Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 27, Number 3—March 2021

Systematic Review of Pooling Sputum as an Efficient Method for Xpert MTB/RIF Tuberculosis Testing during the COVID-19 Pandemic

Luis E. CuevasComments to Author , Victor S. Santos, Shirley Verônica Melo Almeida Lima, Konstantina Kontogianni, John S. Bimba, Vibol Iem, Jose Dominguez, Emily Adams, Ana Cubas Atienzar, Thomas Edwards, S. Bertel Squire, Patricia J. Hall, and Jacob Creswell
Author affiliations: Liverpool School of Tropical Medicine, Liverpool, UK (L.E. Cuevas, K. Kontogianni, V. Iem, E. Adams, A.T. Atienzar, T. Edwards, S.B. Squire); Federal University of Alagoas, Arapiraca, Brazil (V.S. Santos); Federal University of Sergipe, Aracaju, Brazil (S.V.M. Almeida Lima); Bingham University, Karu, Nigeria (J.S. Bimba); National TB Control Program, Vientiane, Laos (V. Iem); Institut d'Investigació Germans Trias i Pujol and Universitat Autònoma de Barcelona, Badalona, Spain (J. Dominguez); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (P.J. Hall); Stop TB Partnership, Innovations and Grants, Geneva, Switzerland (J. Creswell)

Main Article

Table 2

Tuberculosis Xpert results of pools composed of positive and negative samples, with sensitivity and specificity, in a systematic review of pooling sputum as an efficient method for Xpert MTB/RIF and Ultra testing for tuberculosis during the coronavirus disease pandemic

Pooling ratio
Test results, no.
% (95% CI)
% (95% CI)
True pos†
False pos‡
False neg†
True neg‡
(11) 1:5 (Cult neg/SM pos) 20 NA 0 NA 100 (80–100) NR

1:5 (Cult pos/SM neg)
76 (50–92)
94 (87–98)
99 (94–100)
(13) 1:2 14 NA 2 NA 88 (62–98) NR
1:4 14 NA 2 NA 88 (62–98) NR
1:6 11 NA 5 NA 69 (41–98) NR
1:8 10 NA 6 NA 63 (35–85) NR
1:10 13 NA 3 NA 81 (54–96) NR

81 (54–96)
96 (90–99)
100 (95–100)
100 (96–100)
(10) 1:4 19 NA 1 NA 95 (75–100) NR
1:8 20 NA 0 NA 100 (83–100) NR
1:12 16 NA 4 NA 80 (56–94) NR
1:16 39 0 1 0 98 (87–100) NR

*Xpert MTB/RIF and Ultra, Cepheid ( Cult, culture, NA, not applicable; neg, negative; NR, not reported; pos, positive; SM, smear.
†At least one of the patients included in the pool had an Xpert-positive test.
‡All patients included in the pool were Xpert-negative in the individual tests.

Main Article

  1. World Health Organization. WHO monitoring of Xpert MTB/RIF roll-out. Geneva: The Organization; 2019 [cited 2020 Apr 1].
  2. Van Deun  A, Tahseen  S, Affolabi  D, Hossain  MA, Joloba  ML, Angra  PK, et al. Sputum smear microscopy in the Xpert® MTB/RIF era. Int J Tuberc Lung Dis. 2019;23:128. DOIPubMedGoogle Scholar
  3. World Health Organization. WHO: Global TB progress at risk. Geneva: The Organization; 2020. [cited 2020 Nov 1].
  4. Emmanuel  JC, Bassett  MT, Smith  HJ, Jacobs  JA. Pooling of sera for human immunodeficiency virus (HIV) testing: an economical method for use in developing countries. J Clin Pathol. 1988;41:5825. DOIPubMedGoogle Scholar
  5. Morandi  PA, Schockmel  GA, Yerly  S, Burgisser  P, Erb  P, Matter  L, et al. Detection of human immunodeficiency virus type 1 (HIV-1) RNA in pools of sera negative for antibodies to HIV-1 and HIV-2. J Clin Microbiol. 1998;36:15348. DOIPubMedGoogle Scholar
  6. Peeling  RW, Toye  B, Jessamine  P, Gemmill  I. Pooling of urine specimens for PCR testing: a cost saving strategy for Chlamydia trachomatis control programmes. Sex Transm Infect. 1998;74:6670. DOIPubMedGoogle Scholar
  7. Mine  H, Emura  H, Miyamoto  M, Tomono  T, Minegishi  K, Murokawa  H, et al.; Japanese Red Cross NAT Research Group. High throughput screening of 16 million serologically negative blood donors for hepatitis B virus, hepatitis C virus and human immunodeficiency virus type-1 by nucleic acid amplification testing with specific and sensitive multiplex reagent in Japan. J Virol Methods. 2003;112:14551. DOIPubMedGoogle Scholar
  8. Lindan  C, Mathur  M, Kumta  S, Jerajani  H, Gogate  A, Schachter  J, et al. Utility of pooled urine specimens for detection of Chlamydia trachomatis and Neisseria gonorrhoeae in men attending public sexually transmitted infection clinics in Mumbai, India, by PCR. J Clin Microbiol. 2005;43:16747. DOIPubMedGoogle Scholar
  9. Westreich  DJ, Hudgens  MG, Fiscus  SA, Pilcher  CD. Optimizing screening for acute human immunodeficiency virus infection with pooled nucleic acid amplification tests. J Clin Microbiol. 2008;46:178592. DOIPubMedGoogle Scholar
  10. Santos  P, Santos  A, Verma  R, Oliveira  R, Camioli  C, Lemos  E, et al. The utility of pooling sputum samples for mass screening for tuberculosis in prisons using Xpert MTB/RIF Ultra. In: 50th World Conference on International Union Against Tuberculosis and Lung Disease; 2019 Oct 30–Nov 2; Hyderabad, India. Abstract SOA-01-1001-31. Int J Tuberc Lung Dis. 2019;23:S1101 cited 2020 Mar 30.
  11. Zishiri  V, Chihota  V, McCarthy  K, Charalambous  S, Churchyard  GJ, Hoffmann  CJ. Pooling sputum from multiple individuals for Xpert® MTB/RIF testing: a strategy for screening high-risk populations. Int J Tuberc Lung Dis. 2015;19:8790. DOIPubMedGoogle Scholar
  12. Abdurrahman  ST, Mbanaso  O, Lawson  L, Oladimeji  O, Blakiston  M, Obasanya  J, et al. Testing pooled sputum with Xpert MTB/RIF for diagnosis of pulmonary tuberculosis to increase affordability in low-income countries. J Clin Microbiol. 2015;53:25028. DOIPubMedGoogle Scholar
  13. Ho  J, Jelfs  P, Nguyen  PTB, Sintchenko  V, Fox  GJ, Marks  GB. Pooling sputum samples to improve the feasibility of Xpert® MTB/RIF in systematic screening for tuberculosis. Int J Tuberc Lung Dis. 2017;21:5038. DOIPubMedGoogle Scholar
  14. Phuong  NTB, Anh  NT, Van Son  N, Sintchenko  V, Ho  J, Fox  GJ, et al. Effect of two alternative methods of pooling sputum prior to testing for tuberculosis with genexpert MTB/RIF. BMC Infect Dis. 2019;19:347. DOIPubMedGoogle Scholar
  15. Chry  M, Smelyanskaya  M, Ky  M, Codlin  AJ, Cazabon  D, Tan Eang  M, et al. Can the high sensitivity of Xpert MTB/RIF Ultra be harnessed to save cartridge costs? Results from a pooled sputum evaluation in Cambodia. Trop Med Infect Dis. 2020;5:27. DOIPubMedGoogle Scholar
  16. Chakravorty  S, Simmons  AM, Rowneki  M, Parmar  H, Cao  Y, Ryan  J, et al. The new Xpert MTB/RIF Ultra: improving detection of Mycobacterium tuberculosis and resistance to rifampin in an assay suitable for point-of-care testing. MBio. 2017;8:e008127. DOIPubMedGoogle Scholar
  17. World Health Organization. Automated real-time nucleic acid amplification technology for rapid and simultaneous detection of tuberculosis and rifampicin resistance: Xpert MTB/RIF assay for the diagnosis of pulmonary and extrapulmonary TB in adults and children: policy update. Geneva: The Organization; 2013 [cited 2020 Apr 1].
  18. World Health Organization. Global tuberculosis report 2019. Geneva: The Organization; 2019. [cited 2020 Apr 1].
  19. Dowdy  DW, Basu  S, Andrews  JR. Is passive diagnosis enough? The impact of subclinical disease on diagnostic strategies for tuberculosis. Am J Respir Crit Care Med. 2013;187:54351. DOIPubMedGoogle Scholar

Main Article

Page created: December 22, 2020
Page updated: February 23, 2021
Page reviewed: February 23, 2021
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.