Zoonotic-Nematodes-Part-1.pptx

ZOONOTIC NEMATODES Parasitic Zoonosis  Diseases and infections which are naturally transmitted between vertebrate animals and man (WHO)  May include other hosts such as protozoans, helminth and arthropods Capillaria philippinensis  Male worms range from 1.5 – 3.9 mm  Female works ra...

ZOONOTIC NEMATODES Parasitic Zoonosis  Diseases and infections which are naturally transmitted between vertebrate animals and man (WHO)  May include other hosts such as protozoans, helminth and arthropods Capillaria philippinensis  Male worms range from 1.5 – 3.9 mm  Female works range from 2.5 – 5.3 mm  Oviparous and viviparous (oviviparous)  Thin, filamentous anterior end; short and thick posterior end  Esophagus has two rows of secretory cells (stichocytes)  Esophagial structure is called stichosome  Recognized as a new species in the early 1960s from a patient in the Philippines who died of long illness characterized by intractable diarrhea and cachexia. Capillaria philippinensis  Intestinal capillariasis, a zoonotic disease, is characterized by abdominal pain, chronic diarrhea, and gurgling stomach.  Fish-eating birds are the natural hosts of the nematode  Oviviparous Capillaria adult C. philippinensis egg  Peanut-shaped  Striated shell  Flattened bipolar plugs  36 – 45 µm by 20 µm  May embryonate in soil or water C. philippinensis eggs Capillaria?  Life Cycle of C. philippinensis  Adult worms are embedded in the mucosa of the upper small intestines of human host and produce eggs or larvae  Eggs embryonate when it reaches brackish or fresh water  Eggs are ingested by fresh water fish, hatch in the small intestines, and become infective stage  If infected fish is eaten by suitable vertebrae, including humans, the larvae develop into adult worms and start producing larvae in 2 weeks  Larvae produced by adults is capable of autoinfection  Life Cycle of C. philippinensis  Severe pathology – large number of worms Autoinfection Epidemiology  Parasite was first discovered in Tagudin, Ilocos Norte in the 1960s  A new case was discovered in Mankayo, Compostela Valley and new epidemic was reported from Leyte  Cases were reported from Thailand and isolated cases from Iran and Egypt Endemic Regions in the Philippines  Northern Luzon  Eastern Visayas MODE OF  Western Mindanao INFECTION:  Southern Mindanao CONSUMPTION  Northern Mindanao OF RAW FRESH WATER FISH “People eating fishes, fishes eating Pathology and Symptoms  Abdominal pain, diarrhea and borborygmi  Weight loss, malaise, vomiting and anorexia  Protein loss and severe metabolic imbalance  Edema (bipedal)  Malabsorption of fats and sugars  Decreased electroytes specially potassium  Can be fatal if untreated  Bipedal Bipedal Edema Edema caused caused by by protein protein loss loss as as a a result result of of Capillariasis Capillariasis Cachexia or body wasting as a result of long term capillariasi s Diagnosis  Finding the characteristic eggs in the feces  Larvae and adult worms may also be present in the feces  Direct smear, wet mount or stool concentration  Parasites can be recovered from duodenum thru aspiration Treatment  High protein diet and electrolyte replacement for protein and electrolyte loss  Antidiarrheal drugs  Mebendazole: 200 mg. b.i.d. for 20 days  Albendazole: 400 mg. once a day for 10 days  Albendazole is drug of choice  Relapse may occur Prevention and Control  Discouraging people from eating raw fish  Good sanitary practices  Treatment of all infected individuals  Information dissemination/ Educational programs particularly in endemic areas Trichinella spiralis  Trichinella spiralis – most important  Trichinella britovi – second most common  Trichinella nativa  T. murrelli  T. nelsoni,  T. papuae  T. pseudospiralis. Trichinella spiralis  Causative agent of Trichinosis  Adult worms are infrequently seen  The larva has a spear-like burrowing tip at its anterior end  Parasite is usally transmitted from animal to animal (carnivores and omnivores)  Humans are accidental and dead end host  Transmitted to humans by eating of raw or poorly cooked mammal flesh, usually pork  Hosts are final and intermediate host Life Cycle  Adults thrive in the small intestines of animals and produce larvae  Larvae penetrate the mucosa and encyst in skeletal muscles of animal host  Humans get infected by eating the flesh containing the encysted larvae  Larvae migrate to the small intestines of humans and become mature  Male and female copulate and male is dislodged from the intestines while female burrows into the mucosa and deposit the larvae  The larvae penetrate the mucosa and migrate to different parts of the body where they form cyst  Skeletal muscles are their usual site of encystment  Averagelifespan of larva – 5 to 10 yrs, may even reach up to 40! Migratio T. spiralis in the skeletal muscle Trichinella larva Diagnosis  Muscle biopsy is the most definitife diagnostic procedure  Serological tests like latex agglutination test and bentonite flocculation test  Eosinophilia (40% to 80% is common) Treatment  Pain relievers and sedatives  Corticosteroids for symptomatic reief  Thiabendazole and albendazole  No available drug is highly effective in the treatment of human infection Trichinella spiralis infection of muscle tissue with the larval form of T. spiralis, a helminth whose adult stages live in the human intestine. Trichinella spiralis 3 phases of infection o Enteric phase o Invasion Phase o Convalescent phase Trichinella spiralis ➔ LABORATORY 1. Muscle biopsy Immunotests —> Bentonite Flocculation tests —> Bachmann Intradermal test —> Beck’s Xenodiagnosis