Frequency, active infection and load of Leishmania infantum and associated histological alterations in the genital tract of male and female dogs.

Visceral leishmaniasis caused by the protozoan Leishmania infantum is a zoonosis. The domestic dog is the primary reservoir in urban areas. This study aimed to evaluate the frequency, active infection and load of L. infantum in the genital tract of male and female dogs seropositive for this parasite, as well as to identify histological genital alterations associated with this protozoan. We studied 45 male and 25 female L. infantum-seropositive noncastrated dogs from the same endemic area in Brazil. Tissue samples from the testis, epididymis, prostate, vulva, vagina, and uterus were examined by singleplex qPCR and parasitological tests (histopathology, immunohistochemistry, and parasitological culture). The latter were performed for the detection of active infection (parasites able to multiply and to induce lesions). Forty-four (98%) males and 25 (100%) females were positive for L. infantum in the genital tract (epididymis: 98%; vulva: 92%; vagina: 92%; testis: 91%; uterus: 84%; prostate: 66%). Active infection in the genital tract was confirmed in 69% of males and 64% of females (32% in the uterus). Parasite loads were similar in the testis, vulva, epididymis and vagina and lower in the prostate. Only the parasite load in the vagina was significantly associated with the number of clinical signs. Granulomatous inflammation predominated in all organs, except for the prostate. Only in the testis and epididymis was the inflammatory infiltrate significantly more intense among dogs with a higher parasite load in these organs. The high frequency, detection of active infection and similarity of L. infantum loads in the genital tract of infected males and females suggest the potential of venereal transmission of this parasite by both sexes and of vertical transmission by females in the area studied. Additionally, vertical transmission may be frequent since active L. infantum infection was a common observation in the uterus.

Surgical pathology of schistosomiasis.

Schistosomiasis remains an important health problem in many tropical countries and is being seen with increasing frequency in immigrant populations and tourists in developed countries. The pattern of organ involvement and clinical presentation of schistosomiasis in 80 patients (male: female, 9:1) during a five-year period (2001-2005) was examined from archival histopathology records. The urinary bladder was the most common organ affected [50 (62.5%)]. Gastrointestinal, male and female genital schistosomiasis were detected in 12 (15%), eight (10%) and five (6.1%) cases, respectively. Hematuria was the most common presenting symptom [34 (42.5%)], and bladder cancer was the only malignancy found to be associated with the infection. A high clinical index of suspicion usually allows for a preoperative diagnosis where indicated and avoidance of radical surgery. While research for the development of an effective vaccine continues, a plea is made for the expansion of multinational control programs in sub-Saharan Africa.

Morphological features and organ distribution of schistosomal infection.

A total of 74 histologically diagnosed cases of schistosomiasis involving various organs and tissues were reported in the Department of Pathology of the University of Ilorin Teaching Hospital, Ilorin between January 1979 and December 1997. While some of the cases were incidental discoveries, others were the primary causes of patients' clinical problems such as infertility. The ages of patients in this study were relatively higher than the usual childhood or adolescence wherein schistosomiasis is commonest and this is thought to be due to the longer duration required for morphological changes to be established in tissues. A case of urinary bladder schistosomiasis with squamous cell carcinoma was found in a 55-year old man and this lends support to the claim that schistosomiasis of the urinary bladder may predispose to cancer in the organ. Findings in this study underscore the need for high index of suspicion in endemic areas wherein histological examination of appropriate tissue may be all that is needed in what otherwise appears to be a diagnostic enigma.

Laryngeal involvement during post kala-azar dermal leishmaniasis in India.

Post kala-azar dermal leishmaniasis (PKDL) involving the mucus membranes is relatively rare on the Indian sub-continent. We describe 3 cases of PKDL presenting with hoarseness of voice. In one case the skin, nasal, oral, oropharyngeal and laryngeal mucosa had nodular and nodulo-ulcerative lesions; in the 2 other cases, genitalia and anorectal mucosa were also affected. Laryngoscopic examination revealed nodular lesions on the vocal cords. Biopsy smear and culture confirmed their leishmanial origin.

Prevalencia de parasitosis relacionadas con infección genital femenina / Prevalence of parasitic infections related to the female genital tract

Se estudió a 245 mujeres sexualmente activas que acudieron al Hospital Civil de Cuernavaca, de enero a julio de 1994. Los parásitos encontrados en el área genital se identificaron por observación microscópica en fresco, de secreciones cervicovaginales suspendidas en solución salina y preparaciones teñidas con reactivo del lugol. En este estudio, la prevalencia de Trichomonas vaginalis fue de siete casos (2.8 por ciento), encontrándose además quistes de Entamoeba histolytica en 13 casos (5.3 por ciento) y Giardia lamblia en un caso (0.4 por ciento), huevecillos de Ascaris lumbricoides en dos casos (0.8 por ciento) y Trichuris trichiura en un caso (0.4 por ciento). Estas parasitosis llegan a representar un problema frecuentemente, ya que infecciones mixtas con una variedad de parásitos, incluyendo protozoarios y nematodos, se han reportado en otros países, sobre todo en hombres homosexuales: en la mujer, estas infestaciones se atribuyen a la cópula rectal o la diseminación contigua de secreciones, por malos hábitos higiénicos. Por esto consideramos importante que, dentro de las infecciones del tracto vaginal, se incluya la búsqueda de estos parásitos

Schistosoma mansoni: influence of infection on levels of translatable mRNA and on polypeptide synthesis in the ovotestis and albumen gland of Biomphalaria glabrata.

Larval trematode infection causes a disruption of normal reproductive activity in the molluscan intermediate host. Because relatively little is known about the dynamics of this host-parasite interaction, the effect of Schistosoma mansoni infection on translatable mRNA pools and on polypeptide synthesis was examined in the ovotestis (OT) and albumen gland (AG) of Biomphalaria glabrata. Total RNA was isolated from OTs and AGs from uninfected control snails and snails at 14, 21, and 28 days postinfection (pi) with 20 S. mansoni miracidia and subjected to a rabbit reticulocyte in vitro translation system. Quantitative densitometry of autofluorograms of one-dimensional SDS-PAGE slab gels revealed reductions in quantities of total proteins synthesized in vitro from RNA isolated from infected OTs at 21 and 28 days pi, but not at Day 14 pi. Similar reductions were seen in 10 individual polypeptides selected for a more detailed analysis. In contrast to the OT, Day 14 pi-infected AGs exhibited an initial increase in total protein synthesized in the in vitro translation system utilized, followed by significant reductions at 21 and 28 days pi. Selective modulation of labeled polypeptides was evident in 11 polypeptides chosen for a more detailed analysis. This general pattern of parasite inhibitory effects was also seen in parallel pulse-chase studies using [35S]methionine metabolic labeling of in vitro-cultured OTs and AGs. In these experiments, significant reductions in the amounts of labeled polypeptides found in culture supernatants at 14, 21, and 28 days pi were evident. Total polypeptide synthesis also was solubilized AGs from infected snails at 21 and 28 days pi. Results indicate that larval trematode infection induced a generalized disruption of polypeptide metabolism in OTs and AGs of B. glabrata. Such inhibition may occur at both the transcriptional and the translational levels and is initially manifested early in infection, during the time that daughter sporocysts begin to migrate and colonize the digestive gland and OT.

Pathology of Schistosoma haematobium infection in the capuchin monkey (Cebus apella).

Capuchin monkeys exposed to 500-2000 Schistosoma haematobium cercariae were followed for up to 6 1/2 years after infection. Worm burdens decreased as infections became more chronic and decreasing numbers of eggs and active circumoval lesions were found in the bladder and elsewhere. Nodular and hyperplastic epithelial lesions of the urinary bladder were not seen during the first year of infection but occurred in 30% of monkeys examined 1-2 years after infection and in 23% of those examined between the second and third years; they were present in only 3% of monkeys studied 3-6 1/2 years after infection. These epithelial proliferative lesions were located near foci of egg deposition and occurred in the monkeys with the most intense active lesions in the bladder. The lesions regressed in animals followed sequentially. The lesions thus appear not to be neoplastic. Obstructive lesions of the ureter accompanied by hydronephrosis were present in a few animals. The obstructive uropathy did not appear to cause significant morbidity. Mortality was substantial among infected monkeys at most intervals after infection but was rare among uninfected controls.

The pathobiology of Schistosoma haematobium infection in humans.

Schistosoma haematobium infection is a common occurrence in Africa and the Middle East and is the world's leading cause of hematuria. Since more North Americans are venturing into endemic areas and more residents of endemic areas are seeking medical care in North America, pathologists must be able not only to diagnose urinary schistosomiasis but also to provide advice as to further therapy. These endeavors mandate knowledge of the pathobiologic features of the disease. The severity and frequency of the sequelae of urinary schistosomiasis (hydroureter, hydronephrosis, bladder ulcer, and polyposis) and of its complications (bacterial urinary tract infection, renal failure, urothelial cancers) depend on the intensity of infection, i.e., worm burden and tissue egg burden, and the duration of infection. Significant differences in gross and microscopic morphology, clinical laboratory findings, and optimal mode of treatment exist between active (during active egg deposition) and inactive (after cessation of oviposition) disease. Moreover, nearly half of the severe sequelae and complications occur during the inactive phase of the disease, when diagnosis is most difficult. The manifestations of this disease are manifold and complex, and firm understanding of the pathobiologic features is necessary if pathologists are to understand their role in the direction of treatment.

Cutaneous schistosomiasis.

Cutaneous manifestations of schistosomiasis can be produced by human and nonhuman species. They can occur in the invasive stage or oviposition stage. Manifestations in the invasive stage are non-specific and include: 1. severe itching 2. Generalized anaphylactiod reaction with urticarial or erythema multiforme-like eruption. Manifestations in the stage of oviposition are specific and include: 1. Genital and perigenital granulomata; 2. Extragenital cutaneous schistosomal granulomata occurring in sites away from the portocaval anastomoses. The clinical and the histopathologic picture are described. The possible mechanisms of ectopic localisation of schistosomal granulomata are discussed.