High incidence and low case detection rate among contacts of tuberculosis cases in Shanghai, China

BMC Infectious Diseases

Table 3 Incidence of TB disease and detection rates for different screening methods among TB contacts

Screening methods	No. of contacts	TB cases from contact investigation	rate/100,000 (95% CI)	P#	TB cases not detected by contact investigation^a	Total TB cases^b	Detection rate%^c	P
CT+ symptoms	6	0	–		0	–	–	–
PPD+ symptoms	2	0	–		0	–	–	–
IGRA+ symptoms	2	0	–		0	–	–	–
Symptoms	3486	2	57 (7–207)	0.028	19	21	9.5 (2/21)	0.122
chest radiograph+ symptoms	4163	12	288 (149–503)	0.028	32	44	27.3 (12/44)	0.122
chest fluoroscopy + symptoms	478	1	209 (5–1160)		3	4	25.0
Total	8137	15	184 (103–304)		54	69	21.7

# Comparison of detection rates by symptom examination only and symptom examination plus chest radiography or other alternatives
^aTB cases not detected by contact investigation: cases not identified by contact investigation but reported as TB cases in the National TB Report System between January 1, 2010 and March 31, 2015
^bTotal TB cases: cases identified by contact investigation and cases not identified by contact investigation but reported as TB cases in the National TB Report System between January 1, 2010 and March 31, 2015
^cDetection rate = number of TB cases among contacts determined through contact investigation/total number of TB cases × 100%

ISSN: 1471-2334