Prevalence and Molecular Identification of Trypanosomes in Dogs in Enugu North Senatorial Zone, South East Nigeria.

PURPOSE: Dogs are of immense social, psychological and economic importance in Nigeria and are severely affected by African trypanosomosis. However, the prevalence of canine African trypanosomosis (CAT) in Nigeria is underreported and the identification of the parasites relies mostly on basic morphological characteristics under the microscope, which could be misleading. The present study was carried out to determine the prevalence and characterize trypanosomes isolated from dogs in South east Nigeria. METHODS: A cross-sectional survey was carried out to determine the prevalence and molecular identification of trypanosomes in dogs in Enugu North Senatorial Zone (ENSZ), South east Nigeria. Dogs (n = 450) were randomly sampled, their blood collected and some characteristics such as sex, breed, sampling location, season and age duly noted. The blood samples were screened for trypanosomosis using standard trypanosome detection techniques. Trypanosome-positive blood samples were spotted on FTA® cards for molecular identification using nested Tubulin-PCR, ITS-PCR, TgsGP-PCR, and DNA sequencing. Some hematological parameters of the dogs such as packed cell volume (PCV), total leucocyte count (TLC), red blood cell count (RBC) were also determined. RESULTS: Of the 450 dogs sampled, 51 dogs were positive for trypanosomes with a prevalence rate of 11.3% (95% CI = 0.087-0.146). Trypanosoma brucei was the predominant trypanosome species infecting dogs in the study area. T. congolense, T. evansi, and T. vivax were also identified. The prevalence of canine trypanosomosis was significantly associated with season (χ2 = 13.821, df = 1, P = 0.0001) and the sampling location (χ2 = 6.900, df = 2, P = 0.032) while sex, breed, and age were not. The PCV and RBC of the infected dogs were significantly lower (p < 0.0001) than those of the uninfected dogs. CONCLUSIONS: CAT due to T. brucei is very prevalent in Enugu North Senatorial Zone, South east Nigeria and is associated with hematological changes. Our study also detected T. vivax in dogs in South east Nigeria which appears to be the first report of T. vivax in a dog in Nigeria.

Drug-resistant trypanosome isolates populations in dogs in Enugu North Senatorial Zone, Southeastern Nigeria.

African animal trypanosomosis is an important wasting and endemic protozoan disease causing morbidities and mortalities in animals in the sub-Saharan Africa. Currently, chemotherapy is the widely used method of African animal trypanosomosis control, especially in dogs in the sub-Saharan Africa. However, their efficacy is threatened by the emergence of drug-resistant trypanosomes owing to their extensive use and misuse over several decades amongst other factors. Thus, this study focused on the trypanocidal sensitivity and characterization of Trypanosoma species isolated from dogs in Enugu North Senatorial Zone (ENSZ), Southeastern Nigeria. Trypanosoma brucei (n = 44) and T. congolense (n = 4) isolated from naturally infected dogs in ENSZ, Southeastern Nigeria, between January and August 2016 were subjected to single dose test to assess their sensitivity to diminazene aceturate (DA) and isometamidium chloride (ISM). Subsequently, DA and multidrug-resistant isolates were further subjected to DA multi-dose test and CD50 was determined and was used to characterize the drug-resistant trypanosomes. Clones were derived from a randomly selected multidrug-resistant isolate and their sensitivity also assessed. 100% and 83.3% of T. congolense and T. brucei respectively were resistant to the trypanocides. Amongst the drug-resistant isolates, 50%, 16.7%, and 33.3% were resistant to DA, ISM, and both trypanocides respectively with CD50 ranging between 11 and 32.34 mg/kg. Drug-resistant trypanosomes were characterized into highly resistant (CD50 = 11-24.99 mg/kg) and very highly resistant (CD50 = > 25 mg/kg) trypanosome isolates. Clones also expressed high levels of resistance to both DA and ISM with CD50 values between 35.58 and 38.85 mg/kg. Trypanocidal resistance was, thus, confirmed and appears to be widespread in dogs in ENSZ, Southeastern Nigeria. The adoption of an integrated trypanosomosis control strategy in ENSZ is most desirous.

Azithromycin and Diminazene Aceturate Combination Therapy in Experimental Multidrug-resistant Trypanosoma brucei brucei Infection in Albino Rats.

Azithromycin and diminazene aceturate combination therapy in experimental multidrug-resistant Trypanosoma brucei brucei infection in albino rats was evaluated. A total of forty-five female albino rats were used. These rats were randomly assigned to nine groups of five rats each. Group 1 was the uninfected-untreated group while groups 2 - 6 were infected with 1 × 106 trypanosomes suspended in 0.3 ml of normal saline intraperitoneally. Following infection and parasitaemia, group 2 was untreated while group 3 was treated once with 7 mg/kg diminazene aceturate. Groups 4 - 6 were treated with 10, 20 and 30 mg/kg azithromycin respectively for 7 days. Groups 7 - 9 were treated with combination of 7 mg/kg diminazene aceturate (DA) once and 10, 20 and 30 mg/kg azithromycin (AZT) respectively for 7 days. Level of parasitaemia, haematological indices (packed cell volume, total erythrocyte count, total leukocyte count, haemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration), survivability, body weight and rectal temperature were used to assess the effectiveness of the combination therapy. A significant reduction in parasitaemia levels was observed in the DA-treated group and AZT-treated group 6 while clearance of parasitaemia was observed in the DA-AZT treated groups 7 - 9 for periods between 1 and 5 days post treatment. The haematological indices and survivability of the DA-AZT treated groups were better than the DA-treated group despite the relapse recorded in those groups. One rat each in the DA-AZT combination groups survived till the end of the experiment. In conclusion, the DA-AZT combination treatment can be used as a possible adjunct to DA in the treatment of multidrug-resistant T. brucei brucei. The combination also enhanced survivability and decreased the effect of the disease in rats.

Evaluation of the anthelminthic potential of Duranta erecta L. (Verbenaceae) fruits used in Nigerian ethnomedicine as a vermifuge.

ETHNOPHARMACOLOGICAL RELEVANCE: Duranta erecta L. fruits have been reported to have in vitro anthelminthic properties. People living in the tropical South-Eastern part of Nigeria use the plant in folk medicine for the treatment of malaria, abscesses and as a vermifuge. Although there are a few reports about its in vitro anthelminthic activity against different worm categories, scientific reports regarding its in vivo anthelminthic activity are limited. AIM OF THE STUDY: This study was designed with the aim of determining the potential of the plant as an anthelminthic and to verify the claims made by its local users. MATERIALS AND METHODS: Acute toxicity of the plant extract was determined using Lorke's method. Anthelminthic activity was investigated using adult male albino mice experimentally infected with Heligmosomoides bakeri infective L3. Graded ascending doses of the plant extract and Albendazole respectively were orally administered to the mice in the infected groups. Corprological and haematological parameters were recorded within the study period. Twenty-eight (28) days post-infection, all infected mice were humanely sacrificed and the Post-Mortem Adult Worm Burden (WB) was estimated and recorded. RESULTS: The results showed that the extract had an LD50 greater than 5000 mg/kg BW and therefore was not acutely toxic for oral use. It also showed that the plant extract was unable to eliminate the faecal egg output or adult worms in the gastrointestinal tract of infected animals even at the high doses used in the study. This was in contrast to Albendazole which significantly (p < .05) reduced faecal egg counts and worm burdens by 71% and 92% respectively in treated mice. Following infection, there was anaemia in all infected groups seen from results of erythrocytic parameters. Treatment with the plant extract, regardless of the dose, was unable to effectively reverse the effect of parasite infection on erythrocytic parameters. However, treatment with Albendazole positively reversed the anaemia, restoring the mice to pre-infection values by the end of the experiment. The results showed significant (p < .05) increase in WBC counts across all groups following infection with the parasite. Treatment with the plant extract and Albendazole respectively, significantly (p < .05) reduced the WBC counts to near pre-infection values in most treatment groups. CONCLUSION: As a result of the poor anthelminthic effects recorded in the study, it is therefore recommended that Duranta erecta L. fruits be explored for its other useful effects rather than as an anthelminthic.

Effect of diminazene aceturate, levamisole and vitamin C combination therapy in rats experimentally infected with Trypanosoma brucei brucei

OBJECTIVE@#To investigate the effect of diminazene aceturate (DA) alone or in combination with either levamisole and/or Vitamin C in albino rats experimentally infected with Trypanosoma brucei brucei.@*METHODS@#Thirty adult male albino rats, randomly assigned into 6 groups (A-F) of 5 rats each were used. They were either infected with 1×10(6) trypanosomes intraperitoneally (groups A-E) or uninfected (group F). The different groups were treated respectively as follows: group A-with 3.5 mg/kg DA; group B-3.5 mg/kg DA and 7.5 mg/kg levamisole; group C-3.5 mg/kg DA and 100 mg/kg vitamin C; and group D-3.5 mg/kg DA and 7.5 mg/kg levamisole and 100 mg/kg vitamin C. Group E was left untreated. Parameters assessed include: rectal temperature, body weight changes, packed cell volume (PCV), Haemoglobin concentration (Hb), total leucocyte count (TLC) differential leucocyte count (DLC), parasitaemia, clinical signs and survivability.@*RESULTS@#Average pre-patent period of 5 days was recorded. Parasites in the blood were cleared in all treated groups (A-D) within 48 hours post treatment (PT). Untreated rats in group E died between 25 and 32 days post infection (PI). Relapse was not recorded in all the treated groups (A-D). The initial reduction in PCV, Hb, TLC and increases in rectal temperature following infection were reversed by the treatments. The rats that received drug combinations (groups B, C and D) showed faster and higher recovery rates than the uninfected control and group A.@*CONCLUSIONS@#Levamisole and/or Vitamin C combination with DA were more effective in the treatment of rats infected with Trypanosoma brucei brucei.