PARASITOLOGY

P. vivax, P. malariae and P. ovale

belong to the subgenus Plasmodium

PAROXYSM

what do you call to the symptom of MALARIA

MALARIA Definitive host:

Female Anopheles mosquito.

P. falciparum

belong to the subgenus Laverania

Plasmodium ovale

Plamodium vivax

: Benign Tertian Malaria

Plamodium vivax

preferentially infect reticulocytes and young erythrocytes

2 distinct types of sporozoites,

• tachysporozoites (tachy: fast)

• bradysporozoite (brady: slow)

Plasmodium falciparum

: Malignant Tertian Malaria

• pernicious malaria for its infection

Plasmodium falciparum

attack both young and mature erythrocytes and so the population of cells affected is very large

• falx: sickle, parere: to bring forth

• They show a few (6–12) coarse brick-red dots which are called Maurer’s clefts

Plasmodium malariae

: Benign Quartan Malaria

• in which febrile paroxysms occur every fourth day, with 72 hours’ interval between the bouts

Plasmodium malariae

infects older erythrocytes and the degree of parasitization is low

• cold stage

• hot stage

• sweating stage

Clinical features: Benign Malaria

3 successive stages—

Cerebral Malaria

It is the most common cause of death in malignant malaria.

Cerebral Malaria

CAUSE:

Blackwater fever: A syndrome called blackwater fever (malarial hemogloblinuria) is sometimes seen in falciparum malaria, particularly in patients, who have experienced repeated infections and inadequate treatment with quinine.

PERIPHERAL SMEAR

Clinical features: Malignant Tertian Malaria

• Laboratory Diagnosis

Therapeutic:

Objective is to eradicate the erythocytic cycle and clinical cure

erythocytic

INSIDE of BLOOD

exoerythrocytic

OUSITE of BLOOD

Radical cure:

Objective is to eradicate the exoerythrocytic cycle in liver to prevent relapse

PRI MA QUINE

Radical cure

chloroquine

Positive P. vivax, P. ovale and P. malariae cases are treated with

CIN CHONA tree

chloroquine is FROM

ARTE ME SININ

chlorquine resistance: you give

QING HAO SU

ARTE ME SININ

• CHINESE TERM

RTS,S/AS01 (Mosquirix)

Malaria Vaccine

• The world's first approved malaria vaccine, recommended by the WHO in 2021 for children in areas with moderate to high transmission of Plasmodium falciparum

R21/Matrix-M

Malaria Vaccine

• The second WHO-recommended vaccine, approved in October 2023, also targets P. falciparum.

Babesia BABE SIA

• Sporozoites

rodent strain

• Definitive host: Ixodid ticks.

  • Sci. name: IXODES SCAPURALIS

• Infective form:

Toxoplasma gondii

most common protozoan parasite globally,

• Definitive host: STRAY CATS

• Intermediate hosts: Man and other mammals, in which only the asexual cycle takes place.

Isospora belli

Recreational water diarrhea

• cause diarrhea in humans

• Name from from bellium meaning war

• self-limiting

Cryptosporidium Parvum

• OOCYSTS

cause : intractable diarrohea, in AIDS patients, and immunocompromised subjects

• inhabits the small intestine

• INFECTIVE FORM:

Cyclospora cayetanensis

caused:  seasonal outbreaks of prolonged diarrhea,

• with peak prevalence in the warm rainy months

• DOC: COTRIMOXAZOLE

Pneumocystis jirovecii

cause:  pneumocystic pneumonia

• Pneumothorax is a well-known complication of pneumocystic pneumonia

• Immunocompromised patients: HYPOXIA

• commensal in the lung and spreads by respiratory droplets.

• DOC: COTRIMOXAZOLE

Balantidium coli

largest protozoan parasite of humans

Balantidium coli

CAUSE: Dysentery

INFECTIVE FORM: CYST

Natural host: Pig

DOC:  TETRAcycline

CYST

INFECTIVE FORM of AMOEBA

ENTAmoeba HISTOlytica

ONLY PATHOGENIC Intestinal amoeba

ENTAmoeba HISTOlytica

• IRON hemotoxylin

• Nucleus is spherical 4–6 μm in size and contains central karoyosome, surrounded by clear halo and anchored to the nuclear membrane by fine radiating fibrils called the lining network, giving a cartwheel appearance

• NUCLEUS NOT CLEAR SEEN UNLESS You ADD???

MINUTE FORM

Pre cyctic form

• non invasive smaller form

• The parasite, as it occurs free in the lumen as a commensal is generally smaller in size, about 15–20 μm and has been called the

Excystation:

When the cyst reaches caecum or lower part of the ileum, due to the alkaline medium, the cyst wall is damaged by trypsin, leading to excystation

Luminal amoebicides:

Diloxanide furoate, iodoquinol, paromomycin, and tetracycline act in the intestinal lumen but not in tissues

chromatoid bodies are splinter like and irregular.

MTURE cystic?

Entamoeba Coli

• 8

Entamoeba hartmanni

OCCURS wherever E. histolytica is found.

• It is now considered to be a separate species of nonpathogenic commensal intestinal amoeba.

Endolimax nana

• This common commensal amoeba is widely distributed. qIt lives in the human intestine.

• The trophozoite is small (nana: small), less than 10 μm in size with a sluggish motility

• The nucleus has conspicuous karyosome connected to nuclear membrane by one or none coarse strands.

• The cyst is small, oval, and quadrinucleate with glycogen mass and chromidial bars, which are inconspicuous or absent

• It is non -pathogenic.

Iodamoeba buetschlii

• This is widely distributed, though less common than E. coli and E. nana.

• The trophozoite is small, 6–12 μm, with conspicuous nucleus

• prominent karyosome is half the size of the nucleus, having bull’s eye appearance.

• The cyst is oval, uniucleate, and has a prominent iodine qstaining glycogen mass (iodophilic body).

• Hence, the name ‘Iodamoeba’.

• It is non-pathogenic.

Naegleria fowleri

Primary amoebic meningoencephalitis

– caused by

Naegleria fowleri

the brain eating amoeba

Naegleria fowleri

heat-loving (thermophilic) amoeba that thrives in warm water at low oxygen tension and is commonly found in warm freshwater (e.g. lakes, rivers, and springs) and soil

AMOEBOID FORM

Naegleria fowleri 

• INFECTIVE FORM

AMPHOtericin B

Naegleria fowleri

• DOC

  • binds to ergosterol-like sterols in the cell membrane of Naegleria fowleri

cyst

Under unfavorable conditions,  it forms a??

• which undergoes excystation in favorable conditions

• never found: cyst & flagellate form

• found: amoeboid form

CEREBROSPINAL FLUID

• never found

• found

Acanthamoeba Culbertsoni

• Granulomatous amoebic encephalitis

  • caused by

Acanthamoeba Culbertsoni

• chronic amoebic keratitis 

  • caused by

• Trophozoites

• cysts

Acanthamoeba Culbertsoni

• INFECTIVE FORM

Acanthamoeba keratitis

: An infection of the eye that typically occurs in healthy persons and develops from the entry of the amoebic cyst through abrasions on the cornea.

Granulomatous amoebic encephalitis(GAE)

: It is a serious infection of the brain and spinal cord that typically occurs in persons with a compromised immune system

Naegleria fowleri 

WBC in CNS: predominantly NEUTROPHILS

Acanthamoeba keratitis

WBC in CNS: predominantly LUMPHOCYTES

Lumen-dwelling flagellates

Flagellates

• Flagellates found in the alimentary tract and urogenital tract

Hemoflagellates

Flagellates

• Flagellates found in blood and tissues

Giardia lamblia

Giardia intestinalis OLD NAME

Giardia intestinalis

most common protozoan pathogen and is worldwide in distribution

Giardia intestinalis

falling leaf motility

Giardia intestinalis

lives in the duodenum and upper jejunum and is the

• only protozoan parasite found in the lumen of the human small intestine

Giardia intestinalis

CAUSE: steatorrhea

INFECTIVE FORM: CYST

DOC: METROnidazole

LAB TEST: Stool examination, enterotest, ELISA

Giardia intestinalis

INFECTIVE FORM:

DOC:

LAB TEST: 

• INFECTIVE FORM: TROhoZOITES

• DOC: metronidazole

Trichomonas vaginalis

• INFECTIVE FORM

  • divide by binary fission

• DOC

Trichomonas tenax

also known as T. buccalis

• is a harmless commensal which lives in mouth in the periodontal pockets, carious tooth cavities, and less often in tonsillar crypts.

• It is smaller (5–10 μm) than T. vaginalis. qIt is transmitted by kissing, through salivary droplets, and fomites.

• Better oral hygine rapidly eliminates the infection and no therapy is indicated

• TROhoZOITES

• cyst

Trichomonas hominis

• pyriform -shaped, and carries 5 anterior flagella and an undulating membrane that extends the full length of the body.

• found in large intestine

INFECTIVE FORM?

Trypanosoma brucei gambiense

: causing West African sleeping sickness

• CHRONIC

  • LATE CNS invation

  • months to years

• HOST: TSETse FLY

  • glossina PALPALIS

• INFECTIVE FORM: METAcyclic TRYPOmastigote

Trypanosoma brucei gambiense

• HOST - Intermediate host:

• INFECTIVE FORM:

Trypanosoma brucei rhodesiense

: causing East African sleeping sickness.

• ACUTE

  • EARLY CNS invation

  • LESS THAN 9months

• HOST: TSETSE FLY

  • glossina MORSILANS

Trypanosoma brucei rhodesiense

• HOST - Intermediate host

Trypanosoma cruzi,

causing South American trypanosomiasis or Chagas’ disease.

• KISSING BUG

  • Reduviid bug

• METAcyclic TRYPOmastigote

Trypanosoma cruzi

• HOST - Intermediate host

• INFECTIVE FORM

Trypanosoma cruzi

cause:

• ROMANS sign

• CHAGOMA

Trypanosoma rangeli

a nonpathogenic trypanosome causing human infection in South America

SANDLY

• PHLEO boto mus

Leishmania

• HOST - Intermediate host

Leishmania Donovani

cause: Visceral leishmaniasis

• KALA AZAR

• DUM DUM fever

• PROmastigote

• sandfly

Leishmania Donovani

• INFECTIVE FORM

• VECTOR

Leishmania tropica

oriental sore, Baghdad boil

• Cutaneous Leishmaniasis

Leishmania braziliensis complex

Espundia

• Mucocutaneous leishmaniasis

Leishmania mexicana complex

Chiclero's ulcer

• Mucocutaneous leishmaniasis

Epistaxis

and bleeding from gums are common.