title: Sodium azide as a preservative in epidemiological studies of helminth ova in fecal specimens.
abstract: In 20 fecal specimens stored at ambient temperature (30-40 degrees C) for 3-7 days, substantial reductions in hookworm ova load were observed when a sensitive egg counting method (modified Kato's technique) was employed. Aliquots to which sodium azide (3 mg/g of fecal matter) was added showed considerably less reduction. A larger study on 120 specimens confirmed that there was no reduction up to 3 days. Significant decreases, however, occurred by 5 days, and these could not be prevented even by doubling the sodium azide dose (to 6 mg). It is recommended that in epidemiological studies of hookworm infestation in tropical countries, 3 mg of sodium azide should be added per g of fecal matter within 6 h of collection and the specimen tested within 3 days.
authors.affiliation: Institute for Research in Medical Statistics, Madras.
authors.forename: V
authors.initials: V
authors.lastname: Srinivasan
authors.forename: R
authors.initials: R
authors.lastname: Ramakrishnan
authors.forename: L
authors.initials: L
authors.lastname: Prabhakar
mesh_terms: D000293:Adolescent; D000328:Adult; D000723:Ancylostomatoidea / Q000302:isolation & purification*; D000818:Animals; D001386:Azides; D002648:Child; D005243:Feces / Q000469:parasitology*; D005260:Female; D006725:Hookworm Infections / Q000469:parasitology*; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D010270:Parasite Egg Count / Q000379:methods; D011309:Preservation, Biological; D019810:Sodium Azide
chemical_list: D001386:Azides; D007202:Indicators and Reagents; D019810:Sodium Azide