Describe the adaptations of Schistosoma spp to their parasitic mode of life

a) Describe the adaptations of Schistosoma spp to their parasitic mode of life

The parasite utilizes two hosts; the snail and humans; to increase chances of transfer of the parasite from one place to another; have suckers for attachment to host walls; to prevent them from being dislodged; the parasite produces many larval forms (e.g. miracidia, cercariae and redia) in snails; to increase chances of transmission and survival; as this feature poses barriers/difficulties in efforts aimed at eradicating the parasite; cercariae larvae and eggs of the parasite have glands that secrete lytic enzymes; which soften the tissues of humans/snails; to allow for penetration; chemical substances produced by the adult worm; protects the parasite from the action of the hosts’ defense mechanisms; they exist as separate sexes; with the male carrying the female; this ensures that eggs produced by the female are fertilized before being shed into the blood stream; Max. 15 mks


b) Outline five measures that can be employed to prevent and control the spread of the parasite
Proper disposal of human waste; urine and faecal material should not be disposed in water bodies to avoid contamination by the eggs or adult worms; drainage of stagnant water pools and use of molluscides to kill the intermediate hosts (snails); avoid swimming/bathing in snail-infested water bodies; wearing protective clothing such as gloves and gumboots when working or walking in swampy areas; personal hygiene that includes washing hands after visiting the toilet and drinking of boiled or chemically treated water to kill the eggs and the larval forms in the water; proper treatment of infected persons;