Mortality burden from seasonal influenza in Chongqing, China, 2012–2018

Figures & data

Figure 1. The geographical location of Chongqing, China.

Table 1. Annual number of deaths in Chongqing, China, 2012–2018.

	All-cause		CRD^b		P&I^c		COPD^d		IHD^e
Age group	No.^a	Rate	No.^a	Rate	No.^a	Rate	No.^a	Rate	No.^a	Rate
All age
2012	176537	605	109480	375	2874	10	32032	110	17633	60
2013	183419	623	110296	375	2881	10	31736	108	19233	65
2014	195482	658	118670	400	3179	11	34470	116	23848	80
2015	198729	664	120015	401	3106	10	34761	116	24409	82
2016	205696	682	124078	411	3515	12	34500	114	25543	85
2017	186662	612	112194	368	3117	10	31670	104	25501	84
2018	209777	682	127789	416	3467	11	34111	111	31151	101
Total	1356302	4527	822522	2745	22139	74	233280	779	167318	557
Age ≥65
2012	126174	2450	89449	1737	2210	43	28203	1107	14653	285
2013	130521	3725	90566	2584	2327	66	27872	1676	16019	457
2014	142613	3937	98919	2731	2561	71	30683	1783	20404	563
2015	146034	4004	100592	2758	2541	70	31127	1804	20771	569
2016	153177	3705	104918	2538	2969	72	31025	1674	21866	529
2017	141506	3814	95758	2581	2613	70	28617	1702	22070	595
2018	162912	4007	109791	2701	2934	72	31035	1828	27012	664
Total	1002937	25642	689993	17630	18155	464	208562	11573	142795	3663
Age<65
2012	50363	209	20031	83	664	3	3829	16	2980	12
2013	52898	204	19730	76	554	2	3864	15	3214	12
2014	52869	203	19751	76	618	2	3787	15	3444	13
2015	52695	201	19423	74	565	2	3634	14	3638	14
2016	52519	202	19160	74	546	2	3475	13	3677	14
2017	45156	169	16436	61	504	2	3053	11	3431	13
2018	46865	176	17998	67	533	2	3076	12	4139	16
Total	353365	1363	132529	511	3984	15	24718	95	24523	94

^aDenotes number.

^bDenotes circulatory and respiratory disease.

^cDenotes pneumonia and influenza.

^dDenotes chronic obstructive pulmonary disease.

^eDenotes ischemic heart disease.

Table 2. Annual sum of total specimens tested and specimens positive for influenza by type/subtypes in Chongqing, 2012–2018.

Year	Specimens tested	Number (%) of specimens positive for influenza	Number (%)^a by type/subtypes
			A(H1N1)pdm09	A(H3N2)	B
2012	1067	483 (45.3)	1 (0.2)	299 (61.9)	183 (37.9)
2013	3855	369 (9.6)	217 (58.8)	39 (10.6)	113 (30.6)
2014	3486	458 (13.1)	42 (9.2)	273 (59.6)	143 (31.2)
2015	3700	359 (9.7)	8 (2.2)	161 (44.9)	190 (52.9)
2016	4913	515 (10.5)	26 (5.1	208 (40.4)	281 (54.6)
2017	5165	496 (9.6)	192 (38.7)	77 (15.5)	227 (45.8)
2018	4850	267 (5.5)	195 (73.0)	22 (8.2)	50 (19.7)
Total	27036	2947 (10.9)	681 (23.1)	1079 (36.6)	1187 (40.3)

^aProportions of subtype in total positive specimens for total positive specimens.

Figure 2. Weekly number of influenza-associated death per five causes (blue) and the proportion of influenza-positive rate (orange) in Chongqing, 2012–2018.

Table 3. Influenza-associated EMRs in 2012–2018 estimated by negative-binomial model.

Causes of death	No. of excess deaths per 100 000 population per year (95%CI)
	A(H1N1)pdm09	A(H3N2)	B	P-value	Total
All cause
< 65 y	1.0 (0.8–1.1)	0.5 (0.3–0.7)	5.3 (5.2–5.4)	0.001	6.8 (6.3–7.2)
≥65 y	56.5 (50.8–62.1)	13.8 (7.2–20.3)	82.03 (78.6–85.5)	<0.001	152.3 (136.1–168.4)
All ages	7.5 (6.7–8.3)	5.3 (4.5–6.1)	20.6 (20.3–21.0)	<0.001	33.5 (31.5–35.5)
CRD
< 65 y	0.6 (0.5–0.7)	0.5 (0.4–0.6)	2.2 (2.2–2.2)	0.111	3.3 (3.1–3.6)
≥65 y	42.3 (38.2–46.4)	17.8 (13.0–22.6)	61.8 (59.3–64.3)	<0.001	121.9 (110.2–133.7)
All ages	5.5 (5.0–6.1)	4.97 (4.4–5.5)	14.2 (13.9–14.4)	0.001	24.7 (23.3–26.0)
P&I
< 65 y	0.03 (0.02–0.03)	0.02 (0.01–0.03)	0.1 (0.1–0.1)	1.000	0.2 (0.1–0.2)
≥65 y	1.2 (1.1–1.4)	0. 6 (0.4–0.7)	2.1 (2.0–2.2)	0.226	3.9 (3.5–4.3)
All ages	0.2 (0.2–0.2)	0.1 (0.1–0.2)	0.5 (0.5–0.5)	1.000	0.8 (0.7–0.8)
COPD
< 65 y	0.1 (0.1–0.2)	0.2 (0.2–0.2)	0.5 (0.5–0.5)	0.144	0.8 (0.8–0.9)
≥65 y	14.0 (12.6–15.3)	7.9 (6.3–9.5)	23.1 (22.3–24.0)	0.001	45.0 (41.0–48.9)
All ages	1.8 (1.6–1.9)	1.9 (1.7–2.0)	4.9 (4.8–5.0)	0.037	8.5 (8.1–9.0)
IHD
< 65 y	0.2 (0.2–0.2)	0 (−0.02–0.02)	0.3 (0.3–0.3)	1.000	0.5 (0.4–0.5)
≥65 y	12.0 (11.1–12.8)	5.5 (4.5–6.5)	11.1 (10.6–11.6)	0.396	28.6 (26.1–31.0)
All ages	1.7 (1.6–1.8)	1.1 (1.0–1.2)	2.3 (2.2–2.3)	0.401	5.0 (4.7–5.3)