Schistosomiasis Elimination Strategies and Potential Role of a Vaccine in Achieving Global Health Goals

Abstract

Abstract. In March 2013, the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation co-sponsored a meeting entitled "Schistosomiasis Elimination Strategy and Potential Role of a Vaccine in Achieving Global Health Goals" to discuss the potential role of schistosomiasis vaccines and other tools in the context of schistosomiasis control and elimination strategies. It was concluded that although schistosomiasis elimination in some focal areas may be achievable through current mass drug administration programs, global control and elimination will face several significant scientific and operational challenges, and will require an integrated approach with other, additional interventions. These challenges include vector (snail) control; environmental modification; water, sanitation, and hygiene; and other future innovative tools such as vaccines. Defining a clear product development plan that reflects a vaccine strategy as complementary to the existing control programs to combat different forms of schistosomiasis will be important to develop a vaccine effectively.

Efficacy and Safety of Arachidonic Acid for Treatment of Schistosoma mansoni-Infected Children in Menoufiya, Egypt

“…1 Work and recreational activities near fresh water bodies harboring infected snails allow exposure of the skin to the infective stage: the cercaria. On invasion of the epidermis, physiological and biochemical changes lead to transformation to the schistosomula stage characterized by replacement of the cercarial trilaminate membrane by a double lipid bilayer rich in cholesterol and sphingomyelin (SM).…”

“…Large numbers of eggs are retained in the tissues of the intestinal and urinary bladder walls and the liver and responsible for the disease's clinical manifestations by releasing egg antigens that provoke intense immunological reactions. [1][2][3][4] Praziquantel (PZQ) is currently the only drug of choice for treatment of schistosomiasis mansoni. A single oral dose of 40-60 mg/kg body weight consistently produces cure rates of 60-90%.…”

“…A single oral dose of 40-60 mg/kg body weight consistently produces cure rates of 60-90%. 1,3,[5][6][7][8] The side effects are relatively mild, involving essentially headache, dizziness, rashes, nausea, abdominal pain, and diarrhea, symptoms that could be easily explained by the propensity of PZQ to bind to actin. 9,10 Failure of cure after PZQ chemotherapy was consistently associated with high intensity of infection, [5][6][7][8] which required repeated treatments and accelerated the impending threat of schistosome resistance to the drug.…”

Schistosomiasis and the Pulmonary Vasculature (2013 Grover Conference Series)

“…8(p86) Biologically, individuals are susceptible to reinfection after adequate antihelminthic treatment, for reasons that are poorly understood. 10 There is some evidence of a gradual immunity that can develop over years of infection and treatment. However, this same lack of robust adaptive immunity has also substantially limited vaccine development, and no vaccine currently exists for schistosomiasis, although this is an area of active research.…”

Water-based interventions for schistosomiasis control

“…The schistosomulae migrate through several tissues and stages to their residence in the veins (8,9). Adult worms in humans reside in the mesenteric venules in various locations, which are specific for each species (10). For instance, S. japonicum is more frequently found in the superior mesenteric veins draining the small intestine A, and S. mansoni occurs more often in the superior mesenteric veins draining the large intestine B. S. haematobium most often occurs in the venous plexus of bladder C, but it can also be found in the genital tract or rectal venules.…”