Showing papers on "Schistosoma haematobium published in 1986"

The incidence of squamous and transitional cell carcinomas of the urinary bladder in northern Tanzania in areas of high and low levels of endemic Schistosoma haematobium infection

Abstract: Squamous cell carcinoma is the commonest type of bladder malignancy in most areas of northern Tanzania. Of 172 cases of bladder cancer recorded in 9 years, 72% were squamous cell carcinomas. Of these, 46% had Schistosoma haematobium eggs in sections taken from tumour tissue. The geographical distribution of this tumour closely corresponded to the prevalence of S. haematobium infection. The Mt Kilimanjaro area is free of schistosomiasis and virtually lacks squamous cell carcinoma. Although transitional cell carcinoma is rare in all regions of northern Tanzania, the relative frequency of bladder cancer in the Mt Kilimanjaro area was only one-third of that seen in other regions; population-based incidence rates were also very low in this area.

Patterns of Schistosoma haematobium egg distribution in the human lower urinary tract. III. Cancerous lower urinary tracts.

Abstract: The distribution of S. haematobium eggs in urinary bladders containing tumors and removed at surgery has been studied; the majority of these tumors are well differentiated squamous cell carcinomas. The same three anatomic patterns of egg accumulation described in part I of this series (noncancerous lower urinary tracts) were found in these cancerous bladders, but, in addition, most of the tumors were surrounded by a collar of heavy S. haematobium egg deposition. The egg burdens in these collars were, on the average, twice the average egg burden in the remainder of the urinary bladder. These collars do not seem to be artifacts created by growth of the tumor and subsequent displacement of the adjacent normal tissue, creating a region of heavy egg concentrations; rather, these heavy S. haematobium egg concentrations seem to act as promoters of urothelial carcinogenesis.

The effects of Schistosomiasis haematobium on the activity of school children.

Abstract: Schistosomiasis haematobium is prevalent in many parts of Africa, especially among school-age children. It is thought to cause lethargy, but the effect may be masked by the selective exposure of more active children to the disease. Infected children at a primary school in an endemic area in South Africa were used as their own controls in a before-and-after treatment study. Energetic activity was monitored by means of electronic meters before treatment, and at 3 and 6 months after treatment with an antischistosomal drug. Results indicated that the scores of treated children had increased significantly relative to the untreated controls, and that there were differences between the sexes in the change of activity level.

Phenotypic differences in Schistosoma mattheei ova from populations sympatric and allopatric to S. haematobium.

Abstract: INTRODUCfiON Van Wyk (1983) emphasised the importance vf the ruminant parasite Schistosoma mattheei in the epidemio­ logy of human schistosomiasis. He referred to the work of Pitchford (1959, 1961), who discussed the manner and consequences of hybridization between S. mattheei and the human parasite Schistosoma haematobium, stres­ sing the necessity of further studies in order to determine the extent of gene exchange between the two species. He also pointed out that, on account of the considerable variation in the prevalence of the infection in man, dif­ ferent geographical strains of S. mattheei may have evolved through the incorporation of genes of S. haema­ tobium into the gene pool of S. mattheei in regions where these two species exist sympatrically. The present study was undertaken in an attempt to define and describe certain morphological charactenstics of S. mattheei ova from different localities in the RSA and to assess the value of the overall length and breadth of the egg as well as the breadth at various defined dis­ tances from the tip of the spine and posterior end of the egg to distinguish between laboratory-raised represent­ atives of the different isolates.

Cutaneous schistosomiasis in Nigeria. An update.

Abstract: SUMMARY Two patients with schistosomiasis of the skin were seen at the Ahmadu Bello University Teaching Hospital, Kaduna, Northern Nigeria, between June 1978 and December 1980. The first case was not suspected on clinical grounds, but was diagnosed only after terminally-spined ova of Schistosoma haematobium were found in histological sections of the skin lesions. Both patients were successfully treated with niridazole (Ambilhar®). These bring to eight the total number of cases of cutaneous schistosomiasis recorded in Nigeria in the past 40 years, four of which were in indigenous Nigerians. It seems that the high endemicity of the disease confers some degree of natural immunity to the indigenous population, making ectopic forms rare. Clinicians should be aware of the existence of cutaneous forms of the disease and of their excellent response to specific chemotherapy.

Urinary schistosomiasis in Maiduguri, north east Nigeria.

Abstract: From January to December 1983, 12 207 specimens of urine were examined for ova of Schistosoma haematobium and 753 (6·17%) were positive. From this group, 44 adult patients were investigated for urinary tract abnormalities. Haematuria was the commonest presenting symptom (81·8%) followed by lower abdominal pain (77·3%) and dysuria (68·2%). Urinalysis revealed proteinuria in 55·5%, leucocyturia in 90·9% and microhaematuria in 88·6% of patients. Twenty-four hour protein excretion ranged from 230 mg to 2·2 g (mean 960 mg). Serum creatinine was raised in one patient (2·2 mg dl−11), Urological abnormalities included calcification of the bladder in 36·4%, ureteric strictures and dilatations in 65·9%, hydronephrosis in 9·1 %, squamous cell carcinoma of the bladder in 4·5%, vesicle calculus in 2·3%, and multiple granulomatas in the bladder in 2·3% of the patients. The results of the study suggest that a sizeable population of this area is at risk of developing urological complications and consequently chronic rena...

Prevalence of intestinal parasitic infections in Riyadh district, Saudi Arabia.

Abstract: A total of 23,516 stool specimens collected from patients attending three medical centres in Riyadh, Saudi Arabia, were examined for intestinal parasites. Of these 5737 (24.4%) were positive. Entamoeba histolytica (8.8%) and Giardia lamblia (6.3%) were the commonest parasites found, and in the age group of one to 15 years. Giardia was found in 14.8% of males and 11.9% of females. Other intestinal parasites present included Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, Hymeolepis nana. Ancylostoma duodenale, Enterobius vermicularis. Taenia saginata and Schistosoma hematotium.

Dosage trial of a combination of oxamniquine and praziquantel in the treatment of schistosomiasis in Zimbabwean schoolchildren.

Abstract: L'association est efficace a forte dose et on note peu d'effets secondaires. Une synergie est observee dans le cas de la schistosomiase a S. mansoni mais pas dans celle a S. haematobium

The effect of metrifonate in mixed Schistosoma haematobium and Schistosoma mansoni infections in humans.

Abstract: In order to examine the effect of metrifonate, 156 patients with mixed Schistosoma haematobium and mansoni infection were randomly divided into three groups and treated with metrifonate (twice 10 mg/kg body weight), oxamniquine (60 mg/kg) and praziquantel (40 mg/kg), respectively. The output of S. haematobium and S. mansoni ova were quantitatively assessed in urine and stool. Application of metrifonate resulted in a similar reduction of S. haematobium and S. mansoni eggs in the urine, whereas no effect on egg excretion was observed in the stool irrespective of the parasite species. In contrast, oxamniquine influenced the output of S. mansoni ova in stool and urine, but showed no effect on S. haematobium egg excretion. praziquantel was equally effective against both parasite species. The chemotherapeutic effects were not of transient nature since the number of ova of both parasite species remained unchanged five months after treatment. The results clearly indicate that metrifonate acted exclusively on adult worms located in the perivesical plexus irrespective of the parasite species.

Trematode Infections of Man

Abstract: A consideration of the chemotherapy of trematode infections of man will invariably be unevenly distributed with respect to the parasites involved. The great preponderance of attention must be devoted to the blood flukes or schistosomes, because of their great medical importance and because so much is known about their treatment. The remaining flukes, having various degrees of medical importance and having a lesser body of therapeutic lore, can be covered more briefly.

Isolation and characterization of Schistosoma haematobium egg antigens.

Abstract: Schistosoma haematobium soluble egg antigen (ShSEA) was prepared from eggs isolated from the livers of hamsters or mice infected for at least 3 months. Immunoaffinity purified S. haematobium egg antigens (ShSh) were isolated by first passing ShSEA through a column containing anti-S. mansoni hamster IgG coupled to CNBr-activated Sepharose 4B, and recycling the unbound fraction until no more bound material could be eluted with an acid wash. The unbound fraction was then filtered through a second antibody affinity column containing anti-S. haematobium hamster IgG, and in the acid eluate the ShSh antigens were obtained. This antigenic preparation was shown by PAGE to contain at least 6 distinct bands ranging in molecular weight (Mr) from 116 to <31 Kd. A 40 Kd polypeptide was identified by both silver staining and EITB as specific for S. haematobium eggs. In addition, a 55 Kd worm-egg shared antigen was identified as a prominent band in EITB expressed during a primary S. haematobium hamster infection. The sera from hamsters harboring patent S. haematobium or S. mansoni infections were reacted by ELISA with ShSh antigens. The anti-Sh sera showed significantly higher absorbance values than the anti-Sm sera, demonstrating that only a minor population of S. mansoni cross-reactive egg antigens is still present in the ShSh antigens. Sera collected weekly for 13 weeks from hamsters with a primary infection of S. haematobium were then tested by ELISA against ShSh, ShSEA and SmSEA antigens. Antibody levels against both ShSEA and SmSEA were shown to increase early in infection (2 weeks). Moreover, antibody levels to ShSh did not increase until week 5 post-infection. These findings suggest that the purification procedure utilized results in the elimination of most of the S. mansoni worm antigens cross-reactive with S. haematobium eggs. The ShSh antigens had shown a high degree of of sensitivity and stage-species specificity also suggesting their potential as antigens for the immunodiagnosis of schistosomiasis haematobia.

Stage and species specificity of antigens encoded by two geographic strains of Schistosoma Mansoni mRNA

Abstract: Proteins translated in vitro from Schistosoma mansoni adult worm mRNA were assessed for their antigenic specificities compared to different stages, strains and species of the parasite. RNA was extracted from both Puerto Rican and Brazilian parasites and directed the synthesis of high molecular weight proteins. Preabsorption of immune human serum with schistosomula was used to determine whether the in vitro translated proteins contained antigens shared between the adult and this immature stage. Three antigens (Mr 36,000, 29,000, 18,000) were observed to be present in both stages. When adult worm mRNA from 2 different geographic strains of S. mansoni (Puerto Rican and Brazilian) were compared, certain antigenic differences were found in their in vitro translation products (proteins at Mr 78,000, 26,000, 24,000, 22,000, 15,500), suggesting that different antigenic pools may exist in nature. The species specificity of the in vitro proteins was assessed using individual sera from humans whose species of schistosome infection and egg counts were known. Immunoprecipitation with these sera demonstrated that a large number of immunologically cross-reactive proteins were shared between S. mansoni and Schistosoma haematobium but not Schistosoma japonicum. Antigens or antigen complexes at Mr 47,000 and 37,000 were detected only in the immunoprecipitations using anti-S. mansoni sera, whereas an antigen of Mr 39,000 was precipitated only by anti-S. haematobium sera. The recognition of any 1 antigen or group of antigens, however, did not distinguish between intensities of infection.

Further observations on the use of gross haematuria as an indirect screening technique for the detection of Schistosoma haematobium infection in school children in Dar es Salaam, Tanzania.

Abstract: The reliability of using visible haematuria as an indirect screening technique to detect Schistosoma haematobium was investigated in 418 school children from Dar es Salaam, Tanzania. The sensitivity of the test varied significantly with the time of urine collection and the portion of the micturition stream examined. Whereas sensitivity was 50% and accuracy 73% in the morning, in the afternoon sensitivity and accuracy had increased to 75% and 97% respectively if terminal urine samples were examined. It is concluded that visible haematuria is a sensitive, highly accurate and reliable indirect screening test for urinary schistosomiasis provided that the method of collection and examination of the urine samples is standardized.

Diffuse interstitial pulmonary fibrosis and spontaneous pneumothorax associated with Schistosoma haematobium infestation of the lungs. A case report.

Abstract: A patient with Schistosoma haematobium infestation of the lungs is described. The most significant histological change was diffuse interstitial fibrosis. The patient presented initially with spontaneous pneumothorax.

Resumption of Schistosoma haematobium transmission after drought and subsequent flood.

Abstract: (1986). Resumption of Schistosoma haematobium transmission after drought and subsequent flood. Annals of Tropical Medicine & Parasitology: Vol. 80, No. 3, pp. 367-368.

Schistosomiasis in an American medical investigator.

Abstract: A 42-year-old American male researcher contracted schistosomiasis from environmental sources in the course of his observations on human behavior in Upper Egypt. After a long asymptomatic period, he developed various symptoms and Schistosoma haematobium was found in a urine examination. After treatment with Metrifonate, urine examination became negative. However, abdominal pain persisted and most diagnostic tests were negative. Colonoscopic examination and biopsy of the mucosa revealed schistosomiasis. Treatment with Praziquantel was thoroughly effective in clearing the persistent Schistosoma haematobium infection. It is necessary to maintain a high index of suspicion in cases of potential schistosomiasis. The availability of nontoxic treatment is discussed.

Essai de lutte par chimiothérapie contre Schistosoma haematobium en zone irriguée sahélienne au Niger

Abstract: Les 2 medicaments employes. L'oltipraz et le praziquantel n'ont pu etre compares en raison d'un decalage entre leur application. Cependant l'action therapeutique a donne des resultats satisfaisants puisque une reduction, globale de l'oviurie de 74% a ete constatee 1 an 1/2 apres traitement mais une diminution de ce parametre a ete constatee aussi chez les personnes non traitees. Elle pourrait etre nee soit a une variation saisonniere soit a une baisse de la transmission

Field observations on the possibility of using echinostomes to control schistosome infections in snails

Abstract: Des infections experimentales de Bulinus globosus avec a la fois des miracidies de Schistosoma haematobium et des echinostomes montrent que ce dernier est un fort competiteur

Schistosoma haematobium: effect of non-schistosomicidal drugs (tetracycline and sulphadimidine) on schoolchildren.

Abstract: Pupils attending four secondary boarding schools in Mwanza Municipality, Tanzania, were examined parasitologically for Schistosoma haematobium. Prevalence of infection was highest in the age group 17 to 18 years in both sexes whereas the intensity was highest in the age group 15 to 16 years in girls and 17 to 18 in boys. Absence on grounds of sickness among the pupils studied was not related to the infection and the over-all academic performance was not clearly related to S. haematobium infection in either. Two drugs (tetracycline-HCL and sulphadimidine) commonly used for treatment of many bacterial infections in Tanzania were used. Administration of these drugs to schistosomiasis patients showed that both significantly lowered egg excretion and the degree depended on the dosage. Neither drugs affected the hatching of miracidia. It is speculated that the administration of both drugs might contribute to a higher accumulation of the eggs in the tissues. This effect could lead to more pathogenic effects as well as introducing an element of error in the studies on drug trials and chemotherapy. Treatment using metrifonate (Bilarcil) resulted in cure rates of 76% for girls and 93% for boys.

Chemotherapy trial in the battle against Schistosoma haematobium in an irrigated sahelian zone in Niger

Abstract: This study of S. haematobium infection in communities associated with irrigated schemes shows that prevalence rates are unusually high in adults, especially in men; and distribution disease is probably associated with at least the following three factors: (i) distance of the place of residence from the main transmission sites (ii) the dynamics of transmission in the waterbody and (iii) the human/water contact and contamination patterns. During this chemotherapy trial, at the first survey, only a little more than half (57.47%) of the people recorded in the census was present. Five visits of the survey team were necessary to obtain a compliance rate of 80.51% of the entire population. The indifference of the local people to seek diagnosis and treatment increased with succeeding surveys. It is only, during a subsequent treatment survey, carried out during the season of low agricultural activity and following an official written convocation, that a compliance rate similar to that of the first survey was recorded. If treatment is not given immediately after diagnosis as many as a fifth of positive cases do not appear for treatment. Oltipraz and praziquantel were administered. Their effectiveness could not be truly compared as there was a time lag of six months separating the administration of the treatments. However, based on the results of this trial both drugs gave good results especially in egg output intensity. But, a decrease of this parameter was also observed in non treated people. Seasonal variations of egg output or decrease of transmission could be involved.