title: The direct agglutination test as an alternative method for the diagnosis of canine and human visceral leishmaniasis.
abstract: BACKGROUND
  Visceral leishmaniasis is the most severe clinical form of leishmaniasis and is often fatal without proper treatment. Therefore, early and accurate diagnosis is important, but often difficult in endemic areas.
  
  
  OBJECTIVE
  The aim was to evaluate a direct agglutination test as a potential visceral leishmaniasis diagnostic method in endemic areas of Venezuela.
  
  
  METHODS
  The performance of the direct agglutination test, based on freeze-dried Leishmania donovani antigen was evaluated under laboratory conditions using serum samples of humans and dogs from several Venezuelan visceral leishmaniasis endemic areas: Nueva Esparta (Margarita Island), Lara, Anzoátegui and Trujillo Status. The study included confirmed visceral leishmaniasis patients (n=30), visceral leishmaniasis suspected subjects (n=4), healthy controls (n=19) and patients with other confirmed diseases (n=20). In addition, 24 serum samples from dogs with confirmed visceral leishmaniasis and 18 healthy control dogs were tested.
  
  
  RESULTS
  All serum samples of visceral leishmaniasis patients, either active or recovered, were positive. They showed anti-L. donovani titers above 1:1600. Three out of four suspected visceral leishmaniasis cases were also positive, while serum samples from endemic controls and patients with other diseases had titers lower than 1:800. A sensitivity of 100% was obtained for all threshold levels under consideration and 100% specificity at the threshold titer of 1:800 (95% confidence interval: 91-100%). A 93% sensitivity (95% confidence interval: 76-99%) was observed in dog samples, with 100% specificity (95% confidence interval: 79-100%) at the threshold titer of 1:200.
  
  
  CONCLUSIONS
  The direct agglutination test seems suitable for use in epidemiological studies and for serological diagnosis of human visceral leishmaniasis and canine visceral leishmaniasis.
authors.affiliation: Instituto de Biomedicina, Universidad Central de Venezuela, San José, Caracas, Venezuela.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Terán-Angel
authors.forename: Henk
authors.initials: H
authors.lastname: Schallig
authors.forename: Olga
authors.initials: O
authors.lastname: Zerpa
authors.forename: Vestalia
authors.initials: V
authors.lastname: Rodríguez
authors.forename: Marian
authors.initials: M
authors.lastname: Ulrich
authors.forename: Maira
authors.initials: M
authors.lastname: Cabrera
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D002648:Child; D002675:Child, Preschool; D004283:Dog Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D004285:Dogs; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007893:Leishmania donovani / Q000378:metabolism; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D014687:Venezuela / Q000453:epidemiology