Parasites: -Schistosoma -Lung Fluke

Schistosoma 0 There are 3 species of Schistosoma that are important to humans 0 S. mansoni 0 S. japonicum 0 S. haematobium 0 Adult worms live in the circulatory system and the eggs are found in the feces. 0 Different from other flukes because there are male and females. 0 Snail is the intermediate host

Life Cycle 0 Eggs passed in feces 0 Miracidia hatch and find way to a snail species 0 Cercaria enter unbroken skin and migrate to veins near liver.

Symptoms Swimmers itch) 0 Localized bleeding and heals within days at point of cercariae penetration. (Swimmers itch) 0 Symptoms not necessarily caused by worm but by the body’s reaction to the eggs. 0 Stage 1: (1-3 months) 0 Fever, abdominal pain, general feeling of sickness, liver tenderness. Katayama fever 0 Stage 2: 0 Severe liver damage and becomes enlarged as well as the spleen 0 Does lead to death in some cases

Epidemiology 0 Most commonly associated with regions that have poor sanitation. Younger school aged children most at risk.

Treatment / Prevention 0 Prevention: 0 Avoid swimming in freshwater in countries known to have parasite. 0 Drink Safe Water 0 Safe bathing 0 Create better sanitary conditions 0 Using chemicals to kill snails 0 Treatment: 0 Praziquantel for infections 0 Vasnil to treat S. mansoni, also cheaper 0 Most commonly used when infection is on a large scale.

Review Questions 0 What is the intermediate host for Schistosoma? 0 What is the best way to prevent Schistosoma? 0 What is swimmer itch and how is it caused?

Lung Fluke 0 Humans many times are accidental host of these parasites 0 Primary parasite of wild cats such as tigers, lions, leopards other animals like foxes and wolves as well. 0 Main lung fluke to infect humans : Paragonimus

Life Cycle 0 Miracidia find shelled snail and mature 0 Cercariae invade a crustaceans: crabs, lobster, shrimp 0 Get infected by ingesting improperly cooked crustaceans

Symptoms 0 After ingestion they migrate to lungs where they reproduce in the lungs. No symptoms with migration 0 Cough up the eggs and swallow them and then eggs are deposited in our feces. 0 Symptoms similar to a bad cough or bronchitis 0 Because humans are not the as suitable of a host parasite may enter other parts of the body such as the brain, spinal cord and abdominal cavity. 0 Headache, fever, vomiting and some visual disturbance 0 Leads to, in severe cases, convulsive seizures

Epidemiology 0 Most common occurrences in China, the Philippines, Japan, Vietnam, South Korea, Taiwan and Thailand.

Treatment/Prevention 0 Prevention: 0 Cooking crayfish, crabs, lobster and other crustaceans 0 Treatment: 0 Praziquantel taken 3 times daily for 2 days. 0 If daily doses are changed the drug was seen to be ineffective

Group Response 0 In your table group talk and come up with some common themes that have been seen in our investigation of all the parasites covered up to this point. 0 Look at: 0 Life Cycles 0 Hosts 0 Prevention/Treatment 0 Talk about 1 parasite you think has the biggest repercussions for a community stricken with it. 0 Take about 5 minutes to discuss and then we will discuss as a class. Each group will share