Intestinal schistosomiasis and its possible prevention and control

Thesis Abstract

Intestinal schistosomiasis is a parasitic disease caused by the trematode Schistosoma mansoni. It is a major public health concern in many tropical and subtropical regions, particularly in sub-Saharan Africa, where it affects millions of people. The lifecycle of S. mansoni involves freshwater snails as intermediate hosts and humans as definitive hosts. Infection occurs when cercariae, the larval stage of the parasite, penetrate the skin of individuals in contact with contaminated water sources. The clinical manifestations of intestinal schistosomiasis can vary depending on the intensity and duration of infection. Common symptoms include abdominal pain, diarrhea, bloody stool, and hepatosplenomegaly. Chronic infections can lead to severe complications such as portal hypertension, liver fibrosis, and increased risk of hepatocellular carcinoma. The diagnosis of intestinal schistosomiasis is primarily based on the detection of S. mansoni eggs in stool samples using microscopy techniques. Prevention and control strategies for intestinal schistosomiasis primarily focus on interrupting the lifecycle of the parasite and reducing human exposure to contaminated water sources. Mass drug administration (MDA) with praziquantel, the recommended drug for treatment of schistosomiasis, is a key component of control programs. MDA aims to reduce the prevalence and intensity of infection in endemic communities, thereby decreasing the burden of disease. In addition to MDA, other preventive measures include improving access to safe water and sanitation facilities, promoting hygiene practices, and snail control interventions. These integrated approaches target both the human and environmental factors that contribute to the transmission of S. mansoni. Health education and community engagement are essential components of successful control programs, as they help raise awareness about the disease and promote sustainable behavioral changes. Despite the progress made in the control of intestinal schistosomiasis, challenges remain in achieving sustainable elimination of the disease. These challenges include limited access to treatment in remote and marginalized communities, inadequate surveillance systems, and the emergence of drug resistance. Addressing these challenges requires continued investment in research, capacity building, and collaboration among different sectors and stakeholders. Overall, the prevention and control of intestinal schistosomiasis require a comprehensive and multisectoral approach that integrates medical interventions with community engagement, environmental management, and sustainable development strategies. By implementing evidence-based interventions and addressing the underlying social determinants of the disease, it is possible to reduce the burden of intestinal schistosomiasis and improve the health and well-being of affected populations.