Diagnosic Dilemma No. 5 


Contributor: Emeritus Professor John Goldsmid, University of Tasmania

 
This case relates to an 18 year old pregnant African female who presented at a hospital in Zimbabwe for a routine medical check. She was well but a routine blood count elicited the fact that she had a moderate eosinophilia. Stool specimens sent to the laboratory reported the presence eggs of Schistosoma mansoni but no other parasites. A urine specimen was normal except for a small number of active nematodes about 250mu in length which were detected in the specimen (figs 5.1 & 5.2).
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Fig. 5.1 - Nematode detected in urine (low power).
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Fig. 5.2 - Anterior end of worm (High Power)

What is your diagnosis?



 


The nematodes were Rhabditis (Rhabditella) axei, a common free-living nematode found in soil and rotting vegetation world-wide. Larvae of this species can be differentiated from those of Strongyloides by the presence of a small extra median swelling (pseudobulb) in the buccal canal as indicated in Fig. 5.3 and the thin pointed end of the tail as shown in Fig. 5.1.
Fig. 5.3 - High power photomicrograph of anterior end of one of the isolated
worms with the median pseudobulb indicated by an arrowText for image 1 label
Fig. 5.3 - High power photomicrograph of anterior end of one of the isolated worms with the median pseudobulb indicated by an arrow
Rhabditis has been recognised as a pseudoparasite in faeces and urines in a number of countries (Goldsmid, 1970; Beaver, Jung and Cupp, 1984). While the presence of these nematodes in faeces is easy to explain (ingestion with contaminated vegetable food and passage through the digestive tract), their presence in urines is more difficult to explain, especially in males (Beaver, Jung and Cupp, 1984).
In the present case, the worms may have been introduced into the vagina with plant material used for contraception or perhaps with plant bulbs used as vaginal dilators (Goldsmid, 1967). Another possibility is that it was introduced into the vagina by the husband as “runyoka” to prevent unfaithfulness of the wife (Gelfand, 1964).
The eosinophilia would most probably relate to the Schistosoma mansoni infection. As Rhabditella is non-invasive in the tissues, it appeared to be merely a pseudoparasite in this case and thus did not require specific treatment. In this case treatment would be to flush out the worms and any plant material in the vagina with a saline wash-out.
It would be important in a case such as this, to differentiate this species from the parasitic species, Strongyloides stercoralis, a species common in many tropical regions and which would require treatment.
 
References:
Beaver, P.C., Jung, R.C. and Cupp, E.W. (1984). Medical Parasitology. 9th Ed. Lea and Febiger. Philadelphia. p 263. Gelfand, M (1964) Medicine and Custom in Africa. Livingstone. London and Edinburgh. Goldsmid, J.M. (1967). Rhabditella axei in the urine of an African in Rhodesia. J. Helminthol. 41: 305 – 308. Goldsmid, J.M. (1970). Spurious parasites recovered from stools and urines in Rhodesia. C. Afr..J. Med. 16: 173-178. King, C.H. and Mahmoud, A.F. (2001). Schistosomiasis. In: Essentials of Tropical Infectious Diseases. Guerrant, R.L., Walker, D.H. and Weller, P.F. (Eds.). Churchill-Livingstone. Philadelphia. Pp 492 – 496.



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