Clinical Helminthology: Intestinal Nematode (Part 2)

Meromyarian

Hookworm Species are compose pf few cells called

light, sandy, muddy soils or loam

Hookworm survives best in

upper small intestines, lower ileum, hair follicles, pores, unbroken skin, dorsum of the foot or between the toes

Hookworm sites

filariform larva

Hookworm Infective Stage (IS)

unembryonated egg

Hookworm Diagnostic Stage (DS)

Necator americanus
Ancylostoma duodenale

Hookworm species

Skin penetration

Necator americanus Mode of Transmission (MOT)

percutaneous oral
bicast feed
mother-to-child (breast feeding)

Ancylostoma duodenale Mode of Transmission (MOT)

Length: 60-75 um

Width: 35-40 um

Necator americanus egg

Length: 55-60um

Width: 35-40 um

Ancylostoma duodenale egg

sharply bent head

Necator americanus adult

slightly bent head

Ancylostoma duodenale adult

1 pair of semilunar cutting plates
1 median tooth

Necator americanus Buccal Capsule

2 ventral pairs of fused teeth

Ancylostoma duodenale Buccal Capsule

longer than broad

dorsal rays:
deep cleft, bipartite

2 spicules:
fused and barbed

Necator americanus copulatory bursa

short and broad

dorsal rays:
shallow cleft, tripartite

2 spicules:
unfused and not barbed

Ancylostoma duodenale

Rhabditiform larva

Filariform Larva

Infective Form

Hookworms Development Stages of Larvae

Rhabditiform larva

free-living, feeding form

long buccal cavity, small genital primordium

Rhabditiform larva have

Filariform larva

infective, non-feeding form and obligatory parasite

shorter esophagus and distinct pointed tail

Filariform larva have

Infective form

capable of penetrating the skin through contact with soil

• ground itch, dew itch, coolie itch
• iron deficiency anemia
• retardation of the physical, mental or sexual health
• Skin penetration: maculopapules and localized erythema
• Lung migration: bronchitis or pneumonia

Hookworm diseases

Fecal microscopy (recovery of eggs)

Eggs can mature and hatch larva if the stool is kept at RT, without fixative.

Culture Method: Harada-Mori Technique

Hookworm diagnosis

Mebendazole
Pyrantel pamoate

Hookworm treatment

Strongyloides stercoralis

Smallest nematode of man

direct fecal contamination

Strongyloides stercoralis Mode of Transmission (MOT)

wall of small intestine, lungs

Strongyloides stercoralis Final site

filariform

Strongyloides stercoralis Infective Stage (IS)

rhabditiform larva

Strongyloides stercoralis Diagnostic Stage (DS)

Egg, Rhabditiform Larva, Filariform Larva and Adult

Strongyloides stercoralis morphology

Strongyloides stercoralis

Hookworms

Rhabditiform Larvae parasite

short

Strongyloides stercoralis buccal cavity

large

Strongyloides stercoralis genital primordium

long

Hookworms buccal cavity

small

Hookworms genital primordium

Strongyloides stercoralis

Hookworms

Filariform Larvae parasite

long

Strongyloides stercoralis esphagus

notched (curved)

Strongyloides stercoralis tail

short

Hookworms esophagus

pointed

Hookworms tail

short buccal cavity

long and slim esophagus

Strongyloides stercoralis adult

Adult Worm Infection

Larval Penetration

Larval Migration

Strongyloides stercoralis diseases

Light, Heavy, and Immunocompromised

Adult Worm Infection classification

asymptomatic

Adult Worm Infection Light:

Cochin-China diarrhea, Vietnam diarrhea

Adult Worm Infection Heavy:

disseminated strongyloidiasis

Adult Worm Infection Immunocompromised:

dermatitis (ground itch or dew itch or coolie itch)

Larval Penetration disease

pneumonitis, urticaria with eosinophilia, Loeffler's syndrome

Larval Migration diseases

Harada-Mori Culture Method
Baermann funnel technique
Enterotest, Beale's String Test

Strongyloides stercoralis diagnosis

Ivermectin
Albendazole

Strongyloides stercoralis treatment

Strongyloides fuelleborni

It causes the "swollen belly syndrome".

oviparous or larviparous

Capillaria philippinensis may be

Capillaria philippinensis

prevalent in the Northern Philippines

larva in fish

Capillaria philippinensis Infective Stage (IS)

unembryonated egg

Capillaria philippinensis Diagnostic Stage (DS)

Zambales, Southern Leyte, Monkayo, Compostella Valley

Capillaria philippinensis affected areas

ingestion of contaminated fish, shrimp, crabs, or snails

Capillaria philippinensis Mode of Transmission (MOT)

Egg, Adult Male and Adult Female

Capillaria philippinensis morphology

Peanut-shaped
Guitar-shaped

Capillaria philippinensis egg stage

Stichocytes

Stichosome

The adult male has spicule and has unspined sheath.

Capillaria philippinensis adult stage

Stichocytes

rows of secretory cells in the esophagus

Stichosome

the entire esophageal structure

Intestinal capillariasis
Pudoc (Mystery Disease)
Cachexia

Capillaria philippinensis diseases

borborygmus (gurgling sound)
intestinal malabsorption
diarrhea

Pudoc symptoms

Cachexia

comorbid condition with intestinal capillariasis

Fecal microscopy

Capillaria philippinensis diagnosis

albendazole
mebendazole
electrolyte replacement
high protein diet

Capillaria philippinensis treatment

Anisakis

associated with sushi, sashimi and fresh or undertreated fish

marine crustacea (krill)

Anisakis Intermediate host

dolphins, seals, and whales

Anisakis Definitive host

acute gastrointestinal distress granulomatous abscess

Anisakis diseases

Endoscopy

Anisakis Diagnosis

Surgical intervention

Anisakis Treatment