Efficacy of praziquantel and reinfection patterns in single and mixed infection foci for intestinal and urogenital schistosomiasis in Cameroon

Tchuenté, Louis-Albert Tchuem; Momo, Sabine C.; Stothard, J. Russell; Rollinson, David

doi:10.1016/j.actatropica.2013.06.007

Cited by 63 publications

(69 citation statements)

References 28 publications

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“…Microscopy for schistosome eggs is generally only performed on either stool or urine depending on the expected Schistosoma species. It has been reported that in endemic areas with mixed infections, only one will be identified (usually S. haematobium as urine micro-haematuria dipsticks allow easier detection of infections than stool microscopy necessary for S. mansoni ) and large groups of infected patients could go undetected and untreated (Gutman et al 2008; Tchuem Tchuenté et al 2013). With the recent demonstration of schistosomes being capable of forming hybrids between species that allows infection of both humans and ruminants, there will be a greater need for control programmes to identify these hybrid schistosome infections (Huyse et al 2009; Webster et al 2013).…”

Section: Resultsmentioning

confidence: 99%

Tools for diagnosis, monitoring and screening ofSchistosomainfections utilizing lateral-flow based assays and upconverting phosphor labels

et al. 2014

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SUMMARY The potential of various quantitative lateral flow (LF) based assays utilizing up-converting phosphor (UCP) reporters for the diagnosis of schistosomiasis is reviewed including recent developments. Active infections are demonstrated by screening for the presence of regurgitated worm antigens (genus specific polysaccharides), whereas anti-Schistosoma antibodies may indicate ongoing as well as past infections. The circulating anodic antigen (CAA) in serum or urine (and potentially also saliva) is identified as the marker that may allow detection of single-worm infections. Quantitation of antigen levels is a reliable method to study effects of drug administration, worm burden and anti-fecundity mechanisms. Moreover, the ratio of CAA and circulating cathodic antigen (CCA) is postulated to facilitate identification of either Schistosoma mansoni or Schistosoma haematobium infections. The UCP-LF assays allow simultaneous detection of multiple targets on a single strip, a valuable feature for antibody detection assays. Although antibody detection in endemic regions is not a useful tool to diagnose active infections, it gains potential when the ratio of different classes of antibody specific for the parasite/disease can be determined. The UCP-LF antibody assay format allows this type of multiplexing, including testing a linear array of up to 20 different targets. Multiple test spots would allow detection of specific antibodies, e.g. against different Schistosoma species or other pathogens as soil-transmitted helminths. Concluding, the different UCP-LF based assays for diagnosis of schistosomiasis provide a collection of tests with relatively low complexity and high sensitivity, covering the full range of diagnostics needed in control programmes for mapping, screening and monitoring.

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Section: Resultsmentioning

confidence: 99%

Tools for diagnosis, monitoring and screening ofSchistosomainfections utilizing lateral-flow based assays and upconverting phosphor labels

et al. 2014

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“…Today, campaigns for the distribution of this drug focus on periodic administration of the anthelminthic, praziquantel, to kill the adult worms [53]. What is lacking is a sustainable control strategy to prevent re-infection from snail to man [16], [54]. The ability of an invasive, non-native crustacean to eliminate snails was shown in Kenya, with a concomitant reduction of prevalence and intensity of urinary schistosomiasis in school children [55].…”

Section: Discussionmentioning

confidence: 99%

“…While praziquantel effectively kills adult worms inside the definitive host's body, rapid reinfection can occur upon re-exposure to cercariae from infected snails in the environment. [16]–[18].…”

Section: Introductionmentioning

confidence: 99%

The Prawn Macrobrachium vollenhovenii in the Senegal River Basin: Towards Sustainable Restocking of All-Male Populations for Biological Control of Schistosomiasis

et al. 2014

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Early malacological literature suggests that the outbreak of schistosomiasis, a parasitic disease transmitted by aquatic snails, in the Senegal River basin occurred due to ecological changes resulting from the construction of the Diama dam. The common treatment, the drug praziquantel, does not protect from the high risk of re-infection due to human contact with infested water on a daily basis. The construction of the dam interfered with the life cycle of the prawn Macrobrachium vollenhovenii by blocking its access to breeding grounds in the estuary. These prawns were demonstrated to be potential biological control agents, being effective predators of Schistosoma-susceptible snails. Here, we propose a responsible restocking strategy using all-male prawn populations which could provide sustainable disease control. Male prawns reach a larger size and have a lower tendency to migrate than females. We, therefore, expect that periodic restocking of all-male juveniles will decrease the prevalence of schistosomiasis and increase villagers' welfare. In this interdisciplinary study, we examined current prawn abundance along the river basin, complemented with a retrospective questionnaire completed by local fishermen. We revealed the current absence of prawns upriver and thus demonstrated the need for restocking. Since male prawns are suggested to be preferable for bio-control, we laid the molecular foundation for production of all-male M. vollenhovenii through a complete sequencing of the insulin-like androgenic gland-encoding gene (IAG), which is responsible for sexual differentiation in crustaceans. We also conducted bioinformatics and immunohistochemistry analyses to demonstrate the similarity of this sequence to the IAG of another Macrobrachium species in which neo-females are produced and their progeny are 100% males. At least 100 million people at risk of schistosomiasis are residents of areas that experienced water management manipulations. Our suggested non-breeding sustainable model of control—if proven successful—could prevent re-infections and thus prove useful throughout the world.

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“…Today, public health campaigns in endemic regions in the tropics and subtropics focus on mass drug administration using the oral drug, praziquantel. While praziquantel has a high cure rate, re-exposure to infected snails in the environment leads to rapid reinfection of treated patients in endemic areas (Fenwick et al, 2006; Fenwick and Webster, 2006; King et al, 2006; Tchuem Tchuente et al, 2013; Webster et al, 2013). In addition to drug treatment, a complementary approach is to control the populations of snails that serve as intermediate hosts.…”

Section: Introductionmentioning

confidence: 99%

Regulation of laboratory populations of snails (Biomphalaria and Bulinus spp.) by river prawns, Macrobrachium spp. (Decapoda, Palaemonidae): Implications for control of schistosomiasis

2014

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Human schistosomiasis is a common parasitic disease endemic in many tropical and subtropical countries. One barrier to achieving long-term control of this disease has been re-infection of treated patients when they swim, bathe, or wade in surface fresh water infested with snails that harbor and release larval parasites. Because some snail species are obligate intermediate hosts of schistosome parasites, removing snails may reduce parasitic larvae in the water, reducing re-infection risk. Here, we evaluate the potential for snail control by predatory freshwater prawns, Macrobrachium rosenbergii and M. vollenhovenii, native to Asia and Africa, respectively. Both prawn species are high value, protein-rich human food commodities, suggesting their cultivation may be beneficial in resource-poor settings where few other disease control options exist. In a series of predation trials in laboratory aquaria, we found both species to be voracious predators of schistosome-susceptible snails, hatchlings, and eggs, even in the presence of alternative food, with sustained average consumption rates of 12% of their body weight per day. Prawns showed a weak preference for Bulinus truncatus over Biomphalaria glabrata snails. Consumption rates were highly predictable based on the ratio of prawn: snail body mass, suggesting satiation-limited predation. Even the smallest prawns tested (0.5–2g) caused snail recruitment failure, despite high snail fecundity. With the World Health Organization turning attention toward schistosomiasis elimination, native prawn cultivation may be a viable snail control strategy that offers a win-win for public health and economic development.

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Efficacy of praziquantel and reinfection patterns in single and mixed infection foci for intestinal and urogenital schistosomiasis in Cameroon

Cited by 63 publications

References 28 publications

Tools for diagnosis, monitoring and screening ofSchistosomainfections utilizing lateral-flow based assays and upconverting phosphor labels

Tools for diagnosis, monitoring and screening ofSchistosomainfections utilizing lateral-flow based assays and upconverting phosphor labels

The Prawn Macrobrachium vollenhovenii in the Senegal River Basin: Towards Sustainable Restocking of All-Male Populations for Biological Control of Schistosomiasis

Regulation of laboratory populations of snails (Biomphalaria and Bulinus spp.) by river prawns, Macrobrachium spp. (Decapoda, Palaemonidae): Implications for control of schistosomiasis

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