PLoS ONE (Jan 2016)

The Prevalence of Tuberculosis in Zambia: Results from the First National TB Prevalence Survey, 2013-2014.

  • Nathan Kapata,
  • Pascalina Chanda-Kapata,
  • William Ngosa,
  • Mine Metitiri,
  • Eveline Klinkenberg,
  • Nico Kalisvaart,
  • Veronica Sunkutu,
  • Aaron Shibemba,
  • Chishala Chabala,
  • Gershom Chongwe,
  • Mathias Tembo,
  • Lutinala Mulenga,
  • Grace Mbulo,
  • Patrick Katemangwe,
  • Sandra Sakala,
  • Elizabeth Chizema-Kawesha,
  • Felix Masiye,
  • George Sinyangwe,
  • Ikushi Onozaki,
  • Peter Mwaba,
  • Davy Chikamata,
  • Alimuddin Zumla,
  • Martin P Grobusch

DOI
https://doi.org/10.1371/journal.pone.0146392
Journal volume & issue
Vol. 11, no. 1
p. e0146392

Abstract

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BACKGROUND:Tuberculosis in Zambia is a major public health problem, however the country does not have reliable baseline data on the TB prevalence for impact measurement; therefore it was among the priority countries identified by the World Health Organization to conduct a national TB prevalence survey. OBJECTIVE:To estimate the prevalence of tuberculosis among the adult Zambian population aged 15 years and above, in 2013-2014. METHODS:A cross-sectional population-based survey was conducted in 66 clusters across all the 10 provinces of Zambia. Eligible participants aged 15 years and above were screened for TB symptoms, had a chest x-ray (CXR) performed and were offered an HIV test. Participants with TB symptoms and/or CXR abnormality underwent an in-depth interview and submitted one spot- and one morning sputum sample for smear microscopy and liquid culture. Digital data collection methods were used throughout the process. RESULTS:Of the 98,458 individuals who were enumerated, 54,830 (55.7%) were eligible to participate, and 46,099 (84.1%) participated. Of those who participated, 45,633/46,099 (99%) were screened by both symptom assessment and chest x-ray, while 466/46,099 (1.01%) were screened by interview only. 6,708 (14.6%) were eligible to submit sputum and 6,154/6,708 (91.7%) of them submitted at least one specimen for examination. MTB cases identified were 265/6,123 (4.3%). The estimated national adult prevalence of smear, culture and bacteriologically confirmed TB was 319/100,000 (232-406/100,000); 568/100,000 (440-697/100,000); and 638/100,000 (502-774/100,000) population, respectively. The risk of having TB was five times higher in the HIV positive than HIV negative individuals. The TB prevalence for all forms was estimated to be 455 /100,000 population for all age groups. CONCLUSION:The prevalence of tuberculosis in Zambia was higher than previously estimated. Innovative approaches are required to accelerate the control of TB.