Lecture 3 2024 Non Ruminant Strongylida PDF

Strongylida Dr Nur Mahiza Md Isa 25 October 2024 Contents Introduction to Strongylida Ancylostoma Strongylus vulgaris Syngamus trachea 2 STRONGYLIDA (‘Strongyles’) ‘strongyles’ or bursate nematodes a large group of major parasitological significanc...

Strongylida Dr Nur Mahiza Md Isa 25 October 2024 Contents Introduction to Strongylida Ancylostoma Strongylus vulgaris Syngamus trachea 2 STRONGYLIDA (‘Strongyles’) ‘strongyles’ or bursate nematodes a large group of major parasitological significance 3  Morphology 0.5-3.0cm long (male~1cm; female~2cm) anterior end → leafcrowns may be present male posterior end has a copulatory bursa (fan-like & supported by chitinous rods) eggs: thin-shelled, oval & unembryonated when passed out 4  Life cycle: - direct Adult Eggs in faeces Hatch L1 L2 L3 Oral route Skin penetration (hookworms) (other strongyles) (infective stage enters the host) L3 enters hepatic-tracheal migration Ancylostoma (dog & cat) Tissue migration No migration Gaigeria (ruminant) Strongylus (horse) Haemonchus Bunostomum (ruminant) Syngamus (poultry)* Trichostrongylus Oesophagostomum Cooperia (ruminant strongyles) VPM3351 Sem2 2021/22 Dr Nur Mahiza Gastrointestinal system 5 ▪ The eggs will normally be larvated within 18 hours oThe time of larvation depends on temperature, oxygen density and humidity (water) ▪ L1 & L2 feed on materials found in the faeces ▪ L3 has a sheath encapsulating its body including the anterior part of its mouth o it does not feed & depends on the food granules accumulated during the L1 & L2 phases ▪ L3 which is the infective stage can be found in soil & grasses ▪ L3 gains entry into the host through ingestion 6 Ancylostoma Ancylostoma spp. Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma braziliense affects cats & dogs called ‘hookworms’ because of the hook posture of anterior ends large buccal capsule with teeth main pathological effect is the blood sucking activity of larvae & adult worms, causing acute or chronic haemorrhagic anaemia 8  Are dogs or cats infected with Ancylostoma worms contagious for humans? YES!!! Walking with barefoot!! 9 https://wwwnc.cdc.gov/eid/article/15/11/09-0261-f1 10  Life Cycle of Hookworms L1 Rhabditiform L1 larva hatches in the soil (usually in old L2 faeces) L2 Eggs in faeces Larvae enter the L3 small intestine, attach to its mucosa & mature L3 Filariform larva, L3 into adult worms Into (infective Man & stage) causes CLM HEPATIC-TRACHEAL MIGRATION Skinpenetration Skin penetration Larvae penetrate the Blood Blood pulmonary capillaries, enter VPM3351 Sem2 2021/22 Dr Nur 11 the alveoli & are ‘coughed Mahiza up’ & swallowed  Pathogenesis of Hookworms Found within the small intestine particularly at the middle part Attaches to the mucosa & sucks blood (changing sucking sites constantly) Blood loss & haemorrhage Protein loss Anaemia Impaired absorption Hypoproteinaemia Pale & weak Bloody diarrhoea Oedema & ascites with mucus 12 Route of Infection 1. Skin penetration by L3 which undergoes tracheal migration 2. Ingestion of L3 3. Transmammary infection can occur (L3 passed in the milk) 13 Strongylus vulgaris Strongylus vulgaris Strongyle of the horse Leaf crown surrounds the mouth opening Large buccal capsule which contains two rounded teeth Larvae migrate on the endothelium causing arteritis & thrombosis with subsequent infarction & necrosis of areas of the intestine producing colic Adult worms are tissue feeders in caecum & colon; haemorrhage occurs 15 Strongylus species 16  Faeces in the external environment Eggs in the L4→L5→ADULT that feeds on faeces the intestinal mucosa leading to haemorrhage & anaemia L1 ↓ L2 ↓ L3 Grazing on grasses infected with L3 L4 migrates in the wall of endothelium mesenteric artery for months arterioles intestinal mucosa 17 (L4) (L4) Syngamus trachea Syngamus trachea Tracheal worm of poultry Male & female worms are permanently in the copula forming a Y shape Earthworm can act as paratenic host Can cause haemorrhagic tracheitis with excess mucous production 19  Infection may occur in one of three ways: 1. By ingestion of an egg containing an L3 (A). 2. By ingestion of the hatched L3 (B). 3. By ingestion of a transport host containing encapsulated L3s (C). →) Following ingestion, the L3s exsheath in the duodenum (D) of the final host, moult, and pair ( off. They penetrate the intestine and travel first to the liver and then to the lungs (E) via the bloodstream. Two parasitic moults take place in the lungs within 4-7 days after infection. Adult males and females pair off move up to the trachea (tracheitis & cough) and begin copulation in the bronchi and trachea (F). → ( ) Eggs escape from the vulva under the bursa of the permanently attached male and are carried up the trachea in the excess mucus produced in response to infection. They are then swallowed and passed in the feces, completing the cycle. The prepatent period is approximately two weeks with a range of 12-17 days. Various reports have shown that adults VPM3351 may survive for 23-147 Sem2 2021/22 days in chickens, 48-224 days in turkeys Dr Nur Mahiza 20 and approximately 98 days in guinea fowl. VPM3351 Sem2 2021/22 Dr Nur Mahiza 21