L19 Parasitic diseases

Medical parasitology

Protozoa

• kingdom of life

• characteristic

• structure

• kingdoms of life: animals, plants, fungi, Protista (algae and protozoa)

• singled celled, animal-like

  • ex. amoebae, ciliates, flagellates, sporozoans

• structure:

  • cytoplasmic membrane

  • cytoplasm

  • cytostome (mouth)

  • vacuole

  • nucleus w/ DNA

  • ER

  • mitochonrion

  • usually with flagellum

Protozoa Life processes

Protozoa life cycle

• reproduction

• encystment

Infective amoebas general properties

amoebiasis epidemiology

• typical places

• spreading mechanism

• a tropoical and subtropical diseases 

  • spread in tropical more than US cuz sewage used as fertilizers in tropical

• Spread: refer to pic

Amoebiasis life cycle

Amoebiasis

• diagnosis

• treatment

diagnosis

• Trophozoite that has ingested RBC

• 4 nuclei in cysts

• symptom

treatment

• drugs targeting parasites in both feces and the tissue

Naegleria fowleri and acanthamoeba characteristics

Naegleria fowleri life cycle

Naegleria fowleri pathogenesis

• Naegleria infection starts at the nasal mucosa

• The amoeba burrows in, multiplies, and migrate into the brain → primary acute meningoencephalitis: rapid, massive destruction of the brain and spinal tissue.

  • Symptoms: hemorrhage and coma, death in a week

ciliate characteristics

Balantidium Coli Reservoir (Natural habitat)

• large intestines of pigs, and other domestic animals, primates

• cysts are in the feces

anatomy of balantidium coli
* trophozoite vs mature cyst

• Mature cyst only consist of macronucleus

• trphozoite has macro and micronucleus

Balantidium coli prevention

• prevent food or drink contamination with pig manure

Flagellates (mastigophorans) common features

long filamentous flagella

flagellate morphology

• Undulating membrane = wavy fin-like structure for movement

• Axostyle = internal supporting rod

Trichomonads reservoir

• human urogenital tract: 50% asymptomatic

Trichomoniasis symptoms and treatment

Female

• foul smell, green to yellow vaginal discharge

• vulvitis, cervicitis

• urinary frequency and pain

male

• milky discharge

• urethritis

• prostate infection

Treatment

• antibiotic and both sexual partners have to be treated

Giardiasis life cycle

Giardiasis outbreaks example

Hemoflagellates characteristic

vector-borne blood parasites

Developmental stages of hemoflagellates

• amastigote

• promastigote

• epimastigote

• trypomastigote

• amastigote

• promastigote

• epimastigote

• trypomastigote

Infection by T. brucei

• rhodesian form

• gambian form

Pathology of sleeping sickness

• Intermittent fever, enlarged spleen, swollen lymph nodes, joint pain

• Personality change, sleep disturbances

  • Sleepiness during the day

  • Sleeplessness at night

• Advanced neurological disorders:

  – Muscular tremors, shuffling gait, slurred speech, epileptic seizures, paralysis

  – Death: coma, secondary infections, heart damage

Treatment and prevension of sleeping sickness

Why the immune system can not defeat the trypanosome

T. cruzi infection

Leishmaniasis characteristics

Leishmania life cycle

Apicomplexan parasite characteristic

Malaria symptoms

• chills and fever at regular intervals, followed by sweating: 48 to 72 hours, due to synchronous rupturing of RBCs.

• Anemia in young children; organ rupture from accumulated cell debris (spleen, liver and kidneys)

• Long recovery: up to 5 years

Malaria plasmodium species

• P. falciparum - – Most severe malaria

  • Persistent fever, rapid pulse, cough, weakness for weeks without relief, high death rate in acute phase

• P. malariae;

• P. vivax;

• P. ovale

Malaria transmission

Malaria life cycle

Genetic change that wards off malaria

Malaria

• treatment

• diagnosis

• control

treat with antimalaria drugs

Toxoplasmosis characterstic

Toxoplasma gondii infection in pregnant women