Mapping of  Schistosoma mansoni  in the Nile Delta, Egypt: Assessment of the prevalence by the circulating cathodic antigen urine assay

Haggag, Ayat A.; Rabiee, Amal; Elaziz, Khaled M. Abd; Gabrielli, Albis Francesco; Hay, Rehab Abdel; Ramzy, Reda M. R.

doi:10.1016/j.actatropica.2016.11.038

Cited by 38 publications

(34 citation statements)

References 15 publications

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“…Without additional data on the occurrence and/or frequency of egg excretion by those people harboring antigen-producing (CAA and CCA) schistosome worms, the best that can be done is to use the data available. In Burundi [21], Rwanda [54] and Egypt [55], extensive school surveys using KK stool and POC-CCA urine assays indicate that long-term (8 to 25 years) mass drug administration programs with PZQ can achieve national or regional prevalence levels of 1-2% by KK, but that concomitantly in these communities, levels by POC-CCA are much higher (ranging from 10 to 80%). The current WHO guidelines for morbidity control of S. mansoni infections, based on prevalence and intensity by KK, are generally not useful in these settings and are certainly not useful for moving towards elimination, nor were they developed for this new goal.…”

Section: Introductionmentioning

confidence: 99%

Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs?

2017

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Mapping and diagnosis of infections by the three major schistosome species (Schistosoma haematobium, S. mansoni and S. japonicum) has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection. This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes, in the snail vector, favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta. New mapping tools based on detection of worm antigens (circulating cathodic antigen – CCA; circulating anodic antigen – CAA) in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific. Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay (Kato-Katz) or by urine filtration. In very low prevalence areas this is sometimes 6- to10-fold more. Faced with what appears to be a sizable population of “egg-negative/worm-positive schistosomiasis” especially in areas of very low prevalence, national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination. There is a critical need for continued evaluation of the assays involved and to understand the contribution of this “egg-negative/worm-positive schistosomiasis” condition to both individual morbidity and community transmission. There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-017-0275-5) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs?

2017

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“…In Egypt, according to a recent estimate, the average prevalence of S. mansoni infection in five Egyptian governorates in the Nile Delta region is 10.7%; schoolchildren aged 6-15 years were examined using the Urine-Circulating Cathodic Antigen cassette assay (HaGGaG et al 2017). This prevalence rate is considerably higher than expected and has many indications.…”

Section: Introductionmentioning

confidence: 99%

Control of infection of Biomphalaria alexandrina (Ehrenberg, 1831) with Schistosoma mansoni Sambon, 1907 using Eucalyptus camaldulensis

Mossalem¹,

Habib²,

Ghareeb³

2018

Folia Malacol.

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Schistosomiasis infection can be interrupted if the development of miracidia to cercariae in Biomphalaria alexandrina (Ehrenberg) is blocked. This requires an efficient snail's antioxidant system which can be complemented with an exogenous antioxidant source to alleviate the oxidative stress of infection. For this purpose, leaves of Eucalyptus camaldulensis were air-dried, extracted with aqueous methanol (85%) and defatted with petroleum ether. The obtained defatted extract was used to prepare extracts with different solvents. Among these, ethyl acetate showed the highest antioxidant activity and was chosen for the experiments. The effect of ethyl acetate extract on the infection, survivorship, as well as levels of malondialdehyde (MDA), catalase (CAT) and reduced glutathione (GSH) in B. alexandrina were measured in control, untreated infected and treated infected snails on 1, 10, and 30 days post infection (dpi). The snails exposed to ethyl acetate extract showed a significant reduction in the infection rate compared to those infected and untreated. Moreover, the extract decreased the level of MDA and increased CAT and GSH activities in the haemolymph and tissues of the treated snails. The results suggest that ethyl acetate extract from leaves of E. camaldulensis can be used as an antiparasitic compound against the intramolluscan phase of S. mansoni Sambon, 1907.

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“…Due to the the current, sometimes insecure situation, there was an unplanned, relatively long gap between the time of conducting the study and its finalization. However, this should not have caused any change of the level of transmission [40], the quality of peripheral healthcare services or the population education profile in the study area inrural Egypt.…”

Section: Study Site and Populationmentioning

confidence: 99%

“…In 2018, a recent remapping survey using detection of the circulating cathodic antigen (CCA) from S. mansoni [39] was applied in the Nile Delta. This considerably more sensitive diagnostic tool detected S. mansoni infection in 31 districts out of 35 districts in the Nile Delta with prevalence ranging between 10 and 40% [40].…”

Section: Introductionmentioning

confidence: 96%

Elimination of schistosomiasis requires multifactorial diagnostics: evidence from high- and low-prevalence areas in the Nile Delta, Egypt

Elmorshedy

Bergquist²,

Fayed

et al. 2020

Infect Dis Poverty

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Background: Schistosomiasis is one of the neglected tropical diseases (NTDs) selected for worldwide elimination in the near future. Egypt has made strong progress against its two endemic species of Schistosoma mansoni and S. haematobium. The former is prevalent in the Nile Delta with the latter dominating in the Nile south of Cairo. Innovative efforts are needed to reach the goal as further reduction of the prevalence has stalled due to ongoing transmission. In this study we aimed to explore the difference between low and high prevalence villages with regard to knowledge attitude and practice about schistosomiasis, utilization of health services, infection and transmission indices. Methods: A hybrid cross-sectional longitudinal study was conducted with three annual follow-ups conducted during 1994-1996. We used a representative systematic random sampling technique investigating 993 individuals from the high prevalence village and 614 from the low prevalence village. Data were analyzed using SPSS, comparing proportions with the Chi square test and means with the Student t test, and ANOVA. Results: Compliance of faecal sampling and chemotherapy was above 70% in both villages over the whole study period. Selective praziquantel treatment resulted in a significant reduction of prevalence and intensity of infection in both villages, dropping from 35.8% prevalence to 20.6%, in the low-prevalence village, and from 69.5 to 45.9% in the high-prevalence one. Intensity of infection at the base line was 30 eggs per gram (EPG) of stool in the low-prevalence village versus 105 EPG in the high-prevalence village. However, after the second round, reinfection rebounded by 22% in the high-prevalence village, while a slight improvement of the infection indices was demonstrated in the low-prevalence one. The level of knowledge was modest in both villages: people knew about self-protection and treatment, but not much about the role of human excreta for schistosomiasis transmission. While all participants maintained that using the water from the canals was inevitable, inhabitants in the high-prevalence village showed significantly lower scores reflecting higher water contact compared to the low

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Mapping of Schistosoma mansoni in the Nile Delta, Egypt: Assessment of the prevalence by the circulating cathodic antigen urine assay

Cited by 38 publications

References 15 publications

Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs?

Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs?

Control of infection of Biomphalaria alexandrina (Ehrenberg, 1831) with Schistosoma mansoni Sambon, 1907 using Eucalyptus camaldulensis

Elimination of schistosomiasis requires multifactorial diagnostics: evidence from high- and low-prevalence areas in the Nile Delta, Egypt

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