Lung Flukes – Chapter 18, p. 281-285 Paragonimus westermani Oriental Lung Fluke is an important human parasite in the Orient (Japan, Korea, China, SE Asia), Pacific islands (Philippines), and India. It is occasionally found in western Africa and South America. ______________________ human cases It is occasionally found in western Africa and South America. Parasite is not endemic in North America .
Paragonimus westermani Recent cases have been identified in _________________________________ in Minnesota and Wisconsin. Originally misdiagnosed as _________________________________, as the lung pathology mimics this disease.
Morphology of Adult Paragonimus westermani Adults are 8-12 mm long x 4-6 mm wide; 3-5 mm thick. _______________________ is lobed and located on one side of the _______________________ Egg-filled _____________________ is on opposite side of acetabulum. Characteristic structure is the extensive _____________________ - extend from anterior end to posterior end. ________________________ are lobed and are located opposite each other in mid-posterior of body.
Life Cycle of Paragonimus westermani DEFINITIVE HOSTS : Parasite shows low host specificity in that ____________________________ (primarily __________________________________) can serve as a definitive host. - these hosts also serve as ________________________ for transmission to a human. - thus, this parasite is a __________________________
Life Cycle of Paragonimus westermani HABITAT: Adults live in ________________________ _____________________________________________
Life Cycle of Paragonimus westermani 1. Adults occur in pairs in the __________________________ 2. __________________ are released into the bronchioles and move along the respiratory tree by ciliary action. They move into the bronchi trachea pharynx where they are: 1. 2.
Life Cycle of Paragonimus westermani <ul><li>3. Eggs must be released into an aquatic habitat. _________________________ hatch and swim until they penetrate _______________________ first intermediate host. </li></ul><ul><li>Within the snail, sporocyst and redial generations occur. </li></ul>
Life Cycle of Paragonimus westermani 5. _______________________ _________________________ leave the snail and crawl along the pond bottom until they come in contact with a _________________________ (second intermediate host).
Life Cycle of Paragonimus westermani <ul><li>Cercariae penetrate crab or crayfish and encyst in the muscles as _______________________ </li></ul><ul><li>7. When crab or crayfish is eaten raw or poorly cooked, metacercariae excyst in the duodenum. </li></ul><ul><li>- The immature adults bore through the wall of the duodenum. </li></ul><ul><li>- They then ________________________ ________________________ and invade the lung bronchioles and are mature in 2-3 months. </li></ul>
Pathology of Paragonimus westermani Normal bronchiole <ul><li>ADULTS: </li></ul><ul><li>(1) bronchiolar epithelium thickens </li></ul><ul><li>(2) connective tissue capsules are formed around worms. </li></ul><ul><li>(3) these capsules often ulcerate causing hemorrhaging. </li></ul><ul><li>(4) fibrous connective (scar) tissue deposition occurs throughout the lungs. </li></ul><ul><li>Symptoms are difficulty in breathing, coughing, and bloody sputum. </li></ul><ul><li>Infection often __________________________________and can be misdiagnosed </li></ul>
Pathology of Paragonimus westermani IMMATURE ADULTS: Migration of the immatures can be dangerous if the worms ________________________________and end up in ectopic sites such as the ________________________________ Fatalities may occur.
Paragonimus westermani <ul><li>DIAGNOSIS - Identify eggs in the sputum or feces. </li></ul><ul><li>distinct characteristic: _____________ ________________________________ </li></ul><ul><li>Size: 80-118 µm long and 48-60 µm wide </li></ul><ul><li>TREATMENT - _______________________________ is somewhat effective if lung damage is not too severe. </li></ul><ul><li>PREVENTION - </li></ul>SPREAD DISEASE
Paragonimus kellicoti Closely related species – identical to P. westermani DEFINITIVE HOSTS– adults occur in wide variety of _____________________________ including ________________________________________________________________________________________________ - distributed in North America east of the Rocky Mountains - parasite is enzootic in Wisconsin - commonly found in ________________________
Paragonimus kellicoti LIFE CYCLE involves snails as first intermediate hosts and pond crayfish as second intermediate hosts . ________________________________ _____________________________ _____________________________ It is possible that humans could serve as hosts?
Haematoloechus medioplexus (p. 279-280) Frog lung fluke is a common parasite of ___________________________ throughout the world. In Wisconsin? Adults are up to 8 mm long Suckers are small Vitellaria are grape-like Ovary midanterior Oblique testes Extensive uterus covers most of the internal organs
LIFE CYCLE involves _____________________ first intermediate hosts and _____________________ second intermediate hosts . A frog becomes infected by ingesting dragonflies containing ____________________. Why important?
Reproductive System Trematode Prosthogonimus macrorchis (p. 280) Oviduct fluke occurs in _______________________________ ADULTS are commonly studied as a representative digenetic trematode due to its easy morphology.
Reproductive System Trematode Prosthogonimus macrorchis Adults occur in the ________________________________________________________________________________________________________ oviduct
Prosthogonimus macrorchis PATHOLOGY: Parasites can damage the oviduct of the female chicken or duck and ____________________________________________ In the male host - _____________________________