A cross-sectional study on the prevalence and morbidity of schistosomiasis was conducted in the main settlement of the municipality of Alhandra, in the southern coastal region of the state of Paraíba, in 2010. The results of this study were compared with the results of a previous study conducted in the same area in 1979. The systematic sampling per family conglomerate included approximately 10% of the resident population in the urban area of Alhandra. Faecal examinations were performed using the Kato-Katz method. The clinical forms of the disease were classified in accordance with FS Barbosa as Type I - intestinal form, Type II - hepatointestinal form and Type III - hepatosplenic form. The prevalence of the infection in 2010 was 10.05%, whereas in 1979 it was 46.6% among untreated patients. The percentages of the three clinical forms in 2010 were as follows: 95.3% Type I, 4.6% Type II and 0% Type III; in 1979, the percentages were 94.4%, 3% and 2.6% for Types I, II and III, respectively. In 1979, 6.07% of the Biomphalaria glabrata specimens (the intermediate host in this area) excreted cercariae, where in 2010 only 1.27% of the specimens caught excreted the parasite.

The great hope for schistosomiasis treatment began with the development of oxamniquine and praziquantel. These drugs can be administered orally in a single dose and have a high curative power with minor side effects. In this study, we carried out a field experiment involving a population of 3,782 people. The population was examined at four localities in Minas Gerais within the valleys of the Doce and Jequitinhonha Rivers. In this cohort, there were 1,790 patients infected with Schistosoma mansoni (47.3%) and we showed that only 1,403 (78.4%) could be treated with oxamniquine in a single dose of 12.5-20 mg/kg orally. The other 387 (21.6%) were not treated during the first stage because of contraindications (pregnancy or impeditive diseases), absences or refusals. It was observed that, on average, 8.8-17% of the infected patients continued to excrete S. mansoni eggs at the end of the 2nd month after treatment and 30-32% of the cohort was infected by the end of the 24th month. In one of the areas that we followed-up for a total of 30 years, the prevalence of the infection with S. mansoni fell from 60.8-19.3% and the hepatosplenic form of the disease dropped from 5.8-1.3%. We conclude that specific treatment of schistosomiasis reduces the prevalence of infection in the short-term and the morbidity due to schistosomiasis in medium to long-term time frames, but does not help to control disease transmission.

A Esquistossomíase Hematóbica ou Esquistossomíase Urinária é um dos principais problemas de Saúde Pública na África e no Oriente Médio. Uma única dose de praziquantel 40 mg/kg de peso, continua sendo o tratamento de escolha para esta infecção. Os objetivos deste seguimento foram: avaliar o período pós-tratamento de um paciente infectado com Schistosoma haematobium e não submetido à re-exposição e, identificar as complicações da doença e/ou falha terapêutica, após o tratamento com praziquantel, por análise histopatológica de material obtido por biópsia vesical. O tratamento foi repetido sob supervisão médica para assegurar o uso correto do medicamento. Na presença de lesões suspeitas a cistoscopia, o paciente foi submetido a biópsia vesical. As características histopatológicas observadas nos materiais obtidos por biópsia, após cada tratamento, indicaram viabilidade de ovos e atividade dos granulomas.

Schistosomiasis haematobia or urinary schistosomiasis is one of the main public health problems in Africa and the Middle East. A single dose of 40 mg praziquantel per kg body weight continues to be the treatment of choice for this infection. The aims of this follow-up were to study the post-treatment course of a patient infected with S. haematobium and not submitted to re-exposure, and to identify complications of the disease and/or therapeutic failure after praziquantel treatment by histopathological analysis. Treatments were repeated under medical supervision to ensure the correct use of the drug. In view of the suspicion of lesions in cystoscopy, the patient was submitted to bladder biopsy. The histopathological characteristics observed in biopsies obtained, after each treatment, indicated viability of parasite eggs and activity of granulomas.

During thirty years - 1973-2003 - a group of individuals infected by Schistosoma mansoni in Capitão Andrade, Rio Doce Valley, Minas Gerais, Brazil, was evaluated by the same authors, being one of the longest follow-up studies on schistosomiasisis mansoni in an endemic area. The diagnosis of S. mansoni was based on parasitological stool tests. In the clinical classification, three groups were considered: type I - schistosomiasis-infection, type II - hepatointestinal form, and type III- hepatosplenic form. The prevalence of infection were 60.8% in 1973, 36.2% in 1984, 27.3% in 1994, and 19.4% in 2003, while the index of hepatosplenomegaly were respectively 5.8%, 2.8%, 2.3% and 1.3%. The maintenance of high prevalence and severity of clinical forms are probably related to reinfection.

Nós examinamos 87 brasileiros de um grupo de 132 que, entre julho e novembro de 1994, participaram de um missão de paz em Moçambique. Eles serviram em uma área endêmica de esquistossomose haematóbica e nadaram no rio Licungo em períodos de lazer. A idade aritmética deles era 31 anos e todos eram do gênero masculino. O exame de urina revelou que 30 (34,5%) eliminavam ovos de S. haematobium e 55 (63,2%) tinham sorologia positiva pelo teste enzyme-linked immunoelectrotransfer blot com antígeno microsomal purificado de vermes adultos de S. haematobium. Eosinofilia foi encontrada em 30 (34,5%), haematuria em 26(29,9%), disúria em 32(36,8%) e dor lombar em 36(41,4%). Todos que eliminavam ovos pela urina tiveram sorologia positiva. Entre os 25 pacientes com sorologia positiva e sem ovos de S. haematobium no exame de urina, 13 eram sintomáticos e 12 assintomáticos. O tratamento pelo Prazinquantel nos 30 pacientes com urina positiva para ovos de S. haematobium apresentou 70% de cura parasitológica.

We examined 87 Brazilian individuals of a group of 132 that, on July and November 1994, participated in a peace mission in Mozambique. They served in an endemic area for haematobic schistosomiasis, where they swum in Licungo river during leisure time. Their arithmetic mean age was 31 year and all of them were male. Their urine test showed that 30 (34.5%) eliminated S. haematobium eggs and 55 (63.2%) presented positive serology by the enzime-linked immunoelectrotransfer blot test with purified microsomal antigen of S. haematobium adult worms. Eosinophilia was found in 30 (34.5%), haematuria in 26 (29.9%), dysuria in 32 (36.8%) and lombar pain in 36 (41.4%). All of those that eliminated eggs through urine had positive serology. Among the 25 patients with positive serology and without S. haematobium eggs in the urine test, 13 were symptomatic and 12 assymptomatic. The treatment with praziquantel for the 30 patients, with urine positive to S. haematobium eggs, presented 70% of parasitological cure.

A avaliação de esquistossomose urinária em indivíduos procedentes de áreas endêmicas, freqüentemente requer recursos diagnósticos não usados nas áreas de exposição, para determinar as complicações ou estabelecer um critério de cura mais preciso. A cistoscopia e o exame de urina de 24 horas foram realizados, após tratamentos com praziquantel na dose de 40 mg/kg de peso, dose única, em 25 militares brasileiros que participaram de uma Missão de Paz pela ONU em Moçambique no ano de 1994. A idade média dos indivíduos foi de 29 anos e todos apresentavam exame parasitológico de urina positivo. As alterações detectadas pela cistoscopia foram hiperemia e granulomas na submucosa vesical em 59.1% dos indivíduos e somente granulomas em 40.9%. A biópsia vesical revelou granulomas em todos os pacientes e ovos viáveis em 77.3%, mesmo após um período durante o qual os pacientes não mais eliminavam ovos pela urina. Após o tratamento, a cistoscopia seguida por biópsia e avaliação histopatológica, realizada em áreas onde a evolução da doença pode ser monitorada melhor, demonstrou ser um critério mais seguro de cura parasitológica.

The assessment of urinary schistosomiasis in individuals coming from endemic areas often requires diagnostic resources not used in areas of exposure in order to determine complications or to establish more precise criteria of cure. Cystoscopy and 24-hour urine examination were performed, after treatments with praziquantel 40 mg/kg body weight, single dose, on 25 Brazilian military men who were part of a United Nations peace mission to Mozambique in 1994. The median age of the individuals was 29 years and all presented a positive urine parasitological exam. The alterations detected by cystoscopy were hyperemia and granulomas in the vesical submucosa in 59.1% of the individuals and only granulomas in 40.9%. A vesical biopsy revealed granulomas in all patients and viable eggs in 77.3% even after a period during which the patients no longer excreted eggs in urine. Cystoscopy after treatment, followed by biopsy and histopathological evaluation, performed in areas where the evolution of the disease can be better monitored, was found to be a safe criterion of parasitological cure.

Several cases of therapeutic failure of praziquantel used for the treatment of urinary schistosomiasis have been reported. Alternative drugs, like niridazol and metrifonate, have shown a lower therapeutic effect and more side effects than praziquantel. Twenty-six Brazilian military men (median age of 29 years) with a positive urine parasitological exam who were part of a United Nation peace mission in Mozambique in 1994 were treated with 40 mg/kg body weight praziquantel, single dose. They swimmed in Licungo river (Mocuba city, Mozambique) during the weekends. After this, they presented haematuria, dysuria, polakiuria, and lumbar pain. Control cystoscopy examinations carried out between 6 and 24 months after each treatment (including two additional treatments at a minimum interval of 6 months) revealed the presence of viable eggs. Granulomas in the vesical submucosa were observed in 46.2% (12/26) of the individuals. A vesical biopsy confirmed the presence of granulomas in all of these patients and the presence of viable eggs in 34.3% (9/26) of individuals who no longer excreted eggs in urine. The eggs filled with miracidia showed characteristics of viability. Histopathological examination using different strains demonstrated therapeutic failure and the need for repeated treatment. In this study, we demonstrated a low efficacy of praziquantel in the treatment of schistosomiasis haematobia, and the necessity of the urinary bladder biopsy as criterion of cure.

The study had the objective to evaluate the benefits of surgical indication for portal hypertension in schistosomiasis patients followed from 1985 to 2001. Schistosoma mansoni eggs were confirmed by at least six stool examinations or rectal biopsy. Clinical examination, abdominal ultrasonography, and digestive endoscopy confirmed the diagnosis of esophageal varices. A hundred and two patients, 61.3% male (14-53 years old) were studied. Digestive hemorrhage, hypersplenism, left hypochondrial pain, abdominal discomfort, and hypogonadism were, in a decreasing order, the major signs and symptoms determining surgical indication. Among the surgical techniques employed, either splenectomy associated to splenorenal anastomosis or azigoportal desvascularization, esophageal gastric descompression and esophageal sclerosis were used. Follow-up of patients revealed that, independent on the technique utilized, a 9.9% of death occurred, caused mainly by digestive hemorrhage due to the persistence of post-treatment varices. The authors emphasize the benefits of elective surgical indication allowing a normal active life.

The authors describe the evolution of schistosomiasis mansoni in inhabitants of Capitão Andrade, Minas Gerais, Brazil, from 1973 to 1994. The prevalence of infection was 60.8% in 1973, 36.2% in 1984, and 27.3% in 1994. The evolution of the clinical forms of the disease in this group was as follows: unchanged in 76.7%, clinical progression in 8.4% and clinical regression in 14.9%. The reduction of the prevalence and severity of Schistosoma mansoni infection over the 21 years period, can be attributed to treatment of infected subjects performed in the area and to the installation of piped water in their dwellings.

Mast cells and eosinophils actively participate in tissue repair and are prominent components of Schistosoma mansoni granulomas. Since pentoxifillyne (PTX) is an immunomodulatory and antifibrotic substance, we aimed to characterize, by morphological techniques, the effect of this drug on fibrosis developed inside murine hepatic schistosomal granulomatous reaction, beyond the quantification of eosinophil and mast cell populations. The drug (1 mg/100 g animal weight) was administrated from 35 to 90 days post-infection, when the animals were killed. The intragranulomatous interstitial collagen network was analyzed by confocal laser scanning microscopy, the number of eosinophils and mast cells was quantified and the results were validated by t-student test. Treatment did not interfere on the granuloma evolution but caused a significant decrease in the total and involutive number of hepatic granulomas (p = 0.01 and 0.001, respectivelly), and in the intragranulomatous accumulation of eosinophils (p = 0.0001). Otherwise, the number of mast cells was not significantly altered (p = 0.9); however, it was positively correlated with the number of granulomatous structures (r = 0.955). In conclusion, PTX does not affect development and collagen deposition in S. mansoni murine granuloma, but decreases the intragranulomatous eosinophil accumulation possibly due to its immunomodulatory capability, interfering in cellular recruitment and/or differentiation.

After three successive treatments with oxamniquine the continuing elimination of Schistosoma mansoni eggs was observed in patients, who came from various regions of Brazil, with different clinical forms of schistosomiasis. The objective of the present study was to determine the experimental behaviour of five different S. mansoni isolates in Swiss Webster mice that were submitted to treatment with the same drug. The experimental group with failure of treatment showed higher mean number of surviving male worms when it was compared to the group without failure of treatment. These date suggest the possibility of resistance to oxamniquine.

A clinical study on the evolution of patients with schistosomiasis mansoni has been conducted since 1983 at the outpatient clinic of the Infectious and Parasitic Disease Service in the Clementino Fraga Filho University Hospital in Rio de Janeiro, Brazil, comparing prevalence of positive tests for HBsAg, anti-HBsAg, and anti-HBc among patients infected with Schistosoma mansoni coming from various regions of Brazil and with different clinical forms of the disease. A non-significant predominance of HBsAg, anti-HBsAg, and anti-HBc was detected among patients with the hepatosplenic form of schistosomiasis, who presented a more severe clinical evolution with a higher frequency of hematemesis and/or melena, in addition to the development of macronodular cirrhosis and a worse prognosis as compared to patients with the toxemic form, schistosomiasis-infection and the hepatointestinal form.

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitao Andrade and Padre Paraíso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraíba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhao, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin testfor Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic froms of the disease in the southeast areas of Capitao Andrade and Padre Paraíso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mullattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidily the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.