TISSUE%20NEMATODES

1
TISSUE NEMATODES
TISSUE NEMATODES
2
COMMON TISSUE NEMATODE INFECTIONS

• Trichinella spiralis adults in small intestine
  larvae in tissues (mainly in muscles).
• Toxocara canis (dog roundworm) larvae in organs
  (liver brain eyes), causing visceral larva
  migrans
• Dracunculus medinensis (guinea worm) adult female
  in subcutaneous tissues
• Filarial worms

3
Trichinella spiralis
4
Trichinosis
5
Trichinosis

• Pathology
• Adults cause mild gastroenteritis.
• Larvae cause fever, myositis and multi-system
  involvement which may lead to death.
• Diagnosis serology, muscle biopsy.
• Treatment Albendazole or Mebendazole
  corticosteroids

6
Trichinosis
7
Most prevalent in areas where domestic pigs are
allowed to roam freely.
8
Visceral larva migrans

• Mainly affects children who eat soil contaminated
  with emberyonated (infective) eggs of Toxocara
  canis.
• Larvae do not develop in humans but migrate
  continuously in viscera and encapsulate, causing
  tissue damage.

9
Toxocara canis
10

• Pathology Eosinophilia, hepatomegaly,
• retinitis.
• Diagnosis serology, biopsy.
• Treatment Albendazole

11
Dracunculus medinensis
12
Draunculiasis
Caused by Dracunculus medinensis
Adult female lives in subcutaneous tissues,
causing a skin ulcer through which it protrudes
its anterior end. Main pathology due to
secondary bacterial infection and allergic
reactions. Diagnosis clinical picture. Treatment
surgical removal.
13
FILARIAL WORMS (Adult worms microfilariae)

• Onchocerca volvulus
• Adults in subcutaneous swellings
  Microfilariae mainly in skin, eyes causing
  River blindness
• 2. Wuchereria bancrofti, Brugia malayi B.
  timori
• Lymphatic filariasis (adults in lymphatics,
• microfilariae in blood)
• 3. Loa loa
• Adults in subcutaneous and subconjunctival
  tissues, causing Calabar swellings.
• Microfilariae in blood

14
FILARIALIASIS )
15
Loiasis
16
(No Transcript)
17
Onchocerciasis (river blindness)

• Pathology
• Adults worms live in subcutaneous nodules.
• Main pathology caused by microfilariae in
• Skin dermatitis
• Lymph nodes lymphadenopathy
• Eyes blindness
• Diagnosis skin snip to identify microfilariae.
• Treatment Ivermectin

18
(No Transcript)
19
LYMPHATIC FILARIASIS
20
Lymphatic Filariasis
21
LYMPHATIC FILARIASIS

• Mainly caused by Wuchereria bancrofti
• and Brugia malayi
• Pathology
• Due to adult worm obstructing lymphatics.
• Acute lymphadenitis lymphatic varices
• Chronic lymphedema, hydrocele, chyluria.

22
(No Transcript)
23
LYMPHATIC FILARIASIS

• Diagnosis detection of microfilariae in blood in
  early stages of the disease
• Blood film, Knotts method
• ( concentration of 1 ml of blood), best 10 pm to
  2 am (nocturnal periodicity).
• Immunological tests
• Treatment diethylcarbamazine (DEC) or ivermectin

24
Loa loa
25
Loiasis
26
Loiasis

• Pathology Adult worm continously migration in
  subcutaneous and subconjuntival tissues, causing
  Calabar swellings (allergic reactions) and
  conjunctivitis.

27
Loiasis

• Diagnosis detection of microfilariae in blood
  film.
• Treatment diethylcarbamazine (DEC) or
  ivermectin, surgical remonval.

28
NON-FILARIAL TISSUE NEMATODE INFECTIONS
treatment Diagnosis Location in human Mode of transmission Disease Nematode species
Surgical extraction clinical Subcutaneous, mainly in lower limbs Ingestion of infected cyclops in water Dracunculiasis, Guinea worm disease Dracunculus medinensis
albendazole Serology, muscle biopsy Muscles, lungs brain ingestion larvae in under-cooked pork Trichinellosis (trichinosis) Trichinella spiralis
albendazole Serology, ELISA Abdominal organs and brain Ingestion of infective eggs in soil Visceral larva migrans Toxocara canis
29
MAJOR FILARIAL INFECTIONS OF HUMANS
Lab. diagnosis vector Location of microfilaria Location of adult in humans Geographic distribution Disease species
Blood film mosquitoes Blood (nocturnal periodicity) Lymphatic vessels Tropical and subtropical areas elephantiasis Wuchereria bancrofti
Blood film mosquitoes Blood (nocturnal periodicity) Lymphatic vessels Asia elephantiasis Brugia malayi
Skin snip Simulium spp. (black fly) Skin, eyes, no periodicity Subcutaneous nodules Africa, Central and South America, Yemen Onchocerciasis (river blindness) Onchocerca volvulus
Blood film Chrysops spp. (deer fly) Blood (diurnal periodicity) Moving in subcutaneous tissues Central Africa loiasis Loa loa