Sexually Transmitted Diseases - I. I. Mavrov 2005

Parasitic Diseases of the Urogenital System
Schistosomiasis

Urogenital schistosomiasis is a severe helminthic infection prevalent in several countries across Africa and the Middle East. Highly endemic areas stretch from south of the Sahara all the way to the Cape Province in South Africa. In Egypt, more than 50% of the population is infected with schistosomes, while in Iraq, the figure reaches 60–80% among residents of the Tigris and Euphrates river valleys. According to rough estimates, over 40 million people worldwide are infected (WHO, 1960).

Although this disease was historically absent in the former USSR, a significant number of urogenital schistosomiasis cases have been documented among foreign nationals (N. S. Zalyanova, 1962; E. G. Aslamazov, 1968, et al.).

Etiology. The causative agent is Schistosoma haematobium, which parasitizes the human Circulatory system. The parasite penetrates the Skin of individuals who swim or work in Water. Infection can also occur through the ingestion of contaminated water.

Via the circulatory and lymphatic pathways, Schistosoma haematobium migrates to the pelvic Organs, where the female deposits eggs into the vascular lumen. These eggs penetrate the vessel walls and lodge in the submucosa of the Urinary Bladder and genital organs. Through muscular contractions, the eggs pierce the mucous membrane of the bladder and other urogenital structures, from which they are expelled into the external environment via urine. It is also possible that Schistosoma haematobium eggs can be transmitted sexually, particularly among homosexual individuals.

In regions endemic for schistosomiasis, schistosome eggs can be found in both male and FEMALE REPRODUCTIVE ORGANS. In studies conducted in Nigeria, eggs were detected in the urine and isolated from the Urethra in 42% of surveyed men presenting with symptoms of urethritis. However, the exact role that schistosomes play in conditions such as Infertility or spontaneous Miscarriage remains unknown.

The identification of parasitic lesions is based on detecting the pathogen's eggs in vaginal and cervical smears in women, and in urethral smears in men. Schistosomes inhabit the mesenteric and hemorrhoidal vessels, from which they extend through the vascular network of the pelvis and genitals into the reproductive tract.

Helminths typically live for 3–10 years; however, isolated cases have been documented where viable eggs were transmitted by individuals infected 30 years prior (O. V. Baroyan, D. J. Bradley, 1979).

Pathogenesis. Urogenital schistosomiasis is a disease characterized by an extensive pathological process. Its pathology is directly associated with schistosome eggs, predominantly deposited in the submucosa of the urogenital organs. The most typical morphological reaction to tissue penetration by the eggs is a schistosomal infiltrate consisting of Schistosoma haematobium eggs surrounded by histiocytes, plasma Cells, and numerous eosinophils. This manifests as The formation of schistosomal nodules (granulomas) and polypoid growths on the mucosa of the urogenital organs. Over time, ulcers develop which, upon secondary infection, increase in size and transform the mucous membrane into a continuous ulcerated surface.

Significant damage to the submucosal and muscular layers of the urinary bladder leads to its contraction and shrunken state. Furthermore, the bladder mucosa affected by the schistosomal process is prone to malignant transformation (E. G. Aslamazov, 1970).

The pathological process may also involve the Ureters. In most cases, strictures develop within them (frequently presenting as bilateral lesions). Consequently, ureteral dilation extends from bottom to top, progressively involving the renal pelvis and calyces, ultimately leading to chronic renal failure.

In severe urogenital schistosomiasis, renal involvement occurs with secondary obstruction and tortuosity of the lower ureters, induced by schistosomal granulomas and subsequent tissue fibrosis.

P. H. Merrill, E. Wright, and M. S. Hutt (1983) described 16 patients with vulvar schistosomiasis. Histological examination of the affected areas revealed a classic morphological reaction: intense inflammation surrounding both viable and degraded forms of Schistosoma haematobium. An increased number of eosinophils was observed alongside a standard granulomatous reaction. In two patients, adult helminths were visible within the lumen of venous vessels. Although typical pseudoepitheliomatous hyperplasia was noted, there was insufficient evidence of epithelial Dysplasia or malignant transformation.

Patients with schistosomiasis may develop chronic epididymitis accompanied by granulomatous formations. In such cases, patients often experience azoospermia, infertility, and hemorrhagic cystitis (E. Gartman, 1961).

Clinical Features. An acute form of schistosomiasis develops 5–8 days after infection. Dermatitis appears at the site of parasite penetration, accompanied by an allergic reaction in the form of urticaria. Patients complain of generalized weakness, headache, chills, joint pain, and Muscle aches. Urticarial rashes may also appear. Laboratory findings typically show leukocytosis, eosinophilia, and an elevated ESR.

Six to eight weeks post-infection, the disease transitions into a latent stage lasting 3–4 weeks, and occasionally up to 3 months. The subsequent period of disease progression is associated with the migration of helminth eggs through the Tissues toward the venous Vessels of the bladder and ureters (I. K. Padchenko, 1984).

Various urogenital symptoms manifest 4–6 months after infection. In men, the Prostate Gland and Seminal Vesicles become involved in the pathological process, whereas women develop vaginitis and polyps on the vaginal mucosa and cervix. The infection may also spread upward from the urinary bladder to the ureters and renal pelves.

Occasionally, the disease is complicated by bladder fistulas and urolithiasis (stone formation).

The hallmark symptom of the disease is Hematuria. It often has a terminal character and is linked to pathological Changes in the mucosa of the urinary bladder and other urogenital organs; physical exertion, bumpy rides, and spicy foods tend to exacerbate the bleeding. Over time, the intensity and frequency of hematuria decrease due to fibrotic changes in the mucous membrane.

With the onset of a secondary infection, urination becomes frequent and painful. Ureteral strictures cause a dull aching pain in the lumbar region, occasionally culminating in Renal Colic attacks triggered by the obstruction of narrowed segments with Blood clots and mucopurulent discharge.

Patients frequently report weakness, poor appetite, rapid fatigue, Sleep disturbances, and headaches. In some cases, chronic urogenital schistosomiasis remains entirely asymptomatic, being discovered incidentally during routine medical check-ups.

Schistosomiasis can also involve other organs and tissues, including the Liver, Lungs, and Brain.

Diagnosis. Reports of hematuria in an individual arriving from an endemic area strongly suggest the presence of urogenital schistosomiasis.

The simplest diagnostic method involves examining urine sediment for the presence of Schistosoma haematobium eggs. Quantifying the eggs is technically straightforward and is performed by centrifuging a known volume of urine or allowing sedimentation via gravity, followed by microscopic counting on a Glass slide.

Urine samples must be collected repeatedly at different times of day, particularly following physical exertion. Maximum egg excretion in the urine typically occurs during daytime hours, specifically between 12:00 PM and 2:00 PM, necessitating a standardized collection schedule for diagnostic purposes. Early morning urine in many infected individuals contains no eggs.

Patients undergo cystoscopy, radiological imaging, and occasionally endovesicular biopsy.

Treatment. The therapy of schistosomiasis presents a significant challenge. This is due to the fact that treating this condition involves The Use of trivalent antimony preparations (such as tartar emetic, sodium antimony tartrate, fuadin, antiomaline, and astiban) and thioxanthene compounds (miracil D), which frequently induce gastrointestinal adverse effects and exhibit myocardial toxicity.

Praziquantel is a promising agent for the treatment of urogenital schistosomiasis. The drug is administered at a dosage of 40 mg/kg as a single dose, or 1.5–1.75 g divided into 2 doses throughout the day. Other medications, such as metrifonate, hycanthone, and niridazole, are also utilized.

For the Prevention of urogenital schistosomiasis, treatment should be prescribed to all patients diagnosed with helminthiasis to prevent the further spread of the infection.

Special attention must be paid to identifying cases of schistosomiasis among foreign nationals arriving from endemic regions, as well as implementing preventive measures for Ukrainian citizens during their stay in these areas.

A crucial role in controlling schistosomiasis is played by interventions aimed at reducing morbidity and interrupting disease transmission.