No abstract

Parasitic nematodes, especially Haemonchus contortus (Rudolphi), are among the most common and economically important causes of disease in sheep and goats owned by pastoralists and small holder farmers in Africa. The control of these infections relies mainly on the use of anthelmintic drugs. However, herbal preparations are widely used by pastoralists and small holder farmers for the treatment of their livestock against helminth parasites. The anthelmintic effect of acetone leaf extract and fractions of Combretum molle was investigated to determine the relative efficacy of the components against gastrointestinal sheep nematodes. The fractions were obtained by solvent:solvent extraction from the acetone extract. These were evaluated for nematocidal activity by means of an egg hatch (EHA) and larval a development and viability assay (LDVA) in vitro. The effect of the test extracts on the hatchability of eggs and development of first to third stage larvae and the survival rate of the third stage larvae. H. contortus, were used to determine the relative bioactivities. Best-fit LC 50 values were computed using global model of nonlinear regression curve-fitting. The extracts inhibited egg hatching and development of the larvae of H. contortus in a concentration-dependent manner. Best-fit LC 50 values for the egg hatch test were 0.866, 0.333, 0.833, 0.747, and 0.065 mg/mL for acetone extract, n-butanol, hexane, chloroform, and 35% water in methanol fractions, respectively. The best-fit LC 50 values for the LDVA were 0.604, 0.362, 1.077, 0.131 and 0.318 mg/mL for the acetone extract, butanol, hexane, chloroform, and 35% water in methanol fractions, respectively. In the EHA the 35% water in methanol fraction was significantly more active than all the other fractions (p < 0.05); however the activity was not significantly different with the LDVA. C. molle leaf could find application in anthelmintic therapy in veterinary practice.

Toxoplasmosis is an important food borne parasitic zoonoses. However, data on Toxoplasma gondii infection in domestic animals mostly used for human consumption in Nigeria are scarce. We thus conducted a survey on the seroprevalence of T. gondii infection in a representative sample of cattle and pigs in farms and the abattoirs between June and December 2012. Sera from 210 cattle (both sexes) and 302 pigs (both sexes), were examined for T. gondii specific IgG antibodies by indirect Enzyme linked immunosorbent assay (ELISA). The seroprevalences determined were 13.91 % in cattle and 29.14 % in pigs. The antibody levels ranged from 0.499 to 2.103 in cattle, and 0.544 to 3.020 in pigs. The prevalence of IgG anti-T. gondii antibodies was positively correlated with the age. The seroprevalences (26.23 %) and (36.54 %) for adult cattle and pigs respectively, were higher compared to younger groups. However the difference was not significant (P > 0.05) in cattle but significant (P < 0.05) in pigs. In Nigeria, exposure to raw or undercooked foods is a risk factor for T. gondii infection. Knowledge of the prevalence of toxoplasmosis will help to target prevention efforts.

The current control of parasitic nematodes in small ruminants relies on the use of chemical anthelminthics, but the development of resistance and the problem of drug residues require research into alternatives. Acetone extract and solvent-solvent fractions of Vernonia amygdalina Del. (Compositae) were evaluated in vitro for potential anti-parasitic effects against the eggs and larvae of Haemonchus contortus. Significant effects were obtained with the extract and fractions but differences were observed depending on the parasitic stage. The acetone extract and fractions inhibited egg hatching and inhibited larval development and killed larvae of H. contortus in a concentration-dependent manner. Best-fit 50% lethal concentration (LC(50)) values were 957.0, 76.0, 524.0, 309.0 and 224.0 μg/ml for the acetone extract, and the butanol, hexane, chloroform and 35% water in methanol fractions, respectively, when tested against nematode eggs. Best-fit LC(50) values for the larval viability test were 508.2, 485.5, 569.3, 348.9 and 196.6 μg/ml for the acetone extract, and the butanol, hexane, chloroform and 35% water in methanol fractions, respectively. The butanol fraction was most active against nematode eggs while the 35% water in methanol fraction was the most active on nematode larvae, although differences in activity between fractions were not significant (p > 0.05). Overall, these in vitro results suggest that V. amygdalina, traditionally used by small farmers in Western Africa, does possess anti-parasitic properties.