title: Accuracy of prospective space-time surveillance in detecting tuberculosis transmission.
abstract: To improve detection of tuberculosis transmission, public health can supplement contact tracing with space-time surveillance. However, investigation of space-time clusters not due to transmission (false alarms), may lead to costly, unnecessary interventions. We measured the accuracy of prospective space-time surveillance in detecting tuberculosis transmission, assessing the number of clusters containing transmission and the false alarm rate. We simulated monthly prospective applications of a scan statistic using the home addresses and diagnosis dates of all 1566 culture-positive TB cases reported in Montreal during 1996-2007. We verified transmission within the space-time clusters by analyzing the TB genotype. Over 11.5 years, at 1.3 false alarms per month, we detected 89 transmission chains; at 0.05 false alarms per month we detected 5 transmission chains. We found evidence that prospective space-time surveillance for TB leads to a high false alarm rate, limiting its practical utility in settings with TB epidemiology similar to Montreal.
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada. Electronic address: aman.verma@mail.mcgill.ca.
authors.forename: Aman
authors.initials: A
authors.lastname: Verma
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada; Montreal Chest Institute, 3650 St-Urbain, Montreal, Quebec H2X 2P4, Canada; Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec H3H 2R9, Canada. Electronic address: kevin.schwartzman@mcgill.ca.
authors.forename: Kevin
authors.initials: K
authors.lastname: Schwartzman
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada; Montreal Chest Institute, 3650 St-Urbain, Montreal, Quebec H2X 2P4, Canada; Department of Microbiology and Immunology, McGill University, 3775 University Street, Montreal, Quebec H3A 2B4, Canada; Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec H3H 2R9, Canada. Electronic address: marcel.behr@mcgill.ca.
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Behr
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada; Montreal Chest Institute, 3650 St-Urbain, Montreal, Quebec H2X 2P4, Canada. Electronic address: alice.zwerling@mail.mcgill.ca.
authors.forename: Alice
authors.initials: A
authors.lastname: Zwerling
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada; Agence de la santé et des services sociaux de Montréal, Direction de santé publique, 1301 Sherbrooke Street East, Montreal, Quebec H2L 1M3, Canada. Electronic address: rallard@santepub-mtl.qc.ca.
authors.forename: Robert
authors.initials: R
authors.lastname: Allard
authors.affiliation: Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec H3H 2R9, Canada; McGill University Ingram School of Nursing, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada. Electronic address: christian.rochefort@mcgill.ca.
authors.forename: Christian M
authors.initials: CM
authors.lastname: Rochefort
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, 1140 Pine Avenue West, Montreal, Quebec H3A 1A3, Canada; Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec H3H 2R9, Canada; Agence de la santé et des services sociaux de Montréal, Direction de santé publique, 1301 Sherbrooke Street East, Montreal, Quebec H2L 1M3, Canada. Electronic address: david.buckeridge@mcgill.ca.
authors.forename: David L
authors.initials: DL
authors.lastname: Buckeridge
mesh_terms: D002170:Canada / Q000453:epidemiology; D003140:Communicable Disease Control / Q000379:methods / Q000706:statistics & numerical data; D016358:Contact Tracing / Q000379:methods / Q000706:statistics & numerical data; D061827:Dimensional Measurement Accuracy; D060005:Genotyping Techniques; D006801:Humans; D015233:Models, Statistical; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification; D020380:Needs Assessment; D062486:Public Health Surveillance; D013029:Space-Time Clustering; D062211:Spatio-Temporal Analysis; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission
keywords: Prospective surveillance; Space–time clustering; Tuberculosis