Lesson of the week: Subjective change in ejaculate as symptom of infection with Schistosoma haematobium in travellers

Introduction

Several published papers have highlighted increased reporting of schistosomiasis in developed countries.1 2 3 Once considered a rare tropical disease, it has become an important differential diagnosis in those who have travelled in endemic areas and who have haematuria, haematospermia, or acute neurological symptoms; swimming in freshwater lakes in Africa is the principal risk factor.

Nineteen travellers returned to Christchurch, New Zealand, with schistosomiasis over three years.2 Seven of them were men who attended a sexual health clinic with changes in their ejaculate as their principal symptom. We report these cases in detail as the clustering of cases with this presenting symptom is unusual.

Case reports

The median age of the seven men was 27 years. Before diagnosis all had noted changes in their ejaculate over time (range 2 weeks to 8 months). Four had consulted other medical practitioners before attending the sexual health clinic. Another two were referred to our department by their general practitioners for further investigation of semen abnormalities. One attended because his travelling companion had been diagnosed in London as having schistosomiasis. All of the men had swum in Lake Malawi during the preceding 12 months. In one case (number 7) exposure had been only a few hours of swimming at the water's edge. No patient recalled a cercarial itch; this is in keeping with the concept that previous sensitisation is required for the itch to occur.

The alteration in ejaculate included change to a yellow colour (cases 2-4), a reduction in volume (cases 6 and 7), and a reduction in viscosity to the consistency of water (cases 1 and 5) (1). Analysis of seminal fluid from three of the men showed a polymorph infiltrate and Schistosoma haematobium ova. The number and motility of spermatozoa were unaffected. None of the patients recalled that their ejaculate had turned brownish in colour (haematospermia)

Three patients described an associated testicular ache or urethral tingling, and they had been treated for non-gonococcal urethritis. Examination of the prostate gave normal results in all cases.

Light micrograph of Schistosoma haematobium

ARGENTUM/SCIENCE PHOTO LIBRARY

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Three female partners of the affected men were also seen. A complete sexual health examination and screen for parasites gave negative results, but two women were positive for S haematobium on serological testing.

All patients were treated with praziquantel 40 mg/kg and followed up for several months. All seven men reported that their ejaculate returned to normal, and analysis of semen was normal on testing after treatment.

Discussion

A reported alteration in semen is an unusual presenting symptom, even in sexual health clinics. The pattern of change in ejaculate in these cases was quite specific for schistosomal infection.

The site of infection was presumed to be the prostate or seminal vesicles,4 but why an inflammatory reaction with yellow or watery semen occurred rather than haematospermia is unknown. We have found no reference to the symptoms our patients described in the medical textbooks, although there was a case report of schistosomiasis affecting ejaculate in an Australian traveller in 1992.5 A recent report on a series of 10 Spanish travellers recorded haematospermia and clinical prostatitis after freshwater exposure in Mali, but the authors did not comment on other changes in ejaculate.3

The delays in diagnosis and the presumptive diagnosis of and treatment for a sexually transmitted disease by primary care practitioners are not surprising. A high index of suspicion of schistosomiasis should be maintained for any traveller who has visited an endemic area and who complains of an alteration in ejaculate.