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Showing papers on "Schistosoma haematobium published in 2008"


Journal ArticleDOI
TL;DR: The simple faecal sample collection procedure and the high throughput potential of the multiplex real-time PCR provide a powerful diagnostic tool for epidemiological studies on schistosomiasis in remote areas, with possibilities for extension to other helminths or protozoa using additional molecular targets.
Abstract: A multiplex real-time PCR assay for the detection and quantification of Schistosoma mansoni and S. haematobium DNA in faecal samples was developed and evaluated as an alternative diagnostic method to study the epidemiology of schistosomiasis. Primers and probes targeting the cytochrome c oxidase gene were designed for species-specific amplification and were combined with an internal control. Using positive control DNA extracted from adult Schistosoma worms and negative control samples (n=150) with DNA from a wide range of intestinal microorganisms, the method proved to be sensitive and 100% specific. For further evaluation, duplicate stool specimens with varying S. mansoni egg loads were collected in northern Senegal from pre-selected individuals (n=88). The PCR cycle threshold values, reflecting parasite-specific DNA loads in faeces, showed significant correlation with microscopic egg counts both for S. mansoni in stool and S. haematobium in urine. The Schistosoma detection rate of PCR (84.1%) was similar to that of microscopy performed on duplicate stool samples (79.5%). The simple faecal sample collection procedure and the high throughput potential of the multiplex real-time PCR provide a powerful diagnostic tool for epidemiological studies on schistosomiasis in remote areas, with possibilities for extension to other helminths or protozoa using additional molecular targets.

195 citations


Journal ArticleDOI
TL;DR: Although the real-time PCR and CCA strip tests are very different, both show promise in the detection of S. haematobium infections; the PCR has optimal specificity and high sensitivity but the specificity of the CCA strips and the sensitivity of both tools could still be improved.
Abstract: In the detection of parasitic infection, the traditional methods based on microscopy often have low sensitivity and/or specificity compared with the newer, molecular tests. An assay based on real-time PCR and a reagent strip test for detecting circulating cathodic antigen (CCA) have both now been compared with urine filtration and microscopy, in the detection of Schistosoma haematobium infections. Urine samples, obtained from 74 'cases' in areas of Ghana with endemic S. haematobium and 79 'controls' from non-endemic areas, were each checked using the three methods. With the results of the filtration and microscopy taken as the 'gold standard', real-time PCR was found to be 100% specific and 89% sensitive whereas the CCA strips were 91% specific and 41% sensitive. With the samples found to contain > or =50 eggs/10 ml (indicating relatively intense infections), the sensitivities of the PCR and CCA were higher, at 100% and 62%, respectively. As expected, egg counts were negatively correlated with the number of amplification cycles needed, in the PCR, to give a signal that exceeded the background (r=-0.38; P<0.01). Although the real-time PCR and CCA strip tests are very different, both show promise in the detection of S. haematobium infections. The PCR has optimal specificity and high sensitivity but the specificity of the CCA strips and the sensitivity of both tools could still be improved. A more thorough re-evaluation of the sensitivity and specificity of microscopy and these newer diagnostic methods, with an estimation of the cost-effectiveness of each technique, is recommended.

161 citations


Journal ArticleDOI
TL;DR: Surveillance programmes may wish to prioritise evaluation of environmental risk to pinpoint transmission at the micro-geographical level, although water-contact questionnaires are also recommended as a complementary tool to rapidly identify the behaviour patterns of children at most risk of infection in the rural communities of Zanzibar.

126 citations


Journal ArticleDOI
TL;DR: Significant and sustained reduction in S. haematobium infection was achieved by biennial treatment in school-age children in Burkina Faso, which may provide a cost-effective treatment strategy for similar national schistosomiasis control programmes in sub-Saharan Africa.
Abstract: Objective To evaluate the impact on schistosomiasis of biennial treatment with praziquantel (PZQ) among school-age children in Burkina Faso, the first country that achieved full national coverage with treatment of more than 90% of the school-age population. Methods A cohort of 1727 schoolchildren (6–14 years old) was monitored at yearly intervals through a longitudinal survey. Additional groups of schoolchildren were monitored in cross-sectional surveys. Parasitological examinations for Schistosoma haematobium and Schistosoma mansoni were performed, and prevalence and intensity of infection before and after treatment were analysed. Findings Data from the longitudinal cohort show that a single round of PZQ treatment significantly reduced prevalence of S. haematobium infection by 87% (from 59.6% to 7.7%) and intensity of infection by 92.8% (from 94.2 to 6.8 eggs/10 ml of urine) 2 years posttreatment. The impact on infection was also confirmed by a cross-sectional survey 2 years post-treatment. Importantly, the proportion of school-age children with heavy S. haematobium infection decreased from around 25% before treatment to around 2–3% 2 years post-treatment. Cross-sectional comparison of S. haematobium infection in 7-year-old children in their first year at school, who received treatment through community-based drug delivery, also showed significant reduction in both prevalence (65.9%) and intensity of S. haematobium infection (78.4%) 2 years after single treatment. A significant reduction in S. mansoni infection was also achieved. Conclusion Significant and sustained reduction in S. haematobium infection was achieved by biennial treatment in school-age children in Burkina Faso. This may provide a cost-effective treatment strategy for similar national schistosomiasis control programmes in sub-Saharan Africa. Bulletin of the World Health Organization 2008;86:780–787.

116 citations


Journal ArticleDOI
TL;DR: To examine the association between schistosomiasis and reproductive tract symptoms, a large number of patients with confirmed or suspected cases of the disease are referred to a clinic for treatment.
Abstract: OBJECTIVE To examine the association between schistosomiasis and reproductive tract symptoms. METHOD A cross-sectional study was conducted in a Schistosoma haematobium-endemic area of rural Zimbabwe. A total of 483 permanently resident adult women of Mupfure Ward aged 20-49 were interviewed and examined clinically, each providing three consecutive urine samples. Logistic regression analysis was used to control for sexually transmitted diseases (STDs). RESULTS Women with genital sandy patches had significantly more genital itch (P = 0.009) and perceived their discharge as abnormal (P = 0.003). Eighty percent of the women who had genital itch, yellow discharge, and childhood or current waterbody contact had sandy patches. Fifty-two percent of the women with genital sandy patches did not have detectable S. haematobium ova in urine. Genital schistosomiasis was associated with stress incontinence and pollakisuria, but not with menstrual irregularities, current or previous ulcers, or tumours. CONCLUSION Genital schistosomiasis may be a differential diagnosis to the STDs in women who have been exposed to fresh water in endemic areas. Because of the chronic nature of the disease in adults, we suggest to pay special attention to the prevention of morbidity.

80 citations


Journal ArticleDOI
TL;DR: It is demonstrated that praziquantel is efficacious against S. haematobium in Zimbabwe, although low levels of persistent infection warrant further investigation, and the parasitological cure rate was not associated with gender or age.
Abstract: We examined the efficacy of praziquantel against Schistosoma haematobium among primary school children during a school-based deworming programme in the Burma Valley commercial farming area and the Nyamaropa rural areas in Zimbabwe, where the disease is highly endemic. Among 767 individuals infected with S. haematobium, 675 (88.0%) received treatment. Two single oral doses of 40mg/kg praziquantel were given 6 weeks apart. Of the 675 participants, heavy infection intensity was more common in males than females (chi(2)=6.61, P=0.010). Six weeks later, 624 participants (92.4%) were successfully followed up. The overall cure rate was 88.5% and the egg reduction rate was 98.2%. The highest cure rate was among those individuals with light infection. Seventy-two individuals remained infected at 6 weeks post treatment, among which 3 and 69 individuals had heavy and light infection, respectively. Forty-six of these children resolved following a second round of treatment at 6 weeks follow-up. Of the remaining children successfully followed-up, 22 resolved after a third round of treatment 6 months later. A wide range of observed mild and transient side effects were not associated with egg intensity. The parasitological cure rate was not associated with gender or age. Our study demonstrates that praziquantel is efficacious against S. haematobium in Zimbabwe, although low levels of persistent infection warrant further investigation.

76 citations


Journal ArticleDOI
TL;DR: The resulting maps are being used to plan the distribution of praziquantel to participating districts; they will be applied to prioritising control in those wards where prevalence was unequivocally above thresholds for intervention and might direct decision-makers to obtain more information in wards where intervention status was uncertain.

71 citations


Journal ArticleDOI
TL;DR: This work aimed to map the probability of Schistosoma haematobium infection being >50%, a threshold for annual mass praziquantel distribution, in Burkina Faso, Mali, and Niger, 2004–2006, by using Bayesian geostatistical models.
Abstract: We aimed to map the probability of Schistosoma haematobium infection being >50%, a threshold for annual mass praziquantel distribution. Parasitologic surveys were conducted in Burkina Faso, Mali, and Niger, 2004-2006, and predictions were made by using Bayesian geostatistical models. Clusters with >50% probability of having >50% prevalence were delineated in each country.

65 citations


Journal ArticleDOI
TL;DR: The association between the occurrence of bladder cancer and chronic bacterial or viral infections could not be confirmed and the debate remains open as to whether there is any direct link between chronic HPV infection and bladder cancer.
Abstract: This article reviews the literature regarding the possible correlation between infection and occurrence of bladder cancer. The PubMed literature database was searched from inception to January 2008. Keywords of bladder, cancer, parasitic, bacterial, viral and infection, were used. Forty studies were included in the review. Several investigators support the idea that schistosomiasis is aetiologically related to the development of bladder cancer in individuals infected with Schistosoma haematobium. Approximately 70% of those with chronic schistosomiasis who have bladder cancer develop squamous cell rather than transitional cell carcinoma. Several investigators suggest that bacteria may play a role in inducing bladder cancer. Clinically, researchers have linked the development of infection, urinary stones and indwelling catheters with bladder cancer. Nevertheless, to date, no prospective study has examined the association between urinary tract infection and bladder cancer risk. The possibility that infection...

55 citations


Journal ArticleDOI
TL;DR: The rationale for empirical antischistosoma treatment of adolescents and younger adults in areas where S. haematobium is endemic, with praziquantel alone or in combination with existing anti-STI regimens, is discussed.
Abstract: Background In settings in which adequate laboratory service is lacking, the coexistence of urogenital schistosomiasis and sexually transmitted infections (STIs) poses a diagnostic challenge for health care providers in the management of patients with urogenital complaints. Methods Symptoms were recorded with use of a semistructured questionnaire at baseline and in follow-up surveys after STI and Schistosoma haematobium infection had been assessed and systematically treated as part of a community-based study of 253 women and 236 men, aged 15-49 years, living in an area of Madagascar where S. haematobium is endemic. Results Of those infected with S. haematobium, 35% of the women had concordant STI (e.g., infection with Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and/or Trichomonas vaginalis), compared with 17% of the men. Both S. haematobium infection and STI were significantly more common among younger individuals, aged 15-24 years, than among older individuals. A broad spectrum of urogenital symptoms was reported. However, one-half of the women and men who had positive test results for an STI or for S. haematobium infection were asymptomatic. Gross hematuria and dysuria were, in multivariate analysis, associated with S. haematobium infection, as were genitopelvic discomfort in women and ejaculation pain in men. The association became stronger with higher intensity of infection. In bivariate analysis but not in the multiregression model, STI was associated with vaginal discharge and genitopelvic discomfort in women and was associated with urethral discharge in men. Conclusions The rationale for empirical antischistosoma treatment of adolescents and younger adults in areas where S. haematobium is endemic, with praziquantel alone or in combination with existing anti-STI regimens, is discussed.

54 citations


Journal ArticleDOI
TL;DR: S. haematobium infections modulate the expression of genes of the innate immune system (TLR2 and SOCS-3); these are genes that are associated with increased allergic inflammatory processes, providing a molecular link between the negative association of this infection and atopy in rural children in Ghana.
Abstract: BACKGROUND: Helminth infections are prevalent in rural areas of developing countries and have in some studies been negatively associated with allergic disorders and atopy. In this context little is known of the molecular mechanisms of modulation involved. We have characterized the innate immune responses, at the molecular level, in children according to their helminth infection status and their atopic reactivity to allergens. METHODOLOGY/PRINCIPAL FINDINGS: The mRNA expression of several genes of the innate immune system that have been associated with microbial exposure and allergy was examined in 120 school children in a rural area in Ghana. Helminth infections were common and atopy rare in the study area. The analysis of gene expression in ex vivo whole blood samples reflected the levels of corresponding proteins. Using this approach in a population of school children in whom the presence of Schistosoma haematobium infection was associated with protection from atopic reactivity, we found that the level of TLR2 and SOCS-3, genes associated with atopy in the children, were significantly downregulated by presence of S. haematobium infection. CONCLUSIONS: S. haematobium infections modulate the expression of genes of the innate immune system (TLR2 and SOCS-3); these are genes that are associated with increased allergic inflammatory processes, providing a molecular link between the negative association of this infection and atopy in rural children in Ghana.

Journal ArticleDOI
TL;DR: New insight into genital pathology in S. haematobium-infected men and women is provided, however, the clinical significance of these findings needs further exploration.
Abstract: Ultrasonography (US) was applied in this community-based study in northern Madagascar to compare urogenital findings in Schistosoma haematobium-positive individuals (105 women and 116 men) from the high-endemic Sirama village, with urinary egg negative controls (100 women and 108 men) from the neighboring low-endemic Mataipako village. In addition to examination of the urinary tract, the female genitals were examined by transvaginal US, whereas the male genitals were examined by transrectal and transscrotal US. Pathology of the urinary tract was significantly more prevalent among women and men in Sirama. There were no differences in female genital tract between the two study populations, whereas significantly higher proportions of men in Sirama were detected with hyperechogenic and calcified lesions in the seminal vesicles and the prostate. Moreover, the mean size of the seminal vesicles was significantly larger in Sirama. There were no differences with respect to the external male genitals. Six months after anti-schistosome treatment, no changes were observed in the female genital tract in Sirama, whereas hyperechogenicity of the prostate and the seminal vesicles, in addition to size of the seminal vesicles, declined significantly. This study has provided new insight into genital pathology in S. haematobium-infected men and women. However, the clinical significance of these findings needs further exploration.

Journal ArticleDOI
TL;DR: In conclusion, in spite of the long prepatent period of the Egyptian strain of S. haematobium, sensitivity to PZQ was recorded soon after infection and one hundred percent worm eradication was recorded with the higher dose of PZZ in animals treated 75 and 95 days PI.
Abstract: This study investigates the development of the Egyptian strain of Schistosoma haematobium and the resultant immunohistopathology and biochemical changes in organs affected. In addition, the response of different developmental stages of S. haematobium worms to praziquantel (PZQ) was examined. Schistosoma haematobium–infected hamsters were classified into 4 groups and were treated at day 35, 55, 75, and 95 postinfection (PI), respectively. Each group was subdivided into 3 subgroups. Two of them were treated orally with PZQ (300 mg/kg or 500 mg/kg divided equally on 2 consecutive days), and the third group was left without treatment. Treated groups were killed 20 days posttreatment. Infection with S. haematobium became patent 73 days PI; tissue egg load and worm fecundity were higher at 95 days and maximal 115 days PI, with an oogram pattern comparable to that in Schistosoma mansoni infection. In the liver, small cellular granulomas were observed 75 days PI, with preponderance of CD4+ T-cell phenotypes. In t...

Journal ArticleDOI
TL;DR: The results indicate that schistosomiasis treatment may attenuate HIV replication by decreasing systemic inflammation, regardless of HIV status.
Abstract: We previously reported that treatment for schistosomiasis in persons infected with human immunodefi- ciency virus 1 (HIV-1) attenuated HIV replication as measured by plasma HIV RNA. We investigated systemic inflammation as measured by plasma levels of soluble tumor necrosis factor- receptor II (sTNF-rII), interleukin-8, (IL-8), and IL-10 during schistosomiasis and HIV co-infection and after schistosomiasis treatment. The cohort was composed of 378 persons who were or were not infected with HIV-1, Schistosoma haematobium ,o rS. mansoni. Schistosomiasis-infected persons were randomized to receive praziquantel (40 mg/kg) at baseline or at the three-month follow-up. sTNF-rII and IL-8 were positively associated with schistosomiasis intensity as measured by circulating anodic antigen (CAA), regardless of HIV status. Interleukin-10 was positively associated with CAA in HIV-negative partici- pants. IL-8 levels were higher in S. mansoni-infected individuals. Treatment for schistosomiasis caused a decrease in levels of sTNF-rII (P < 0.05) and IL-10 (P < 0.001). Our results indicate that schistosomiasis treatment may attenuate HIV replication by decreasing systemic inflammation.

Journal ArticleDOI
TL;DR: Travelers and new immigrants and those returning to high-risk areas to visit friends and family should be screened for signs and symptoms of acute and chronic schistosomiasis, and Physicians caring for travelers and immigrants must be familiar with the signs andptoms and able to diagnose and treat it correctly.
Abstract: Schistosomiasis is caused by trematode parasites of one of five species, Schistosoma mansoni, Schistosoma haematobium, Schistosoma japonicum, Schistosoma intercalatum, or Schistosoma mekongi, acquired via skin contact with fresh water containing infectious larval cercariae. Between 1 and 8 weeks after exposure, acute schistosomiasis presents as dermatitis, fever, fatigue, or eosinophilia. If untreated, long-term infection may cause anemia or undernutrition and may progress to liver fibrosis, portal hypertension, or hydronephrosis. Schistosomiasis represents a threat to residents and visitors in all endemic areas of Africa, Asia, and South America. Travelers should be made aware of infection risk if they become exposed to untreated fresh water. New immigrants and those returning to high-risk areas to visit friends and family should be screened for signs and symptoms of acute and chronic schistosomiasis. Physicians caring for travelers and immigrants must be familiar with the signs and symptoms of schistosomiasis and must be able to diagnose and treat it correctly.

Journal ArticleDOI
TL;DR: The important contribution of Pirajá da Silva, the Brazilian medical doctor, who found schistosomiasis in Brazil is highlighted and was fundamental in favour of the dualist theory, or better, for the identification of Schistosoma haematobium and SchistOSoma mansoni, as two different species.

Journal ArticleDOI
TL;DR: The ability of microsatellite loci to reveal genetic diversity within the trematode Schistosoma haematobium is demonstrated for the first time and primers used are suggested to be useful for population genetic analyses of S. haem atobium.
Abstract: The ability of microsatellite loci to reveal genetic diversity within the trematode Schistosoma haematobium is demonstrated for the first time. Nine novel polymorphic microsatellite markers were isolated and their viability assessed on 36 S. haematobium adult worm individuals from three geographical populations. Allelic diversity and gene diversity ranged from two to seven and from 0.29 to 0.76, respectively, suggesting high variability between individuals and between unrelated populations. Three primers also amplified Schistosoma mansoni and two Schistosoma japonicum. The results suggest these primers are useful for population genetic analyses of S. haematobium.

Journal ArticleDOI
TL;DR: Age–gender prevalence profiles of urinary schistosomiasis according to the questionnaire responses are characterized to compare the profiles to field survey data from selected regions, and if the profiles varied spatially throughout Tanzania is determined.
Abstract: OBJECTIVES To characterize age-gender prevalence profiles of urinary schistosomiasis according to the questionnaire responses, compare the profiles to field survey data from selected regions, and determine if the profiles varied spatially throughout Tanzania. METHODS In 2004, a national school-based questionnaire survey for self-reported schistosomiasis and blood in urine (BIU) was conducted in all regions of mainland Tanzania, to assist targeted mass distribution of praziquantel. Field survey data were collected in six north-western and five coastal regions using microscopic examination of urine samples for the presence of Schistosoma haematobium eggs and assessment of micro-haematuria with chemical reagent strips. Bayesian logistic regression models were created to calculate age-gender profiles adjusted for demographic and ecological covariates and spatial correlation in the questionnaire data. Separate odds ratios (OR) for age-gender effects were calculated in each administrative area. RESULTS Data were obtained from > 2.5 million schoolchildren. Boys had higher prevalence of self-reported schistosomiasis and BIU than girls. In boys, prevalence according to the questionnaire and field surveys followed similar age profiles. However, in girls, prevalence according to the field surveys increased in older age groups, but flattened out or decreased according to the questionnaire, indicating the latter underestimated prevalence in older girls. In the models, little spatial correlation was evident in the OR for the age-gender effects, suggesting that these did not vary spatially. CONCLUSION Age-gender patterns of urinary schistosomiasis were consistent in different geographical areas of Tanzania. Because the questionnaire underestimated prevalence in older girls, we propose that upward calibration of observed prevalence is done for older females only.

Journal ArticleDOI
TL;DR: The urinary schistosomiasis prevalence, confirmed by urine microscopy, of 12.9% in the selected school children within Minna, in spite of its urban status, suggests that Minna is an endemic area, and the state requires an effective urinary schistsomiasis control programme.
Abstract: The study was carried out in Minna Metropolis, between August and December, 2005, with a total of 387 school children interviewed and 217 urine samples analysed. This research employs the use of questionnaires, validation of questionnaires by urinalysis and the microscopic examination of the urine samples. The research is aimed at appreciating prevalent level of urinary schistosomiasis in Minna metropolis. The overall prevalence of urinary schistosomiasis, as confirmed by the presence of egg of Schistosoma haematobium was 12.9%, reported blood in the urine 34.4%, microhaematuria 52.5%, protenuria 32.7% and red blood cells 24.6%. The frequency of gross haematuria, and the degree of microhaematuria and proteinuria detectable by chemical reagent strips was observed to correlate with intensity of infection. The urinary schistosomiasis prevalence, confirmed by urine microscopy, of 12.9% in the selected school children within Minna, in spite its urban status, suggests that Minna is an endemic area, and the state requires an effective urinary schistosomiasis control programme. A major concern which represents a serious issue in the study includes the very poor level of awareness about the possible cause of urinary schistosomiasis or reported blood in the urine, as only 0.78% of the children have knowledge about the infection and 12% of the children that reported having blood in their urine have visited a health center.

Journal ArticleDOI
TL;DR: The cheapest approach to the overall problem of schistosomiasis in this part of Nigeria would therefore be wide-spread mass drug distributions, without screening for at-risk populations.
Abstract: Both Schistosoma haematobium and S. mansoni are endemic in Nigeria. Since 1999 the ministries of health of Plateau and Nasarawa states, assisted by The Carter Center, have provided mass drug administrations with praziquantel to villages where >20% of the school-aged children tested with urine dipsticks have been found to have haematuria (presumed to be caused by S. haematobium). The current extent of S. mansoni in Nigeria remains relatively unknown because the tests needed to detect human infection with this parasite are difficult to perform in many endemic areas. In a cross-sectional survey involving 924 children, the prevalence of S. mansoni was determined in 30 villages (in four local government areas) that had been excluded from mass praziquantel administrations because the prevalence of haematuria in their school-aged children had been found to be <20%. Seventeen (57%) of the surveyed villages had sufficient S. mansoni (i.e. prevalences of at least 10%) to warrant treatment. The results indicated that, if both S. haematobium and S. mansoni are taken into account, 81% of the villages in the four local government areas studied require treatment, compared with 50% if only S. haematobium is considered. At the moment, the costs of the village-by-village diagnosis of S. haematobium and S. mansoni would be greater than those of the presumptive treatment of the school-aged children in all villages. Until improved and cheaper rapid diagnostic methods for S. mansoni become available, the cheapest approach to the overall problem of schistosomiasis in this part of Nigeria would therefore be wide-spread mass drug distributions, without screening for at-risk populations.

Journal ArticleDOI
TL;DR: A preliminary analysis of sentinel surveillance data of the European Network on Imported Infectious Disease Surveillance (TropNetEurop) shows 88 cases of imported schistosomiasis for 2007, which gives a good idea about how this infection is brought into Europe.
Abstract: A preliminary analysis of sentinel surveillance data of the European Network on Imported Infectious Disease Surveillance (TropNetEurop) shows 88 cases of imported schistosomiasis for 2007 (17 cases of Schistosoma haematobium, 44 of S. mansoni, 3 of S. japonicum, and 27 unknown species, e.g. early stage, Katayama fever) [1]. Although clinical reporting data for schistosomiasis are notoriously difficult to assess due to the chronic nature of the disease and thus very long periods before diagnosis is confirmed, the analysis gives a good idea about how this infection is brought into Europe.

Journal ArticleDOI
TL;DR: Transmission of S. haematobium was primarily focused in the irrigating channels during the dry hot season at the beginning of afternoon in irrigated perimeters of the Niger River valley, and results should lead to improve the output of sistosomiasis control methods within irrigated areas.
Abstract: Background Currently, the control of urinary schistosomiasis is mostly based on mass treatment. Characterization of Schistosoma haematobium transmission could lead to adding new methods to the control strategy. Methods We carried out malacological and cercariometrical surveys in irrigated perimeters of the Niger River valley. A semi-monthly follow-up was performed in three main sites of human-water contact in a village located at the border of the irrigated perimeter. Bulinids were collected during 20 min; after identification based on the shell morphology, their parasites were characterized by isoelectrofocalisation. The cercariometrical technique by differential filtration was used to evaluate the density of cercariae in every site with two 20 litres samples of water collected at various periods of the day (9, 12, 15 and 18 h). Results In the arm of the river, the cercariometry never showed cercariae whereas only some Bulinus truncatus, all negative, were collected. In the channels, B. truncatus and B. globosus were observed and highest density was found during the dry season. Only B. truncatus was naturally infested. Homozygote BB phenotype (characteristic of S. haematobium) was observed in all positive molluscs. Using cercariometry, more than two third of cercariae were collected at 3:00 PM. Conclusion Transmission of S. haematobium was primarily focused in the irrigating channels during the dry hot season at the beginning of afternoon. These results should lead to improve the output of S. haematobium control methods within irrigated areas.

Journal ArticleDOI
TL;DR: Intermediate hosts of Schistosoma haematobium, the causative agent of urinary schistosomiasis, in Lake Malaŵi include: Bulinus globosus, a member of the B. africanus group and B. nyassanus, a diploid member ofThe truncatus/tropicus species complex.
Abstract: Intermediate hosts of Schistosoma haematobium, the causative agent of urinary schistosomiasis, in Lake Malawi include: Bulinus globosus, a member of the B. africanus group and B. nyassanus, a diploid member of the B. truncatus/tropicus species complex. We compared genetic variability between isolates of S. haematobium from the southern part of the lake (Cape Maclear), where both B. globosus and B. nyassanus play a role as intermediate hosts, and isolates from the northern part, where only B. globosus is host. Data show that the S. haematobium isolates from these two areas of Lake Malawi cannot be distinguished using nuclear or mitochondrial sequences and are capable of cross-infections.

Journal ArticleDOI
TL;DR: The clinical case of a patient with hematuria caused by bladder schistosomiasis is presented, which shows the existence of unusual diseases in the setting.
Abstract: Immigration is a real phenomenon in our country with direct consequences into the public health system. In the attendance to these patients we do not have to forget the existence unusual diseases in our setting. We presented the clinical case of a patient with hematuria caused by bladder schistosomiasis.

01 Jan 2008
TL;DR: The transmission of Schistosoma haematobium is being successfully interrupted in Khuzestan Province, southwestern Iran and total elimination of urinary schistosomiasis appears to be possible if the health authorities in neighboring areas can be persuaded to adopt a similar strategy of integrated control.
Abstract: Objective: To determine the present status of urinary schistosomiasis in Khuzestan Province, southwestern Iran. Methodology: Urine samples were collected from 3400 villagers residing in the high risk areas in Khuzestan Province, mainly from school children (80%) from 2005-2007. During a sequential visit by our team urine specimens were collected between 10:00am and 14:00pm. Each person was given a prenumbered bottle in the field, and the name of the person including age and sex was entered against the appropriate number on a form kept by the investigating team. Results: In this province, the transmission of Schistosoma haematobium is being successfully interrupted as none of the samples were found positive. Conclusion: Total elimination of urinary schistosomiasis appears to be possible if the health authorities in neighboring areas can be persuaded to adopt a similar strategy of integrated control. The plan for the future is to continue monitoring transmission, by passive surveys in local health centers and active case-finding among schoolchildren, and to continue snail sampling and focal mollusciciding.

Journal ArticleDOI
TL;DR: A 24-year-old male Egyptian complained of cramp-like upper abdominal discomfort and weight loss over 4 weeks, and biopsy suggested schistosomiasis of the ileocaecal valve, which had infiltrated all layers but had not metastasised to the regional lymph nodes.
Abstract: A 24-year-old male Egyptian complained of cramp-like upper abdominal discomfort and weight loss (3 kg) over 4 weeks. Physical examination merely gave evidence of the weight loss and of a slightly prominent gas-filled abdomen, mild diffuse abdominal tenderness and considerable borborygmus. Radiology of the intestines revealed chronic subileus of the small intestine caused by stenosis of the ileocaecal valve, which was impassable by coloscope. Biopsy suggested schistosomiasis of the ileocaecal valve. Examination of the resected ileocaecum showed a typical signet-ring carcinoma of the ileocaecal valve which had infiltrated all layers but had not metastasised to the regional lymph nodes (pT3, N0, M0). Typical eggs of Schistosoma haematobium were present in the mucosa of the tumour segment and of the neighbouring tissues. It is possible that chronic intestinal schistosomiasis is a potentially precancerous condition, similar to schistosomiasis of the urinary bladder.

Journal ArticleDOI
TL;DR: Exfoliated cells in the urine of S. haematobium-infected patients were screened for squamous cell abnormalities through cytopathological examinations and severely dysplastic to frankly malignant squamous cells were observed in 1 male and 2 females, while no abnormality was observed in the controls.
Abstract: Schistosoma haematobium infection is endemic in Nigeria, with substantial transmissions in all the states of the federation and a high prevalence rate in schools. Literature has linked bladder cancer, mostly squamous cell type, with long-term S. haematobium infections. The objective of this descriptive study was to screen exfoliated cells in the urine of S. haematobium-infected patients for squamous cell abnormalities through cytopathological examinations. Study participants were drawn from Imala Odo, a community near Oyan Dam in Abeokuta North Local Government Area, Ogun state, Southwest Nigeria. Due to a considerable day-to-day variation of S. haematobium eggs in urine, 3 rounds of 200 ml of urine samples were collected on 3 different days from 32 infected patients and 10 uninfected controls and examined. Cytological preparations of the infected 15 males and 8 females and 10 controls (5 males and 5 females) were screened for squamous cell abnormalities. Severely dysplastic to frankly malignant squamous cells were observed in 1 (3.1%) male and 2 (6.3%) females, while no abnormality was observed in the controls.

Journal Article
TL;DR: The prevalence rate of urinary Schistosomiasis in this community is found to be 51% and no significant difference in the prevalence of UTI among children with urinary schistosomeiasis and those without, however, urgent control measures should be instituted to address this public health problem.
Abstract: Background Reports of studies on the relationship between Schistosoma haematobium and urinary tract infection from different regions are conflicting. Hence, the need to determine the situation in each endemic area. Objective To determine if S. haematobium infection is associated with Urinary Tract Infection (UTI) among children in an endemic area of Cross River State, Nigeria. Subjects and methods Mid-stream urine specimen was collected under strict aseptic procedures into wide-mouthed screw-capped sterile plastic containers. All the specimens were kept in a cooler at approximately 4 degrees C for 5-10 hr before delivery to the laboratory. Urine microscopy was carried out by gram staining and urine was cultured using blood agar and Mac Conkey agar plates. Collection of urine specimens for schistosoma ova was done between 10.00 am and 2.00 pm when ova count of S. haematobium is expected to be at its peak. Results Prevalence of urinary schistosomiasis was 51.0%. One hundred and seventy five (77.4%) of those infected had mild intensity of infection ( 0.68. Conclusion This study has found the prevalence rate of urinary Schistosomiasis in this community to be 51% and no significant difference in the prevalence of UTI among children with urinary schistosomiasis and those without. However, considering the high prevalence of urinary schistosomiasis seen in this study, urgent control measures should be instituted to address this public health problem.

01 Jan 2008
TL;DR: PCR proved highly significant in diagnosis of active intestinal schistosomiasis with a sensitivity of 97.2%, specificity of 100%, predictive value of positive (PVP) of 100, predictivevalue of negative (PVN) of 98, and a diagnostic accuracy of 98.9%.
Abstract: Material and Methods : The individuals under study were categorized into four groups. Group I included 36 patients with active intestinal schistosomiasis. Group II included 20 patients with past history of intestinal schistosomiasis. Group III included 20 patients with Schistosoma haematobium and other parasitic infections, and finally group IV which included 15 individuals serving as negative controls. For all groups under study stool and urine were examined for parasitic ova; serum was examined for S. mansoni circulating DNA by PCR and for the detection of bilharzial antibody by IHAT. Results: PCR proved highly significant in diagnosis of active intestinal schistosomiasis with a sensitivity of 97.2%, specificity of 100%, predictive value of positive (PVP) of 100%, predictive value of negative (PVN) of 98.2% and a diagnostic accuracy of 98.9%. All cases in group II, III, and IV were negative. IHAT results showed a sensitivity of 77.8% in group I, 90.0 % in group II, 25% in group III and in group IV all cases were negative. The specificity of IHAT in the diagnosis of active intestinal schistosomiasis was 85.7%, with PVP 84.8% and PVN 78.9%; the diagnostic accuracy was 81.6%. Conclusion : S. mansoni DNA detection may be used as a valuable and species specific test for diagnosis of early infection or in situations of low worm burden in which other diagnostic methods show low sensitivity and specificity. Early treatment of such cases avoids the occurrence of irreversible pathological damage by the deposited eggs.

Journal ArticleDOI
TL;DR: The case of a patient who was diagnosed as having RPF and schistosomiasis caused by Schistosoma haematobium with histological documentation is reported and it is postulate that there is a causal relationship between these two conditions.