Bioactivity of miltefosine against aquatic stages of Schistosoma mansoni, Schistosoma haematobium and their snail hosts, supported by scanning electron microscopy

<p>Abstract</p> <p>Background</p> <p>Miltefosine, which is the first oral drug licensed for the treatment of leishmaniasis, was recently reported to be a promising lead compound for the synthesis of novel antischistosomal derivatives with potent activity <it>in vivo </it>against different developmental stages of <it>Schistosoma mansoni</it>. In this paper an <it>in vitro </it>study was carried out to investigate whether it has a biocidal activity against the aquatic stages of <it>Schistosoma mansoni </it>and its snail intermediate host, <it>Biomphalaria alexandrina </it>, thus being also a molluscicide. Additionally, to see whether miltefosine can have a broad spectrum antischistosomal activity, a similar <it>in vitro </it>study was carried out on the adult stage of <it>Schistosoma haematobium</it>, the second major human species, its larval stages and snail intermediate host, <it>Bulinus truncutes</it>. This was checked by scanning electron microscopy.</p> <p>Results</p> <p>Miltefosine proved to have <it>in vitro </it>ovicidal, schistolarvicidal and lethal activity on adult worms of both <it>Schistosoma </it>species and has considerable molluscicidal activity on their snail hosts. Scanning electron microscopy revealed several morphological changes on the different stages of the parasite and on the soft body of the snail, which further strengthens the current evidence of miltefosine's activity. This is the first report of mollusicidal activity of miltefosine and its <it>in vitro </it>schistosomicidal activity against <it>S.haematobium</it>.</p> <p>Conclusions</p> <p>This study highlights miltefosine not only as a potential promising lead compound for the synthesis of novel broad spectrum schistosomicidal derivatives, but also for molluscicidals.</p

Strongyloidiasis in Oceania

Strongyloidiasis is a potentially fatal disease caused by species of Strongyloides (Nematoda). In Oceania, two species infect humans: S. stercoralis and S. kellyi. S. stercoralis is widespread throughout Oceania and causes serious disease in any age group. S. kellyi is localised to Papua New Guinea and causes serious disease in infants. Infective larvae enter the body through the skin and migrate through the tissues. Adult females live in the mucosa of the proximal small intestine. The life cycle of S. stercoralis includes autoinfection, unusual in parasitic worms, whereby some of the offspring of the parasitic adults become infective in the lower intestine and complete the life cycle in the same person. This ensures that the infection persists, and the population of the worms can increase out of control, usually when the person is immunodeficient or immunosuppressed. The worms can be eliminated by oral ivermectin, and the person is probably cured if their serology is negative 6 months after treatment. This chapter contains details of the life cycles, transmission, clinical manifestations, diagnostic tests and how to interpret them, most effective treatment options, how to ensure that treatment has been effective and what to consider when developing effective prevention and control strategies

Strongyloidiasis in Oceania

Strongyloidiasis is a potentially fatal disease caused by species of Strongyloides (Nematoda). In Oceania, two species infect humans: S. stercoralis and S. kellyi. S. stercoralis is widespread throughout Oceania and causes serious disease in any age group. S. kellyi is localised to Papua New Guinea and causes serious disease in infants. Infective larvae enter the body through the skin and migrate through the tissues. Adult females live in the mucosa of the proximal small intestine. The life cycle of S. stercoralis includes autoinfection, unusual in parasitic worms, whereby some of the offspring of the parasitic adults become infective in the lower intestine and complete the life cycle in the same person. This ensures that the infection persists, and the population of the worms can increase out of control, usually when the person is immunodefi cient or immunosuppressed. The worms can be eliminated by oral ivermectin, and the person is probably cured if their serology is negative 6 months after treatment. This chapter contains details of the life cycles, transmission, clinical manifestations, diagnostic tests and how to interpret them, most effective treatment options, how to ensure that treatment has been effective and what to consider when developing effective prevention and control strategies