)
|
|
0.017
|
|
|
0.001
|
|
<$500
|
260(23.3)
|
33(36.7)
|
|
246(22.7)
|
47(37.6)
|
|
293(24.3)
|
$500-$1000
|
644(57.7)
|
42(46.7)
|
|
627(57.9)
|
59(47.2)
|
|
686(56.8)
|
>$1000
|
213(19.1)
|
15(16.7)
|
|
209(19.3)
|
19(15.2)
|
|
228(18.9)
|
Education level
|
|
|
0.669
|
|
|
0.272
|
|
Illiterate or elementary school
|
287(25.7)
|
27(30.0)
|
|
284(26.2)
|
30(24.0)
|
|
314(26.0)
|
Junior high school
|
737(66)
|
56(62.2)
|
|
713(65.9)
|
80(64.0)
|
|
793(65.7)
|
High school and above
|
93(8.3)
|
7(7.8)
|
|
85(7.9)
|
15(12.0)
|
|
100(8.3)
|
Length of time working in current location
|
< 0.001
|
|
|
< 0.001
|
|
One year and above
|
665(59.5)
|
73(81.1)
|
|
634(58.6)
|
104(83.2)
|
|
738(61.2)
|
6–12 months
|
267(23.9)
|
15(16.7)
|
|
264(24.4)
|
18(14.4)
|
|
282(23.4)
|
< 6 months
|
184(16.5)
|
2(2.2)
|
|
183(16.9)
|
3(2.4)
|
|
186(15.4)
|
Average number of clients in the past month
|
< 0.001
|
|
|
< 0.001
|
|
<=30
|
626(56.0)
|
32(35.5)
|
|
612(56.5)
|
46(36.8)
|
|
658(54.5)
|
31–60
|
352(31.5)
|
51(56.7)
|
|
333(30.8)
|
70(56.0)
|
|
403(33.4)
|
> 60
|
139(12.4)
|
7(7.8)
|
|
137(12.7)
|
9(7.2)
|
|
146(12.1)
|
Consistent condom uses with clients in the past month
|
0.969
|
|
|
0.099
|
|
No
|
387(34.6)
|
31(34.4)
|
|
383(35.4)
|
35(28.0)
|
|
418(34.6)
|
Yes
|
730(65.4)
|
59(65.6)
|
|
699(64.6)
|
90(72.0)
|
|
789(65.4)
|
Providing anal sex for clients
|
< 0.001
|
|
|
< 0.001
|
|
No
|
903(80.8)
|
57(63.3)
|
|
889(82.2)
|
71(56.8)
|
|
960(79.5)
|
Yes
|
214(19.2)
|
33(36.7)
|
|
193(17.8)
|
54(43.2)
|
|
247(20.5)
|
Regular partner (boyfriend or husband)
|
0.153
|
|
|
0.015
|
|
No
|
273(24.4)
|
16(17.8)
|
|
270(25)
|
19(15.2)
|
|
289(24.0)
|
Yes
|
843(75.5)
|
74(82.2)
|
|
811(75)
|
106(84.8)
|
|
917(76.0)
|
HIV testing in the past twelve months
|
< 0.001
|
|
|
< 0.001
|
|
No
|
782(70.0)
|
31(34.4)
|
|
773(71.4)
|
40(32.0)
|
|
813(67.4)
|
Yes
|
335(30.0)
|
59(65.6)
|
|
309(28.6)
|
85(68.0)
|
|
394(32.6)
|
Syphilis testing in the past twelve months
|
< 0.001
|
|
|
< 0.001
|
|
No
|
778(69.7)
|
33(36.7)
|
|
777(71.8)
|
34(27.2)
|
|
811(67.2)
|
Yes
|
339(30.3)
|
57(63.3)
|
|
305(28.2)
|
91(72.8)
|
|
396(32.8)
|
STD symptoms in the past twelve months
|
< 0.001
|
|
|
< 0.001
|
|
No
|
665(59.5)
|
11(12.2)
|
|
659(60.9)
|
17(13.6)
|
|
676(56.0)
|
Yes
|
452(40.5)
|
79(87.8)
|
|
423(39.1)
|
108(86.4)
|
|
531(44.0)
|
Sexual behaviors
The median number of clients in the past month was 28.0(16.0–40.0). Most participants always used condoms when having sex with clients in the past month (65.4%, 789/1207) and had a regular partner (76.0%, 917/1207). One-fifth (20.5%, 247/1207) of the participants had ever provided anal sex for clients. Approximately half (44.0%, 531/1207) of the participants had STD-related symptoms over the past twelve months. (Table 1)
Chlamydia and gonorrhea testing
The testing rate of gonorrhea and chlamydia in the past twelve months were 7.5% (90/1207) and 10.4% (125/1297). Seventy-five (6.2%, 75/1207) participants were tested for both gonorrhea and chlamydia within the past twelve months. Additionally, the testing rate of HIV and syphilis were 32.6% (394/1207) and 32.8% (396/1207) in the past year. (Fig. 1)
Factors correlated with chlamydia testing
In the multivariable analysis, chlamydia testing is positively correlated with low titer (adjusted Odds Ratio (aOR) = 3.53, 95%CI:1.23–10.14), number of clients in the past month (aOR = 1.03, 95%CI:1.01–1.05), consistent condom use with clients in the past month (aOR = 1.79 95%CI:1.12–2.86), providing anal sex for clients (aOR = 2.36, 95%CI:1.54–3.60), having regular partners (aOR = 3.12, 95%CI:1.72–5.68), having STD symptoms in the past twelve months (aOR = 4.09, 95%CI:2.62–6.40), having HIV testing in the past twelve months (aOR = 5.16, 95%CI:3.21–8.30), and having syphilis testing in the past twelve months (aOR = 6.90, 95%CI:4.21–11.22) after adjusting for age, ethnicity, marital status, education level, marital status, monthly income, household registration, and length of time working in the current location. (Table 2)
Table 2
Factors associated with chlamydia testing among FSW in Southern China, 2018 (N = 1207)
Characteristics
|
Crude Model
|
Adjusted Model#
|
OR (95%CI)
|
P
|
OR (95%CI)
|
P
|
Workplace
|
Middle tier
|
Ref
|
-
|
Ref
|
-
|
Low tier
|
4.06(1.47 ~ 11.18)
|
0.007
|
3.53(1.23 ~ 10.14)
|
0.019
|
Average number of clients in the past month (continue variable)
|
|
1.04(1.01 ~ 1.07)
|
0.041
|
1.03(1.01 ~ 1.05)
|
0.043
|
Consistent condom uses with clients in the past month
|
No
|
Ref
|
|
Ref
|
|
Yes
|
1.41(0.93 ~ 2.13)
|
0.101
|
1.79(1.12 ~ 2.86)
|
0.016
|
Providing anal sex for clients
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
3.50(2.38 ~ 5.16)
|
< 0.001
|
2.36(1.54 ~ 3.60)
|
< 0.001
|
Regular partner (boyfriend or husband)
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
1.86(1.12 ~ 3.09)
|
0.017
|
3.12(1.72 ~ 5.68)
|
0.002
|
STD symptoms in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
5.44(3.66 ~ 8.09)
|
< 0.001
|
4.09(2.62 ~ 6.40)
|
< 0.001
|
HIV testing in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
5.32(3.57 ~ 7.92)
|
< 0.001
|
5.16(3.21 ~ 8.30)
|
< 0.001
|
Syphilis testing in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
6.82(4.5 ~ 10.33)
|
< 0.001
|
6.90(4.21 ~ 11.22)
|
< 0.001
|
Note: # Model adjusted for age, ethnicity, marital status, education level, marital status, monthly income, household registration and length of time working in current location |
Factors correlated with gonorrhea testing
In the multivariable analysis, gonorrhea testing was positively correlated with number of clients in the past month (aOR = 1.02, 95% CI:1.00-1.04), providing anal sex for clients (aOR = 1.82; 95% CI: 1.11–2.96), having regular partners (aOR = 2.59, 95% CI: 1.35–4.99), having STD symptoms over the past twelve months (aOR = 3.33, 95% CI: 2.03–5.46), HIV testing in the past twelve months (aOR = 3.94, 95% CI: 2.34–6.65) and syphilis testing in the past twelve months (aOR = 3.27, 95% CI: 1.96–5.46) after adjusting for age, ethnicity, marital status, education level, marital status, monthly income, household registration, and length of time working in the current location. (Table 3)
Table 3
Factors associated with gonorrhea testing among FSW in Southern China, 2018 (N = 1207)
Characteristics
|
Crude Model
|
Adjusted Model#
|
OR (95%CI)
|
P
|
OR (95%CI)
|
P
|
Workplace
|
Middle-level venue
|
Ref
|
|
Ref
|
|
Low-level venue
|
2.78(1.01 ~ 7.70)
|
0.049
|
1.95(0.68 ~ 5.59)
|
0.216
|
Average number of clients in the past month (continue variable)
|
|
1.02(1.00 ~ 1.04)
|
0.043
|
1.02(1.00 ~ 1.04)
|
0.045
|
Consistent condom uses with clients in the past month
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
1.01(0.64 ~ 1.59)
|
0.969
|
1.15(0.69 ~ 1.92)
|
0.583
|
Providing anal sex for clients
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
2.44(1.55 ~ 3.85)
|
0.001
|
1.82(1.11 ~ 2.96)
|
0.017
|
Regular partner (boyfriend or husband)
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
1.50(0.86 ~ 2.62)
|
0.155
|
2.59(1.35 ~ 4.99)
|
0.004
|
STD symptoms in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
4.03(2.58 ~ 6.29)
|
< 0.001
|
3.33(2.03 ~ 5.46)
|
< 0.001
|
HIV testing in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
5.32(3.57 ~ 7.92)
|
< 0.001
|
3.94(2.34 ~ 6.65)
|
< 0.001
|
Syphilis testing in the past twelve months
|
No
|
Ref
|
-
|
Ref
|
-
|
Yes
|
6.82(4.5 ~ 10.33)
|
< 0.001
|
3.27(1.96 ~ 5.46)
|
< 0.001
|
Note: # Model adjusted for age, ethnicity, marital status, education level, marital status, monthly income, household registration, length of time working in the current location |