Table 1. Demographic characteristics of the reported vivax malaria cases in China (2013–2020).

Item	2013			2014			2015			2016			2017	2018	2019	2020	P -value †
	IMP	IND		IMP	IND		IMP	IND		IMP	IND		IMP	IMP	IMP	IMP
Abbreviations: NA=not available; IMP=imported cases; IND=domestic cases; PCR=polymerase chain reaction. * Unclear indicates that the risk exposure could not be estimated in populations such as children, retirees, students, unemployed persons, etc. Missing data were not included in the statistical analysis. †P value was calculated by chi-squared test or Kruskal-Wallis test.
Total	867	68		798	45		836	24		685	1		573	397	289	234
Sex																	<0.001
Female	61	20		47	11		86	7		97	0		105	57	47	30
Male	806	48		751	34		750	17		588	1		468	340	242	204
Age group (years)																	0.072
<5	3	0		6	3		9	0		9	1		10	4	1	2
5–18	28	14		17	3		35	5		38	0		35	20	10	17
19–59	832	47		766	37		776	18		615	0		510	353	263	204
≥60	4	7		9	2		16	1		23	0		18	20	15	11
Occupation																	<0.001
Outdoors	NA	NA		NA	NA		80	1		233	0		379	272	190	152
Indoors	NA	NA		NA	NA		13	0		34	0		34	39	33	13
Unclear*	NA	NA		NA	NA		21	1		84	0		125	77	63	38
Missing	NA	NA		NA	NA		722	22		334	1		35	7	3	31
Diagnosis health facility																	<0.001
Provincial-level CDC	38	3		21	0		1	0		7	0		5	2	1	0
Provincial-level hospital	48	2		45	0		49	2		58	0		38	33	23	12
City-level CDC	37	1		25	0		18	0		11	0		9	3	3	2
City-level hospital	140	6		124	3		125	5		141	0		135	104	72	53
County-level CDC	307	16		301	19		253	11		166	1		98	68	33	22
County-level hospital	133	17		149	13		152	1		143	0		106	96	83	76
Township hospital	90	20		73	8		197	5		153	0		170	89	68	62
Village clinic	12	1		4	1		5	0		0	0		1	1	5	6
Private clinic	61	2		56	1		36	0		6	0		11	1	1	1
Missing	1	0		0	0		0	0		0	0		0	0	0	0
PCR confirmation																	<0.001
Yes	625	51		714	38		772	22		647	1		547	385	289	233
No	242	17		84	7		64	2		38	0		26	12	0	1