LESSON 4: MEDICAL AND PUBLIC HEALTH PARASITOLOGY

OBLIGATORY PARASITE

TYPE OF PARASITE

• Parasite that cannot survive outside of a host.

• Ex. Schistosoma (blood fluke)

FACULTATIVE PARASITE

TYPE OF PARASITE

• Parasite that is capable of existing independently of a host

• Ex. Strongylogides

ENDOPARASITE

TYPE OF PARASITE

• Parasite that is established inside of a host

• Ex. Plasmodium

ECTOPARASITE

TYPE OF PARASITE

• Parasite that is established in or on the exterior surface of a host

• Ex. Fleas

INFESTATION

TYPE OF PARASITE

Organism involved: Ectoparasites

Characteristics: Lodgment of the parasite on the surface of the susceptible host

INFECTION

TYPE OF PARASITE

Organism involved: Endoparasites

Characteristics: Invasion/Modification of the parasite within the host’s body

Pathogenic

According to Pathogenicity:

• Causes disease in the host

• Ex. Plasmodium species (cause malaria)

Non-pathogenic

According to Pathogenicity:

• Doesn’t cause disease and may live harmlessly in the host

• Ex. Entamoeba coli

Obligate

Facultative

Accidental/incidental

According to need for host:

Monoxenous

According to number of host required in the life cycle:

• Completes life cycle by one host

• Ex. Enterobius vermicularis (Pinworm)

Heteroxenous

According to number of host required in the life cycle:

• It requires two or more hosts to complete the life cycle

• Ex. Plasmodium species

ACCIDENTAL OR INCIDENTAL HOST

TYPE OF HOST

• Host other than the normal one that is harboring a parasite

DEFINITIVE HOST

TYPE OF HOST

• Host in which the adult sexual phase of parasite development occurs

INTERMEDIATE HOST

TYPE OF HOST

• Host in which the larval asexual phase of parasite development occurs

RESERVOIR HOST

TYPE OF HOST

• Host harboring parasites that are parasitic for humans and from which humans may become infected

TRANSPORT HOST / PARATENIC / PHORETIC

TYPE OF HOST

• Host responsible for transferring a parasite from one location to another

CARRIER

TYPE OF HOST

• Parasite-harboring host that is not exhibiting any clinical symptoms but can infect others

SYMBIOSIS

PARASITE-HOST RELATIONSHIP

• Living together; the association of two living organisms, each of a different species.

COMMENSALISM

PARASITE-HOST RELATIONSHIP

• Association of two different species of organisms that is beneficial to one and neutral to the other.

MUTUALISM

PARASITE-HOST RELATIONSHIP

• Association of two different species of organisms that is beneficial to both.

PARASITISM

PARASITE-HOST RELATIONSHIP

• Association of two different species of organisms that is beneficial to one at the other’s expense.

COMMENSAL

PARASITE-HOST RELATIONSHIP

• Relating to commensalism; the association between two different organisms in which one benefits and has a neutral effect on the other.

PATHOGENIC

PARASITE-HOST RELATIONSHIP

• Parasite that has demonstrated the ability to cause disease.

Mode of transmission

PARASITIC LIFE CYCLE

Three common components:

• This is how the parasite enters the host

Infective stage

PARASITIC LIFE CYCLE

Three common components:

• This is the stage of the parasite that can infect the host

Diagnostic stage

PARASITIC LIFE CYCLE

Three common components:

• This is the stage of the parasite that can be detected in the laboratory

DIRECT

PARASITIC LIFE CYCLE

• Only one host in the entire cycle

INDIRECT

PARASITIC LIFE CYCLE

• Two or more hosts in the life cycle

Gastrointestinal and Urogenital tracts

DISEASE PROCESSES AND SYMPTOMS

Major body associated with such processes:

• These are the parasites that live in intestines, stomach, anus, urinary track, or reproductive organs

• Usually they are acquired through ingestions, water or food, or ingestion on the contaminated water and food, or sexual transmission

Blood and tissue

DISEASE PROCESSES AND SYMPTOMS

Major body associated with such processes:

• Parasites that invades the blood and even the muscle and tissues of the body

Liver, Lung, and other major organs

DISEASE PROCESSES AND SYMPTOMS

Major body associated with such processes:

• These parasites usually they migrate from one area to another area and usually some of vital organs cause infection

Miscellaneous locations

DISEASE PROCESSES AND SYMPTOMS

Major body associated with such processes:

• Parasite can also affect the skin, the eyes, the brain, lymphatics, or even subcutaneous tissues

Elephantiasis

SYMPTOMS ASSOCIATED WITH PARASITIC DISEASE PROCESSES

• Because of microfilaria worms

• common in the province of philippines (mindanao)

• Usually common in farmers

Diarrhea

Fever

Chills

Abdominal pain

Abdominal cramping

SYMPTOMS ASSOCIATED WITH PARASITIC DISEASE PROCESSES

Common symptoms are:

Antiparasitic medications

TREATMENT

PARASITIC TREATMENT OPTIONS

common option is ______

1. Type of the parasite

2. Host safety

3. Drug resistant

4. Route and the duration of administration

5. Patient factors

TREATMENT

Considerations in treatment:

Good personal hygiene

Proper sanitation practices

Proper handling, cooking, and protection of food

Use of insecticides and other chemicals

Development and implementation of parasite awareness education programs

PREVENTION AND CONTROL

PARASITE PREVENTION AND CONTROL STRATEGIES

Most common are:

trophozoite (active; motile; feeding stage)

cyst (dormant; inactive; resistant stage; can survive in harsh conditions)

AMOEBAS

2 forms of amoeba:

Entamoeba histolytica

AMOEBAS

Pathogenic in humans:

• cause Amoebic dysentery

Naegleria flowleri

AMOEBAS

Pathogenic in humans:

• causes Primary amoebic meningoencephalitis which is rare and deadly

Acanthamoeba species

AMOEBAS

Pathogenic in humans:

• cause Keratitis and Granulomatous amoebic encephalitis

Entamoeba coli

AMOEBAS

Nonapathogenic in humans:

• commensal in the intestine

Entamoeba coli

Entamoeba hartmanni

AMOEBAS

Non-pathogenic in humans:

Entamoeba histolytica

Naegleria flowleri

Acanthamoeba species

AMOEBAS

Pathogenic in humans:

Entamoeba histolytica

Entamoeba hartmanni

Entamoeba coli

Entamoeba polecki

Endolimax nana

Iodamoeba butschlii

AMOEBAS

Intestinal species:

Entamoeba gingivalis

Naegleria fowleri

Acanthamoeba species

AMOEBAS

Non-Intestinal species:

Naegleria amoebic and Acanthamoeba species

AMOEBAS

Free living amoebas:

trophozoite and cyst

FLAGELLATES

They can exist in the 2 forms:

Giardia lamblia

FLAGELLATES

• Giardia intestinalis old name is _______

Giardia intestinalis

FLAGELLATES

• It causes Giardiasis

Trichomonas vaginalis

FLAGELLATES

• Urine specimen

• Mode of transmission: through sexual contact

• Causes Trichomoniasis

Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense

HEMOGLAGELLATES

• Caused by tsetse fly

• It causes African sleeping sickness

Trypanosoma cruzi

HEMOGLAGELLATES

• Caused by kissing bug or reduviid bug

• It causes Chagas disease

Leishmania species

HEMOGLAGELLATES

• From the vector sandfly

• It causes Leishmaniasis

Balantidium coli

CILIATES

• Reservoir host: pigs

• It has 2 types of nuclei: macronucleus and micronucleus

• Pathogenic ciliates

Cryptosporidium parvum

SPOROZOA

• Common in immunocompromised patients especially HIV patients

Toxoplasma gondii

SPOROZOA

• From cat feces

• It can be transmitted through ingestion of cat feces

• It causes Toxoplasmosis

Ascaris lumbricoides

ROUNDWORMS

• It causes ascariasis

Enterobios vermicularis

ROUNDWORMS

• It causes Pruritus ani

• Usually, kids are affected

Strongyloids stercoralis

ROUNDWORMS

• Through skin penetration

Trichinella spiralis

ROUNDWORMS

• Found in the muscle

• cyst

• trophozoite

ROUNDWORMS

• Infective stage: ________

• Diagnostic stage: _______

Wucheriria bancrofti

TISSUE ROUNDWORMS

• It causes Elephantiasis

bite of a mosquito (insect vector)

TISSUE ROUNDWORMS

• Mode of transmission: _________

blood smear and tissue biopsy

TISSUE ROUNDWORMS

• Specimen: _________

Taenia saginata

TAPEWORMS

• Source: undercooked beef

• Beef tapeworm

Taenia solium

TAPEWORMS

• Source: undercooked pork

• Pork tapeworm

• It causes Cysticercosis

Diphyllobothrium latum

TAPEWORMS

• Source: undercooked freshwater fish

• Fish tapeworm

• It causes B12 deficiency specifically Megaloblastic anemia

Echinococcus granulosus

TAPEWORMS

• Source: dogs; intermediate host (sheep)

• It causes Hydatid cyst

Fasciolopsis buski

Heterophyes heterophyes

Metagonimus yokogawai

FLUKES

Intestinal species:

Fasciola hepatica

Clonorchis sinensis

FLUKES

Liver Species:

Paragonimus westermani

FLUKES

Lung specie:

Schistosoma mansoni

Schistosoma japonicum

Schistosoma haematobium

FLUKES

Blood species:

Centipedes

ANTHROPODS

Class Chilopoda:

Tongueworms

ANTHROPODS

Class Pentastomida:

Ticks

Mites

Spiders

Scorpions

ANTHROPODS

Class Arachnida:

Crabs

Crayfish

Copepods

ANTHROPODS

Class Crustacea:

Mosquitoes

Lice

Fleas

Bugs

ANTHROPODS

Class Insecta:

Ectoplasm

GENERAL CHARACTERISTICS OF PROTOZOANS

• these are outer clear gel-like layer often involved in movement and feeding

Endoplasm

GENERAL CHARACTERISTICS OF PROTOZOANS

• inner granular layer that contains organelles, animal organelles

Flagella

GENERAL CHARACTERISTICS OF PROTOZOANS

Locomotory apparatus:

• thread-like, long whip-like structures arising from the surface of the cell.

• For movement and feeding

• Ex. Giardia lamblia

Cilia

GENERAL CHARACTERISTICS OF PROTOZOANS

Locomotory apparatus:

• shorter, needle-like or hair-like structures, found all throughout the cell.

• Ex. Balantidium coli

Pseudopods / Pseudopodia

GENERAL CHARACTERISTICS OF PROTOZOANS

Locomotory apparatus:

• False-feet, temporary cytoplasmic extensions.

• Ex. Entamoeba histolytica

Entamoeba histolytica

GENERAL CHARACTERISTICS OF PROTOZOANS

• _________ is pathogenic that causes amebiasis

• Unique characteristic: it has RBCs inside

Undulating membrane

GENERAL CHARACTERISTICS OF PROTOZOANS

Locomotory apparatus:

• Flexible sheet of material that joins the flagella to the surface of the cell.

• Ex. Trichomonas vaginalis

Trichomonas vaginalis

GENERAL CHARACTERISTICS OF PROTOZOANS

• _______ is found in urine specimen

• Common in female

• Sexually transmitted disease

Apical complex

GENERAL CHARACTERISTICS OF PROTOZOANS

Locomotory apparatus:

• Consists of polar rings, subpellicular tubules, conoid, rhoptries, and micronemes, for penetration and invasion of the target cell.

• Non-motile protozoan

• Ex. Toxoplasma gondii

Egg

GENERAL CHARACTERISTICS OF METAZOANS

• which is infective or environmental stage; resistant to harsh environment

Larva

GENERAL CHARACTERISTICS OF METAZOANS

• this is the developmental stage; this may live in intermediate host or environment; immature stage

Adult

GENERAL CHARACTERISTICS OF METAZOANS

• sexually mature stage; usually inhabits the definitive host

Fecal specimen

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• ________ should be collected before any radiologic procedures that use barium sulfate because it will obscure the visualization of the parasite.

Certain antibiotic

Antimalarial medications

Antidiarrheal products that are not absorbed

Mineral oil

Bismuth

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

Some medications intake that may interfere with detection include:

pea-sized

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• Collect only a ______ amount of stool

three

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• As a general rule, before therapy, at least ____ fecal specimens should be collected

Castor oil or mineral oil laxatives

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• ________ should be avoided because oil decreases the motility of the trophozoite form of intestinal protozoans.

Name of the patient

Birthdate

Time of collection

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• Ensure proper, accurate, and correct labeling of the specimen.

half an hour or 30 mins

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• Liquid samples should be examined within ______ of collection.

1 hour

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• Soft and semisoft stools should be examined within ____ of collection

3°C or 5°C; 4 hours

SPECIMEN COLLECTING, PROCESSING AND EXAMINING OF STOOL SPECIMENS

• If examination is not possible right away, the specimen can be refrigerated at _____ for up to ____.

STOOL

SPECIMEN PROCESSING AND LABORATORY DIAGNOSIS

SPECIMEN: ____________

USE:

• Most commonly submitted sample for parasitology studies

• Microscopic (ova and parasites) and macroscopic techniques

• Fresh or preserved sample