Chronic Urinary Schistosomiasis Presenting as Hydronephrosis in a 26 Year-old Male
Department
Eastern Virginia Medical School
Graduate Level
Doctoral
Graduate Program/Concentration
Doctor of Medicine
Presentation Type
Poster Presentation
Abstract
Introduction/Case Presentation:
A 26-year-old male who recently immigrated to the United States from Mauritania presented to the ED with one day of worsening left flank pain accompanied by nausea, vomiting, and chills. He reported a past medical history of kidney stones which had always passed spontaneously, as well as a history of gross hematuria as a child. A CT scan showed a 5mm obstructing stone in the left distal ureter with severe left hydroureteronephrosis, along with small, layering stones in the mid- and distal right ureter without hydronephrosis. Additionally, it revealed circumferential calcifications along the dome of the bladder, suspicious for urinary schistosomiasis. Urology was consulted and he was discharged from the ED on medical expulsive therapy with outpatient urology follow-up. Three days later, he returned to the ED with continued uncontrolled left flank pain and nausea. CT findings were unchanged from previous, and he was admitted for surgical stone management. Cystoscopy revealed numerous submucosal calcifications consistent with schistosomiasis exposure, and left retrograde pyelogram showed a 5mm pinpoint distal ureteral stricture. Attempts to navigate through the stricture failed, so a nephrostomy tube was placed for temporary decompression. He was given one dose of praziquantel for empiric treatment of schistosomiasis and Schistosoma antibodies were drawn, which came back negative. Two months later, a ureteral reimplantation was performed for definitive management of the stricture, and the excised stricture was sent to pathology, which revealed chronic granulomatous inflammation, fibrosis, and calcified schistosome eggs. He was then referred to our Infectious Disease clinic for outpatient follow-up for the diagnosis of chronic urinary schistosomiasis.
Discussion:
This case offers an opportunity to review the epidemiology and management of schistosomiasis, a parasitic flatworm infection that is extremely common in endemic areas but a relatively rare finding in the United States. The infection is spread via unbroken skin contact with contaminated freshwater when schistosome larvae penetrate human skin and invade the bloodstream. Schistosomiasis has an acute and chronic form: acute schistosomiasis syndrome is a systemic hypersensitivity reaction to schistosome antigens and immune complexes. Chronic infection can occur in a variety of organs depending on the tropism of the species present and is the result of egg deposition and subsequent immune response. Our patient’s findings of fibrosis and calcification of the ureteral and bladder wall is consistent with longstanding infection by S. haematobium or an S. haematobium-hybrid species. Several different tools can be used to diagnose infection and monitor for successful treatment, including microscopic identification of eggs, antigen and antibody tests, imaging, and biopsy, but appropriate knowledge is needed on how to use and interpret these tests properly to guide management. In our case, serology may have been negative due to the use of S. mansonii antigens, which has lower sensitivity for S. haematobium antibodies. As praziquantel is not 100% effective at eliminating infection, it is vital to know when repeat treatment is needed, as risks of longstanding infection include bladder neck or ureteral obstruction, as seen in our patient, as well as bladder cancer, classically squamous cell carcinoma.
Keywords
Case Report, Schistosomiasis
Chronic Urinary Schistosomiasis Presenting as Hydronephrosis in a 26 Year-old Male
Introduction/Case Presentation:
A 26-year-old male who recently immigrated to the United States from Mauritania presented to the ED with one day of worsening left flank pain accompanied by nausea, vomiting, and chills. He reported a past medical history of kidney stones which had always passed spontaneously, as well as a history of gross hematuria as a child. A CT scan showed a 5mm obstructing stone in the left distal ureter with severe left hydroureteronephrosis, along with small, layering stones in the mid- and distal right ureter without hydronephrosis. Additionally, it revealed circumferential calcifications along the dome of the bladder, suspicious for urinary schistosomiasis. Urology was consulted and he was discharged from the ED on medical expulsive therapy with outpatient urology follow-up. Three days later, he returned to the ED with continued uncontrolled left flank pain and nausea. CT findings were unchanged from previous, and he was admitted for surgical stone management. Cystoscopy revealed numerous submucosal calcifications consistent with schistosomiasis exposure, and left retrograde pyelogram showed a 5mm pinpoint distal ureteral stricture. Attempts to navigate through the stricture failed, so a nephrostomy tube was placed for temporary decompression. He was given one dose of praziquantel for empiric treatment of schistosomiasis and Schistosoma antibodies were drawn, which came back negative. Two months later, a ureteral reimplantation was performed for definitive management of the stricture, and the excised stricture was sent to pathology, which revealed chronic granulomatous inflammation, fibrosis, and calcified schistosome eggs. He was then referred to our Infectious Disease clinic for outpatient follow-up for the diagnosis of chronic urinary schistosomiasis.
Discussion:
This case offers an opportunity to review the epidemiology and management of schistosomiasis, a parasitic flatworm infection that is extremely common in endemic areas but a relatively rare finding in the United States. The infection is spread via unbroken skin contact with contaminated freshwater when schistosome larvae penetrate human skin and invade the bloodstream. Schistosomiasis has an acute and chronic form: acute schistosomiasis syndrome is a systemic hypersensitivity reaction to schistosome antigens and immune complexes. Chronic infection can occur in a variety of organs depending on the tropism of the species present and is the result of egg deposition and subsequent immune response. Our patient’s findings of fibrosis and calcification of the ureteral and bladder wall is consistent with longstanding infection by S. haematobium or an S. haematobium-hybrid species. Several different tools can be used to diagnose infection and monitor for successful treatment, including microscopic identification of eggs, antigen and antibody tests, imaging, and biopsy, but appropriate knowledge is needed on how to use and interpret these tests properly to guide management. In our case, serology may have been negative due to the use of S. mansonii antigens, which has lower sensitivity for S. haematobium antibodies. As praziquantel is not 100% effective at eliminating infection, it is vital to know when repeat treatment is needed, as risks of longstanding infection include bladder neck or ureteral obstruction, as seen in our patient, as well as bladder cancer, classically squamous cell carcinoma.