Single doses of ivermectin 400 micrograms/kg-1: the most effective dosage in bancroftian filariasis.

Forty-three Wuchereria bancrofti carriers were given four successive semi-annual single doses of ivermectin 100 micrograms.kg-1 (IVER 100). The geometric mean microfilaremia (mf) recurrence percentage as compared to the pre-initial treatment mf level was 35%, 21%, 17% and 17% at 6, 12, 18 and 24 months, respectively. However, the recurrence of mf 6 months after the fourth treatment remained high in several individuals: 15 have been considered as 'bad responders' and 28 as 'good responders' individuals. At month 24 (M 24), they were randomly allocated into 2 groups. A first group was treated with a fifty and a sixth dose of IVER 100, at M24 and M30, respectively; the second one was treated, at the same time, with single doses of IVER 400 micrograms.kg-1 (IVER 400). At M 36, the mf recurrence percentage (mf M36/mf M0) was significantly higher in patients treated with IVER 100 than IVER 400 (11% vs 1%, p < 10(-4). From the group IVER 100, 6 out of the 8 'bad responders' remained 'bad responders' whereas there were none of the 7 in the group IVER 400. Moreover, there were only 2 more patients in the group IVER 100 showing sustained complete zero mf, whereas they were 13 in the group IVER 400. Single doses of IVER 400 were effective on 'bad responders'; IVER 400 must be recommended for semi-annual mass treatment in bancroftian filariasis.

Trypanosomiase humaine africaine. Etude d' un score de presomption de diagnostic au Congo

Une enquete cas-temoins a ete realisee au Congo afin de definir une grille de score de presomption de la maladie du sommeil a T.b. gambiense basee sur une selection de criteres cliniques et epidemiologiques de la trypanosomiase; utilisable par les structures sanitaires peripheriques. L'enquete a ete realisee sur 163 cas et 326 temoins. Les signes cliniques et les symptomes retenus sont: fievre; cephalees; prurit et lesions de grattage; diarrhee; odemes; adenopathies cervicales; troubles du sommeil; troubles de l'appetit; troubles sexuels; psychisme; signes neurologiques et autres troubles cliniques mineurs. Les autres criteres retenus sont les antecedents de trypanoso- miase humaine africaine (THA) et /'existence dun cheptel dans la concession. L'analyse des resultats confirme qu'il n'existe pas de critere ou groupe de criteres pathognomo-niques. Aucun des criteres selectionnes n'est suffisamment discriminant pour permettre une selection des trypanosomes parmi des consultants. Une grille de score de presomption semble donc de peu d'utilite au niveau peripherique; ceci est d'autant plus vrai si l'on considere l'augmentation de la charge de travail. Le faible pouvoir discriminant des signes cliniques et des symptomes ainsi que des autres parametres de la trypanosomiase africaine met en evidence la difficulte de mise en place dune strategie d'integration efficiente en temps qu'outil diagnostique precoce