Attitude And The Practice Of Affirmative Action For Female Students The Case Of Mekelle University

Schistosomiasis is a chronic parasitic disease, affecting over 200 million people andrncausing over 300,000 deaths per year mainly in sub-Saharan Africa. Strains from thernsame or different geographical locations have shown differences in egg production,rninfectivity, pathogenicity and susceptibility to chemotherapy. The objective of thisrnstudy was to assess the dynamics, genetic polymorphism and structure of Schistosomarnmansoni isolates from four endemic foci in Ethiopia. In a cross-sectional studyrninvolving 1,073 study participants from Kemissie (10°43'30''N, 039°04'20''E), WondornGenet (07°05'35''N, 038°36'66''E), Ziway (07°56'37''N, 038°43'25''E), and Sille-Elgorn(05°28'39''N, 037°26'02''E), stool specimens were collected and examined forrnSchistosoma mansoni infection using Kato method. Stool specimens were againrncollected from 91 positive individuals for molecular studies. The overall prevalence andrnintensity of Schistosoma mansoni infection from study subjects of Kemissie, WondornGenet and Ziway was found to be 60.48% and 273 eggs per gram of stool, respectively.rnOut of 288 miracidia genotyped at a molecular level, 164 unique alleles were countedrnfor all the 11 loci typed from Kemissie (127), Sille-Elgo (102), Wondo Genet (123) andrnZiway (94). At a population level, the mean number of alleles per locus, allelic richness,rnexpected heterozygosity in Hardy–Weinberg equilibrium and pairwise FST valuesrnranged from 8.5 to 11.5, 3.46-20.8, 0.66–0.73 and 3.57–13.63%, respectively. ThernBayesian structuration showed 67.5-87.3% genetic differentiation of the studyrnpopulations. The PCA and the Bayesian STRUCTURE had shown four clusters ofrnpopulation. Generally, high level of genetic diversity and population differentiationrncharacterized the S. mansoni isolates of Ethiopia. Genetic diversity and multiplicity ofrninfection with Schistosoma mansoni isolates among and within individual subjects fromrnthe four endemic areas of Ethiopia at infrapopulation level also showed a value of 3.09rnto 7.55, 1-1.96, 0.59–0.73 and 0.1763–0.4989, mean number of alleles per locus, allelicrnrichness, expected heterozygosity in Hardy–Weinberg equilibrium and FIS, respectively.rnMean estimated genetically unique adult worm pairs within hosts ranged from 66-92%rnrevealing the occurrence of infection of a single host with multiple S. mansoni strains.rnThe data also indicated the occurrence of inter- and intra-host genetic variations. Basedrnon previous suggestions about the East African origin of S. mansoni, the present studyrnenabled us to speculate that Ethiopia could be the probable country of origin for schistosomes. However, definite conclusion requires further investigation using otherrngenetic markers.rnKey words: Ethiopia, Schistosoma mansoni, Microsatellite, Genetic diversity,rnPopulation structure

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