Acaricide failure has been on the rise in the western and central cattle corridor of Uganda. In this study, we identified the tick species associated with acaricide failure and determined their susceptibility to various acaricide molecules used for tick control in Uganda. In this cross sectional study, tick samples were collected and identified to species level from 54 purposively selected farms (from 17 districts) that mostly had a history of acaricide failure. Larval packet test was used to screen 31 tick populations from 30 farms for susceptibility at discriminating dose (DD) and 2 × DD of five panels of commercial acaricide molecules belonging to the following classes; amidine, synthetic pyrethroid (SP), organophosphate (OP) and OP-SP co-formulations (COF). Resistance was assessed based on World Health Organization criteria for screening insecticide resistance. Of the 1357 ticks identified, Rhipicephalus (Rhipicephalus) appendiculatus and Rhipicephalus (Boophilus) decoloratus were the major (95.6 %) tick species in farms sampled. Resistance against SP was detected in 90.0 % (27/30) of the tick populations tested. Worryingly, 60.0 % (18/30) and 63.0 % (19/30) of the above ticks were super resistant (0 % mortality) against 2 × DD cypermethrin and deltamethrin, respectively. Resistance was also detected against COF (43.3 %), OP chlorfenvinphos (13.3 %) and amitraz (12.9 %). In two years, 74.1 % (20/27) of the farms had used two to three acaricide molecules, and 55.6 % (15/27) rotated the molecules wrongly. Multi-acaricide resistance (at least 2 molecules) was detected in 55.2 % (16/29) of the resistant Rhipicephalus ticks and significantly associated with R. decoloratus (p = 0.0133), use of both SP and COF in the last 2 years (p < 0.001) and Kiruhura district (p = 0.0339). Despite emergence of amitraz resistance in the greater Bushenyi area, it was the most efficacious molecule against SP and COF resistant ticks. This study is the first to report emergence of super SP resistant and multi-acaricide resistant Rhipicephalus ticks in Uganda. Amitraz was the best acaricide against SP and COF resistant ticks. However, in the absence of technical interventions, farmer-led solutions aimed at troubleshooting for efficacy of multitude of acaricides at their disposal are expected to potentially cause negative collateral effects on future chemical tick control options, animal welfare and public health.
Porcine Circovirus type 2 (PCV2) infections and associated diseases have been rarely studied in Africa. There is no report of PCV2 infection-associated morbidity and the level of awareness of stakeholders has never been investigated in Uganda. This cross sectional survey investigated the occurrence of Porcine Circovirus type 2 - systemic disease (PCV2-SD) among pigs and the associated level of awareness of stakeholders in Central Uganda. Data were collected using questionnaires, Focus Group Discussions (FGDs), key informant interviews and laboratory investigations. All respondents (n = 131) and farmers attending FGDs (n = 31) had never heard of PCV2-SD and only 16.7% (n = 2) of the interviewed animal health workers (n = 12) knew about the disease. Among the farms, 20 piglets presenting with a chronic wasting and a persistent diarrhea were detected and sampled for laboratory investigations. Severe lymphoid depletion with histiocytic and macrophage infiltration in lymphoid organs (n = 8), shortening of intestinal villi (n = 9), abscesses in various organs (n = 15) and granulomatous pneumonia (n = 2) were the major histopathological lesions described. Immunohistochemistry and PCR assays on organs with implicating lesions confirmed PCV2 infection in 25% (n = 5) of the 20 pigs. The study confirmed the occurrence of PCV2 infections among piglets with persistent diarrhea on pig farms in central Uganda and revealed a low level of associated knowledge among farmers and veterinary practitioners. The study arouses the need for systematic studies on prevalence of PCV2 infections and sensitization of stakeholders on occurrence of PCV2 infections in Uganda.
1 January 2016 in American Journal of Clinical and Experimental Medicine
Several plants are used by farmers for the treatment of gastrointestinal nematodes (GIN) in goats. However, their phytochemical properties, efficacy and safety is largely unknown. A trial was therefore designed to determine in vivo efficacy of ethanolic extract of Cassia nigricans against gastrointestinal nematodes (GIN) in goats. Cassia nigricans leaves were collected from Arua District, Uganda. Ethanolic extraction method was to prepare extracts and the experimental goats were dosed accordingly. Treatments were assigned to five (5) groups of goats (n=9) as follows: Group A, the negative control (30ml of distilled water; group B, the positive control (Albendazole 10%, 8mg/kg). Groups C, D and E received extracts at 50, 100 and 150mg/kg, respectively. Live weights (LWs kg), faecal samples (for faecal egg count reduction (FECR) based on eggs per gram (EPGs) of faeces, packed cell volume (PCV %), total protein (TP g/dL), body condition scores (1-5) and Faffa Malan Chart (FAMACHA scores 1-5) were taken on day 1 of the experiment and subsequently at 7-day intervals for 4 weeks. Results revealed that a significant increase in LWs by 2nd week was observed in goats treated with Albendazole from 20.8 ± 1.9 to 21.9 ± 1.8 (p ≤ 0.05). No change in LWs and in TP was observed in all other groups (p ≥ 0.05). Only Albendazole treated group exhibited a significant increase of PCV in the 2nd week (p ≤ 0.05). EPGs were observed to significantly drop in those treated with Albendazole by the 2nd week from 300 ± 91 to 0 ± 0 and extract at 150 mg/kg dose from 740 ± 236 to 60 ± 25 (p ≤ 0.05). The FECR for Albendazole, 50, 100 and 150 mg/kg doses of the extract were found to be 100%, 37.3%, 66.6% and 83.8% respectively. Only at 150 mg/kg dose did the extract show moderate efficacy in reducing mixed Strongyle spp faecal egg counts in goats. Strongyles spp. were the most predominant genera of nematodes found in goats. Further evaluations of leaf extracts and other plant parts is necessary to establish its potential as a source of local effective remedy against gastro-intestinal nematodes in goats.