Active transmission of Trypanosoma brucei gambiense Dutton, 1902 sleeping sickness in Abraka, Delta State, Nigeria

Active surveillance of Human African trypanosomiasis (HAT) or sleeping sickness was undertaken in 3 agrarian villages in Ethiope East Local Government Area of Delta State, Nigeria. Card Agglutination Trypanosomiasis Test (CATT) was used qualitatively for mass screening with undiluted fresh whole blood (WB) and quantitatively for diagnosis in serum dilution tests. Thereafter, palpation for enlarged cervical lymph gland (ECLG) was followed by parasitological examination of aspirate using wet film, haematocrit centrifugation technique (HCT) and mini-anion exchange centrifugation technique (mAECT). Only one confirmed case of sleeping sickness was diagnosed out of the 491 samples screened. The results showed 43 (9.8%) serological positive cases in WB/ CATT test. 12 (27.9%) suspected cases that reacted at &lt1/4 titre in serum dilution test were highly suspected serological positive but parasitological negative cases. The study indicates that there is ongoing active transmission of Gambian type sleeping sickness in Abraka focus of Nigeria. The highly suspected cases will be followed up. Many cases might have gone undetected and more villages within the same focus were not covered. Moreover, a large-scale multi-disciplinary disease surveillance, vector and animal reservoir studies are required to determine the true situation of HAT in this focus. KEY-WORDS: Transmission, Gambian Trypanosomiasis, Screening, Blood, Serum, Diagnosis

Result of 2004 extended trypanosomosis survey of ruminants at Kachia Grazing Reserve, North Central Nigeria

Tsetse fly and trypanosome prevalence in ruminants were estimated in April and August, peak months of the dry and rainy seasons in the Kachia Grazing Reserve (KGR) of Kaduna State, North Central Nigeria. This study was subsequent to reports of seasonal outmigration of semi nomadic Fulani from the grazing reserve due to death of cattle from trypanosomosis. Result of blood samples showed an overall parasitological infection rate of 17.4%. Infection rates in cattle, sheep and goats were, 18.6%, 9.5% and 5.1% respectively. Over all higher infection rate in the rainy season was attributed to abundance of tsetse and other hematophagus flies. Infection rate in younger animals (21.9%) was higher compared to those of older animals (16.5%). Trypanosoma vivax was the dominant infecting trypanosome specie followed by T. congolense and T. brucei.It was concluded that tsetse fly and trypanosomosis constituted dual plagues limiting economic livestock production and settling of the pastoralists in the grazing reserve. This warrants application of sustainable integrated control measures to enhance utilization of abundant fodder at the reserve.Key words: Kachia grazing reserve, trypanosomosis, ruminants, infection rates, Nigeria. Resultat de l'enquete de trypanosomose extension de 2004 des ruminants a la reserve de piscine Kachia, Nigeria Centrale du NordLa prévalence de la mouche tsé-tsé et du trypanosome chez les ruminants a été estimée en avril et août, les mois de pointe des saisons secanes et pluvieuses dans la réserve de pâturage de Kachia (KGR) de l'État de Kaduna, dans le nord du centre du Nigeria. Cette étude a été postérieure à des rapports d'émigration saisonnière de Fulani semi-nomades provenant de la réserve de pâturage en raison de la mort de bovins de la trypanosomose. Le résultat des échantillons de sang a montré un taux global d'infection parasitaire de 17,4%. Les taux d'infection chez les bovins, les ovins et les chèvres étaient respectivement de 18,6%, 9,5% et 5,1%. Le taux d'infection plus élevé pendant la saison des pluies a été attribué à l'abondance de mouches tsé-tsé et d'autres mouches hématophobes. Le taux d'infection chez les animaux plus jeunes (21,9%) était plus élevé par rapport à ceux des animaux plus âgés (16,5%). Trypanosoma vivax était le trypanosome infectant dominant suivi de T. congolense et T. brucei.On a conclu que la mouche tsé-tsé et la trypanosomose constituaient des fléaux doubles limitant la production d'élevage économique et la colonisation des pasteurs dans la réserve de pâturage. Cela justifie l'application de mesures de contrôle intégrées durables pour améliorer l'utilisation de fourrages abondants dans la réserve.Mots clés: réserve de pâturage de Kachia, trypanosomose, ruminants, taux d'infection, Nigeri