title: Hyperendemic bancroftian filariasis in the Kingdom of Tonga: the application of the membrane filter concentration technique to an age-stratified blood survey.
abstract: A survey carried out in Tonga, an area of hyperendemic subperiodic Wuchereria bancrofti filariasis, compared the diagnostic efficiency of the membrane-filtration and stained blood film techniques. Membrane filter concentration of 1 ml blood revealed a microfilaria rate that was approximately the same for all age groups, from 5 to 9 years old to  greater than 50 years old, about 70%. The microfilaria rate by examination  of stained 60 mm-3 thick blood films was lower for all age groups. Membrane filter concentration detected  7.8 times as many infections as thick film diagnosis in the 5- to 20- and 21- to 50-year-old groups, and 1.6 times in the  greater than 50-year-old group. Concentration revealed the prsence of microfilariae in the blood of 5 of 8 patients with gross elephantiasis, whereas microfilariae were found in the stained thick-film of only 1 of these individuals.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001769:Blood / Q000469:parasitology; D002648:Child; D002675:Child, Preschool; D004604:Elephantiasis / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005368:Filariasis / Q000175:diagnosis* / Q000453:epidemiology; D005374:Filtration / Q000379:methods*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008722:Methods; D008875:Middle Aged; D011114:Polynesia; D014957:Wuchereria / Q000302:isolation & purification*; D014958:Wuchereria bancrofti / Q000302:isolation & purification*
chemical_list: D008567:Membranes, Artificial