VPA 211: General Veterinary Parasitology and Helminthology (3+1)

TYPES OF PARASITISM

• Infections refer to parasitism of host by internal parasites (e.g. amphistomes in livestock)  

• Infestations refer to parasitism of host by external parasites (fleas, lice, ticks, flies etc.).

      Infestation with ectoparasites

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• Autoinfection refers to a condition where the juvenile infective form of a parasite, without escaping from the host infects the same host e.g. Enterobius vermicularis
• Hyperinfection refers to a condition where the juvenile form of a parasite without exiting the host penetrates in an area adjacent to the site of predilection and establishes in the same host e.g. Strongyloides sp.
• Congenital (Transuterine or Transplacental) infection is transmission of parasites from the dam to the foetus across placental membranes e.g. Toxocara canis in dogs
• Transmammary (Transcolostral) is transmission of parasites from the dam to the young one through the milk of the infected dam e.g . (Toxocara cati in cats)

 

• Transovariantransmission is transmission of parasite from the female parent to the progeny through the ova. E.g. Babesia bigemina in ticks

• Transtadial (stage to stage) is transmission of parasite from one stage to another stage of the vector as in Theleria annulata in Hyalomma spp. of ticks
• Zoonoses are diseases common to humans and animals (Singular – Zoonosis). According to WHO (1959), zoonoses are diseases transmissible between vertebrate animals and man.

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• Anthropozoonoses is a disease of  animals transmitted to humans e.g., Cystic echinococcosis from animals to humans 

• Zooanthroponoses is a disease of humans transmitted to animals e.g. Taenia solium from humans to pigs