Prevalence and distribution of Echinococcus spp. in wild and domestic animals across Africa: A systematic review and meta-analysis.

Cystic echinococcosis (CE), a worldwide zoonosis, is highly prevalent in Africa particularly in northern and eastern Africa where data are more abundant than other regions. However, harmonization of available data through systematic review and meta-analysis may foster improved transboundary cooperation for the control of CE in Africa. Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, research articles (from 2000 to 2019) were retrieved from ScienceDirect, PubMed, African Journals OnLine and Google Scholar databases. A total of 98 studies of 806,624 animals from 13 countries comprising 264,016 goats, 247,326 sheep, 251,106 cattle, 28,314 camels, 4,764 buffaloes, 2,920 equids, 1,966 pigs, 408 wild boars and 50 Norway rats were available for systematic review and meta-analysis of pooled prevalence including 5,048 dogs, 345 lions, 220 hyenas, 94 wolves and 47 jackals/foxes analysed for Echinococcus infection. In total, 46,869 animals were infected and pooled prevalence of CE in intermediate hosts was highest in camels (17.1%; 95% CI: 12.1-22.8) and lowest in pigs (0.3%; 95% CI: 0.1-0.6). Results also showed uneven species/genotype distribution across the continent such that Echinococcus granulosus sensu stricto (G1, G3) constituted 74.45% of the total isolates from East Africa, E. canadensis (G6/7) accounted for 60.3% and 97.4% in North and West Africa, respectively, while 81.3% of E. ortleppi (G5) were recorded for southern Africa. The comparatively higher prevalence estimates for eastern and northern Africa than other regions indicate where efforts on CE management should now be given greater attention in Africa. Additionally, this study also advocates for better cooperation between countries within the same sub-region and the establishment of joint CE control programmes.

[Differential Expression of Six wnt Gene Family Members in Echinococcus granulosus Protoscoleces and Adult Worms].

Objective: To investigate the differential mRNA expression and tissue distribution of wnt [wingless-type mouse mammary tumor virus (MMTV) integration site family, wnt] gene members wnt1, wnt2, wnt4, wnt5, wnt11A and wnt11B in protoscoleces and adult worms of Echinococcus granulosus. Methods: The mRNA expression of wnt1, wnt2, wnt4, wnt5, wnt11A and wnt11B was determined by qRT-PCR. Tissue distribution of wnt1, wnt2, wnt4, wnt5, wnt11A and wnt11B in Echinococcus granulosus protoscoleces was determined by the whole-mount in situ hybridization. Results: The qRT-PCR results showed that the mRNA expression levels of wnt1 and wnt2 in the adult worms were 1.49 （P>0.05） and 2.53 folds（P<0.05） of those in the protoscoleces, respectively. The mRNA expression levels of wnt4, wnt5, wnt11A and wnt11B in the protoscoleces were 25.00（P<0.01）, 33.33（P<0.01）, 14.29（P<0.01） and 1.03 folds（P>0.05） of those in the adult worms, respectively. In brief, there was no significant difference of mRNA expression in wnt2 and wnt11B between protoscoleces and adult, but there was a significant difference of mRNA expression in wnt1, wnt4, wnt5 and wnt11A between protoscoleces and adults. Results of the whole-mount in situ hybridization showed that in protoscoleces wnt1 was mainly localized in the epidermal tissue, wnt2 in suckers, wnt4 in suckers and rostellum, wnt5 and wnt11B in suckers and epidermal tissue, and wnt11A in rostellum and hooks. Conclusion: The mRNA expression of wnt2 in adult E. granulosus was higher than that in protoscoleces, and the mRNA expression ofwnt4, wnt5, wnt11A and wnt11B in protoscoleces was higher than that in the adult worms. The six wnt gene family members were all distributed in the forward region of protoscoleces.