title: Evaluation of Giant African Pouched Rats for Detection of Pulmonary Tuberculosis in Patients from a High-Endemic Setting.
abstract: BACKGROUND
  This study established evidence about the diagnostic performance of trained giant African pouched rats for detecting Mycobacterium tuberculosis in sputum of well-characterised patients with presumptive tuberculosis (TB) in a high-burden setting.
  
  
  METHODS
  The TB detection rats were evaluated using sputum samples of patients with presumptive TB enrolled in two prospective cohort studies in Bagamoyo, Tanzania. The patients were characterised by sputum smear microscopy and culture, including subsequent antigen or molecular confirmation of Mycobacterium tuberculosis, and by clinical data at enrolment and for at least 5-months of follow-up to determine the reference standard. Seven trained giant African pouched rats were used for the detection of TB in the sputum samples after shipment to the APOPO project in Morogoro, Tanzania.
  
  
  RESULTS
  Of 469 eligible patients, 109 (23.2%) were culture-positive for Mycobacterium tuberculosis and 128 (27.3%) were non-TB controls with sustained recovery after 5 months without anti-TB treatment. The HIV prevalence was 46%. The area under the receiver operating characteristic curve of the seven rats for the detection of culture-positive pulmonary tuberculosis was 0.72 (95% CI 0.66-0.78). An optimal threshold could be defined at ≥ 2 indications by rats in either sample with a corresponding sensitivity of 56.9% (95% CI 47.0-66.3), specificity of 80.5% (95% CI 72.5-86.9), positive and negative predictive value of 71.3% (95% CI 60.6-80.5) and 68.7% (95% CI 60.6-76.0), and an accuracy for TB diagnosis of 69.6%. The diagnostic performance was negatively influenced by low burden of bacilli, and independent of the HIV status.
  
  
  CONCLUSIONS
  Giant African pouched rats have potential for detection of tuberculosis in sputum samples. However, the diagnostic performance characteristics of TB detection rats do not currently meet the requirements for high-priority, rapid sputum-based TB diagnostics as defined by the World Health Organization.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Klaus
authors.initials: K
authors.lastname: Reither
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Levan
authors.initials: L
authors.lastname: Jugheli
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Tracy R
authors.initials: TR
authors.lastname: Glass
authors.affiliation: Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Sasamalo
authors.affiliation: Ifakara Health Institute, Bagamoyo, Tanzania.
authors.forename: Francis A
authors.initials: FA
authors.lastname: Mhimbira
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania.
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Weetjens
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania.
authors.forename: Christophe
authors.initials: C
authors.lastname: Cox
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania; Department of Psychology, Western Michigan University, Kalamazoo, Michigan, United States of America.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Edwards
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania; Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands.
authors.forename: Christiaan
authors.initials: C
authors.lastname: Mulder
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania.
authors.forename: Negussie W
authors.initials: NW
authors.lastname: Beyene
authors.affiliation: Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO), Morogoro, Tanzania; Department of Psychology, Western Michigan University, Kalamazoo, Michigan, United States of America.
authors.forename: Amanda
authors.initials: A
authors.lastname: Mahoney
mesh_terms: D000328:Adult; D000818:Animals; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011446:Prospective Studies; D012372:ROC Curve; D051381:Rats; D012903:Smell / Q000502:physiology*; D013183:Sputum / Q000382:microbiology*; D013636:Tanzania; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology