2. GENERAL CHARACTERISTICS OF NEMATODES
They assume three basic morphologic
forms: Egg, Larvae and Adult worms
Reproduce sexually with male and
female worms
Complete digestive tract and
complete reproductive systems
3. TAXONOMIC CLASSIFICATION
Intestinal Species
E. vermicularis
T. trichura
N. americanus
A. duodenale
Phylum A. lumbricoides
Class S. stercoralis
Nemathelminthes
Nematoda
Intestinal- Tissue
Species
T. spiralis
D. medinensis
4. ASCARIS LUMBRICOIDES
Ascaris lumbricoides
Common Name Giant Intestinal Roundworm
Infective Stage Embryonated Egg
Habitat Small Intestine
Mode of Transmission Ingestion of contaminated food/ water
Diagnostic Specimen Feces
6. ENTEROBIUS VERMICULARIS
Enterobius vermicularis
Common Name Pinworm
Infective Stage Embryonated Egg
Habitat Large Intestine
Mode of Transmission Ingestion of egg/ autoinfection
Diagnostic Specimen Feces/ Cellophane Tape prep
7. TRICHURIS TRICHURA
Trichuris trichura
Common Name Whipworm
Infective Stage Embryonated Egg
Habitat Large Intestine
Mode of Transmission Ingestion of egg via contaminated food/ water
Diagnostic Specimen Feces
9. NECATOR AMERICANUS AND ANCYLOSTOMA
DUODENALE
Necator americanus and Ancylostoma duodenale
Common Name Hookworm
Infective Stage Third Stage Filariform Larvae
Habitat Small Intestine
Mode of Transmission Skin Penetration of Infective Larvae
Diagnostic Specimen Feces
11. STRONGYLOIDES STERCORALIS
Strongyloides stercoralis
Common Name Threadworm
Infective Stage Third Stage Filariform Larvae
Habitat duodenum and upper jejunum
Mode of Transmission Skin Penetration of Infective Larvae/ autoinfection
Diagnostic Specimen Feces
12. TRICHINELLA SPIRALIS
Trichinella spiralis
Common Name Trichinia worm
Infective Stage Encysted Larvae
Habitat Striated muscle tissue
Mode of
Transmission Ingestion of raw/ undercooked contaminated meat
Diagnostic Specimen skeletal muscle biopsy/ Blood (LDH, Aldolase, CPK, eo ct)
13. CAPILLARIA PHILIPPINENSIS
Capillaria philippinensis
Common Name NA
Infective Stage Encysted Larvae
Habitat Small Intestine
Mode of Transmission Ingestion of raw/ undercooked contaminated fish
Diagnostic Specimen Feces
14. THE FILARIAE- GENERAL CHARACTERISTICS
Two morphologic forms: Adult worms and
Microfilariae
Adult worms are usually creamy
white and assume a filariform shape
Have both male and female
forms
Females lay live microfliariae
Require arthropod vectors
Exhibit periodicity
(Nocturnal/ diurnal)
15. WUCHERERIA BANCROFTI
Wuchereria bancrofti
Common Name Bancroft's Filaria
Infective Stage L3 Larva
Habitat Lymphatics and blood
Mode of Transmission Bite from infected mosquito (Culex, Aedes or Anopheles)
Diagnostic Specimen Giemsa stained smear (collected at night)/ Knott's Technique
16. BRUGIA MALAYI
Brugia malayi
Common Name Malayan Filaria
Infective Stage L3 Larva
Habitat Lymphatics and Blood
Bite from infected mosquito ( Anopheles, Aedes, Mansonia,
Mode of Transmission Amigeres)
Diagnostic Specimen Giemsa stained smear (collected at night)/ Knott's Technique
17. WUCHERERIA BANCROFTI V.S. BRUGIA MALAYI
Distinguishing Wuchereria Brugia malayi
Characteristics bancrofti
Sheath in Giemsa unstained Pink
Nuclei Regularly spaced, Irregularly spaced
separately situated and overlapping
Tail none Single row of nuclei
that reach tail’s end
Terminal Nuclei None 2 nuclei, which
bulge the cuticle;
conspicuously
placed
Appearance in Blood Smoothly curved Kinky
film
18. LOA LOA
Loa loa
Common Name African Eye Worm
Infective Stage L3 Larva
Habitat Subcutaneous tissue, the eye and bridge of nose
Mode of
Transmission Bite from infected Chrysops silacea or C. dimidiata (Deer Fly)
Diagnostic Giemsa stained smear (collected at midday 10:15to 2:15)/ Knott's
Specimen Technique
19. ONCHOCERCA VOLVULUS
Onchocerca volvulus
Common Name Blinding Filaria
Infective Stage L3 Larva
Habitat Subcutaneous tissue, nodules and eyes
Mode of Transmission Bite from infected Simulium Blackfly
Diagnostic Specimen Giemsa stained smear of skin snips
20. MANSONELLA OZZARDI AND MANSONELLA
PERSTANS
Mansonella ozzardi and Mansonella perstans
Common Name Ozzard's Filaria and Perstans Filaria
Infective Stage L3 Larva
Habitat Blood and various tissue
Mode of Transmission Bite from infected Simulium Blackfly or Culicoides (sucking midge fly)
Diagnostic Specimen Fresh Giemsa stained blood smear
