Schistosomiasis, also known as snail fever, is a disease caused by parasitic flatworms called schistosomes. The urinary tract or the intestines may be infected and signs and symptoms may include abdominal pain, diarrhea, bloody stool, or blood in the urine.
Microscopic identification of eggs in stool or urine is the most practical method for diagnosis. Stool examination is performed when infection with Schistosoma mansoni or S. japonicum is suspected, and urine examination should be performed if S. haematobium is suspected. Eggs can be present in the stool in infections with all Schistosoma species.
Scientists at the University of Lisbon examined whether the Ziehl–Neelsen (ZN) stain, also known as the acid- fast stain, would be helpful in detection and identification of Schistosoma eggs. In histological sections, S. mansoni eggshells appear as ZN positive and S. haematobium shells as ZN negative. The staining target of the responsible ZN component (carbolfuchsin) in the shell is unknown and because carbolfuchsin is supposed to stain mycolic acids in the mycobacterial cell wall, unidentified substances in the eggshell were proposed as target. Fuchsin is a known nucleic acid stain, and it was already shown that mycobacteria with insufficiently retained carbolfuchsin may be invisible in bright-field microscopy; yet, they can be easily detected because of a strong red fluorescence when excited with green light.
Read more: Acid-Fast Stain Identifies Schistosoma Eggs
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| Positive staining of Schistosoma mansoni eggs |
Source: ganfyd
