Micrognome » clinical parasitology

Common enteric parasites

micrognome — Sun, 06 Nov 2011 11:20:13 +0000

Clinical Parasitology

This list captures a typical top ten common enteric parasites of medical importance, though the order of importance will vary around Australia. Information on Entamoeba histolytica is given, as this species is a common reason for a test request even if a positive result is relatively uncommon. The pathogenic role of several of the other parasite species is debatable, and detection may be more useful as an indication of poor hygiene, recent international travel or immune compromise. Further details at the CDC.

Species	Diagnostic stage	Size	Key features
Blastocystis hominis	round-oval form	6-40um	Large central vacuole surrounded by small nuclei
Cryptosporidium parvum	oocyst	4-5um	Round, pink on modified acid-fast stain
Endolimax nana	cyst & trophozoite	Cyst, 5-10m; troph, 6-12um	Oval cyst – 4 nuclei; troph variable chromatin
Entamoeba coli	cyst & trophozoite	Cyst, 10-35um; troph, 15- 50um	Cyst – 8-16 nuclei; troph – uneven periph chromatin, large karyosome
Entamoeba histolytica	cyst & trophozoite	Cyst, 10-20um; troph, 16- 20um	Cyst – 4 nuclei; troph – even periph chromatin, central karyosome, may have ingested erythrocytes
Enterobius vermicularis	egg	50-60um long, 20-40um wide	Flattened on one side, colourless
Giardia lamblia	Cyst & trophozoite	Cyst, 8-19um long; troph, 10-20um	Oval or round cyst; troph pear-shaped, 2 nuclei, flagellate
Hymenolepis nana	egg	30-45um	6-hook oncosphere at centre of thin walled egg
Iodamoeba butschlii	cyst & trophozoite	Cyst, 5-20um; troph, 8- 20um	cyst – large glycogen vacuole; troph – large karyosome
Schistosoma spp.	egg	S.mansoni egg = 115- 175um long; S.haematobium egg = 112-170um long	S.mansoni egg, prominent lateral spine; S.haematobium egg , terminal spine
Strongyloides stercoralis	first stage larva	180-380um long	Short buccal cavity, mid-body genital primordium

Malaria matters

micrognome — Sat, 13 Nov 2010 12:02:55 +0000

Now that the MicroGnome can reliably get lecture notes onto this Blog, here is the Malaria series for students of tropical medicine:

Factm malaria 1

Factm malaria 2

Factm malaria 3

Factm malaria 4

Serious tummy trouble

micrognome — Thu, 08 Jul 2010 13:04:32 +0000

If you missed this week’s Tropical Medicine Breakfast, here are the notes. An illustrated version of the Clinical Parasitology unit will appear later when the enteric infection module is complete.

Malaria revision

micrognome — Wed, 14 Apr 2010 02:58:26 +0000

Clinical Tropical Medicine sessions started yesterday at the QEII Medical Centre with malaria 1 and 2
Self-assessment questions follow for those thinking about doing the FACTM part 1 exam this year
- Here are some questions based on the first two Malaria modules.
- Additional self-assessment exercises for prospective candidates on the ACTM website .

Problem 1

What parasitic infection is this and why?

(both results are from the same blood sample)

Show answer

Likely non-falciparum malaria.
The HRP 2 P. falciparum band is absent on the rapid test.
A weak band is present against the P. vivax – P. ovale – P. malariae position.
There are no features in the thin film pointing to P. falciparum
The trophozoites could belong to one of several Plasmodium species

Problem 2

What infection is this and why?

(both views are from the same blood film)

Show answer

Likely non-falciparum malaria.
A single, amoeboid Plasmodium trophozoite is present inside and RBC
The RBC is not deformed and has faint Schuffner’s dots
Lower panel shows a likely gametocyte which is not crescent-shaped
There are no features in the thin film pointing to P. falciparum
The trophozoites could belong to one of several Plasmodium species

Here’s the clinical parasitology mini-lecture you may have missed, now in its new, minimalist version.

Download (PDF, 778.59KB)

pés descalços em Brasil

micrognome — Wed, 07 Apr 2010 05:17:12 +0000

Pobre homem! Tudo que fêz era andar ao lado do rio , e o que aconteceu! Isto pode acontecer mais perto d’aqui, mas os australianos gostam de viajar no ultramar.

Going troppo in Nedlands

micrognome — Wed, 07 Apr 2010 04:44:56 +0000

Postgraduate tropical medicine training has finally arrived.

The long-anticipated clinical tropical medicine course for the ACTM part 1 Fellowship exam will start next week

at 0650hr (finishes 0755hr, prompt)
on Tuesday, 13th April
in the Emergency Department seminar room at Sir Charles Gairdner Hospital
the course starts with Malaria modules 1 and 2
aimed at registrar and consultant level

Those intending to attend should e-mail to ensure we have enough muffins & coffee ordered for breakfast.

Supplementary materials can be found here:

Barefoot in Brazil

micrognome — Wed, 07 Apr 2010 00:03:03 +0000

A 26 year old fit and well mining engineer returns from working in north-eastern Brazil with an intensely pruritic rash on both feet, present for several weeks.

He has been self treating the rash with over-the-counter creams and tablets from Brazil, and has also self-traumatised the area with a penknife.

1 What is the diagnosis?

2 What is the treatment?

Answers

The Stafinator, 7th April.