Nematodes Flashcards
Nematodes Classification as per habitat
Intestinal - Small and Large intestine
Somatic (different organs)
Nematodes affecting Small intestine
Round worn
Hookworm
Strongyloides
Nematodes affecting large intestine
LET
Trichuris
Enterobius
Example of Somatic Nematodes
La,la,lu
Filaria
Trichinella
Dracunculus
Classification of nematodes on basis of Eggs/Larvae
Viviparous
Oviparous
Ovoviviparous
Viviparous Nematodes
Directly lays down larvae
Ex - La La Lu
Filaria, Trichinella, Dracunculus
Oviparous Nematodes and Examples
Lays egg - later turns into larvae
Ex - laTER
Roundworm, Hookworm, Trichuris, Enterobius
Ovoviviparous Nematodes and Examples
Lay egg and it immediately hatch out into larvae
Example - Strongyloides
Most common helminthic infection in the world
Ascaris lumbricoides/Roundworm
Male and females shape in Ascaris lumbricoides
Females - longer
Males - curved post. End, Shorter
Infective form in case of Ascaris lumbricoides
Egg/Embryonated egg
Route of transmission and location affected by Ascaris lumbricoides
Route - Oral
Location - Small intestine , Also lung stage +
IP in case of Ascaris lumbricoides infection
60-75 days
Clinical features in case of Ascaris lumbricoides
Malabsorption
Loeffler’s syndrome/Eosinophilic Pneumonitis
Difference between fertilized and unfertilized eggs in Ascaris lumbricoides sample
Fertilized egg - Thick albumin coat, Crescentric space +, Float in saturated salt solution
These things doesn’t seen in Unfertilized egg
Treatment of Ascaris lumbricoides
Albendazole
Visceral larva migrans/Ocular larva migrans means
infection caused by parasitic roundworms passed from animals to humans
Visceral larva migrans life cycle
Ingestion of Non human roundworms - Rhabditiform larva - Filariform larva - Pass through LN and blood and reaches right side of heart but unable to pass through Pulmonary circulation - invades visceral organs
Trichuris Trichura AKA
Whipworm
Infective form in case of Trichuris Trichura
Embryonated egg
Route of transmission and location affected in case of Trichuris Trichura/Whipworm
Route - Ingestion
Location - Large intestine
No lung stage
IP in case of Trichuris Trichura
70-90 days
Clinical features seen in case of Trichuris Trichura
Dysentery - blood in stools - IDA
Recurrent Rectal prolapse
Endoscopy finding in case of Trichuris Trichura
Often shows Adult worms attached to Bowel mucosa (Coconut cake reaction)
Treatment of Trichuris Trichura
Albendazole
Enterobius vermicularis AKA
Pinworm or Threadworm
Location of Enterobius vermicularis
Vermiform appendix (extreme tip)
Male and female shape in case of Enterobius vermicularis
Fusiform shape
Female - longer
Male - Shorter, curved/coiled post end
On Ant end - Presence of cervical alae
Infective stage in case of Enterobius vermicularis
Embryonated egg
Route and location affected in case of Enterobius vermicularis
Route - Oral
Location - Large intestine, No lung stage
Autoinfection in case of Enterobius vermicularis
Perianal pruritis - scratch - deposit egg in Nails - leads to autoinfection (ingested again)
Retroinfection in case or Enterobius vermicularis
Larvae go back into intestine
IP and treatment of Enterobius vermicularis
IP - 35-45 days
Treatment - Albendazole
Enterobius vermicularis lays egg where and at what time, C/F
At night, lays egg at perianal region - causes Perianal pruritus (Can spread to genital areas)
Sample collecting methods in case of Enterobius vermicularis
Collect eggs with help of NIH Swab
Scotch tape method (Infants)
Shape of egg of Enterobius vermicularis
D shape - Planoconcave egg with tadpole larva
Finding on appendix biopsy in case of Enterobius vermicularis
Cervical alae seen
Ancylostoma AKA
Hookworm
Ancylostoma AKA
Hookworm
Ancylostoma Species seen in new world
Necator americanus
Ancylostoma species seen in Old world
Ancylostoma duodenale
Infective form in case of Ancylostoma
Filariform larvae
Route of transmission and location of Ancylostoma/Hookworm
Route - Penetration of skin
Location - Small intestine
Lung stage +
Route of transmission and location of Ancylostoma/Hookworm
Route - Penetration of skin
Location - Small intestine
Lung stage +
IP and treatment of Ancylostoma
IP - 40 to 100 days
Treatment - Albendazole
IP and treatment of Ancylostoma
IP - 40 to 100 days
Treatment - Albendazole
Clinical features in case of Ancylostoma
Ground itch
Creeping eruption
IDA (SI)
Pulmonary symptoms
Clinical features in case of Ancylostoma
Ground itch
Creeping eruption
IDA (SI)
Pulmonary symptoms
Diagnosis of Ancylostoma
Egg with blastomeres
Unembryonated egg - Fresh stool
Chandeler index
Average no. Of hookworm eggs per gram of feces for the entire community
How much Chandler index is a public health problem
Above 300
Female and male shape in case of Ancylostoma
Female - Longer
Male - Shorter, Capsulatory bursa + , Post end have umbrella like expansion
Eggs and Rhabditiform larva in case of Ancylostoma duodenale and Necator americanus
Both have same
Adult worm is larger in Ancylostoma duodenale or Necator americanus
Ancylostoma duodenale - larger
Necator americanus - shorter
Which is more pathogenic - Ancylostoma duodenale and Necator americanus
Ancylostoma duodenale - more pathogenic
Necator americanus - less pathogenic (ground itch more severe)
Which is more pathogenic - Ancylostoma duodenale and Necator americanus
Ancylostoma duodenale - more pathogenic
Necator americanus - less pathogenic (ground itch more severe)