Showing papers on "Schistosoma haematobium published in 2005"
TL;DR: It was shown that children lightly infected with S. haematobium had lower P. falciparum densities than those not infected, suggesting a negative interaction between both parasites.
Abstract: Studies with animal models have suggested the possibility of interactions between parasites during con- current infections and have raised the question of a similar phenomenon in humans. The present survey was undertaken to assess the impact of urinary schistosomiasis on the susceptibility of children to malaria. It was carried out in Senegal between September 2001 and March 2002 among 523 children 3-15 years of age. We tested the association between Plasmodium falciparum densities and the load of Schistosoma haematobium egg excretion using a linear mixed model because data were not independent. After controlling for age, sex, and season, we showed that children lightly infected with S. haematobium (1-9 eggs/10 mL of urine) had lower P. falciparum densities than those not infected ( �0.34, 95% confidence interval �0.85, �0.10), suggesting a negative interaction between both parasites.
141 citations
TL;DR: It is concluded that underlying schistosomiasis is associated with protection against clinical falciparum malaria in an age-dependent manner.
Abstract: Plasmodium falciparum and Schistosoma haematobium are co-endemic parasitic diseases with worldwide distribution Evidence suggests interactions occur between helminthic and malaria infections, although it is unclear whether this effect is beneficial or harmful to the host Malian children 4-14 years of age with asymptomatic S haematobium infection (SP) (n = 338) were prospectively matched by age, sex, and residence to children without schistosomiasis (SN) (n = 338) who were cleared of occult intestinal parasites, and followed-up for one malaria transmission season (25 weeks) The time to the first clinical malaria infection, incidence of malaria episodes, and parasitemia were recorded Age associated protection from malaria in children with schistosomiasis was observed SP children (4-8 years of age) compared with SN children demonstrated delayed time to first clinical malaria infection (74 versus 59 days; P = 004), fewer numbers of malaria episodes (155 versus 181 infections; P = 003) and lower geometric mean parasite densities (6,359 versus 9,874 asexual forms/mm(3); P = 007) at first infection No association between schistosomiasis and P falciparum malaria was observed in children 9-14 years of age We conclude that underlying schistosomiasis is associated with protection against clinical falciparum malaria in an age-dependent manner
141 citations
TL;DR: The prevalence of gynecologic S. haematobium infection in the female genitals is described and the presence of ova was not a predictor for ulcers, papillomata, leukoplakia, polyps, or cell atypia.
Abstract: Up to 75% of women with urinary schistosomiasis have Schistosoma haematobium ova in the genitals. This study aimed to describe the prevalence of gynecologic S. haematobium infection and to differentiate the disease from sexually transmitted infections (STIs). Gynecologic and laboratory investigations for S. haematobium and STIs were performed in 527 women between the ages of 20 and 49 in rural Zimbabwe. Genital homogenous yellow and/or grainy sandy patches, the commonest type of genital pathology, were identified in 243 (46%) women. Grainy sandy patches were significantly associated with S. haematobium ova only. Genital S. haematobium ova was also significantly associated with homogenous yellow sandy patches, mucosal bleeding, and abnormal blood vessels. The presence of ova was not a predictor for ulcers, papillomata, leukoplakia, polyps, or cell atypia. Mucosal sandy patches seem to be pathognomonic for S. haematobium infection in the female genitals. Coexistence of ova and other lesions may not be causal.
133 citations
TL;DR: This study is the most comprehensive characterization of S. haematobium antigens to date and describes novelantigens in all schistosome species.
Abstract: Background Schistosomiasis is a major parasitic disease affecting >200 million people in the developing world, and 400 million people are at risk for infection. This study aimed to identify and compare proteins recognized by serum samples from schistosome-exposed individuals before and after curative praziquantel treatment. Methods Proteins recognized by pooled serum samples from Schistosoma haematobium-exposed Zimbabweans were determined by 2-dimensional Western blotting and identified by mass spectrometry. Results Serum samples recognized 71 spots, which resolved to 26 different characterized proteins. Eleven of these proteins have not previously been shown to be immunogenic in natural human infection or in experimental models of schistosomiasis, making them novel antigens in the parasite. Pretreatment serum samples recognized 59 spots, which resolved to 21 different identified proteins. Posttreatment serum samples recognized an additional 12 spots, which resolved to 8 different identified proteins. Of these 8 proteins, 3 had putative isoforms recognized before treatment, and 5 (calreticulin, tropomyosin 1, tropomyosin 2, paramyosin, and triose phosphate isomerase) did not. Conclusions This study is the most comprehensive characterization of S. haematobium antigens to date and describes novel antigens in all schistosome species. Posttreatment results are consistent with praziquantel treatment inducing quantitative and qualitative changes in schistosome-specific antibody responses.
95 citations
TL;DR: The clinicopathological features of schistosomiasis of the appendix are discussed, based on the clinical presentation, operative findings and morphological changes in the specimens of patients seen in Ibadan between 1980 and 1989.
Abstract: The clinicopathological features of schistosomiasis of the appendix are discussed, based on the clinical presentation, operative findings and morphological changes in the specimens of patients seen in Ibadan between 1980 and 1989. Schistosoma haematobium was implicated as the causal agent of a granulomatous inflammatory reaction with eosinophilia and fibrosis. Intramuscular oviposition was associated with frank acute appendicitis, and serosal involvement resulted in peritoneal adhesions, with ileoileal intussusception in one patient. The actual role of schistosomal infestation as a contributory factor in appendicitis is still open to debate, but the diagnosis must be entertained in patients in the tropics with features of acute appendicitis or recurrent abdominal pain.
92 citations
TL;DR: It is shown that subjects bearing the IL13-1055T/T genotype were on average much less infected than individuals with other genotypes, which is in agreement with the fact that this cytokine enhances resistance to infection by schistosome in humans.
Abstract: Millions of humans are exposed to schistosome infections, which cause severe kidney and liver disease and 280,000 deaths annually. Th2-mediated immunity is critical to human defenses against this pathogen and susceptibility to infection is controlled by a major genetic locus that includes IL4, IL5, and IL13 genes. These observations led us to evaluate whether certain polymorphisms in IL4, IL5, or IL13 determine schistosome infection. The study was performed in two Dogon villages where Schistosoma haematobium is endemic. Schistosome infections were evaluated by counting eggs and measuring worm Ags in urine. Genetic polymorphisms were determined by restriction enzyme analysis or by primer extension and denaturing high-performance liquid chromatography analysis. Associations were tested using family-based association tests and logistical regression analysis. The alleles IL13-1055C (p = 0.05) and IL13-591A (p = 0.01) are shown, by family-based association test, to be preferentially transmitted to children with the 10% highest infections. A logistic regression analysis that included IL13-1055 G/G, G/T and T/T genotypes, age, gender, and village of residency, applied to the whole study population, showed that subjects bearing the IL13-1055T/T genotype were on average much less infected than individuals with other genotypes. Previous studies on asthma indicated that the IL13-1055T allele increased gene transcription, which is in agreement with the fact that this cytokine enhances resistance to infection by schistosome in humans.
87 citations
TL;DR: Lot Quality Assurance Sampling provides a rapid, valid and cost‐effective method for guiding decision makers in allocating finite resources for the control of schistosomiasis in Uganda.
Abstract: Summary
Rapid and accurate identification of communities at highest risk of morbidity from schistosomiasis is key for sustainable control. Although school questionnaires can effectively and inexpensively identify communities with a high prevalence of Schistosoma haematobium, parasitological screening remains the preferred option for S. mansoni. To help reduce screening costs, we investigated the validity of Lot Quality Assurance Sampling (LQAS) in classifying schools according to categories of S. mansoni prevalence in Uganda, and explored its applicability and cost-effectiveness. First, we evaluated several sampling plans using computer simulation and then field tested one sampling plan in 34 schools in Uganda. Finally, cost-effectiveness of different screening and control strategies (including mass treatment without prior screening) was determined, and sensitivity analysis undertaken to assess the effect of infection levels and treatment costs. In identifying schools with prevalences ≥50%, computer simulations showed that LQAS had high levels of sensitivity and specificity (>90%) at sample sizes <20. The method also provides an ability to classify communities into three prevalence categories. Field testing showed that LQAS where 15 children were sampled had excellent diagnostic performance (sensitivity: 100%, specificity: 96.4%, positive predictive value: 85.7% and negative predictive value: 92.3%). Screening using LQAS was more cost-effective than mass treating all schools (US$218 vs. US$482/high prevalence school treated). Threshold analysis indicated that parasitological screening and mass treatment would become equivalent for settings where prevalence ≥50% in 75% of schools and for treatment costs of US$0.19 per schoolchild. We conclude that, in Uganda, LQAS provides a rapid, valid and cost-effective method for guiding decision makers in allocating finite resources for the control of schistosomiasis.
85 citations
TL;DR: A low efficacy of praziquantel in the treatment of schistosomiasis haematobia is demonstrated, and the necessity of the urinary bladder biopsy as criterion of cure is demonstrated.
Abstract: 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.
81 citations
TL;DR: The results of the present study suggest that male urogenital schistosomiasis may constitute a risk factor for HIV transmission, as a result of egg-induced inflammation in the semen-producing pelvic organs.
Abstract: In this study, we investigated the seminal inflammatory response to egg infestation of the urogenital organs in 240 semen-donating men aged 15-49 years living in a Schistosoma haematobium-endemic area of Madagascar. In 29 subjects (12%) with excretion of > or =5 ova/ejaculate, leukocytospermia (>10(6) leukocytes/mL) and the presence of seminal lymphocytes and eosinophil leukocytes were each significantly more prevalent than in 74 subjects (31%) who were S. haematobium negative (P<.01). In addition, seminal levels of interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor- alpha were significantly higher among seminal egg-excreting subjects than among infection-negative subjects (P<.001). Sexually transmitted infection (STI) with Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and/or Trichomonas vaginalis did not act as a confounding factor for the observed associations. At follow-up, 6 months after systematic antischistosomiasis and STI syndrome treatment at baseline, the prevalence of seminal leukocytes decreased significantly among the previously seminal egg-positive subjects. The same tendency was observed for the posttreatment levels of cytokines. Numerous studies have already shown an association between STI-associated genital inflammation and human immunodeficiency virus (HIV) propagation. Therefore, the results of the present study suggest that male urogenital schistosomiasis may constitute a risk factor for HIV transmission, as a result of egg-induced inflammation in the semen-producing pelvic organs.
77 citations
TL;DR: It is suggested that adult HIV-1-related immunodeficiency does not impair the ability to excrete eggs in low-intensity infection with S. haematobium, S. mansoni, or both and that infection with HIV- 1 may not have major implications for diagnosis and surveillance of schistosomiasis.
Abstract: Background. Stunted development and reduced fecundity of Schistosoma parasites in immunodeficient mice and the impaired ability of human immunodeficiency virus 1 (HIV-1)-infected humans to excrete schistosome eggs have been described. This study explores the effect that HIV-1-associated immunodeficiency has on the excretion of schistosome eggs in a large cohort of coinfected individuals. Methods. In a cross-sectional survey, urine and stool samples were obtained from and HIV-1 status was determined for 1545 individuals. More extensive data, including quantitative measures of intensity of infection in schistosomiasis and immunodeficiency, were collected in the Mupfure schistosomiasis and HIV longitudinal cohort, composed of 379 participants of whom 154 were coinfected with HIV-1 and Schistosoma parasites. Results. In the cross-sectional survey, the overall prevalence of schistosomiasis was 43.4%, and 26.3% of the participants were infected with HIV-1. Schistosome infections were due to Schistosoma haematobium in 63.6% of cases, S. mansoni in 18.1% of cases, and dual infections in 18.4% of cases. Intensities of Schistosoma infections, measured by the number of eggs excreted and by the level of circulating anodic antigens, did not differ between HIV-1-negative and HIV-1-positive participants coinfected with S. haematobium, S. mansoni, or both. CD4 cell counts were significantly lower in HIV-1-positive participants and in S. mansoni-infected HIV-1-negative participants than in other participants. Conclusion. The present study suggests that adult HIV-1-related immunodeficiency does not impair the ability to excrete eggs in low-intensity infection with S. haematobium, S. mansoni, or both and that infection with HIV-1 may not have major implications for diagnosis and surveillance of schistosomiasis.
69 citations
TL;DR: Among the three species, Schistosoma japonicum is remarkable at conserving energy during the host-finding process, and exhibiting swift migration through the skin to reach the predilection site sooner and mature earlier compared with Schistsoma mansoni and SchistOSoma haematobium.
TL;DR: Significance of differences between agro-ecosystems of S. haematobium and S. mansoni infection intensity showed significant positive relations to the surface of uncultivated inland valleys, whereas surface water on rice cultivated land showed significant negative relations with infection intensity of each schistosomiasis species.
TL;DR: It is concluded that S. haematobium does not have a praziquantel-insensitive window longer than in S. manson, in spite of its much longer maturation period, and refractoriness of immature stages can be overcome at higher drug concentrations.
TL;DR: AV, if given continuously for long time, has a pronounced antischistosomal action especially when accompanied with contraceptive intake and promising results may encourage further investigation with the intention of their possible application on treatment of schistosomiasis as a complement strategy to praziquantel chemotherapy.
TL;DR: Temperature and altitude, followed by the type of water-body, seemed to be the more important factors that had a significant influence on the distribution of this group in South Africa.
Abstract: As intermediate host of Schistosoma haematobium and S. mattheei, the Bulinus africanus group plays a major role in the transmission of urinary and bovine schistosomiasis, diseases that negatively affect the health status of millions of people and their livestock in South Africa. Bulinus spp. can also play a role in the transmission of cercarial dermatitis (swimmer’s itch) caused by the immune reaction of incompatible hosts to the penetration of cercariae of non-human schistosomes. This can cause considerable discomfort to humans bathing in infested waters. This article focuses on the geographical distribution and habitats of this group as reflected by the samples taken from 2 930 collection sites on record in the database of the National Freshwater Snail Collection (NFSC) at the Potchefstroom Campus of the North-West University. The 414 different loci (1/ 16 -degree squares) on record, reflect an extensive distribution from the western parts of the NorthWest to Gauteng, Mpumalanga, Limpopo and KwaZulu-Natal Provinces and the coastal areas of the Eastern Cape Province. Details of each habitat as described by collectors during surveys, as well as altitude and mean annual temperature and rainfall of each locality, were processed and chi-square and effect size values were calculated. A decision tree constructed from all the available data indicated that temperature and altitude, followed by the type of water-body, seemed to be the more important factors that had a significant influence on the distribution of this group in South Africa. The role of the B. africanus group in the transmission of schistosome species is briefly discussed and the urgent need for co-ordinated surveys to update the geographical distribution of host snails, as well as the schistosome parasites in South Africa, is stressed.
TL;DR: With the exception of hookworm infection, soil-transmitted helminthiasis and intestinal schistosomiasis were significantly less seen in 2002 compared to the baseline than in 2002, suggesting that the previous chemotherapy of schoolchildren and villagers in 1996 and 1998 might have led to a reduced transmission of schistOSomiasis in the following years.
TL;DR: The urine-albumin assay has particular promise as a biochemical marker of S. haematobium induced kidney- and upper urinary tract-morbidity and could play a role in better describing and monitoring the occurrence, severity and evolution of urinary schistosomiasis disease.
Abstract: As part of a urinary schistosomiasis control programme on Zanzibar, an aged cross-sectional survey of 305 children from three schools on Unguja was conducted to investigate the relationships between levels of excreted albumin and haemoglobin in urine and Schistosoma haematobium infection status. Diagnosis was determined by standard parasitological methods, dipstick reagents for microhaematuria, visual inspection for macrohaematuria as well as collection of case-history questionnaire data for self-diagnosis. Prevalence of infection as determined by parasitology was 53.9% and approximately, one quarter of the children examined were anaemic ( 40 mg l -1 , as measured with the HemoCue urine-albumin photometer, had sensitivity, specificity, positive and negative predictive values of 0.90, 0.83, 0.86 and 0.89 respectively against 'gold-standard' parasitology. There was a clear association of reported pain upon micturition for children with elevated urine-albumin levels, with an odds ratio of 20 to 1. Levels of excreted blood in urine were quantified with the HemoCue Plasma/Low Hb photometer. However, dipsticks remain the method of choice for urine-haemoglobin of 0.1 g l -1 and below. Urine parameters over a 24-h period were assessed in a small sub-sample. Reductions in both albumin and haemoglobin excretion were observed in 11 children 54 days after praziquantel treatment. It was concluded that these rapid, high-through-put, portable HemoCue assays could play a role in better describing and monitoring the occurrence, severity and evolution of urinary schistosomiasis disease. The urine-albumin assay has particular promise as a biochemical marker of S. haematobium induced kidney- and upper urinary tract-morbidity.
TL;DR: Morphological and biological data suggest that S. haematobium replaced S. guineensis in areas of Cameroon through introgressive hybridization.
Abstract: Interactions between schistosomes are complex with some different species being able to mate and hybridize. The epidemiology of schistosomiasis in specific areas of South West Cameroon has evolved remarkably over 30 years as a result of hybridization between Schistosoma guineensis and S. haematobium. Morphological and biological data suggest that S. haematobium replaced S. guineensis in areas of Cameroon through introgressive hybridization. Data are reported on the use of single stranded conformational polymorphism (SSCP) analysis of the nuclear ribosomal second internal transcribed spacer (ITS2) of individual schistosomes from hybrid zones of Cameroon. The data show that since 1990 S. haematobium has completely replaced S. guineensis in Loum, with S. haematobium and the recombinants still present in 2000. This study illustrates the complexities of the dynamics between S. haematobium and S. guineensis in South West Cameroon.
TL;DR: The prevalence of urinary schistosomiasis in Ikpeshi, a rural community of Edo State, Nigeria showed that 195(65%) out of 300 volunteers harboured Schistosoma haematobium ova in their urine.
Abstract: The prevalence of urinary schistosomiasis in Ikpeshi, a rural community of Edo State, Nigeria showed that 195(65%) out of 300 volunteers harboured Schistosoma haematobium ova in their urine. Eosinophiluria was markedly significant > 5 eosinophilic leucocyturia/hpf and reported among 250 (83.3%) inhabitants. Of these, ova were absent in 55 (22.0%) of urine samples but had other associated urinary symptoms namely; proteinuria or haematuria or both. Eosinophiluria among the inhabitants with light infections as described by 50 ova/10ml of urine) was 107 ± 76.20 x 109/L. In all, the eosinophiluria showed a positive correlation with the S . haematobium ova excreted in their urine (r = 0.40046, p African Journal of Biotechnology Vol. 4 (2), pp. 183-186, 2005
TL;DR: The frequency of urinary disease is increased by infections acquired early during life, is regulated by strong clinical immunity in certain subjects, and may be dependent on hereditary factors.
Abstract: Background. Schistosoma haematobium infection causes severe urinary disease and considerable mortality. The factors that determine disease progression from mild to severe stages are not fully understood. Methods. Here we describe a cross-sectional epidemiological study of kidney and bladder diseases in 2 Dogon populations with different exposure to S. haematobium infection. Results. Early and high exposure resulted in more-severe disease, especially among young subjects, without clear evidence of a more-rapid development of immunity. Nevertheless, 50%-60% of subjects of all age classes in both villages showed no evidence of disease. Kidney and bladder disease peaked biphasically among young subjects and adults >25 years old. The first peak corresponded with infections of maximum intensity, whereas the second peak occurred among adults with infections of very low intensity. Kidney disease was correlated with circulating anodic antigen concentration in serum, whereas bladder disease was correlated with egg count and eosinophil cationic protein concentration in urine. Kidney and bladder disease did not correlate. Severe kidney disease was more frequent in certain families. Conclusions. The frequency of urinary disease is increased by infections acquired early during life, is regulated by strong clinical immunity in certain subjects, and may be dependent on hereditary factors. Kidney and bladder disease may involve different mechanisms of pathogenesis, which may differ between children and adults.
TL;DR: Late benefits of remote antischistosomal therapy were estimated among long-term residents of an area with high transmission of Schistosoma haematobium (Msambweni, Kenya) by comparing infection and disease prevalence in two local adult cohorts.
Abstract: Late benefits of remote antischistosomal therapy were estimated among long-term residents of an area with high transmission of Schistosoma haematobium (Msambweni, Kenya) by comparing infection and disease prevalence in two local adult cohorts. We compared 132 formerly treated adults (given treatment in childhood or adolescence > or = 10 years previously) compared with 132 age- and sex-matched adults from the same villages who had not received prior treatment. The prevalence of current infection, hematuria, and ultrasound bladder abnormalities were significantly lower among the previously treated group, who were found to be free of severe bladder disease. Nevertheless, heavy infection was equally prevalent (2-3%) in both study groups, and present rates of hydronephrosis were not significantly different. Therapy given in childhood or adolescence appears to improve risk for some but not all manifestations of S. haematobium infection in later adult life. Future prospective studies of continued treatment into adulthood will better define means to obtain optimal, community-based control of S. haematobium-related disease in high-risk locations.
TL;DR: There is very little possibility of immediate gene mutation due to the parasite-derived substances in schistosomiasis-related carcinogenesis, as tested by the umu-test and HGPRT gene mutation assay.
TL;DR: In this paper, the prevalence of schistomasiasis infection in school children in Molodo, an irrigated rice growing region of Mali, was determined by determining the prevalence and lesions identified by ultrasonography among children living in this region.
Abstract: Summary Aim To study schistomasiasis infection in school children in Molodo, an irrigated rice growing region of Mali, by determining the prevalence of schistomasiasis and lesions identified by ultrasonography among children living in this region. Methods This cross sectional study included 346 children aged 7 to 14 years selected at random from five schools in Molodo. We tested for hematuria using urine dipsticks and searched for Schistosoma haematobium eggs in urine and S. mansoni eggs in stools. Ultrasonography of the liver, spleen and urinary tract was performed. Results The prevalences of Schistosoma haematobium and S. mansoni infection were 72% (range: 66.9-76.6%) and 68.2% (range: 60.9-71.2%) respectively; 55.1% of the children had co-infection. Ultrasonography of the urinary tract revealed an irregular bladder wall as the most frequent abnormality (3.4% of children). Abdominal ultrasonography demonstrated type B hepatic fibrosis in four children (1.1%), type C in one (0.3%) and type D in one (0.3%). Conclusion Few schistosomiasis lesions were detected by ultrasonography compared with the prevalence of S. haematobium and S. mansoni infections. This observation is probably related to mass treatment programs conducted during a national anti-schistosomiasis program.
TL;DR: No infected snails can now be found in the Jazan region of Saudi Arabia and new cases of human infection with S. haematobium are only being detected in border villages (and are attributed to infections beyond the region, in areas where active transmission is still taking place).
Abstract: Among the inhabitants of the Jazan region of Saudi Arabia, the prevalence and intensity of Schistosoma haematobium infection have been kept very low for several years, by sustained control efforts. The success of the interventions, which were based on case finding, the treatment of infected individuals, and the chemical and environmental control of freshwater snails, led, in mid-2002, to a strategy to eliminate human infection with S. haematobium from Jazan. The strategy, which was based on regular chemotherapy, snail control (made easier by the focality of transmission in the area) and health education, with screening at primary-healthcare centres, by mobile teams and at diagnostic units, appears to have been successful. No infected snails can now be found in the region and new cases of human infection with S. haematobium are only being detected in border villages (and are attributed to infections beyond the region, in areas where active transmission is still taking place). Total elimination appears possible if the health authorities in neighbouring areas can be persuaded to adopt a similar strategy of control.
TL;DR: Urinary schistosomiasis was present amongst settlement dwellers at low prevalence (7.2%) and intensity levels (mostly < 200eggs/10ml.) Transmission was patchy.
Abstract: Schistosomiasis is endemic in South Africa and continues to pose public health challenges especiallyindynamicallychangingareas, eg. informal settlements. Asurvey was conductedin the central Pieter maritzburg area, KwaZulu-Natal, to determine the prevalence, distribution and intensity of urinary schistosomiasis (Schistosoma haematobium) amongst occupants of informal settlements and to establish the distribution of snail hosts in relation to the settlements. Results revealed urinary schistosomiasis to be present amongst settlement dwellersatlowprevalence(7.2%)and intensity levels (mostly < 200eggs/10ml.) Transmission was patchy. Infected snail hosts (Bulmm africanus) were found in nearby rivers and dams and an active focus ofS. haematobium transmission was discovered in a city park - the first example of urban schistosomiasis from South Africa. A structured interview questionnaire was administered to settlement occupants to provide ancillary data. The public health implications of schistosomiasis co...
TL;DR: The results suggested that Bulinus sp.
Abstract: A description is given of the morphological variation of the shell, the radula features and the copulatory organ of Bulinus sp. (2n=36) from four populations in the western Cameroon crater lakes. To assess the role of diploid snails belonging to the Bulinus natalensis/tropicus complex in the transmission of urinary schistosomiasis in Cameroon, the relation between Bulinus sp. (from four Cameroon crater lakes) and Schistosoma haematobium (from three transmission foci) were studied. Bulinus sp. in the present study refers to the diploid snail (2n=36) tentatively identified as Bulinus natalensis or as Bulinus tropicus in the Cameroon crater lakes. The percentage infection of snails challenged ranged from 03.33 to 06.00% for Nchout Monoun population and from 01.85 to 04.76% for Monoun Ngouondam population. No progeny from Petponoun-East and Petponoun-West were experimentally successfully infected with S. haematobium. All the 351 snails dissected were euphallic. Previous malacological surveys revealed the absence of Bulinus sp. naturally infected with human schistosomes. These results suggested that Bulinus sp. was not susceptible to infection with S. haematobium in the Cameroon Western highland crater lakes. These observations justify the absence of transmission foci (for urinary schistosomiasis) in this area.
Journal Article•
TL;DR: In this article, two batches of animals were used to test the efficacy of 10 derivatives of 2-amino-5-nitrothiazoles against schistosomiasis.
Abstract: Schistosomiasis is considered one of the most important human helminth infection in terms of morbidity and infectivity (Chitsulo et al. Acta Trop 2000, 77, 41; Engles et al. Acta Trop 2002, 82, 139; Shelly et al. Mol Biochem Parasitol 1993, 60, 93). Derivatives of 2-amino-5-nitrothiazoles have shown activity against Schistosoma mansoni (S. mansoni) and Schistosoma haematobium (S. haematobium), but due to their toxic effect we synthesized new derivatives of a heteroaromatic amine with thiazole moiety. Required thiazole derivatives were prepared via 1 and 2. In this work, two batches of animals were used to test the efficacy of 10 derivatives of thiazole against schistosomiasis. The first batch of Swiss albino mice was infected with S. mansoni and was treated with 5 × 50 mg/kg b.w. The second batch of golden hamsters was infected with S. haematobium and was treated with 5 × 100 mg/kg b.w. Parasitological parameters, biochemical studies, and granuloma diameter were estimated. Results indicated that in the case of S. mansoni infected mice, compounds 2 (2-amino-4-thiazoliniminium chloride) and 20 (2,4-diamino thiazole) showed moderate efficacy (50% worm reduction). While compounds 18 (4-dicyanomethylene-4, 5-dihydrothiazo-2-yl)-N,N-dimethylimidoformamide) and 21 2-(dimethylamino) methylene-1,3-thiazol-4-yl)-N,N-dimethylimidoformamide) showed 83% and 90% worm reduction with some normalization of liver function and significant reduction in hepatic granuloma diameters. In the case of S. haematobium infected hamsters, compound 15 showed reduction of worms by about 50% with improvement in kidney function. The high effect of compounds 18 and 21 compared to 2, 15, and 20 could be attributed to the dimethylimidoformamide moieties combined with the thiazole ring. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:121–222, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20072
Journal Article•
TL;DR: L'examen anatomopathologique retrouva des lesions inflammatoires granulomateuses d'origine bilharzienne, qui furent rattachees a Schistosoma haematobium, espece habituellement responsable.
Abstract: The purpose of this report is to describe a case of pulmonary schistosomiasis treated at la Fondation Jeanne Ebori in Libreville, Gabon. This case is exceptional due to the rarity of the disease and the schistosomiasis agent involved. The patient was a 47-year-old woman who presented with recurrent right-sided pneumonia 6 months after initial hospitalization and nonspecific antimicrobial therapy. Her general status was altered by hyperthermia, right chest pain, and repetitive bouts of hemoptysia. Because etiological diagnosis could not be achieved and clinical condition was deteriorating, the decision was taken to perform exploratory thoracotomy. Based on operative findings, medial and lower lobectomy was performed. Histological examination demonstrated granulomatous inflammatory lesions due to bilharziosis. Infection was attributed to Schistosoma haematobium that is the most common agent in pulmonary localizations. However Ziehl coloration raised the possibility of involvement of Schistosoma intercalatum that has never been observed in the lung and of a hybrid species. Natural hybridization between S. haematobium and S. intercalatum and the presence of active transmission of the Schistosoma hybrid has been suspected in Gabon.
TL;DR: Among the occupational groups examined, students/pupils were the most infected followed by individuals in other trades, while none of those who use pipe borne and bore-hole water exclusively was infected.
Abstract: Schistosomiasis was surveyed in Wurukum, situated in Makurdi Local Government Area, of Benue State, between the months of April and July 2001. A total of 400 samples, made up of 200 urine and 200 stool samples were collected. The stool samples were prepared using the formol-ether concentration technique, while the urine samples were prepared using the sedimentation technique. Samples were examined microscopically for eggs of schistosomes. The overall prevalence of urinary schistosomiasis ( Schistosoma haematobium ) in the study area was 23.0%. Schistosoma mansoni infection was not detected. Males were slightly more infected (23.7%) than females (22.4%) (p > 0.05). Among the occupational groups examined, students/pupils were the most infected followed by individuals in other trades. Individuals that made use of streams were the most infected (prevalence 43.3%), while none of those who use pipe borne and bore-hole water exclusively was infected (p Key words: urinary schistosomiasis, prevalence, water sources Journal of Medical Laboratory Science Vol.12(2) 2003: 47 - 51