Diagnostic performance of two specific schistosoma japonicum immunological tests for screening schistosoma haematobium in school children in Zambia.

Dipstick Dye Immunoassay (DDIA) and Indirect Haemagglutination Assay (IHA), are two commercially available kits which have been widely used for screening Schistosoma japonicum in P.R. China. Whether they can be used for screening of Schistosoma haematobium are not clear. In order to evaluate the diagnostic efficiency of DDIA and IHA for screening Schistosoma haematobium, serum samples were collected from pupils in endemic areas in Zambia, Southern Africa, and tested by DDIA and IHA by single-blind manner. Meanwhile, the pupils were microscopically examined by infection with Schistosoma and soil-transmitted helminths, visually observed for parasite eggs. Of the enrolled 148 pupils, 61% tested positive for S. haematobium infection, while 31% and 36% of pupils were infected with hookworm and Ascaris respectively. Regarding the parasitological tests as reference standard, for the diagnosis of S. haematobium infection, IHA performed higher sensitivity (74%, 95% CI: 65%-83%) than that of DDIA (60%, 95%CI: 49%-70%). The sensitivities of IHA and DDIA are significant higher in 10-14 years old students than those of 7-9 years old group. The specificity of DDIA and IHA were 61% (95%CI: 49%-74%) and 72% (95%CI: 60%-84%), respectively. The co-infection with STHs decreased the specificity of DDIA but had no impact on that of IHA. Our study indicated that IHA has more potential as an alternative diagnostic tool for identifying schistosomiasis haematobium but need further improvement.

Real-time PCR for diagnosis of imported schistosomiasis.

BACKGROUND: The diagnosis of schistosomiasis currently relies on microscopic detection of schistosome eggs in stool or urine samples and serological assays. The poor sensitivity of standard microscopic procedures performed in routine laboratories, makes molecular detection methods of increasing interest. The aim of the study was to evaluate two in-house real-time Schistosoma PCRs, targeting respectively S. mansoni [Sm] and S. haematobium [Sh] in excreta, biopsies and sera as potential tools to diagnose active infections and to monitor treatment efficacy. METHODS: Schistosoma PCRs were performed on 412 samples (124 urine, 86 stools, 8 biopsies, 194 sera) from patients with suspected schistosomiasis, before anti-parasitic treatment. Results were compared to microscopic examination and serological assays (enzyme-linked immunosorbent assay (ELISA), indirect haemagglutination (HA) and Western Blot (WB) assay). RESULTS: Compared to microscopy, PCRs significantly increased the sensitivity of diagnosis, from 4% to 10.5% and from 33.7% to 48.8%, for Sh in urine and Sm in stools, respectively. The overall sensitivity of PCR on serum samples was 72.7% and reached 94.1% in patients with positive excreta (microscopy). The specificity of serum PCR was 98.9%. After treatment, serum PCR positivity rates slowly declined from 93.8% at day 30 to 8.3% at day 360, whereas antibody detection remained positive after 1 year. CONCLUSION: Schistosoma PCRs clearly outperform standard microscopy on stools and urine and could be part of reference methods combined with WB-based serology, which remains a gold standard for initial diagnosis. When serological assays are positive and microscopy is negative, serum PCRs provide species information to guide further clinical exploration. Biomarkers such as DNA and antibodies are of limited relevance for early treatment monitoring but serum PCR could be useful when performed at least 1 year after treatment to help confirm a cured infection.

Evaluation of a novel micro-sampling device, Mitra™, in comparison to dried blood spots, for analysis of praziquantel in Schistosoma haematobium-infected children in rural Côte d'Ivoire.

Pharmacokinetic (PK) studies with paediatric populations are increasing in importance for drug development. However, conventional PK sampling methods are characterised by invasiveness and low patient adherence, unsuitable for use with sensitive population, such as children. Mitra™ is a novel volumetric absorptive micro-sampling device, which offers an alternative to the dried blood spotting (DBS) technique, a current popular sampling technique within PK studies. We tested Mitra™ for the first time in the framework of a randomised controlled trial in rural Côte d'Ivoire. Thirty-five school-aged children, infected with Schistosoma haematobium, were sampled with both DBS and Mitra™, at 10 time points after treatment with praziquantel (PZQ). An extraction method for PZQ from Mitra™ was developed, optimised and validated. Analytes, namely R- and S-praziquantel (R-/SPZQ) and the main human metabolite, R-trans-4-OH-praziquantel, were measured using liquid chromatography-tandem mass spectrometry and the results were compared with Bland-Altman analysis to determine agreement between matrices. PK parameters, such as maximal plasma concentration and area under the concentration-time curve, were estimated using non-compartmental analysis. While we observed strong positive correlation (R2 > 0.98) and agreement between both matrices within the calibration line and quality control samples, Mitra™ revealed higher concentrations of all the analytes in the majority of patients' samples compared to DBS sampling, namely 63% samples for RPZQ, 49% for SPZQ and 78% for the metabolite were overestimated. While T1/2 and Tmax were in agreement between both matrices, area under the curve and maximal blood concentration were up to 2× higher for Mitra™ samples, with P < 0.005 for all parameters except Cmax of SPZQ, which was not significantly different between the two matrices. The reasons for the higher PZQ concentrations, more pronounced in incurred Mitra™ samples compared to spiked samples, are yet to be fully explored. Mitra™ appears superior to DBS in terms of simplicity and practicality however labelling issues and the high price of Mitra™ are difficult to overlook.

Epidemiological, clinical, diagnostic and economic features of an immigrant population of chronic schistosomiasis sufferers with long-term residence in a non-endemic country (North Metropolitan area of Barcelona, 2002-2016).

BACKGROUND: Schistosomiasis, one of the neglected tropical diseases (NTD) listed by the WHO, is an acute and chronic parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Complications of long-term infestation include liver cirrhosis, bladder tumors and kidney failure. The objective of this study was to carry out a clinical and epidemiological characterization of a schistosomiasis-diagnosed immigrant population with long-term residencein the EU as well as to evaluate the diagnostic methods available to date. METHODS AND RESULTS: A total of 61 individuals with Schistosoma infection who received medical attention between June 2002 and June 2016 at the North Metropolitan International Health Unit in Barcelona (Catalonia, Spain), were included in the study. All patients were sub-Saharan African immigrants. The majority were male (91.8%) with a median age of 34 years. Symptoms attributable to infection such as haematuria, abdominal pain and dysuria were recorded in up to 90% of patients. The percentage of eosinophils decreased amongst older patients (p = 0.002) and those with symptoms associated with urinary tract infections (p = 0.017). Serology was used for diagnosis in 80.3% of the cases, with microscopic examination showing the remaining 9.8% positive for parasite eggs. Direct microbiological diagnosis was more useful in patients with less than 5 years of residence in the EU (p = 0.05). Chronic complications were present in 22 (36%) of the patients, with renal failure affecting 20 (33%). Of these 20, 6(10%) developed terminal renal failure and required hemodialysis, while 3 (5%) received a renal transplantation. CONCLUSION: Morbidity associated with chronic long-term schistosomiasis is frequent among African immigrants in non-endemic countries. Better diagnostic tools and appropriate early treatment would prevent the development of visceral damage. Thorough screening in selected patients would also be useful to avoid chronic complications.

The effect of hookworm infection and urinary scistosomiasis on blood hemoglobiin concentration of schoolchildren living in northern Mozambique / Infecções por ancilostomídeos e Schistosoma haematobium e sua correlação com a concentração sanguínea de hemoglobina em crianças moçambicanas

This study aims to assess the association between schistosomiasis and hookworm infection with hemoglobin levels of schoolchildren in northern Mozambique. Through a cross-sectional survey, 1,015 children from five to 12 years old in the provinces of Nampula, Cabo Delgado and Niassa were studied. Hookworm infection and urinary schistosomiasis were diagnosed, through Ritchie and filtration methods, with a prevalence of 31.3% and 59.1%, respectively. Hemoglobin levels were obtained with a portable photometer (Hemocue®). The average hemoglobin concentration was 10.8 ± 1.42 g/dL, and 62.1% of the children presented levels below 11.5 g/dL, of which 11.8% of the total number of children had hemoglobin levels below 9 g/dL. A multiple linear regression analysis demonstrated negative interactions between hemoglobin levels and ancylostomiasis, this being restricted to the province of Cabo Delgado (β = -0.55; p < 0.001) where an independent interaction between hemoglobin levels and urinary schistosomiasis was also observed (β = -0.35; p = 0.016). The logistical regression model indicated that hookworm infection represents a predictor of mild (OR = 1.87; 95% CI = 1.17-3.00) and moderate/severe anemia (OR = 2.71; 95% CI = 1.50 - 4.89). We concluded that, in the province of Cabo Delgado, hookworm and Schistosoma haematobium infections negatively influence hemoglobin levels in schoolchildren. Periodical deworming should be considered in the region. Health education and improvements in sanitary infrastructure could achieve long-term and sustainable reductions in soil-transmitted helminthiases and schistosomiasis prevalence rates.

Este estudo tem como objetivo avaliar a relação entre a ancilostomíase e a esquistossomíase urinária com as concentrações sanguíneas de hemoglobina em crianças escolares no norte de Moçambique. Em estudo transversal, 1.015 crianças com idade entre cinco e 12 anos foram incluídas, nas Províncias de Nampula, Cabo Delgado e Niassa. A ancilostomíase e a esquistossomíase urinária foram diagnosticadas através das técnicas de Ritchie e de filtração da urina, respectivamente; prevalências de 31,3% e 59,1% foram observadas. As concentrações sanguíneas de hemoglobina foram obtidas com um fotômetro portátil (Hemocue). A concentração média de hemoglobina foi 10,8 ± 1.42 g/dL, 62,1% das crianças apresentaram concentração abaixo de 11,5 g/dL e 11,8% apresentaram nível abaixo de 9 g/dL. A regressão linear múltipla demonstrou interações negativas entre os níveis de hemoglobina e i) a infecção por ancilostomídeos (β = -0,55; p < 0,001) e ii) a esquistossomíase urinária (β = -0,35; p = 0,016), ambas associações restritas à Província de Cabo Delgado. Também em Cabo Delgado, o modelo de regressão logística demonstrou que a infecção por ancilostomídeos representa um preditor de anemia leve (OR = 1,87; 95% CI = 1,17-3,00) e anemia moderada/grave (OR = 2,71; 95% CI = 1,50 - 4,89). O estudo conclui que em Cabo Delgado, Moçambique, as infecções por ancilostomídeos e Schistosoma haematobium estão significativamente associadas a uma menor concentração sanguínea de hemoglobina em crianças em idade escolar. A administração periódica de anti-helmínticos deve ser feita regularmente. Melhorias na infraestrutura sanitária das regiões estudadas são as medidas mais eficazes para controle destas parasitoses.

Effect on school attendance and performance of iron and multiple micronutrients as adjunct to drug treatment of Schistosoma-infected anemic schoolchildren.

BACKGROUND: Relationships among Schistosoma haematobium, anemia, and iron deficiency have been documented, and all have been found to be associated with a decline in school attendance and lower performance. OBJECTIVE: To assess the effect of single or combined iron and multiple micronutrients and/or praziquantel on school attendance and achievement in randomly selected 7- to 12-year-old anemic children with documented S. haematobium infection (n = 406) in Mali over a 3-month period. METHODS: Schistosomiasis infection was diagnosed by the presence of schistosome eggs in the urine. Venous blood samples (5 mL) were drawn from an antecubital vein for hemoglobin assessment. Children were randomly assigned to one of four treatment groups: praziquantel alone, praziquantel + iron, praziquantel + multiple micronutrients, and praziquantel + multiple micronutrients + iron. School attendance was defined by the number of days the child was absent from class. Achievement was defined by the child's overall school grades. RESULTS: Changes within treatment groups from baseline to the end of study were found for attendance (p < .001) but not for achievement (p > .05). Significant supplement treatments by age group interactions were found in 7- to 9-year-old children for attendance. Further exploration of treatment effects in this age group showed that only iron treatment's main effect was significant on attendance (p = .049) and was of borderline significance on school grades (p = .08). CONCLUSIONS: Combined praziquantel and iron treatment improved children's school attendance and performance better than praziquantel alone, particularly among younger children.

Schistosome infection intensity is inversely related to auto-reactive antibody levels.

In animal experimental models, parasitic helminth infections can protect the host from auto-immune diseases. We conducted a population-scale human study investigating the relationship between helminth parasitism and auto-reactive antibodies and the subsequent effect of anti-helminthic treatment on this relationship. Levels of antinuclear antibodies (ANA) and plasma IL-10 were measured by enzyme linked immunosorbent assay in 613 Zimbabweans (aged 2-86 years) naturally exposed to the blood fluke Schistosoma haematobium. ANA levels were related to schistosome infection intensity and systemic IL-10 levels. All participants were offered treatment with the anti-helminthic drug praziquantel and 102 treated schoolchildren (5-16 years) were followed up 6 months post-antihelminthic treatment. ANA levels were inversely associated with current infection intensity but were independent of host age, sex and HIV status. Furthermore, after allowing for the confounding effects of schistosome infection intensity, ANA levels were inversely associated with systemic levels of IL-10. ANA levels increased significantly 6 months after anti-helminthic treatment. Our study shows that ANA levels are attenuated in helminth-infected humans and that anti-helminthic treatment of helminth-infected people can significantly increase ANA levels. The implications of these findings are relevant for understanding both the aetiology of immune disorders mediated by auto-reactive antibodies and in predicting the long-term consequences of large-scale schistosomiasis control programs.

Impact of iron supplementation on schistosomiasis control in Zambian school children in a highly endemic area.

AIM: To study impact of once weekly iron supplementation on praziquantel cure rate, Schistosoma haematobium reinfection, and haematological parameters in pupils aged between 9 and 15 years of age in Nchelenge district, Zambia. METHODS: Pupils in the intervention group received once weekly dose of ferrous sulphate at 200 mg while those in the control received once weekly vitamin C at 100 mg for up to 9 months. Both study groups received a single dose of praziquantel at baseline. RESULTS: S haematobium reinfection intensity was significantly lower in boys in the intervention group than in boys in the control group at 6 months (P < 0.001) and 9 months (P < 0.001) of supplementation. Significantly lower S haematobium reinfection intensity was found in girls in the intervention group than in girls in the control group only at 6 months of supplementation (P = 0.018). Boys in the intervention group were 42% (Adjusted Risk Ratio = 0.58, 95% confidence interval 0.39, 0.86) less likely to be reinfected with S haematobium than in the control group at 6 months follow up. CONCLUSION: Once weekly iron supplementation can decrease S haematobium reinfection after 6 months and should be incorporated into school based schistosomiasis control programs in highly endemic areas.

Coinfections with Schistosoma haematobium, Necator americanus, and Entamoeba histolytica/Entamoeba dispar in children: chemokine and cytokine responses and changes after antiparasite treatment.

The effect of polyparasite infections on cytokine and chemokine responses as well as the effect of antiparasite treatment was studied in children without parasite infection (the G0 group), in children singly infected with Schistosoma haematobium (the G1 group), and in children multiply infected with S. haematobium/Schistosoma mansoni, Entamoeba histolytica/Entamoeba dispar, and Necator americanus (the G3+ group). Linear regression analysis disclosed a significant risk for coinfection with hookworm and Schistosoma species. Polyparasite infections detected in 23% of children before treatment were present in 5% at 15 months after treatment. Chemokine responses to S. mansoni adult worm antigen (SmAg) diminished after treatment for macrophage inflammatory chemokine (MIP)-1alpha/chemokine (C-C motif) ligand (CCL)-3 (among G3+ children, by a factor of 200 [95% confidence interval {CI}, 33-1111]) and for MIP-1beta/CCL-4 (among G3+ children, by a factor of 26 [95% CI, 6-117]) but were enhanced for thymus- and activation-regulated chemokine/CCL-17 (among G3+ children, by a factor of 10 [95% CI, 3-32]) (P < .001 for all). In response to E. histolytica antigen, interleukin (IL)-13 levels increased after treatment among G1 children by a factor of 138 (95% CI, 12-1569) and among G3+ children by a factor of 21 (95% CI, 7-64) (P < .001 for both). Cellular production of interferon (IFN)-gamma in response to SmAg decreased 4 weeks after treatment among G3+ children, whereas T helper cell type 2 (Th2) IL-13 production was enhanced among G1 and G3+ children. In summary, polyparasite infections with S. haematobium/S. mansoni, E. histolytica/E. dispar, and N. americanus generated prominent proinflammatory cytokine and chemokine responses, and, after antihelminth treatment, the inflammatory chemokine response lessened as the Th2 responsiveness in coinfected children increased.

Malaria co-infection in children influences antibody response to schistosome antigens and inflammatory markers associated with morbidity.

The epidemiological coexistence of schistosomiasis and malaria is frequently observed in developing countries. Co-infection with malaria in children could influence the development of acquired immunity associated with the resistance or the pathology of schistosomiasis. In the present study, performed during May to June 1996 in Senegal, the humoral immune response to Schistosoma haematobium 28 kDa glutathione S-transferase (Sh28GST) vaccinal antigen and to soluble egg antigens (SEA) has been evaluated in individuals infected by S. haematobium. Specific immunoglobulin G3 (IgG3) and IgE responses were significantly higher in co-infected children with Plasmodium falciparum compared with children infected with S. haematobium only. In addition, circulating levels of interferon-gamma (IFN-gamma), interleukin-10 (IL-10), and soluble tumor necrosis factor receptor II (sTNF-RII), 3 parameters associated with schistosomiasis morbidity, were significantly increased in co-infected children. Taken together, this study indicated that malaria co-infection can both influence the acquired specific immune response to schistosome antigens and unbalance the regulation of inflammatory factors closely involved in schistosomiasis pathology.

Anthelmintic treatment improves the hemoglobin and serum ferritin concentrations of Tanzanian schoolchildren.

To investigate the relationships between helminth infections and iron status among school-aged children, 1,115 Tanzanian children in grades 2 through 5 were randomly assigned to treatment or control groups. The children in the treatment group were screened for infection with Schistosoma haematobium and hookworm at baseline, 3 months, and 15 months; infected children were given albendazole against hookworm and praziquantel against schistosomiasis. The control group received a placebo and did not undergo parasitological screening until 15 months after the baseline. Hematological variables were compared between the treatment and control groups. The main results were, first, that the hemoglobin concentration significantly improved after treatment for hookworm (p < .001) by 9.3 g/L in children treated for hookworm only and by 8.8 g/L in children treated for hookworm and schistosomiasis. The ferritin concentration also improved in children treated for schistosomiasis (p = .001) or hookworm (p = .019). Second, a longitudinal analysis of the data from the children in the control group showed that hookworm and schistosomiasis loads were negatively associated with hemoglobin and ferritin concentrations. Moreover, ferritin concentrations increased as C-reactive protein levels increased. Overall, the results showed that anthelmintic treatment is a useful tool for reducing anemia in areas with high hookworm and schistosomiasis endemicity. The empirical relationship between ferritin and C-reactive protein indicated that simple procedures for adjusting cutoff points for the use of ferritin as an indicator of low iron stores were unlikely to be useful in this population.

Cytokine responses to mitogen and Schistosoma haematobium antigens are different in children with distinct infection histories.

Prevalence of Schistosoma haematobium infection in children from two neighbouring villages in Zimbabwe was 77.1% and 40.3%, respectively. The age-intensity data indicated peak intensities of infection at a lower age in the high prevalence village. This study investigated whether the difference in infection histories was reflected in a difference in cytokine profiles between children resident in these two villages. Blood samples were taken to assay for cytokine secretion 1 year after treatment for schistosomiasis. They were cultured with phytohaemagglutinin (PHA), schistosome egg antigens (SEA) or cultured without stimulant and tested for the presence of interleukin (IL)-4, IL-5, IL-10, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-gamma. Blood samples from children from the low prevalence village were more likely to produce IL-4 (P < 0.0001) and produced higher levels of IFN-gamma (P < 0.02) and GM-CSF (P < 0.03) when cultured with PHA for 24 h. Residence in the high prevalence village was associated with production of IL-10 (P < 0.006) and GM-CSF (P < 0.04) in response to culture with SEA and IL-5 (P < 0.02) with PHA for 48 h. The interaction between age and village was not significant for these results; however, there was a significant interaction between age and village for IL-5 detected in blood samples cultured with PHA for 24 h (P < 0.01). These results concur with previous observations that major patterns of cytokine production can be related to immunosuppression, but also indicate an underlying pattern which reflects the importance of history of infection to the immune response.

The effect of different anthelmintic treatment regimens combined with iron supplementation on the nutritional status of schoolchildren in KwaZulu-Natal, South Africa: a randomized controlled trial.

A randomized controlled trial in KwaZulu-Natal (South Africa) of 428 primary-school pupils (stratified into 6 groups by age, sex and intervention) measured the effect of different anthelmintic treatments and iron supplementation regimens provided twice at 6-monthly intervals for 1 year (1996/97). Half the pupils received iron supplementation (ferrous fumarate 200 mg weekly for 10 weeks). Pupils received 2 anthelmintic regimens, either (i) albendazole 400 mg plus praziquantel 40 mg/kg or (ii) albendazole 400 mg on 3 consecutive days plus praziquantel 40 mg/kg or (iii) placebo. Baseline prevalences of Ascaris 55.9%, Trichuris 83.6%, hookworm spp. 59.4%, were reduced after 12 months for single-dose albendazole treatment to Ascaris 17.4% (P < 0.005), Trichuris 61.5% (NS), hookworm spp. 0% (P < 0.005), and for triple-dose albendazole treatment to Ascaris 14.8% (P < 0.005), Trichuris 25.0% (P < 0.01), hookworm 0% (P < 0.005). Schistosoma haematobium 43.4% was reduced among treated groups to 8.3% (P < 0.005). There were no significant changes in the anthropometry of the different treatment groups at either 6 or 12 months post treatment. Twelve months after treatment there was a significant increase in haemoglobin levels (P = 0.02) among pupils receiving triple-dose albendazole, praziquantel and ferrous fumarate; pupils receiving no anthelmintic treatment showed a significant decrease as did pupils who received triple-dose albendazole and praziquantel but no iron. Regular 6-monthly anthelmintic treatment significantly reduced the prevalence of Ascaris, hookworm spp. and S. haematobium infections (P < 0.05). Triple-dose treatment for Trichuris was significantly more effective than a single dose of albendazole 400 mg (P = 0.002). In areas with schistosomiasis, hookworm infection and high prevalence of Trichuris infection, combination treatment with praziquantel, triple-dose albendazole, plus iron supplementation, is likely to improve pupils' health and haemoglobin levels.

Exposure, infection and immune responses to Schistosoma haematobium in young children.

Behavioural, parasitological and immunological data were obtained from 48 children up to 6 years old, resident in a Schistosoma haematobium endemic area in Zimbabwe. The children averaged more than 1 contact with infective water bodies every 3 days and all showed immunological evidence of exposure (an anti-cercarial and/or anti-egg antibody response). IgM was the dominant isotype and appeared in the youngest children, followed by IgA, IgE and IgG3. However, only 38 children showed evidence of infection (an anti-egg response or eggs in urine) and only 14 were excreting eggs. The best estimates from these data are that less than 1 in 100 contacts results in infection and less than 1 in 1000 result in egg output. This suggests that there may be substantial attrition of invading cercaria even in naïve individuals.

Effects of calcitriol on eosinophil activity and antibody responses in patients with schistosomiasis.

OBJECTIVE: Parasitic infestations are known to elicit T-helper lymphocyte type 2 (Th-2) reactions, characterized by a pronounced eosinophila and high IgE levels. In humans both elevated specific IgE levels and eosinophil counts are associated with resistance to reinfection with schistosomiasis. This study aimed to establish whether the Th-2 reaction could be enhanced with calcitriol (vitamin D3). Calcitriol has been shown to cause a shift from Th-1 to Th-2 type reactions when applied locally to the skin. METHODS: Fifty-nine patients with Schistostoma haematobium infection were randomized to one of four treatment modalities, i.e. (a) praziquantel (PZQ) 60 mg.kg-1 orally on day 1, (b) PZQ 60 mg.kg-1 on day 1 plus calcitriol 1 microgram per day orally for 5 consecutive days, (c) calcitriol 1 microgram per day for 5 consecutive days or (d) placebo. Blood for differential counts, eosinophil cationic protein (ECP), specific IgE and IgG to whole-worm antigen, as well as urine samples for egg counts, were collected on days 0 and 21. RESULTS: Baseline values did not differ significantly between the groups. Calcitriol alone resulted in significant increases in circulating lymphocytes (median increase of 5.5%) and the percentage of eosinophil vacuolization (mean increase 28%). It, however, significantly decreased ECP levels (mean decrease 46%). PZQ in combination with calcitriol significantly enhanced production of specific IgE (mean increase 213%) and IgG (mean increase of 170%) and tended to increase eosinophil vacuolization (mean increase 22%). All these changes also differed significantly from those in the placebo group. The specific IgE and IgG levels were also significantly higher than the already increased levels seen with PZQ treatment only. ECP levels were, however, not significantly affected by combination therapy, whereas PZQ alone significantly enhanced ECP production (mean increase 93%). CONCLUSIONS: The increases in specific IgE responses and percentage of eosinophil vacuolization favour a Th-2 type of reaction. The ECP values viewed in isolation may, paradoxically, indicate a Th-1 response; this could, however, have been an artefact due to the method of ECP detection ex vivo. Finally, it would seem that calcitriol does cause some immune augmentation when combined with PZQ therapy in patients with schistosomiasis. However, long-term follow-up is needed to prove that these findings would translate into resistance against re-infection.

Circulating antigens in schistosomiasis: detection of 31/32-kDa proteins in sera from patients infected with Schistosoma japonicum, S. mansoni, S. haematobium, or S. intercalatum.

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect 31/32-kDa schistosome proteins as circulating antigens in sera from schistosomiasis patients. A monoclonal antibody was used as a capture antibody and rabbit antiserum raised against purified 31/32-kDa proteins was the detecting antibody. Positive results were obtained with patients infected with Schistosoma japonicum (88%; n = 69), S. mansoni (80%; n = 56), S. haematobium (100%; n = 40), or S. intercalatum (94%; n = 65). Sera from uninfected Chinese and African individuals and from Chinese patients with trichinosis, cysticercosis, or paragonimiasis did not react in the assay. This ELISA appears to be valuable in diagnosing infections by all major human schistosome species.

A preliminary report on the prognostic value of selected diagnostic enzymes among certain malignant and schistosomal malignant patients.

The study is a trial to test certain biochemical parameters as differential diagnostic markers between some pathological malignant cases. The first part of the present article was carried out in order to investigate the effect of both cancerous infestation and schistosomal infection on Lactate dehydrogenase (LDH), two transaminases (ALT and AST) activities and total proteins in both serum and tumor tissue isolated from bladder carcinoma patients. The activities were measured in neighboring mucosa to carcinoma tissues together with bladded tissues excised because of malignant lesions and malignant tissues excised because of urinary schistosomiasis, in Egyptian human patients. The second part was design in order to estimate the effect of cancerous disorders on the previous parameters in serum and isolated tumors among colonic carcinoma patients. In addition, the study was extended to explore the changes that might occurred in serum LDH isoenzymatic pattern among some selected cases from these patients.

Detection of circulating schistosome antigens in serum and urine of schistosomiasis patients and assessment of cure by a monoclonal antibody.

From a panel of monoclonal antibodies (MAb), an IgM monoclonal antibody (7F1/6B) reactive with repetitive epitopes on S. mansoni soluble egg antigen was selected. This MAb was employed both as antigen capture and detection antibody in a sandwich ELISA and had a detection limit < 1 ng S. mansoni SEA/mi. Serum and urine samples were collected from rural students who had S. mansoni (169 subjects) or mixed S. mansoni and S. haematobium (64 subjects) infections. Samples were collected before and at 4, 8 and 12 weeks after praziquantel therapy. Circulating schistosome antigens (CSA) were demonstrated in 90% of sera and 97% of urine samples of S. mansoni group and in 91% of sera and 100% of urine samples of mixed infection group. All sera from 29 uninfected individuals, 30 patients with other parasites and 70% of 55 S. haematobium-infected subjects were negative in this assay. CSA level in serum and urine samples correlated positively with the number of S. mansoni eggs/g stool in both groups. A significant reduction in CSA level was observed in serum and urine samples after praziquantel therapy. By 12 weeks post-treatment, negativity was 98% in sera and 97% in urine of S. mansoni-infected group and 98% in sera and 91% in urine of mixed infection group. The data demonstrate that the use of MAb 7F1/6B for the detection of CSA provides a sensitive method for immunodiagnosis of schistosomiasis and monitoring of cure.

Urinary schistosomiasis associated with hepatitis C virus infection.

We studied 26 adult patients referred for cystoscopy: 13 consecutive patients with schistosome ova on bladder biopsy and antibodies to Schistosoma species in serum were classified as having urinary schistosomiasis, while 13 consecutive patients without schistosome ova on bladder biopsy and who were negative for antibodies to Schistosoma species in serum served as controls. Nine of 13 patients (70%) and none of 13 controls (p < 0.0005) had antibodies to hepatitis C virus in serum (anti-hepatitis C virus). All controls and patients who were negative for anti-hepatitis C virus had normal serum alanine aminotransferase levels, while 2 of 9 (22%) positive for anti-hepatitis C virus had elevated levels. Our study shows that patients with urinary schistosomiasis are at high risk for anti-hepatitis C virus positivity and that some of them may have active liver disease. Therefore, it is imperative to screen patients with urinary schistosomiasis for associated hepatitis C virus infection and liver disease.

Impact of Schistosoma haematobium infection and of praziquantel treatment on anaemia of primary school children in Bertoua, Cameroon.

There is some debate as to the extent to which Schistosoma haematobium haematuria may be the cause of anaemia. Our goal was to evaluate the impact of a single 40 mg kg-1 dose of praziquantel on anaemia. Since praziquantel does not reduce the hookworm intensity of infection (a major cause of anaemia in children in the area) changes in the prevalence of anaemia in the study population should be due only to the elimination of S. haematobium. Seven hundred and seventy-one primary schoolboys from Bertoua (East Cameroon) were divided into four groups: high infection, moderate infection treated with praziquantel or placebo, and non-infected. Haemoglobin concentrations of the children were determined at the onset of the study and 6 months after the praziquantel intervention. Mean haemoglobin concentrations were not significantly different for no infection or for mild or heavy infection by S. haematobium. A factorial analysis of variance using S. haematobium intensity of infection, malaria and intestinal parasite infections and age as independent variables and haemoglobin concentration as the dependent variable show that only age and malaria infection show a significant relationship with haemoglobin concentration. Despite treatment with praziquantel, all the children in the treatment groups had lower mean haemoglobins 6 months after intervention. A factorial analysis of variance using age, malaria infection and the treatment category as independent variables and the difference in haemoglobin concentration as the dependent variable shows that only malaria infection showed a significant relationship with haemoglobin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)