Ancylostoma duodenale PDF

Port Said University Faculty of Medicine Parasitology department Ancylostoma duodenale. By Dr. Wafaa Mohammed Zaki Professor of medical parasitology Faculty of Medicine Suez Canal University  Objectives  De...

Port Said University Faculty of Medicine Parasitology department Ancylostoma duodenale. By Dr. Wafaa Mohammed Zaki Professor of medical parasitology Faculty of Medicine Suez Canal University  Objectives  Describe the morphological features of Ancylostoma duodenale.  Identify with illustration the life cycle of Ancylostoma duodenale.  Enumerate the clinical picture of Ancylostomaiasis.  Explain the laboratory methods for diagnosis of Ancylostomaiasis.  list the strategy of prevention and control of Ancylostomaiasis.  Ancylostoma duodenale Distribution: Europe, areas bordering the Mediterranean, South America, India & China. Habitat: small intestine of man Definitive host: Man Morphology: # Adults are small and cylindrical # Mouth contains chitinized buccal capsule. # Oesophagus is club- shaped. # There are single male and paired female reproductive organs. #The posterior end of male has copulatory bursa with riblike rays. Life Cycle: Stages in the life cycle : eggs  Rhabditiform larva  filariform larva  adult. - Man is the only host for Ancylostoma duodenale. Eggs Shape : oval with an empty space between the shell and content Size: 60 x 40 μm Shell: thin egg shell Color: colorless and transparent Content: 4-8 cell (unembryonated) Immature eggs pass in feces (20,000 eggs ⁄ day). Rhabditiform larva : 225 × 15 microns when hatched grow to about 500- 700 microns in five days, it has a long buccal cavity. Filariform Larva : 700 microns, has a pointed tail, oesophagus 1/3 body length. mtherald.com Mode of infection: A- Penetration of the filariform larvae (infective stage) to the feet skin. Larvae pass through migration route (circulation , heart, lung, trachea, pharynx, oesophagus, stomach and intestine). B- Oral route. Life cycle  Eggs are passed in the stool , and under favorable conditions (moisture, warmth, shade), larvae hatch in 1 to 2 days and become free-living in contaminated soil.  These released rhabditiform larvae fter 5 to 10 days (and two molts) become filariform (L3) larvae that are infective.  On contact with the human host, the larvae penetrate the skin and are carried through the blood vessels to the heart and then to the lungs.  They penetrate into the pulmonary alveoli, ascend the bronchial tree to the pharynx, and are swallowed.  The larvae reach small intestine, where they mature into adults. Adult attach to the intestinal wall with resultant blood loss by the host. Pathology and clinical picture: Disease : Ancylostomiasis 1) Stage of skin penetration: itching a condition known as (Ground itch). 2) Stage of migration: In lungs usually produce pneumonitis, bronchitis, eosinophilia cough and low grade fever. 3) Intestinal phase: Nausea, vomiting, epigastric discomfort and sometimes diarrhea. 4- Chronic phase: results in severe anaemia (0.1-0.2 mL of blood may be withdrawn by Ancylstoma in 24 hour), weakness, loss of appetite and edema. Heavily infected children may have physical, mental and sexual retardation.. Pica Diagnosis: I- Clinical diagnosis is not sufficient. II- Laboratory diagnosis for detection of eggs: a) Direct fecal films. b) Concentration techniques. c) For quantitative assessments of infection, Kato-Katz can be used. III- Blood tests for anemia: Eosinophilia high particularly iron deficiency, can help to confirm the diagnosis. Treatment: Mebendazole 100 mg twice daily for 3 days. Prevention and control: 1. Sanitary disposal of faecal wastes. 2. The use of night soil as fertilizer must be prohibited. 3. Education of the public as to the method of transmission of the disease. 4. Mass treatment of infected cases. 5. Wearing protective clothes.