Evaluation of circulating cathodic antigen (CCA) urine-cassette assay as a survey tool for Schistosoma mansoni in different transmission settings within Bugiri District, Uganda.

Diagnosis of schistosomiasis at the point-of-care (POC) is a growing topic in neglected tropical disease research. There is a need for diagnostic tests which are affordable, sensitive, specific, user-friendly, rapid, equipment-free and delivered to those who need it, and POC is an important tool for disease mapping and guiding mass deworming. The aim of present study was to evaluate the relative diagnostic performance of two urine-circulating cathodic antigen (CCA) cassette assays, one commercially available and the other in experimental production, against results obtained using the standard Kato-Katz faecal smear method (six thick smears from three consecutive days), as a 'gold-standard', for Schistosoma mansoni infection in different transmission settings in Uganda. Our study was conducted among 500 school children randomly selected across 5 schools within Bugiri district, adjacent to Lake Victoria in Uganda. Considering results from the 469 pupils who provided three stool samples for the six Kato-Katz smears, 293 (76%) children had no infection, 109 (23%) were in the light intensity category, while 42 (9%) and 25 (5%) were in the moderate and heavy intensity categories respectively. Following performance analysis of CCA tests in terms of sensitivity, specificity, negative and positive predictive values, overall performance of the commercially available CCA test was more informative than single Kato-Katz faecal smear microscopy, the current operational field standard for disease mapping. The current CCA assay is therefore a satisfactory method for surveillance of S. mansoni in an area where disease endemicity is declining due to control interventions. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, the urine POC CCA test is an attractive tool to augment and perhaps replace the Kato-Katz sampling within ongoing control programmes.

Notes on the use of urine-CCA dipsticks for detection of intestinal schistosomiasis in preschool children.

Urine-dipstick diagnostic tests that detect schistosome circulating cathodic antigen (CCA) have the potential to provide more sensitive and rapid testing for intestinal schistosomiasis in field-based surveys; this is especially so when examining preschool children, from whom it may be difficult to obtain consecutive stool samples. To assess the performance of urine dipsticks, 569 preschool children from four villages along the shore of Lake Albert, Uganda, were screened for Schistosoma mansoni by Kato-Katz (K-K) examination of a single stool sample and CCA urine dipsticks. The prevalence of infection was 32.2% by K-K and 40.0% by CCA tests. Sensitivity and specificity were influenced by whether 'trace' results from the CCA test were characterised as positive or negative for infection with S. mansoni; ambiguities around this issue need to be resolved. Nevertheless, the CCA test showed particular promise for routine epidemiological screening in this setting.

Efficacy of praziquantel syrup versus crushed praziquantel tablets in the treatment of intestinal schistosomiasis in Ugandan preschool children, with observation on compliance and safety.

Preschool children (aged ≤5 years) have so far been overlooked by mass treatment campaigns targeting schistosomiasis, even though praziquantel (PZQ) has been shown to be well tolerated and effective within this age group. The WHO provided the Ugandan Ministry of Health with a syrup formulation of PZQ with the aim of assessing its safety and efficacy in comparison with crushed PZQ tablets for the treatment of intestinal schistosomiasis in preschool children. This study included 1144 preschool children randomly assigned to two treatment arms (PZQ syrup or crushed PZQ tablet) regardless of infection status for direct comparison. Diagnosis of intestinal schistosomiasis was assessed using single stool sample, double Kato-Katz smear examinations. Parasitological cure was assessed 3 weeks after treatment. The observed cure rate was 80.9% for the PZQ syrup arm and 81.7% for the crushed PZQ tablet arm, with egg reduction rates of 86.1% and 89.0%, respectively. Pre-treatment infection intensity was observed to influence cure rates significantly, with cure rates of 88.6% for light infections, 74.5% for moderate infections and 67.4% for heavy infections. No significant difference was found in non-compliance between the PZQ syrup (11.1%) and crushed PZQ tablet (14.7%) arms. PZQ syrup and crushed PZQ tablets have very similar efficacies in the treatment of intestinal schistosomiasis in preschool children.

Field survey for strongyloidiasis in eastern Uganda with observations on efficacy of preventive chemotherapy and co-occurrence of soil-transmitted helminthiasis/intestinal schistosomiasis.

Following our previous field surveys for strongyloidiasis in western Uganda, 120 mothers and 232 children from four villages in eastern Uganda were examined, with two subsequent investigative follow-ups. As before, a variety of diagnostic methods were used: Baermann concentration, Koga agar plate and strongyloidid enzyme-linked immunosorbent assay (ELISA), as well as Kato-Katz faecal smears for detection of eggs of other helminths. At baseline, the general prevalence of Strongyloides stercoralis was moderate: 5.4% as estimated by Baermann and Koga agar methods combined. A much higher estimate was found by ELISA (42.3%) which, in this eastern setting, appeared to be confounded by putative cross-reaction(s) with other nematode infections. Preventive chemotherapy using praziquantel and albendazole was offered to all participants at baseline. After 21 days the first follow-up was conducted and 'cure rates' were calculated for all parasites encountered. Eleven months later, the second follow-up assessed longer-term trends. Initial treatments had little, if any, effect on S. stercoralis, and did not alter local prevalence, unlike hookworm infections and intestinal schistosomiasis. We propose that geographical patterns of strongyloidiasis are likely not perturbed by ongoing praziquantel/albendazole campaigns. Antibody titres increased after the first follow-up then regressed towards baseline levels upon second inspection. To better define endemic areas for S. stercoralis, careful interpretation of the ELISA is warranted, especially where diagnosis is likely being confounded by polyparasitism and/or other treatment regimens; new molecular screening tools are clearly needed.

A parasitological survey, in rural Zanzibar, of pre-school children and their mothers for urinary schistosomiasis, soil-transmitted helminthiases and malaria, with observations on the prevalence of anaemia.

'Kick-out-Kichocho' is an integrated helminth-control initiative that is aimed at reducing the burden of urinary schistosomiasis and soil-transmitted helminthiases (STH) on Zanzibar Island (Unguja), in Tanzania. Like other initiatives based on preventive chemotherapy, the programme is mainly school-based and, consequently, pre-school children (aged < or =6 years) are not targeted specifically. To assess the importance of urinary schistosomiasis, STH and malaria, as well as the occurrence of anaemia and growth retardation among these younger children, an epidemiological survey has been undertaken, in a rural area of Unguja, among 152 pre-school children and their 113 mothers. In the pre-school children investigated, urinary schistosomiasis was rare because of the children's lack of contact with environmental water. Malaria was also rare in the children, probably as a consequence of the study season, the widespread use of insecticide-treated bednets and the good access to first-line antimalarial drugs. In contrast, the prevalences of infection with at least one soil-transmitted helminth and of anaemia were alarmingly high among the pre-school children, at 50.0% [95% confidence interval (CI)=40.4%-59.6%) and 73.4% (CI=?65.2%-80.5%), respectively; the corresponding values in the children's mothers were 35.2% (CI=25.4%-45.9%) and 25.9% (CI=18.0%-35.3%). In the rural study area, Kandwi was identified as a hamlet with particularly high levels of transmission of soil-transmitted helminths, and household aggregations of STH were common. To reduce the present health inequities, the future integration of pre-school children within ongoing anthelmintic-control programmes in schools is strongly recommended.

Soil-transmitted helminthiasis among mothers and their pre-school children on Unguja Island, Zanzibar with emphasis upon ascariasis.

Soil-transmitted helminthiasis (STH) is a scourge to the health and well-being of infants and pre-schoolchildren throughout many parts of sub-Saharan Africa. To improve maternal and child health, regular de-worming is recommended and often delivered from mother and child health (MCH) clinics, yet there have been few studies monitoring the progress and impact of interventions on local levels of disease. A cross-sectional parasitological survey, supplemented with questionnaires, was therefore conducted across 10 Ungujan villages examining mothers (n=322) and their pre-school children (n=359). Within children, mean prevalence of ascariasis, trichuriasis and hookworm was 8.6% (95% CI 5.5-11.8), 18.9% (95% CI 14.5-23.4) and 1.7% (95% CI 0.2-3.5) while in mothers mean prevalence was 6.7% (95% CI 3.7-9.7), 11.9% (95% CI 8.0-15.8) and 1.9% (95% CI 0.2-3.5), respectively. There was, however, significant spatial heterogeneity of STH by village, 2 villages having much elevated levels of infection, although general access to anthelminthics and utilization of village MCH clinics was good. Levels of parasite aggregation (k) were determined and a multilevel logistic regression model identified access to a household latrine [OR=0.56 (95% CI 0.32-0.99)] and having an infected household member [OR=3.72 (95% CI 2.22-6.26)] as observed risk factors. To further investigate worm burdens of Ascaris lumbricoides, adult worms were expelled using Combantrin and measured. A negative relationship between mean worm burden and mean worm mass was found. Villages in the north of Unguja represent locations where there is elevated prevalence of both ascariasis and trichuriasis and it appears that local factors are particularly favourable for transmission of these helminths. From a perspective of control, in such locations, intervention efforts should be stepped up and greater efforts placed upon improving household sanitation.