Table 3.
Demographic characteristics associated with infector cases that have transmitted to another sampled or non-sampled case within 4 years. Cases collected after 2010 and extrapulmonary cases are excluded. Odds ratios are calculated through ordered logistic regression by number of secondary infections, and P-values by the Wald chi-squared test, adjusted for age, sex, year and lineage
|
Infector /total |
% infectors |
Odds ratio (95 % CI) |
P-value |
|
|---|---|---|---|---|
|
Year |
||||
|
1995–1998 |
99/337 |
29.4 |
1 |
|
|
1999–2001 |
95/346 |
27.5 |
0.9 (0.6–1.2) |
|
|
2002–2004 |
89/367 |
24.3 |
0.8 (0.6–1.1) |
|
|
2005–2007 |
61/288 |
21.2 |
0.6 (0.4–0.9) |
|
|
2008–2010 |
25/218 |
11.5 |
0.3 (0.2–0.5) |
<0.01 |
|
Lineage |
||||
|
1 |
48/243 |
19.8 |
0.8 (0.6–1.2) |
|
|
2 |
20/61 |
32.8 |
1.6 (0.9–2.7) |
|
|
3 |
48/185 |
25.9 |
1.4 (0.9–1.8) |
|
|
4 |
253/1067 |
23.7 |
1 |
0.05 |
|
Age group (years) |
||||
|
<20 |
13/55 |
23.6 |
1.6 (0.7–3.2) |
|
|
20–29 |
116/411 |
28.2 |
2.1 (1.4–3.2) |
|
|
30–39 |
132/547 |
24.1 |
1.8 (1.2–2.7) |
|
|
40–49 |
69/290 |
23.8 |
1.8 (1.2–2.8) |
|
|
50+ |
39/253 |
15.4 |
1 |
0.01 |
|
Sex |
||||
|
Female |
206/815 |
25.3 |
1 |
|
|
Male |
163/741 |
22.0 |
0.8 (0.7–1.1) |
0.18 |
|
HIV status |
||||
|
Negative |
112/469 |
23.9 |
1 |
|
|
Positive on ART |
14/78 |
17.9 |
1.0 (0.5–1.9) |
|
|
Positive no ART |
155/639 |
24.3 |
1.0 (0.7–1.3) |
1.0 |
|
Previous TB |
||||
|
Yes |
35/171 |
20.4 |
0.9 (0.6–1.3) |
|
|
No |
334/1385 |
24.1 |
1 |
0.43 |
|
TB type |
||||
|
Smear-positive |
329/1218 |
27.0 |
1 |
|
|
Smear-negative |
40/338 |
11.8 |
0.4 (0.2–0.5) |
<0.01 |
|
Outcome |
||||
|
Completed |
262/1011 |
25.9 |
1 |
|
|
Died |
67/337 |
19.9 |
0.6 (0.5–0.9) |
|
|
Lost/transferred |
40/191 |
20.9 |
0.7 (0.4–1.0) |
<0.01 |
|
Isoniazid Resistance |
||||
|
Resistant |
19/108 |
17.6 |
0.6 (0.4–1.0) |
|
|
Sensitive |
347/1402 |
24.8 |
1 |
0.07 |
|
Rifampicin resistance |
||||
|
Resistant |
2/15 |
13.3 |
0.5 (0.1–1.8) |
|
|
Sensitive |
363/1495 |
24.3 |
1 |
0.36 |
|
Recent residence |
||||
|
Karonga |
263/1131 |
23.3 |
1 |
|
|
Other Malawi |
59/247 |
23.9 |
1.0 (0.7–1.3) |
|
|
Other country |
20/90 |
22.2 |
0.8 (0.5–1.4) |
0.78 |
|
Birthplace |
||||
|
Karonga |
242/942 |
25.7 |
1 |
|
|
Other Malawi |
52/299 |
17.4 |
0.6 (0.4–0.8) |
|
|
Other country |
66/281 |
23.5 |
0.9 (0.6–1.2) |
0.02 |
ART, antiretroviral therapy