Ascaris lumbricoides

Ascaris lumbricoides it is one of the comments and most wide spread of all human parasites.It is particularly common in areas of inadequate sanitation and where untreated human faeces are used as fertilizer.

1. Ascaris lumbricoides
HUDA ALISLAMTALAB
B.SC., M.SC. MEDICAL PARASITOLOGY
UNIVERSITY OF MEDICAL SCIENCES AND TECHNOLOGY
(UMST)

2. Egg detection
•Both fertilized and unfertilized eggs can be detected by
stool examination
Larva detection
•During the early pulmonary migratory phase, larvae can
be found in sputum or gastric aspirates before the eggs
appear in the stool.
Adult worm detection
•Adult worms may be detected in stool of the patients by
naked eye.
•X-ray of the GIT may demonstrate the adult worms in the
intestine.

3. Eggs of A. lumbricoides
1-Fertilized eggs
2-Unfertilized eggs
•Usually fertilized eggs are found in faeces but
occasionally infertile eggs are passed when worms in
intestine are mostly female.
•Eggs may not be seen if only male worms present

5. Fertilized eggs
•Yellow-brown, oval or round
•Shell is often covered by an uneven albuminous
coat (mammilated).
•Contains a central granular mass which is the
unsegmented fertilized ovum

6. Fertilized eggs

7. Fertilized eggs

8. Decorticated egg
•This term is used to describe an egg that has no
albuminous coat.
•A decorticated egg has a smooth shell and appears
pale yellow or colorless.

9. Unfertilized eggs
•It is darker in colour and has a
thinner wall and more granular
albuminous covering.
•More elongated than a fertilized egg
•Contains a central mass of large
granules.

10. Unfertilized and fertilized egg

12. A.Lumbricoideslarva emerging
from a fertile egg

13. A.lumbricoides adult worms
•Freshly expelled (through anus or mouse ) Ascaris worms
are pinkish in colour with an appearance similar to
earthworms
•Adult female worms measure 20-35cm and male worms
measure 15-30 cm
•The tail of mail is curved

14. A.lumbricoidesexpelled through
anus or mouse

18. Females of A.lumbricoides

19. Males of A.lumbricoides

21. Indirect diagnosis
Antibodies can be detected by methods such as
•ELISA
•IFA (Indirect fluorescent antibody test)
•IHA(Indirect hemagglutination test)
Serology is useful:
•In pulmonary phase (In case stool microscopy fails)
•For seroepidemiological purpose

22. Other Methods
•Eosinophilia is prominent during the early lung
stage, but disappears later.
•Presence of Charcot Leyden crystals in sputum
and stool.

28. Visceral Larva Migrans
Caused by :
Toxocara canis (dog roundworm)
Toxocara cati (cat round worm).

29. Any question ??