Transmission network analysis to complement routine tuberculosis contact investigations.
OBJECTIVE
We examined the feasibility and value of network analysis to complement routine tuberculosis (TB) contact investigation procedures during an outbreak.


METHODS
We reviewed hospital, health department, and jail records and interviewed TB patients. Mycobacterium tuberculosis isolates were genotyped. We evaluated contacts of TB patients for latent TB infection (LTBI) and TB, and analyzed routine contact investigation data, including tuberculin skin test (TST) results. Outcomes included number of contacts identified, number of contacts evaluated, and their TST status. We used network analysis visualizations and metrics (reach, degree, betweenness) to characterize the outbreak.


RESULTS
secondary TB patients and more than 1200 contacts. Genotyping detected a 21-band pattern of a strain W variant. No HIV-infected patients were diagnosed. Contacts prioritized by network analysis were more likely to have LTBI than nonprioritized contacts (odds ratio=7.8; 95% confidence interval=1.6, 36.6). Network visualizations and metrics highlighted patients central to sustaining the outbreak and helped prioritize contacts for evaluation.


CONCLUSIONS
A network-informed approach to TB contact investigations provided a novel means to examine large quantities of data and helped focus TB control.
Andre
McKenzie
M
Division of Tuberculosis Elimination, Centers for Disease Control and Prevention, Atlanta, Ga 30333, USA.
Ijaz
Kashef
K
Tillinghast
Jon D
JD
Krebs
Valdis E
VE
Diem
Lois A
LA
Metchock
Beverly
B
Crisp
Theresa
T
McElroy
Peter D
PD
D000293:Adolescent; D000328:Adult; D002487:Centers for Disease Control and Prevention, U.S.; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D016358:Contact Tracing / Q000379:methods*; D004196:Disease Outbreaks; D005240:Feasibility Studies; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D009825:Oklahoma / Q000453:epidemiology; D011635:Public Health Administration / Q000379:methods*; D040442:Public Health Informatics; D012944:Social Support; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D014481:United States