title: Sodium azide: ineffective as a faecal preservative for parasitological diagnosis.
abstract: Sodium azide was compared with 10% formalin to evaluate sodium azide's effectiveness as a faecal preservative for intestinal helminths and protozoa. Faecal specimens collected from Haiti were preserved in sodium azide and in 10% formalin and analysed after 1.5, 6.5 and 11.5 weeks by examining direct wet-mount preparations. Sodium azide did not preserve the morphology of either helminths or protozoa as well as 10% formalin did. However, sodium azide prevented embryogenesis of helminth eggs, while some helminth eggs in 10% formalin contained living larvae. Biosafety guidelines regarding the toxicity, reactivity, and disposal of sodium azide were strictly followed. Use of 10% formalin is a significantly better choice than sodium azide for preserving parasites when accurate identification of parasites and biosafety are the main concerns.
authors.affiliation: Division of Parasitic Diseases, Atlanta, Georgia 30333.
authors.forename: S P
authors.initials: SP
authors.lastname: Wahlquist
authors.forename: M L
authors.initials: ML
authors.lastname: Eberhard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001386:Azides; D002648:Child; D002675:Child, Preschool; D056890:Eukaryota; D005243:Feces / Q000469:parasitology*; D005557:Formaldehyde; D006376:Helminths; D006801:Humans; D007223:Infant; D008875:Middle Aged; D010274:Parasitology / Q000379:methods; D011309:Preservation, Biological; D019810:Sodium Azide
chemical_list: D001386:Azides; D005557:Formaldehyde; D019810:Sodium Azide