Rationale: South African adolescents carry a high tuberculosis disease burden. It is not known if schools are high-risk settings for Mycobacterium tuberculosis (MTB) transmission. Objectives: To detect airborne MTB genomic DNA in classrooms. Methods: We studied 72 classrooms occupied by 2,262 students in two South African schools. High-volume air filtration was performed for median 40 (interquartile range [IQR], 35-54) minutes and assayed by droplet digital PCR (ddPCR)-targeting MTB region of difference 9 (RD9), with concurrent CO2 concentration measurement. Classroom data were benchmarked against public health clinics. Students who consented to individual tuberculosis screening completed a questionnaire and sputum collection (Xpert MTB/RIF Ultra) if symptom positive. Poisson statistics were used for MTB RD9 copy quantification. Measurements and Main Results: ddPCR assays were positive in 13/72 (18.1%) classrooms and 4/39 (10.3%) clinic measurements (P = 0.276). Median ambient CO2 concentration was 886 (IQR, 747-1223) ppm in classrooms versus 490 (IQR, 405-587) ppm in clinics (P < 0.001). Average airborne concentration of MTB RD9 was 3.61 copies per 180,000 liters in classrooms versus 1.74 copies per 180,000 liters in clinics (P = 0.280). Across all classrooms, the average risk of an occupant inhaling one MTB RD9 copy was estimated as 0.71% during one standard lesson of 35 minutes. Among 1,836/2,262 (81.2%) students who consented to screening, 21/90 (23.3%) symptomatic students produced a sputum sample, of which one was Xpert MTB/RIF Ultra positive. Conclusions: Airborne MTB genomic DNA was detected frequently in high school classrooms. Instantaneous risk of classroom exposure was similar to the risk in public health clinics.
Rationale: South African adolescents carry a high tuberculosis disease burden. It is not known if schools are high-risk settings for Mycobacterium tuberculosis (MTB) transmission. Objectives: To detect airborne MTB genomic DNA in classrooms. Methods: We studied 72 classrooms occupied by 2,262 students in two South African schools. High-volume air filtration was performed for median 40 (interquartile range [IQR], 35-54) minutes and assayed by droplet digital PCR (ddPCR)-targeting MTB region of difference 9 (RD9), with concurrent CO2 concentration measurement. Classroom data were benchmarked against public health clinics. Students who consented to individual tuberculosis screening completed a questionnaire and sputum collection (Xpert MTB/RIF Ultra) if symptom positive. Poisson statistics were used for MTB RD9 copy quantification. Measurements and Main Results: ddPCR assays were positive in 13/72 (18.1%) classrooms and 4/39 (10.3%) clinic measurements (P = 0.276). Median ambient CO2 concentration was 886 (IQR, 747-1223) ppm in classrooms versus 490 (IQR, 405-587) ppm in clinics (P < 0.001). Average airborne concentration of MTB RD9 was 3.61 copies per 180,000 liters in classrooms versus 1.74 copies per 180,000 liters in clinics (P = 0.280). Across all classrooms, the average risk of an occupant inhaling one MTB RD9 copy was estimated as 0.71% during one standard lesson of 35 minutes. Among 1,836/2,262 (81.2%) students who consented to screening, 21/90 (23.3%) symptomatic students produced a sputum sample, of which one was Xpert MTB/RIF Ultra positive. Conclusions: Airborne MTB genomic DNA was detected frequently in high school classrooms. Instantaneous risk of classroom exposure was similar to the risk in public health clinics.
Entities:
Keywords:
adolescent; air sampling; ddPCR; school; tuberculosis
Authors: Jason R Andrews; Mark Hatherill; Hassan Mahomed; Willem A Hanekom; Monica Campo; Thomas R Hawn; Robin Wood; Thomas J Scriba Journal: Am J Respir Crit Care Med Date: 2015-03-01 Impact factor: 21.405
Authors: B J Marais; C C Obihara; R P Gie; H S Schaaf; A C Hesseling; C Lombard; D Enarson; E Bateman; N Beyers Journal: Arch Dis Child Date: 2005-11 Impact factor: 3.791
Authors: Robin Wood; Carl Morrow; Samuel Ginsberg; Elizabeth Piccoli; Darryl Kalil; Angelina Sassi; Rochelle P Walensky; Jason R Andrews Journal: PLoS One Date: 2014-09-02 Impact factor: 3.240
Authors: Benjamin Patterson; Carl Morrow; Vinayak Singh; Atica Moosa; Melitta Gqada; Jeremy Woodward; Valerie Mizrahi; Wayne Bryden; Charles Call; Shwetak Patel; Digby Warner; Robin Wood Journal: Gates Open Res Date: 2018-06-08
Authors: Eugene T Richardson; Carl D Morrow; Darryl B Kalil; Samuel Ginsberg; Linda-Gail Bekker; Robin Wood Journal: PLoS One Date: 2014-05-07 Impact factor: 3.240
Authors: Ruvandhi R Nathavitharana; Alberto L Garcia-Basteiro; Morten Ruhwald; Frank Cobelens; Grant Theron Journal: EBioMedicine Date: 2022-03-23 Impact factor: 11.205