title: The effect of eight half-yearly single-dose treatments with DEC on Wuchereria bancrofti circulating antigenaemia.
abstract: The effect of eight half-yearly treatment rounds with diethylcarbamazine (DEC; 6mg/kg bodyweight) on Wuchereria bancrofti-specific circulating filarial antigen (CFA), a marker of adult worm infection, was followed in 79 individuals who were CFA-positive before start of treatment. Half of these were also microfilariae (mf)-positive. Microfilaraemia decreased rapidly after onset of treatment and became undetectable after four treatments. Circulating antigenaemia also decreased progressively, but at a much slower rate. After two, four and eight treatment rounds, the mean CFA intensity was reduced by 81, 94 and 98%, and the prevalence of CFA positivity was 85, 66 and 57%, compared with pre-treatment, respectively. CFA clearance rates were negatively related to pre-treatment CFA intensities, and were higher among pre-treatment mf-negative individuals than among pre-treatment mf-positive individuals. Even among patients who had pre-treatment CFA intensities above the upper measuring level (32000antigen units), and who continued to have intensities above this level after treatment, a decrease in post-treatment CFA intensities was obvious from a continuous decrease in ELISA optical density values. Repeated DEC therapy thus appears to have a slow but profound and persistent macrofilaricidal effect, which in the long run may be beneficial to populations undergoing DEC-based control interventions by reducing the probability of future morbidity development.
authors.affiliation: DBL-Institute for Health Research and Development, Jaegersborg Alle 1D, 2920 Charlottenlund, Denmark. pesimonsen@dblnet.dk
authors.forename: Paul E
authors.initials: PE
authors.lastname: Simonsen
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Magesa
authors.forename: Dan W
authors.initials: DW
authors.lastname: Meyrowitsch
authors.forename: Mwele N
authors.initials: MN
authors.lastname: Malecela-Lazaro
authors.forename: Rwehumbiza T
authors.initials: RT
authors.lastname: Rwegoshora
authors.forename: Walter G
authors.initials: WG
authors.lastname: Jaoko
authors.forename: Edwin
authors.initials: E
authors.lastname: Michael
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D004049:Diethylcarbamazine / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D019353:Endemic Diseases; D005260:Female; D005368:Filariasis / Q000150:complications / Q000188:drug therapy*; D005369:Filaricides / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012423:Rural Health; D013636:Tanzania / Q000453:epidemiology; D016896:Treatment Outcome; D014958:Wuchereria bancrofti / Q000276:immunology
chemical_list: D000947:Antigens, Helminth; D005369:Filaricides; C045193:Wuchereria antigen; D004049:Diethylcarbamazine