OTHER PROTOZOANS & ARTHROPODS

Entamoeba histolytica

• flask shaped colonic perforation

• Amoebic Liver Disease

• Commensal Amoeba

Diagnostic Stage:

• Mature Stages

Infective Stage:

• Mature Stages

MOT:

• Ingestion

Definitive Host:

• Humans

Naegleria fowleri

• enter through the Olfactory neuroepithelium

  • Causes PAM

• Trophozoites in CSF and Tissue flagellated forms in CSF

Acanthamoeba spp & Balamuthia mandrillaris

• enter through the Lower Respiratory Tract or Ulcerated or Broken skin

  • Causes GAE

• Cysts & Trophozoites in CSF

Balantidium coli

• Largest

• Only ciliate that can infect humans

• Kidney bean shaped macronucleus, round micronuclei

Infective stage:

• Cyst

MOT:

• Ingestion of contaminated food / water

Giardia lamblia

• assoc. w/ steatorrhea & Gay Bowel Syndrome

• Old man with eyeglasses appearance

• Entero string test

• Falling leaf motility

Infective stage:

• Cyst

MOT:

• Ingestion of contaminated food / water

Trichomonas vaginalis

• Sexually Transmitted

• Ping pong Infection

• Jerky tumbling motion

Trypanosoma cruzi

• Chagas disease

• Vector = Triatomine bug / Reduviid bug / Kissing bug

• Infective Stage = Trypomastigote

Trypanosoma brucei

• African Sleeping sickness

• Vector = Tsetse fly (Glossine sp.)

• Infective Stage = Trypomastigote

Leishmania sp.

• Leishmaniasis

• Vector = Sand Fly (Phlebotomus sp.)

• Infective Stage to sand fly = Amastigote

Babesia Microti

• Vector = Deer Tick (ixodes)

• Infective Stage to humans = Sporozoites

• Infective Stage to ticks = Gametes/gametocytes

• Spx: Blood

• Tetrads / Maltese cross formation

• Babesia = Often confused w/ falciparum

Plasmodium spp

• Vector = Female Anopheles Mosquito

• Infective Stage = Sporozoites

• Female Gametocyte = Macrogametocyte

• Male Gametocyte = Microgametocyte

• Definitive Host: Mosquito

• Intermediate Host = Human

Schizont / Sporozoites

Plasmodium in human = Schizogony

• Product = ?

• Infective Stage = ?

Sporozoite / Gametocytes

Plasmodium in Mosquito = Sporogony

• Product = ?

• Infective Stage = ?

P. falciparum

• Most Severe

• Infects young & old RBCs

• Black Water Fever

• Cerebral Malaria

• Has banana shaped gametocytes

• Double chromatin dots on ring stage

• Only ring & gametocyte are seen

P. vivax & P. ovale

• assoc. Malarial relapse (hypnozoite forms)

• Schuffner’s dots

• round (vivax) & ovale (oval)

P. malariae

• band forms

Arthropods

• bilaterally symmetrical invertebrate animals with segmented bodies, jointed appendages and hard outer covering or exoskeletons

Envenomization

Ingestant and inhalant allergens

Myiasis

Entomophobia and delusory parasitoses

Ectoparasitism (lisa, kuto, ticks)

Food, water and household pests

Ways by which arthropods affect humans:

Pest

• An arthropod becomes a ______ when it causes annoyance or nuisance, or when it causes harm to a man and properties

Vector

• An arthropod becomes a ______ when it becomes infected and capable of transmitting a pathogen that causes infection or disease

Infected Vector

• Vector that acquired the parasite from an infected human or animal

Infective Vector

• Vector that supports the growth of the stage of parasite that is infective to humans

Parasitic Lice

MOST COMMON ARTHROPODS:

• Associated with pediculosis, crabs

• Serves as vector for rickettsial infections (epidemic typhus, trench fever) and relapsing fever (Borrelia recurrentis)

Flees

MOST COMMON ARTHROPODS:

• Xenophsylla cheopis

Cockroach

MOST COMMON ARTHROPODS:

• Ascaris and Trichuris, as well as Salmonella, Proteus, Escherichia and Citrobacter were found in _______

Ticks

MOST COMMON ARTHROPODS:

• Hard Ticks (Ixodidae), Soft Ticks (Argasidae)

Mites

MOST COMMON ARTHROPODS:

• Sarcoptes scabiei

  • Produces scabies, the only species that produces human disease