PARASITOLOGY RECAP
PARASITE
A parasite is an organism that depends on another organism for its nourishment and survival.
Nature of parasite: I could be arthropod, helminthes or
TYPES OF PARASITE
There are several forms of parasites which includes;
1. Endo-parasite - these parasites live inside the body or system of their host for their nourishment and survival.
Examples of Endo-parasites
Roundworms, tapeworms, hookworms. Whipworms, etc…
2. Ecto-parasite - these parasites outside the body of their host.
Examples of Ecto-parasites
Arachnids (ticks and mites), insects (mosquitoes, tsetse flies, fleas and lice)
3. Obligate parasite – these parasites depend completely upon its hosts for their survival. It cannot live outside the
host body.
4. Facultative parasite – these parasites is capable of independent existences in addition to their parasitic life.
5. Pathogenic parasite – these parasites cause disease to their hosts.
,HOST
It is an organism which harbors parasites. The parasites get their nourishment from the host.
TYPES OF HOST
1. Definitive Host- The host, in which the adult parasite lives and undergoes sexual reproduction, is called the
definitive host, e.g. mosquito acts as definitive host in malaria. The definitive host may be a human or any other
living being. However, in majority of human parasitic infections, man is the definitive host (e.g. filarial,
roundworm, hookworm).
2. Intermediate host- The host, in which the larval stage of the parasite lives or asexual multiplication takes
place, is called the intermediate host.
3. Direct life cycle: When a parasite requires only single host to complete its development, it is called as direct life
cycle, e.g. Entamoeba histolytica requires only a human host to complete its life cycle.
4. Indirect life cycle: When a parasite requires 2 or more species of host to complete its development, the life
cycle is called as indirect life cycle, e.g. malaria parasite requires both human host and mosquito to complete its
life cycle
, PARASITE INFECTIVE STAGE DIAGNOSTIC STAGE
Plasmodium spp. Sporozoites Gametocytes
Wuchereria bancrofti 3rd stage larvae microfilariae
Leishmania spp. Promastigotes amastigotes
Trypanosoma spp. Metacyclic trypomastigotes bloodstream trypomastigotes
Schistosoma spp. cercariae Eggs shed in feaces and urine
Onchocerca volvulus 3rd stage larvae microfilariae
Ascaris lumbricoidses Embryonated eggs Fertilized and unfertilized eggs
feaces
Cryptosporidium Thick-walled oocyst Thick-walled oocyst
Toxoplasma gondii Tachyzoites, bradyzoites
sporozoites
PARASITES INFECTIONS/DISEASES ZOONOTIC/NON-ZOONTIC
Plasmodium spp Malaria Only Knowlesi malaria is zoonotic
Trypanosoma spp Trypanosomiasis Zoonotic
Leishieminia spp Leishmaniasis Zoonotic
Wuchereria bancrofti Lymphatic filariasis Non-zoonotic
Schistosoma spp Schistosomiasis Non-zoonotic
Onchocerca volvulus Onchocerciasis Non-zoonotic
Ascaris lumbricoidses Ascariasis Non-zoonotic
Toxoplasma gondii Toxoplasmosis Zoonotic
Cryptosporidium Cryptosporidiosis Zoonotic
Taenia Saginata Taenia Solium Taeniasis Non-zoonotic
Giardia lambila Giardiasis Zoonotic
PARASITE
A parasite is an organism that depends on another organism for its nourishment and survival.
Nature of parasite: I could be arthropod, helminthes or
TYPES OF PARASITE
There are several forms of parasites which includes;
1. Endo-parasite - these parasites live inside the body or system of their host for their nourishment and survival.
Examples of Endo-parasites
Roundworms, tapeworms, hookworms. Whipworms, etc…
2. Ecto-parasite - these parasites outside the body of their host.
Examples of Ecto-parasites
Arachnids (ticks and mites), insects (mosquitoes, tsetse flies, fleas and lice)
3. Obligate parasite – these parasites depend completely upon its hosts for their survival. It cannot live outside the
host body.
4. Facultative parasite – these parasites is capable of independent existences in addition to their parasitic life.
5. Pathogenic parasite – these parasites cause disease to their hosts.
,HOST
It is an organism which harbors parasites. The parasites get their nourishment from the host.
TYPES OF HOST
1. Definitive Host- The host, in which the adult parasite lives and undergoes sexual reproduction, is called the
definitive host, e.g. mosquito acts as definitive host in malaria. The definitive host may be a human or any other
living being. However, in majority of human parasitic infections, man is the definitive host (e.g. filarial,
roundworm, hookworm).
2. Intermediate host- The host, in which the larval stage of the parasite lives or asexual multiplication takes
place, is called the intermediate host.
3. Direct life cycle: When a parasite requires only single host to complete its development, it is called as direct life
cycle, e.g. Entamoeba histolytica requires only a human host to complete its life cycle.
4. Indirect life cycle: When a parasite requires 2 or more species of host to complete its development, the life
cycle is called as indirect life cycle, e.g. malaria parasite requires both human host and mosquito to complete its
life cycle
, PARASITE INFECTIVE STAGE DIAGNOSTIC STAGE
Plasmodium spp. Sporozoites Gametocytes
Wuchereria bancrofti 3rd stage larvae microfilariae
Leishmania spp. Promastigotes amastigotes
Trypanosoma spp. Metacyclic trypomastigotes bloodstream trypomastigotes
Schistosoma spp. cercariae Eggs shed in feaces and urine
Onchocerca volvulus 3rd stage larvae microfilariae
Ascaris lumbricoidses Embryonated eggs Fertilized and unfertilized eggs
feaces
Cryptosporidium Thick-walled oocyst Thick-walled oocyst
Toxoplasma gondii Tachyzoites, bradyzoites
sporozoites
PARASITES INFECTIONS/DISEASES ZOONOTIC/NON-ZOONTIC
Plasmodium spp Malaria Only Knowlesi malaria is zoonotic
Trypanosoma spp Trypanosomiasis Zoonotic
Leishieminia spp Leishmaniasis Zoonotic
Wuchereria bancrofti Lymphatic filariasis Non-zoonotic
Schistosoma spp Schistosomiasis Non-zoonotic
Onchocerca volvulus Onchocerciasis Non-zoonotic
Ascaris lumbricoidses Ascariasis Non-zoonotic
Toxoplasma gondii Toxoplasmosis Zoonotic
Cryptosporidium Cryptosporidiosis Zoonotic
Taenia Saginata Taenia Solium Taeniasis Non-zoonotic
Giardia lambila Giardiasis Zoonotic
