Efficacy of repeated doses of diminazene aceturate (Dinazene®) in the treatment of experimental Trypanosoma brucei infection of Albino rats.

The efficacy of repeated doses of Dinazene® in Albino rats experimentally infected with Trypanosoma brucei (Gboko strain) was investigated. A total of 30 adult female Albino rats weighing 130-190 g were used for the study. They were assigned to six groups (groups A-F) of five rats each. Groups A-D were infected intraperitoneally with 1.0 × 106 trypanosomes in 400 µL of PBS diluted blood while groups E (uninfected treated) and F (uninfected untreated) served as controls. The rats in the groups A-D as well as those in group E were treated with 7.0 mg/kg body weight at day 11 post infection. Groups B, C and D however received two, three and four repeated doses of the drug at weekly intervals following initial treatment. There was complete clearance of the parasite within 120 h post treatment. Parasitaemia, packed cell volume (PCV), total red blood cell (RBC) and white blood cell (WBC) counts, haemoglobin concentration (Hb), rectal temperature, and body weight were used to assay the efficacy of treatment. Following treatment and parasite clearance from the blood, there was improvement (P<0.05) in the values of parameters measured when compared to the uninfected controls. However, relapse infection was observed in the rats of group A, B and C, with a resultant decline in clinical condition and values of parameters used to assess efficacy. We concluded that four consecutive treatments using same dose at weekly intervals proved efficacious in the experimental management of T. brucei infection in rats.

Gastrointestinal helminth parasites of local chickens from selected communities in Nsukka region of south eastern Nigeria.

The prevalence of gastrointestinal helminths of local chickens in Nsukka region of Southeastern Nigeria was studied using 125 free range local birds purchased from four communities in Nsukka zone namely, Obollo-afor, Orba, Nsukka urban and Owerre Eze-orba. The birds were sacrificed humanely and their oesophagus, crop, proventriculus, gizzard, small intestine and caecum examined for the presence of gastrointestinal helminths. Worms when present were isolated and identified using standard parasitological procedures. The study identified four species of cestodes namely Raillietina echinobothridia, R. tetragona, R. cesticillus and Choanotaenia infundibulum and two species of nematodes namely, Ascaridia galli and Heterakis gallinarum. Results obtained showed 96.8 % prevalence of gastrointestinal helminth parasites in the birds with cestodes being the more prevalent class (70.4 %). Raillietina spp was the most prevalent cestode encountered and A. galli the most prevalent nematode. Prevalence rates of infections recorded 14.4 % for nematode species, 26.4 % for cestodes and 56 % for mixed infections of nematodes and cestodes. It was concluded that local chickens are common in the area and could serve as a potential source of helminth infections to intensively managed birds in the study area.

Effects of Trypanosoma brucei infection and diminazene aceturate therapy on testicular morphology and function of Nigerian local dogs.

The effects of Trypanosoma brucei infection on testicular morphology and function and the changes associated with treatment of infected dogs with diminazene aceturate were studied using fifteen Nigerian adult male dogs. The dogs were randomly assigned into three groups A, B and C consisting of five dogs each. Groups A and B were infected with 1 × 10(6) trypanosomes and group C was the uninfected control. Following infection, parasitaemia levels were monitored daily whereas the rectal temperature, body weight, packed cell volume, scrotal circumference and serum testosterone levels were monitored weekly. At parasitaemia peak, dogs in group A were orchidectomised while dogs in group B were treated with 7.0mg/kg body weight of diminazene aceturate (DA). Dogs in groups B and C were later orchidectomised on day 73 of the experiment. The harvested testes and epididymides were weighed and the epididymal sperm reserves of all the dogs determined. Also the sperm quality (mass activity, sperm motility and sperm morphology) were determined. The testes were sectioned after processing and studied histomorphologically. Acute trypanosomosis was observed following infection. The low serum testosterone levels observed from day 14 post infection (pi) gradually improved following treatment. Testicular weight, epididymal weight and sperm quality were significantly low (p<0.05) in the infected dogs when compared to the control group but gradually improved following treatment. Histomorphological studies revealed testicular degeneration characterized by depopulation of seminiferous tubules and depletion of spermatogenic cells in dogs of group A whereas the tissue sections of the testes of dogs in group B were similar to those of the control group. It was therefore concluded that infection of dogs with T. brucei adversely affected testicular morphology and function. Treatment with diminazene aceturate reversed the reproductive abnormalities caused by the parasite.

Efficacy of levamisole and ivermectin in the control of bovine parasitic gastroenteritis in the sub-humid savanna zone of southeastern Nigeria.

Faecal egg count reduction test was used to evaluate the efficacy of levamisole and ivermectin in the control of bovine parasitic gastroenteritis in a part of Nigeria not previously surveyed. Ninety (90) randomly selected N'dama cattle from two herds in Nsukka, Enugu State of Nigeria, were studied. The animals were divided into two groups, namely, levamisole and ivermectin treatment groups. Faecal samples were collected prior to the administration of the respective anthelmintic and faecal egg count/gram of faeces determined. Post-treatment faecal samples were collected after 10 and 14 days of levamisole and ivermectin administration, respectively, and faecal egg count (FEC) determined. Thereafter, the faecal egg count reduction was calculated based on the formula [Formula: see text]. Pooled faecal samples for the respective treatment groups were cultured for larval identification and count. Pre-treatment FEC showed that the animals were readily infected with gastrointestinal nematodes with mean FEC of 233.0 ± 35.13 and 302.0 ± 19.94, respectively, for the levamisole- and ivermectin-treated groups. Post-treatment FEC of 0 was recorded for both groups, showing a 100% reduction of the pre-treatment faecal egg count. We concluded that the anthelmintics used in this work were very effective in the control of bovine parasitic gastroenteritis in the study areas, and no resistance was detected.

Comparative serum biochemical changes in mongrel dogs following single and mixed infections of Trypanosoma congolense and Trypanosoma brucei brucei.

The serum activities of alkaline phosphatase (AP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and the serum levels of conjugated bilirubin (CB), blood urea nitrogen (BUN) and creatinine were studied following single and mixed infections of mongrel dogs with Trypanosoma congolense and Trypanosoma brucei brucei. Twenty mongrel dogs of both sexes aged between 3 and 6 months, and weighing between 2.5 and 5.9 kg were used for the study. The dogs were kept in clean metal cages in a fly-proof house and were fed and given water ad libitum. The twenty dogs were divided into four groups of five dogs each. Group I dogs were uninfected control, group II were infected with T. congolense, group III were infected with T. brucei brucei and group IV were infected with both T. congolense and T. brucei brucei. Each dog in the infected groups II and III was inoculated intraperitonealy (i/p) with 1.0 ml of PBS diluted blood containing 1.0×10(6) trypanosomes whereas each infected dog in group IV (mixed infection) was inoculated with 0.5 ml of the PBS diluted blood containing 0.5×10(6)T. congolense and 0.5 ml of the PBS diluted blood containing 0.5×10(6)T. brucei brucei i/p. Parasites were detectable in the blood of the infected dogs in groups II, III, and IV 10-13 days post infection (PI) with the mean pre-patent period (PP) of 12, 10, and 11 days respectively. Trypanosome infection caused a significant (P<0.05) increase in the serum activities of AP, ALT, AST and the serum levels of creatinine, CB, and BUN. The significant increases in the serum levels of CB, BUN, and creatinine and serum activities of AP and AST became noticeable from day seven PI in all the infected groups whereas that of ALT became noticeable from day 14 PI and increased continuously until the experiment was terminated. These increases however did not differ significantly (P>0.05) between the infected groups in most cases. It was thus concluded that single or mixed infection of mongrel dogs with T. congolense and T. brucei brucei resulted in significant increases in the serum activities of AP, AST, ALT and serum levels of creatinine, CB and BUN which in most cases did not differ significantly (P>0.05) among the infected groups.