Examining DNA fingerprinting as an epidemiology tool in the tuberculosis program in the Northwest Territories, Canada

Figures & data

Table I DNA cluster frequencies

Assigned cluster number	Number grouped into cluster	Percent
NWT1	79	40.5
NWT2	78	40.0
NWT3	10	5.1
NWT4	8	4.1
NWT5	5	2.6
NWT6	2	1.0
NWT7	2	1.0
NWT8	2	1.0
Unique DNA fingerprints	9	4.7
Total	195	100

Fig. 1 Dendrogram of clustering analysis of the IS6110 RFLP patterns of the strains in this study. Dendrogram nodes and associated sub-branches that fit the cluster definition (≥85% pattern similarity) are highlighted in bold. The NWT clusters are represented as follows: • NWT1; *NWT2; ♦ NWT3; [odot] NWT4; ▪ NWT5; ▴ NWT6; NWT7; NWT8.

Table II Description of case's characteristics from DNA clusters and bivariate analysis

		DNA cluster grouping
		NWT1	NWT2	All others	NWT1 versus NWT2	NWT1 versus all others	NWT2 versus all others
Case characteristics		n=79	n=78	n=38	(p-value)	(p-value)	(p-value)
Mean Age (SD)		42 (24)	44 (23)	48 (20)	0.047	0.137	0.814
Gender (%)	Male	43 (54)	50 (64)	27 (71.0)	0.126	0.064	0.299
	Female	36 (46)	28 (36)	11 (29.0)
Ethnicity (%)	Dene	75 (94.9)	71 (91.0)	26 (68.4)	0.548*	<0.001*	<.001
	Inuit	1 (0.7)	1 (1.3)	6 (15.8)
	Metis	0 (0)	2 (2.6)	0 (0)
	Non-Aboriginal	3 (3.7)	3 (3.8)	0 (0)
	Immigrant	0 (0)	1 (1.3)	6 (15.8)
	Missing	1 (0.7)	0 (0)	0 (0)
Employment (%)	Yes	45 (57.0)	35 (44.9)	23 (60.5)	0.054	0.681	0.020
	No	12 (15.2)	27 (34.6)	8 (21.0)
	Child/student	12 (15.2)	10 (12.8)	4 (10.5)
	Missing	10 (12.6)	6 (7.7)	3 (8.0)
Community –	A	29 (36.7)	18 (23.1)	2 (5.3)	0.001*	<0.001*	<0.001*
major (%)	B	27 (34.2)	1 (1.3)	0 (0)
	C	7 (8.9)	24 (30.8)	11 (28.9)
	Others	16 (20.2)	35 (44.8)	25 (65.8)
Excessive Alcohol	Yes	35 (44.3)	41 (52.6)	15 (39.5)	0.065	0.485	0.120
No	40 (50.6)	29 (37.2)	19 (50.0)
	Missing	4 (7.6)	8 (10.2)	4 (10.5)
Drug use	Yes	27 (34.2)	24 (30.8)	13 (34.2)	0.487	0.489	0.436
	No	46 (58.2)	44 (56.4)	20 (52.6)
	Missing	6 (7.6)	10 (12.8)	5 (13.2)
Homeless	Yes	3 (3.8)	16 (20.5)	4 (10.5)	0.003	0.313	<0.001
	No	70 (88.6)	55 (70.5)	34 (89.5)
	Missing	6 (7.6)	7 (9.0)	0 (0)
Smoker	Yes	15 (19.0)	14 (18.0)	2 (5.3)	0.574	0.060	0.057
	No	53 (67.1)	48 (61.5)	27 (71.0)
	Missing	11 (13.9)	16 (20.5)	9 (23.7)
HIV	Positive	0 (0)	0 (0)	0 (0)		0.144	0.130
	Negative	40 (51.6)	40 (51.3)	15 (39.5)
	Missing	39 (49.4)	38 (48.7)	23 (60.5)
Latent tuberculosis infection	Yes	40 (50.6)	36 (46.1)	18 (47.4)	0.213	0.299	0.574
No	38 (48.1)	42 (53.8)	20 (52.6)
Prior contact	Yes	44 (55.7)	40 (51.3)	7 (18.4)	0.262	<0.001	0.001
	No	35 (44.3)	38 (48.7)	31 (81.6)
Pulmonary TB	Yes	68 (86.1)	69 (88.5)	31 (81.6)	0.500	0.473	0.337
	No	11 (13.9)	9 (11.5)	7 (18.4)

* Chi-squared test by Phi, remainder by Fisher exact test.

Fig. 2 SNA of NWT1 DNA fingerprint cluster. The yellow circles represent the cases and the red squares represent the communities. The heavy black lines represent cases reported within 2 years, while the lighter lines represent exposure between the cases exceeding 2 years.

Fig. 3 SNA of NWT2 DNA fingerprint cluster. The green circles represent the cases and the red squares represent the communities. The heavy black lines represent cases reported within 2 years, while the lighter lines represent exposure between the cases exceeding 2 years.