title: Cost-effectiveness analysis of PCR for the rapid diagnosis of pulmonary tuberculosis.
abstract: BACKGROUND
  Tuberculosis is one of the most prominent health problems in the world, causing 1.75 million deaths each year. Rapid clinical diagnosis is important in patients who have co-morbidities such as Human Immunodeficiency Virus (HIV) infection. Direct microscopy has low sensitivity and culture takes 3 to 6 weeks 123. Therefore, new tools for TB diagnosis are necessary, especially in health settings with a high prevalence of HIV/TB co-infection.
  
  
  METHODS
  In a public reference TB/HIV hospital in Brazil, we compared the cost-effectiveness of diagnostic strategies for diagnosis of pulmonary TB: Acid fast bacilli smear microscopy by Ziehl-Neelsen staining (AFB smear) plus culture and AFB smear plus colorimetric test (PCR dot-blot).From May 2003 to May 2004, sputum was collected consecutively from PTB suspects attending the Parthenon Reference Hospital. Sputum samples were examined by AFB smear, culture, and PCR dot-blot. The gold standard was a positive culture combined with the definition of clinical PTB. Cost analysis included health services and patient costs.
  
  
  RESULTS
  The AFB smear plus PCR dot-blot require the lowest laboratory investment for equipment (US$ 20,000). The total screening costs are 3.8 times for AFB smear plus culture versus for AFB smear plus PCR dot blot costs (US$ 5,635,760 versus US$ 1,498, 660). Costs per correctly diagnosed case were US$ 50,773 and US$ 13,749 for AFB smear plus culture and AFB smear plus PCR dot-blot, respectively. AFB smear plus PCR dot-blot was more cost-effective than AFB smear plus culture, when the cost of treating all correctly diagnosed cases was considered. The cost of returning patients, which are not treated due to a negative result, to the health service, was higher in AFB smear plus culture than for AFB smear plus PCR dot-blot, US$ 374,778,045 and US$ 110,849,055, respectively.
  
  
  CONCLUSIONS
  AFB smear associated with PCR dot-blot associated has the potential to be a cost-effective tool in the fight against PTB for patients attended in the TB/HIV reference hospital.
authors.affiliation: Universidade Luterana do Brasil-ULBRA, Canoas/RS/Brazil. luciene.scherer@hotmail.com
authors.forename: Luciene C
authors.initials: LC
authors.lastname: Scherer
authors.forename: Rosa D
authors.initials: RD
authors.lastname: Sperhacke
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruffino-Netto
authors.forename: Maria Lr
authors.initials: ML
authors.lastname: Rossetti
authors.forename: Claudia
authors.initials: C
authors.lastname: Vater
authors.forename: Paul
authors.initials: P
authors.lastname: Klatser
authors.forename: Afrânio L
authors.initials: AL
authors.lastname: Kritski
mesh_terms: D001938:Brazil; D015658:HIV Infections / Q000150:complications; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000191:economics* / Q000379:methods; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000191:economics* / Q000209:etiology / Q000382:microbiology