Estimation of canine Leishmania infection prevalence in six cities of the Algerian littoral zone using a Bayesian approach

PLoS One. 2015 Mar 20;10(3):e0117313. doi: 10.1371/journal.pone.0117313. eCollection 2015.


A large-scale study on canine Leishmania infection (CanL) was conducted in six localities along a west-east transect in the Algerian littoral zone (Tlemcen, Mostaganem, Tipaza, Boumerdes, Bejaia, Jijel) and covering two sampling periods. In total 2,184 dogs were tested with an indirect fluorescent antibody test (IFAT) and a direct agglutination test (DAT). Combined multiple-testing and several statistical methods were compared to estimate the CanL true prevalence and tests characteristics (sensitivity and specificity). The Bayesian full model showed the best fit and yielded prevalence estimates between 11% (Mostaganem, first period) and 38% (Bejaia, second period). Sensitivity of IFAT varied (in function of locality) between 86% and 88% while its specificity varied between 65% and 87%. DAT was less sensitive than IFAT but showed a higher specificity (between 80% and 95% in function of locality or/and season). A general increasing trend of the CanL prevalence was noted from west to east. A concordance between the present results and the incidence of human cases of visceral leishmaniasis was observed, where also a maximum was recorded for Bejaia. The results of the present study highlight the dangers when using IFAT as a gold standard.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algeria / epidemiology
  • Animals
  • Bayes Theorem
  • Cities / epidemiology*
  • Confidence Intervals
  • Dog Diseases / diagnosis
  • Dog Diseases / epidemiology*
  • Dogs
  • Ecosystem*
  • Fluorescent Antibody Technique, Direct
  • Fluorescent Antibody Technique, Indirect
  • Geography
  • Leishmaniasis / diagnosis
  • Leishmaniasis / epidemiology
  • Leishmaniasis / veterinary*
  • Models, Biological
  • Prevalence

Grant support

This work was supported by Belgian Directorate-General for Development Co-operation: scholarship AA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.