PROF. MITEMA SIMON O

The efficacies of pyrethrum marc and of albendazole against experimental sheep gastrointestinal nematode infection were compared.  Sheep were infected orally with     10 000 larvae (Haemonchus spp. (60.1%), Oesophagostomum spp. (13.9%), Trichostrongylus spp. (13.2%), Cooperia spp. (8.3%), Nematodirus spp. (3.5%), Strongyloides spp. (0.8%) and Ostertagia spp. (0.2%).  Faecal egg count reduction in albendazole-treated sheep was 100% by day 4 following treatment, compared to 37.03%, 31.3%, 38.9% and 51.8% on days 4,6,8 and 10 in pyrethrum marc-treated sheep.  These reductions were statistically significant on days 8 and 10 post-treatment (p<0.05).  The potential for using pyrethrins for helminth treatment is discussed.

The efficacies of pyrethrum marc and of albendazole against experimental sheep gastrointestinal nematode infection were compared.  Sheep were infected orally with     10 000 larvae (Haemonchus spp. (60.1%), Oesophagostomum spp. (13.9%), Trichostrongylus spp. (13.2%), Cooperia spp. (8.3%), Nematodirus spp. (3.5%), Strongyloides spp. (0.8%) and Ostertagia spp. (0.2%).  Faecal egg count reduction in albendazole-treated sheep was 100% by day 4 following treatment, compared to 37.03%, 31.3%, 38.9% and 51.8% on days 4,6,8 and 10 in pyrethrum marc-treated sheep.  These reductions were statistically significant on days 8 and 10 post-treatment (p<0.05).  The potential for using pyrethrins for helminth treatment is discussed.

Antimicrobial agents are useful for control of bacterial infections in food animals and man. Their prudent use in these animals is important to control any possible development and transfer of resistance between animals and man. The objective of this study was to generate quantitative information to evaluate antimicrobial usage patterns by animal species, route of administration, antimicrobial class and type of use from 1995 to 1999 in Kenya. Theses data are essential for risk analysis and planning and can be helpful in interpreting resistance surveillance data, and evaluating the effectiveness of prudent use efforts and antimicrobial resistance mitigation strategies. Data on quantities of active substance classes were collected from the official records of the Pharmacy and Poisons Board of the Ministry of Health and analysed in MS Excel 2000 program. The mean antimicrobial consumption for the 5-year period was 14 594 ± 1457 kg per year. This was distributed in the various antimicrobial classes as follows: 7975 kg (54.65%) of tetracyclines, 3103.96 kg (21.27%) of sulfonamides and 954.5 kg (6.56%) of aminoglycosides, 905 kg (6.20%) of β-lactams, 94 kg (0.64%) of quinolones, 35 kg (0.24%) of macrolides and 24 kg (0.16%) of others (tiamulin). Mean consumption per year among the various food animals was: 10 989 ± 357 kg in large animals (cattle, sheep, pigs and goats), 2906 ± 127 kg in poultry alone and 699 ± 427 kg in both large animals and poultry. These quantities represented 56.56% (8255 kg) consumption per year for parenteral use, 41.79% (6098 kg) for oral use and 1.65% (241 kg) for topical use (intramammary and eye ointments) in cattle. With respect to intended use in food producing animals, the mean consumption per year was: 13 178 kg (90.30%) for therapeutic use (ST), 4 kg (0.03%) for prophylactic treatment (PT) and 1411 ± 246 kg (9.67%) was used both for therapeutic and prophylactic purposes (GPT). The study confirmed that antimicrobials are not used for growth promotion in Kenya. There was no specific trend in the quantities of active antimicrobial classes. This study has revealed that the tetracyclines, sulfonamides and trimethoprim, nitrofurans aminoglycosides, β-lactams and the quinolones are the most commonly used drugs in food-producing animals in Kenya. Tetracyclines contributed approximately 55% of the total consumption, and there was an increasing trend in the consumption of quinolones from 1998.

The prevalence of gastrointestinal helminths was investigated by the examination of 255 faecal samples from different age groups and sexes of camels maintained in a communal grazing environment in northern Kenya between November 1992 and March 1993. In addition, 73 fresh faecal samples from anaemic camels and those with an eggs per gram (epg) count of >1000 were cultured for larval identification. The results showed that peak worm infestations occurred during and soon after the onset of rains. Female camels had significantly higher egg counts than males. Immature bulls had lower egg counts than calves which had lower egg counts than adults. More than 80% of the parasites identified were nematodes, of which Haemonchus was most frequent, followed by Trichostrongylus; relatively few of the camels were infected with Cooperia, Bunostomum, Oesophagostomum, Strongyloides and Ostertagia. The most frequent cestode was Moniezia. Eggs of Fasciola were identified in a few of the camels; this is the first report of fascioliasis in camels in Kenya.

Two groups of 6 rats each received subcutaneous injections of 2.3 mg/kg or 5.0 mg/kg of quinuronium, respectively, on two consecutive days, while 5 rats injected with physiological saline served as controls. Clinical signs of muscular tremors, jumps, enlarged and hyperemic eyeballs, lacrimation, depression and anorexia were observed following administration of quinuronium. One rat receiving 5 mg/kg died before termination of the study. When killed 48 h after the first injection, the quinuronium-treated rats had a higher liver weight/body weight ratio compared to the controls. Quinuronium resulted in hepatic centrilobular fatty degeneration, but no depletion of hepatic glutathione (GSH). The present findings suggest that glutathione depletion does not seem to be involved in quinuronium hepatotoxicity.