Medical parasitology

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Medical parasitology

• Protists

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Phylum Sapcomastigophora, Subphylum Sarcodina
amoebas

• Morphology

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Phylum Sapcomastigophora, Subphylum Sarcodina
amoebas

• Diversity

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Amoebas of medical importance

• Entamoeba hystolytica
• Entamoeba hartmani
• Entamoeba coli
• Entamoeba gingivalis
• Iodamaeba buetschlii
• Endolimax nana
• Naegleria fowleri

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Entamoeba hystolytica

• Entamoeba hystolytica causes amebic dysentery,
  amoebiasis.
• 3rd the most common cause of parasitic death
  (after malaria and schistosomiasis).
• Different strains. Virulent strains can hydrolyse
  tissues.

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Entamoeba hystolytica. Life cycle
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Entamoeba hystolytica

• Development trofozoite, precyst with glycogen,
  cyst with 1 nucleus, metacyst with 4 nucleus,
  metacystic trophozoite (small amoebula), amoeba.
• Primary intestine infection feed on mucosa and
  bacteria in large intestine, make tissue
  invasions, hydrolyze mucosa cells, erode ulcers,
  reach submucosa and blood vessels, perforate
  colon, cause peritonitis and death. Acute or
  chronic diarrhoea, cramps, vomiting, malaise
  etc.
• Secondary infection transferred by blood to
  liver, lungs, skin, brain etc., produce toxins.
  Hepatic amebiasis cause abscess, pulmonary
  lesions, cardiac failure, exhaustion, death.

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Entamoeba hystolytica

• Incubation period 8-10 days.
• Diagnosis
• in stool samples, smear examination (alive
  amoebas and cysts)
• Immunological methods.

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Entamoeba hystolytica

• Distribution

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Entamoeba hystolytica

• Epidemiology World wide. Prevalence 1-40. The
  most susceptible at age 25-30.
• In tropics, in flood areas, during the war.
• Human resistance increase from North to South.
• Distribution depends on manner of disposal of
  human waste. Main sources of cysts contaminated
  water and food, house fly, use of human faeces as
  fertilizers.
• Reservoirs dogs, pigs, monkeys.

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Entamoeba hystolytica

• Prophylaxis
• Personal hygiene
• Drinking water for the crisis regions
• Safety of the toilets
• Isolation of vectors (flies)
• Treatment
• Diodoquine, Metronidazole,
• Dehydroemetine vai Emetine
• Stopping of dehydratation of the body

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Amoebas

• Entamoeba coli
• Iodamoeba buetschlii
• Endolimax nana
• Low pathogenesis in humans.
• Reservoirs- primates, pigs.

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Entamoeba gingivalis

• Commensals in the mouth cavity, bronchi.
  Prevalence 100

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Naegleria fowleri

• Life cycle

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Naegleria fowleri

• Life cycle

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Naegleria fowleri

• Free living in water. Development flagellate
  form, amoeboid form, cyst.
• Causes primary amoebic meningoencephalitis. Cause
  acute disease, fatal illness. Children the most
  susceptible.
• Source water with free living amoeba.
• Infection water, nasal cavity, nasal passages,
  lyses of epithelium, olfactory nerve, cranium.
• Prevalence very low, seasonal, world-wide.

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Naegleria fowleri

• Prophylaxis
• Safety of swimming pools, even indoor ones (check
  the presence, if any cases was registered do
  not allow to swim, disinfect)
• Diagnostics
• Immunological
• Cultivation in the bacterial medium
• Inoculation into lab animals (intracerebral)
• Treatment
• Amphotericin B, intra-venous

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Acanthamoeba spp. - akantamoebas

• Common in nature. Since 1984 has been revealed in
  human.
• Can cause damage of eyes
• Can induce granular amoebial meningitis
• Can induce diffuse dermal lesions
• Connected with human immune suppression and
  weakness

Bojata acs
Bojata smadzenu garoza
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Acanthamoeba spp.

• Life cycle

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Blastocystis hominis blastocistosis

• Life cycle, inhabits intestine

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Blastocystis hominis blastocistoze

• Diagnostically forms in the faeces
• vacuolar
• granular
• cysts
• amoeboidal

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Blastocystis hominis blastocistosis

• Symptoms diarrhoea, vomiting, abdominal cramps,
  meteorism, itching of anus. Chronic disease
  lasting some weeks to years. Different strains
  with different virulence. Probable not deadly
  disease. Also probable explanation of uncertain
  diarrhoeas e.g. 3550 cases in Latvia (Latvian
  Centre of Infectology).
• Prophylaxis hygiene.
• Treatment as in ammoebiasis?

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Phylum Ciliophora ciliates
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Balantidium coli

• Life cycle

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Balantidium coli

• Common in tropics, rare in temperate climate.
• Effects and epidemiology similar to Entamoeba
  hystolitica.
• Digest the content of intestine, produce
  proteolytic enzymes, ulcer, secondary infection,
  perforation. Infections in other organs.
• Mean prevalence 1, in Philippines common.
• Reservoir in cecum, colon, in different
  vertebrates, pigs.

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Balantidium coli

• Prophylaxis
• As in amoebiasis
• Treatment
• Oxitetracycline, Iodoquinol

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• entamoeba histolytica http//www.youtube.com/watch
  ?vCG3bpxAESgU
• http//www.youtube.com/watch?NR1vyacSXnJgRVwfe
  atureendscreen