Effectiveness of an integrated intervention in the control of endo- and ectoparasites of pigs kept by smallholder farmers in Mbeya rural and Mbozi districts, Tanzania.

This study was conducted to evaluate effectiveness of an integrated management intervention in the control of endo- and ectoparasites of pigs kept by smallholder farmers in Mbeya Rural and Mbozi districts of southern highlands of Tanzania. A repeated cross-sectional group randomization design was employed, with 10 villages in the intervention group and six villages in the control group. The intervention consisted of improving pig confinement, feeds and feeding practices, and strategic anthelmintic treatment of pigs with oxfendazole, to primarily control Taenia solium (porcine) cysticercosis and nematodes; and with ivermectin to control ectoparasites and nematodes. Blood and faecal samples, ectoparasite specimens and skin scrapings were collected at baseline and two follow-up rounds, at an interval of seven months. A total of 482, 460 and 421 pigs were sampled in 221, 196 and 139 households at baseline, first and second follow-up visits respectively. Sero-prevalence of PC, prevalence and burden of gastrointestinal (GI) nematodes and prevalence of ectoparasites were determined using Ag-ELISA, McMaster faecal egg counting technique and body searches/skin scrapings, respectively. Mann Whitney test was used to measure intervention effect by comparing changes from baseline values of prevalence and faecal egg counts between the two groups. No significant difference (p > 0.05) was observed between the two groups, in changes from baseline of sero-prevalence of PC. The intervention significantly reduced prevalence of Trichuris suis (p = 0.044) and mean faecal egg counts of Ascaris suum (p = 0.02) from baseline to first follow-up. The intervention showed a substantial effect on the prevalence of ectoparasites as it significantly reduced overall prevalence of ectoparasites (p = 0.026), lice (p = 0.045), ticks (p = 0.049) and mites (p = 0.013) from baseline to first follow-up, and prevalence of ectoparasites, lice and mites from baseline to second follow-up (p = 0.052, p = 0.03, p = 0.017 respectively). This study has demonstrated a moderate effect of the intervention on controlling GI nematodes and ectoparasites, but no effect on sero-prevalence of PC. The reported ineffectiveness of the intervention against PC is probably an underestimation because serology is not able to provide quantitative data. It may also be a result of reduced compliance as this was a field study. Nevertheless, further studies are needed to better understand transmission dynamics of PC and explore One Health approaches including treatment of the human population against taeniosis to better secure public health.

Risk factors for prevalence of pig parasitoses in Mbeya Region, Tanzania.

A cross-sectional study was carried out to determine risk factors for prevalence of common endo- and ectoparasites of pigs kept by smallholder farmers in Mbozi and Mbeya (Rural) districts of Mbeya Region, in Tanzania. A total of 482 pigs from 220 households of 16 villages, eight in each district were randomly selected and examined. Prevalence of Taenia solium cysticercosis was 11.5%, gastrointestinal nematodes 63.7% and ectoparasites 21.2% based on Ag-ELISA, McMaster technique and full body searches/ear scrapings, respectively. Nematode eggs identified were strongyles (Oesophagostomum spp. and Trichostrongylus spp.), Ascaris suum, Trichuris suis and Strongyloides ransomi with prevalence of 57.4%, 17.5%, 5.3% and 1.1%, respectively. Four groups of ectoparasites were identified, i.e. lice (Haematopinus suis), ticks (Rhipicephalus spp., Amblyomma spp., Haemaphysalis spp. and Boophilus spp.), fleas (Ctenocephalides canis) and mites (Sarcoptes scabiei var. suis and Demodex phylloides), with prevalence of 19.1%, 2.1%, 0.4%, and 1.2%, respectively. Pigs in Mbeya (Rural) District had higher odds for porcine cysticercosis (OR=2.63, 95% CI: [1.22-5.55]). Poor pen hygiene and infrequent antiparasitic treatment were identified to be risk factors for prevalence of nematode infections (OR=1.95 [1.09-3.52] and OR=1.78 [1.06-2.94], respectively). The odds for high nematode burdens increased in cases of poor pen hygiene (OR=4.20 [2.54-6.62]) and poor feed quality (OR=3.7 [1.66-8.33]). Pigs not treated with antiparasitic drugs within the last three months had higher odds for ectoparasite (OR=4.0 [1.78-9.09]) and lice infestations (OR=8.33 [1.96-14.28]) than treated pigs. This study has shown that parasitoses constitute a major burden for smallholder pigs in Mbeya Region and major risk factors included infrequent antiparasitic treatment, poor pen hygiene and poor feed quality. Cost-effective intervention strategies are needed to improve pork production, secure pig welfare and ensure safe pork for human consumption.

Productivity and parasitic infections of pigs kept under different management systems by smallholder farmers in Mbeya and Mbozi districts, Tanzania.

An on farm experiment was carried out to assess the effects of production systems on the performance of local pigs kept by smallholder farmers. Six villages from Mbeya and Mbozi districts, Tanzania were purposely selected based on the prominent pig production systems: free range, semi-confinement and total confinement. Fifteen pig keeping households were randomly selected from each village to participate in the study. A participatory rural appraisal and structured questionnaire were used for collecting information from the households on pig production and reproduction performance. In addition, a total of 180 weaner pigs, 2-3 months old, were purchased and randomly allocated to the 90 participating households. The pigs were subjected to three production systems: free range (M1), confinement with local diet (M2) and confinement with a compounded diet and anthelmintic treatment (M3). The anthelmintic treatment (piperazine citrate) was administered at 1 g per kg body weight. Faecal and blood samples were collected at month three of the experiment to assess the burden of intestinal helminths and sero-prevalence of Taenia solium cysticercosis, respectively. Sows kept under free range system were reported to have smaller litter size both at farrowing and at weaning compared to those kept under confinement. The experiment showed pigs under M3 had higher (P < 0.05) liveweight gains (136 g/day) compared to pigs in M2 (73 g/day) and M1 (68 g/day). In addition, pigs in M3 had higher body length and heart girth size with the feed to gain ratio of 8.5. Free range pigs tended to have lower faecal egg counts for most worm species compared to permanently confined pigs. Sero-prevalence of Taenia solium cysticercosis was 26%, with village prevalence ranging from 8 to 52%. Although pigs kept in M3 performed better than the rest, the compounded feed was too expensive for the farmers to afford. Locally available feed types combined with vitamin and mineral supplements may be a more sustainable option.