Discrepancy in the transmissibility of multidrug-resistant mycobacterium tuberculosis in urban and rural areas in China

Figures & data

Figure 1. Sample enrolment in Songjiang (A) and Wusheng (B).

Table 1. Characteristics of pulmonary tuberculosis patients in Songjiang and Wusheng.

	Songjiang (%)	Wusheng (%)	p value
Total	2212	1289
Sex			<0.001
Female	673 (30.4)	271 (21.0)
Male	1539 (69.6)	1018 (79.0)
Age	30.0 (24.0, 48.0)	50.0 (32.0, 61.0)	<0.001
Occupation
Farmer	266 (12.0)	1096 (85.0)	<0.001
Others	1946 (88.0)	193 (15.0)
Internal migrant			–
No	560 (25.3)	–
Yes	1652 (74.7)	–
History of tuberculosis			0.069
New cases	2088 (94.4)	1197 (92.9)
Retreated cases	124 (5.6)	92 (7.1)
Diagnosis delay/weeks	3.7 (2.1, 6.1)	3.9 (1.3, 5.6)	<0.001
Chest cavitation			0.965
No	1524 (68.9)	889 (69.0)
Yes	688 (31.1)	400 (31.0)
Sputum smear status			0.047
Negative	1011 (45.7)	634 (49.2)
Positive	1201 (54.3)	655 (50.8)
Drug resistance profile			0.749
Pan-susceptible	1936 (87.5)	1128 (87.5)
Other DR	173 (7.8)	95 (7.4)
MDR	103 (4.7)	66 (5.1)
Beijing strain			<0.001
No	403 (18.2)	523 (40.6)
Yes	1809 (81.8)	766 (59.4)

Continuous data were expressed as median (interquartile range) and categorized data as n (%). Comparison between groups were tested by the chi-square test or Wilcoxon rank sum test.

Figure 2. (A) Phylogeny, clustering, and resistance profile of 2212 Mycobacterium tuberculosis strains isolated in Songjiang. (B) The sublineage composition of isolates from patients in Songjiang. (C) The sublineage composition of isolates from patients in Wusheng.

Table 2. Multivariable logistic regression of risk factors for clustering in Songjiang and Wusheng.

	Songjiang				Wusheng
	Non-clustered (%)	Clustered (%)	aOR* (95% CI)	p value	Non-clustered (%)	Clustered (%)	aOR^# (95% CI)	p value
Total	1654	558			942	347
Sex
Female	535 (79.5)	138 (20.5)	Ref		196 (72.3)	75 (27.7)	-
Male	1119 (72.7)	420 (27.3)	1.59 (1.26, 1.99)	<0.001	746 (73.3)	272 (26.7)	-	-
Age
<25	455 (70.9)	187 (29.1)	4.01 (2.62, 6.15)	<0.001	115 (58.1)	83 (41.9)	2.54 (1.66, 3.88)	<0.001
25–44	681 (73.8)	242 (26.2)	3.38 (2.24, 5.11)	<0.001	248 (75.6)	80 (24.4)	1.16 (0.77, 1.73)	0.472
45–64	298 (78.4)	82 (21.6)	1.92 (1.26, 2.92)	0.002	386 (74.4)	133 (25.6)	1.23 (0.85, 1.78)	0.273
≥65	220 (82.4)	47 (17.6)	Ref		193 (79.1)	51 (20.9)	Ref
Internal migrant
No	396 (70.7)	164 (29.3)	Ref		-	-	-
Yes	1258 (76.2)	394 (23.8)	0.48 (0.37, 0.63)	<0.001	-	-	-	-
Drug resistance profile
Pan-susceptible	1427 (73.7)	509 (26.3)	Ref		835 (74.0)	293 (26.0)	Ref
Other DR	144 (83.2)	29 (16.8)	0.57 (0.37, 0.87)	0.008	70 (73.7)	25 (26.3)	1.00 (0.61, 1.62)	0.985
MDR	83 (80.6)	20 (19.4)	0.64 (0.38, 1.06)	0.081	37 (56.1)	29 (43.9)	2.34 (1.38, 3.94)	0.001
Beijing strain
No	346 (85.9)	57 (14.1)	Ref		397 (75.9)	126 (24.1)	Ref
Yes	1308 (72.3)	501 (27.7)	2.24 (1.65, 3.03)	<0.001	545 (71.1)	221 (28.9)	1.19 (0.91, 1.54)	0.199

*Adjusted for sex, age, internal migrant, chest cavitation, drug resistance profile and Beijing strain. ^#Adjusted for age, history of tuberculosis, diagnosis delay, drug resistance profile and Beijing strain.

Figure 3. (A) Forest plot of the impact of lineage 2, katG S315 T, rpoB S450L and compensatory mutations (CMs) on MDR-TB transmission risk. (B) Number of new and retreated MDR-TB cases in Wusheng, stratified by clustered (red) and non-clustered (blue) cases. (C) Number of new and retreated MDR-TB cases in Songjiang, stratified by clustered (red) and non-clustered (blue) cases.

Data availability

The datasets used and analyzed during the current study are not accessible online, but may be made available upon written request to the corresponding author. Sequencing data were deposited in the Genome Sequence Archive (https://bigd.big.ac.cn/gsa) under BioProject PRJCA008815 and PRJCA010372.