hookworm infestation
TRANSCRIPT
HOOKWORM INFESTATION
By: DR.
SAURAV POUDEL 16th
October 2016. 16th October 2016
Prevalence of Hookworm• Hookworm affects about 576 million people globally
• Predominates in tropic and subtropic regions• Disease of developing and under-developed world, disease
of the poorest of the poor• Most vulnerable:
– Children– Pregnant women– Persons without shoes or adequate protective clothing– Agriculturalists
Worldwide Infection
Offending Pathogens
Majority of hookworm infections in humans caused by
1) Ancylostoma duodenale (an-cy-CLO-sto-ma doe-AH-den-al)
2) Necator americanus (ne-KAY-tor am-er-i-CON-us)
N. americanus and A. duodenale
• 0.10 mm length, 0.4 mm diameter. Female > Male
• 9000 eggs/day, eggs have 3-5 yrs survival
• Buccal capsule set with two crescent-shaped cutting plates on ventral side
• Ingests 30 µl blood/day
• 12 mm in length, 0.6 mm in diameter. Female > Male
• 20,000 eggs/day, eggs have 1 yr survival
• Buccal capsule set with symmetric pair of sharp teeth on ventral side.
• Ingests 260 µl blood/day
Hookworm Egg and Larvae
\
Nectar americanus
Ancylostoma duodenale
Common name: Old world hookworm Habitat: Small intestine Definitive host: Human Route of infection: Filariform larvae penetrate the skin of human Infective stage: Third stage larvae ( filariform) Diagnostic stage: Eggs in Stool Disease: Hookworm infection, Ancylostomiasis Geographic Distribution: Southern Europe, North parts of Africa, China,
India, and Japan.
Ancylostoma hooks
Chitinous teeth plates
Egg• 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).
Clinical manifestations:
1-Invasion stage: The skin, at the site of entry of filariform larvaMaculopapular lesions “ ground itch” or “dew itch”Itching, edema.
2-Migration stage: passage of the larvae in the lung leads to: Haemorrhages and pneumonia, cough, fever, eosinophilia.
Ground itch or “dew itch”
3-Intestinal stage:
1) sucking of blood by the worm (iron-dificiency anaemia ),• Severe anaemia leads to weakness.• 0.15-0.26 mL of blood may be withdrawn by a Ancylstoma in 24 hour. • Approximately 50% of the red blood cells are hemolyzed 2) Bleeding at the site of attachment and after movement to a new sites.
3) Toxic substances . -intestinal ulcers: flatulence, nausea, vomiting ,diarrhea.
Symptoms Associated with Infection
• Skin Infection– stinging, burning, itching, pruritus, papulovesicular rash -
can last up to 2 wks• Lung Infection– pneumonia, cough --rare and mild.
• Ingestion– throat soreness, hoarseness, nausea, vomiting
• GI Infection– anemia, bloody stool (from former attachment sites),
abdominal pain
Ancylostoma caninumAncylostoma braziliense
Ancylostoma caninumDog hookworm
Ancylostoma brazilienseCat hookworm
Both cause creeping eruptions
Infection
Lab Diagnosis
1. Direct Method:Examination of stool :A macroscopic examination of stool is necessary
to find out the adult worms.A microscopical examination of stool may easily
demonstrate the presence of characterestic hookworm eggs.
2. Study of Duodenal contents:The material obtained by duonenal intubation
may sometime reveal either eggs or the adult worms.
Indirect methos:Examination of blood: Anaemia,eosinophilia.Occult blood test: positive reaction(charcot-
leyden crystals are found in stool.
Treatment
• Albendazole 400 mg orally in a single dose. Or 200 mg in children 1-2 yrs of age.• Mebendazole 100mg orally twice a day for 3 days.• Pyrantal pamoate 11mg/kg to a maximum of 1
gram day for 3 days.• Topical albendazole are useful for creeping
eruption.• Iron therapy may be as important as worm
eradication..
Prevention and Control
• Sanitary disposal of human faeces• Wearing of footwear• Health education• Treatment of infected individuals
THANK YOUFrom : Dr. Saurav Poudel. [email protected] (if any query).