title: Front-loaded sputum microscopy in the diagnosis of pulmonary tuberculosis.
abstract: The objectives of this study are to describe the acid-fast bacilli (AFB) yield of a front-loaded scheme in which an additional on-the-spot specimen (Xspot [Xs]) was collected 1h after the first spot specimen and to compare the default rate between the front-loaded and standard schemes. The performance of the front-loaded sputum microscopy was also compared with the standard World Health Organization (WHO) method for the diagnosis of pulmonary tuberculosis (PTB) in Anambra State, Nigeria.
  
  
  
  A total of 1487 individuals with presumptive pulmonary TB participated. Participants' age ranged from 15years and above. Three sputum specimens were submitted as spot-early morning-spot. An additional specimen (Xs) was submitted 1h after the first spot. The sputum smears were stained using the Ziehl-Neelsen technique.
  
  
  
  A total of 183 (12.3%) patients were AFB positive. The front-loaded scheme identified 182 (99%) TB patients, whereas the standard scheme identified 183 (100%) TB patients. The difference was not statistically significant (p>.05). The first two specimens of each scheme (S-Xs vs. S-M) identified 176 (96.2%) and 181 (98.9%) of PTB patients, respectively. Neither difference was statistically significant (p>.05). Default during the diagnostic process was 11% in the standard but only 0.7% in the front-load scheme. The difference was significant (p<.05).
  
  
  
  Front-loaded smear microscopy has similar performance compared with the standard scheme. More presumptive PTB cases defaulted in the standard than in the front-loaded scheme. Front-loaded smear microscopy could therefore be used in the diagnosis in PTB in Anambra State.
authors.affiliation: Department of Microbiology, Abia State University, Uturu, Nigeria. Electronic address: nwachukwundubuisi82@yahoo.com.
authors.forename: Nwachukwu O
authors.initials: NO
authors.lastname: Ndubuisi
authors.affiliation: Department of Microbiology, Abia State University, Uturu, Nigeria.
authors.forename: Onyeagba R
authors.initials: OR
authors.lastname: Azuonye
authors.affiliation: Department of Microbiology, Abia State University, Uturu, Nigeria.
authors.forename: Nwaugo O
authors.initials: NO
authors.lastname: Victor
authors.affiliation: Department of Microbiology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria.
authors.forename: Okonkwo C
authors.initials: OC
authors.lastname: Robert
authors.affiliation: Bacteriology Unit, Saint Charles Borromeo Hospital, Onitsha, Nigeria.
authors.forename: Obiekwe
authors.initials: O
authors.lastname: Vivian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy / Q000379:methods*; D008875:Middle Aged; D009549:Nigeria; D011446:Prospective Studies; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D055815:Young Adult
keywords: Default; Diagnosis; Front-loading; Pulmonary tuberculosis; World Health Organization standard