DIAGNOSTIC PARASITOLOGY SERVICES

1-MICROSPORIDIOSIS

Causative organisms: Enterocytozoon bieneusi, Encephalitozoon spp.

Diagnosis:

© Microscopical examination of strong trichrome stained faecal/urine smears for microsporidial spores.

© PCR technique for species differentiation.

2-CRYPTOSPORIDIOSIS

Causative organism:  Cryptosporidium spp.

Diagnosis:

© Microscopy after acid fast staining of faecal smears using a modified Ziehl-Neelsen stain .

© PCR technique for species differentiation.

3-FREE LIVING AMOEBAE

Granulomatous Amoebic Encephalitis (GAE)

Primary Amoebic Meningoencephalitis (PAM)

Causative organisms: Acanthamoeba spp., Balamuthia spp. (GAE), Naegleria fowleri (PAM)

Diagnosis:

S  Microscopy and culture.

S  PCR technique for species differentiation

Specimens: CSF for culture and antibodies

4-AMOEBIC KERATITIS

Causative organism: Acanthamoeba spp.

Diagnosis:

o       Microscopy and culture.

o       PCR technique for species differentiation

Specimens:

t  Contact lens and/or wash fluids.

t  Corneal scrapes.

t  Submitted cultures.

5-AMOEBIASIS

Intestinal amoebiasis/ amoebic dysentery and invasive amoebiasis

Organisms investigated: Entamoeba histolytica (pathogenic) or Entamoeba dispar (non-pathogenic).

Diagnosis:

t  Formol-ether concentration and microscopical examination of faeces for cysts.

t  Direct microscopy of fresh faeces /pus for trophozoites

6-BABESIOSIS

Causative organism: Babesia spp.

Diagnosis: microscopical examination of thin and thick blood films for parasites stained with Giemsa and Field’s

Specimens: 2 thin (methanol-fixed) and 2 thick (unfixed) blood films sent in a slide container.

N.B.: Blood should be taken at peak of parasite density as indicated by fever; however parasites may be found in the absence of fever and the examination of blood films should NOT be delayed. Repeat blood films may be necessary to demonstrate infection. Blood should be taken into EDTA and films made with a minimum of delay.

7-CYCLOSPORIASIS

Causative organism :Cyclospora cayetanensis

Diagnosis: microscopical examination of faecal smears stained by modified Ziehl-Neelsen for oocysts and direct microscopy following formol-ether concentration

8-ENTEROBIASIS

Threadworm or Pinworm

Causative organism:  Enterobius vermicularis

Diagnosis: microscopical examination for ova

Specimens: adhesive tape smears of perianal skin and perianal swab

Repeated samples over 4 to 6 consecutive days may be necessary to exclude diagnosis.

9-GIARDIASIS

Causative organism: Giardia intestinalis (syn., G. lamblia, G. duodenalis)

Diagnosis:

t  Microscopy of fresh faeces for trophozoites and cysts formol-ether concentration and microscopical examination for cysts.

t  PCR technique.

10- INTESTINAL PARASITIC INFECTIONS WITH HELMINTHS AND PROTOZOA

(General)

A wide range of nematodes, cestodes, trematodes and protozoa are dealt with; some are listed individually e.g. amoebiasis, cryptosporidiosis, cyclosporiasis,  giardiasis, microsporidiosis s and  schistosomiasis.

Diagnosis:

© Macroscopical examination of faeces for adult worms and segments.

© Direct microscopy of fresh faeces for trophozoites.

© Formol-ether concentration of faeces and microscopy for ova, cysts and larvae.

© PCR technique.

11-SCHISTOSOMIASIS

Parasite: Schistosoma  mansoni, S. haematobium, S. japonicum, S. intercalatum, and S. mekongi

Diagnosis:

S  Formol-ether concentration and microscopy of faeces for ova.

S  Microscopical examination of urine after concentration or filtration.