Parasitology Introduction

Overall description of parasites

Epidemeology

the study/analysis of distribution of a disease

parasitology

study of parasite and their relationship to their hosts

Nest/Brood parasitism

one organism relies on another organism to raise their young

Kleptoparasitism

one organism steals food from another organism

Distribution of human parasites causes

Irrigation projects, Nightsoil, Poor sanitation, Ignorance, Migration

Zoonoses

a disease in animals that can be transmitted to humans

Parasite transmission strategies

1. encystment

2. vector

Reservoir host

an animal that harbors an infection that can be transmitted to humans or domestic animals

-may or may not show symptoms

-makes it hard to control disease

Phoresis

+/0 one organism associated with another for the purpose of transport

Commensalism

+/0 relationship benefits one partner without obviously affecting the other

Mutualism

+/+ relationship in which both organisms benefit

Parasitism

± one lives on or in another living organism, obtaining from it part or all of its nutrition and imposing a net detrimental effect on the host

Parasitoid

organisms whose larvae develop by feeding inside the body of a host

Ectoparasite

infestation

lives outside of the host

Endoparasite

infection

lives inside the host

Obligate parasite

parasite requires the host for survival

Facultative parasite

a free-living organism normally but becomes parasitic in certain conditions

What type/degree of parasite it Naegleria fowleri

Facultative

Accidental parasite

organism ended up in the wrong host

Permanent Host

the parasite is in this host from early life to maturity (one host)

Temporary Host

the parasite is free-living for part of it’s life cycle

Definitive Host

The host in which the parasite undergoes sexual maturity

Intermediate Host

The host in which the parasite undergoes development but not sexual maturity

Paratenic Host

a host that bridges the gap between hosts, no development occurs

Hyperparasite

parasite within a parasite

Dead-end Host

Parasite won’t be able to transmit to a new host and dies within the host

Opportunistic Parasite

organism that only causes much harm when the host is immunocompromised

Binary Fission

asexual reproduction where one cell divides into two

Multiple Fission

asexual reproduction where nucleus undergoes multiple divisions

Monoecious

an individual can produces both egg and sperm (hermaphrodite)

“one-house”

Dioecious

an individual can produce only one type of gamete

“two-house”

Types of damage parasites can cause to host

1. Mechanical

2. Cell Destruction

3. Inflammatory Reaction

4. Competition for Host Resources

Oral-Fecal

egg or cyst passed through feces and ingested

Example: Giardia

Consumption

host eating infected food/water

Biting vector transmission

biting insect introduces parasite through biting of host

Ex. malaria transmitted via mosquito