Table 1.

The Prevalence of Syphilis Among Blood Donors

Group			2013	2014	2015	2016	2017	2018	2019	2020
Gender	Male	Positive	187	222	228	235	187	172	159	165
		Total	40384	42,363	46,024	48,304	54,322	53,969	58,035	59,092
		Prevalence	0.46%	0.52%	0.50%	0.49%	0.34%	0.32%	0.27%	0.28%
	Female	Positive	149	165	166	157	141	105	133	89
		Total	23678	25,967	26,883	29,297	28,649	30,824	34,060	33,980
		Prevalence	0.63%	0.64%	0.62%	0.54%	0.49%	0.34%	0.39%	0.26%
	χ2		7.904	3.546	4.707	0.885	10.423	0.261	9.219	0.237
	P value		0.005	0.060	0.030	0.347	0.001	0.609	0.002	0.626
Region	Local	Positive	45	50	45	66	55	43	36	37
		Total	17073	16,207	17,417	17,969	20,667	21,393	22,759	26,967
		Prevalence	0.26%	0.31%	0.26%	0.37%	0.27%	0.20%	0.16%	0.14%
	Foreign	Positive	291	337	349	326	273	234	256	217
		Total	46860	52,034	55,396	59,488	62,193	63,377	69,262	66,110
		Prevalence	0.62%	0.65%	0.63%	0.55%	0.44%	0.37%	0.37%	0.33%
	χ2		30.579	25.207	34.006	8.950	11.752	13.896	24.210	25.685
	P value		<0.001	<0.001	<0.001	0.003	0.001	<0.001	<0.001	<0.001
Donation history	First-time	Positive	311	361	370	370	302	260	273	229
		Total	55358	59,699	63,858	66,965	71,651	72,771	78,802	43,012
		Prevalence	0.56%	0.60%	0.58%	0.55%	0.42%	0.36%	0.35%	0.53%
	Repeat	Positive	25	26	24	22	26	17	19	25
		Total	8704	8631	9049	10,636	11,320	12,022	13,293	50,065
		Prevalence	0.29%	0.30%	0.27%	0.21%	0.23%	0.14%	0.14%	0.05%
	χ2		10.868	12.331	14.556	21.822	9.134	14.767	14.904	197.891
	P value		0.001	<0.001	<0.001	<0.001	0.003	<0.001	<0.001	<0.001
Education level	Lower	Positive	233	288	308	295	248	207	218	191
		Total	35061	38,983	42,131	43,670	44,792	45,103	47,924	43,447
		Prevalence	0.80%	0.98%	1.00%	0.87%	0.65%	0.52%	0.45%	0.44%
	Higher	Positive	103	99	86	97	80	70	74	63
		Total	28972	29,337	30,772	33,913	38,164	39,685	44,160	49,304
		Prevalence	0.29%	0.25%	0.20%	0.22%	0.18%	0.16%	0.17%	0.13%
	χ2		29.025	47.868	67.465	57.665	61.936	51.760	60.020	82.235
	P value		<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Age	18–29	Positive	82	102	101	93	64	74	66	65
		Total	9124	14,208	19,309	22,431	25,174	30,674	36,741	36,381
		Prevalence	0.90%	0.72%	0.52%	0.41%	0.25%	0.24%	0.18%	0.18%
	30–39	Positive	138	147	137	132	107	83	82	65
		Total	27513	28,234	27,840	28,718	29,815	28,374	28,997	29,751
		Prevalence	0.50%	0.52%	0.49%	0.46%	0.36%	0.29%	0.28%	0.22%
	40–49	Positive	100	118	128	139	122	89	95	90
		Total	18126	17,193	17,159	17,842	18,898	17,652	18,444	18,914
		Prevalence	0.55%	0.69%	0.75%	0.78%	0.65%	0.50%	0.52%	0.48%
	50–60	Positive	16	20	28	28	35	31	49	34
		Total	9299	8695	8599	8610	9084	8093	7913	7995
		Prevalence	0.17%	0.23%	0.33%	0.33%	0.39%	0.38%	0.62%	0.43%
	χ2		47.163	28.702	22.187	37.024	43.812	25.765	68.773	50.532
	P value		<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Notes: The prevalence among different groups of blood donors= Positive number of this group/Total number of this group.