Preface

Chapter 6 **Spinal Cord Schistosomiasis 121**

**VI** Contents

**Section 3 Drugs and Vaccines 149**

Marques Allegretti

**Schistosomiasis 179**

Rashika El Ridi and Hatem Tallima

André Ricardo Ribas Freitas and Rodrigo Nogueira Angerami

Claudineide Nascimento Fernandes de Oliveira, Rosimeire Nunes de Oliveira, Tarsila Ferraz Frezza, Vera Lúcia Garcia Rehder and Silmara

Chapter 7 **Study on Schistosomiasis mansoni and Comorbidity with**

Maria José Conceição and José Rodrigues Coura

Chapter 9 **Solving the Riddle of the Lung-Stage Schistosomula Paved the Way to a Novel Remedy and an Efficacious Vaccine for**

**Hepatitis B and C Virus Infection 143**

Chapter 8 **Tegument of Schistosoma mansoni as a Therapeutic Target 151**

Schistosomiasis is a major public health problem in 76 countries of the developing world, yet information on prevalence and risk maps is incomplete, and often contradictory. To correct this caveat, Ricardo J.P.S. Guimarães et al. created a Geographic Information System (GIS) database, containing all social and socieconomic factors, and environmental variables, such as snail distribution, vegetation index, precipitation, temperature, and sanitation, at small communities and city levels in the Minas Gerais State, Brazil. The database was used together with multiple linear regressions to estimate the schistosomiasis positivity index, and build a schistosomiasis risk map for Minas Gerais State. The methodology used in this study can be utilized to control schistosomiasis in the areas with occurrence of the disease, and can also be used to take preventive measures to decrease or eradicate the disease transmission.

Akande and Odetola relied on community-based pilot control trials for obtaining correct and accurate estimates of schistosomiasis prevalence in Ethiopia, Tanzania, and Nigeria. Monday Francis Useh, in his chapter: Schistosomiasis, specifically reported that Schistosoma haematobium and Schistosoma mansoni infections have been widely detected in all parts of Nigeria although the former predominates. A total of 30 million Nigerians, 18% of 162 millions population, are infected with schistosomiasis, with the school age children carying the greatest burden of the disease. Of note, infection with S. haematobium was reported in all the regions in Nigeria with a prevalence as high as 60-75% among schoolchildren in some communities. N'Guessan Aya Nicaise proposed lasting solutions for fighting schistosomiasis in the Cote d'Ivoire, where urinary schistosomiasis, and soil-transmitted helminthiasis (especially hookworms), which infect > 50% of the population, prevail. The study was conducted in epidemiological context of large dam in Côte-d'Ivoire, in Taabovillage, a hyperendemic schistosomiasis locality located near Lake of the great dam Taabo, with prevalence of urinary schistosomiasis among school children reaching 94% at the start of the study. Awareness campaigns and treatments were carried out by the school teachers and Community health workers. Sociological surveys were made before treatment to understand risk behaviors. Nevertheless, slight reduction in prevalence to 74% was obtained, likely due to continuous transmission of the parasite. It was noteworthy that there was no enthusiasm for the treatment, for the simple reason that these parasites are considered by the majority of the population as non-serious illnesses and less dreadful.

The Chapters in the section "Clinical Schistosomiasis" are thus timely elaborating on the dangers not only of chronic, but also of acute schistosomiasis. According to Matheus Fernandes Costa-Silva et al., the clinical findings most commonly observed in acute schistosomiasis patients include fever, general weakness, headache, nausea, vomiting, diarrhea, anorexia, colic, weight loss, dry cough and hepatosplenomegaly accompanied by a marked eosinophilia and leucocytosis. Additionally, acute schistosomiasis is difficult to diagnose, as the clinical findings may be confounded with a number of infections such as visceral leishmaniasis, typhoid fever, malaria, tuberculosis, viral hepatitis, mononucleosis and bacterial infections. Chronic schistosomiasis mansoni and haematobium are certainly even more dangerous because of their deleterious effects on the liver, intestine, and/or urinary bladder, and additionally may involve the spinal cord, leading to neuroschistosomiasis, as documented by André Ricardo Ribas Freitas and Rodrigo Nogueira Angerami. The proportion of patients who go from schistosomiasis to medullar neuroschistosomiasis is unknown. There are several indications that this disease has been under-diagnosed, and difficult to diagnose. This situation has been changing in the last years, particularly in Brazil, due to the improvement in diagnostic tools and increase of cases in patients of of endemic countries. Finally, chronic infection with schistosomes increases the patient susceptibility to infection with viruses, namely hepatitis B and C viruses as reported by Maria Jose´Conceição and José Rodrigues Coura in the last Chapter of this section.

Accordingly, the Chapters included in the section "Drugs and Vaccines" are most welcome. Praziquantel is essentially the only drug commercially available and widely used for treatment of schistosomiasis mansoni, haematobium, and japonica. Claudineide Nascimento Fernandes de Oliveira et al. reviewed both the clinical plants that may display schistosomicidal activity and the schistosomes tegument structure, and found that fractions of plants belonging to the genus Phyllanthus L have powerful schistosomicidal effects via destruction of the tegument. The tegument lesions were thoroughly described using modified scanning and transmission electron microscopy techniques. In the last chapter of the book, Rashika El Ridi and Hatem Tallima proposed arachidonic acid as effective remedy against schistosomiasis mansoni and haematobium. The mechanism of action is likely the activation of parasite tegument associated neutral sphingomyelinase, hydrolysis of apical membrane sphingomyelin, and perturbations of the outer lipid bilayer, allowing access of host antibodies, destruction of the tegument, and eventual worm attrition. They further reported that several dogmas hinder the development of an effective vaccine, and provided rationale and evidence for the efficacy of a vaccine based on larval excretory-secretory products and Type 2 cytokines, such as interleukin-25 and 33, as adjuvants.

The chapters of this book are intended to provide useful information and strong initiative for researchers and clinicians in the field of schistosomiasis and other parasitic diseases.

At the end I wish to thank InTech, particularly Mrs. Ivona Lovric and Mr. Oliver Kurelic, for the opportunity to edit this interesting, important, and timely book, which I dedicate to the Martyrs of the Arab Spring Revolution, and to schistosome-infected children worldwide.

> **Rashika El Ridi** Zoology Department, Faculty of Science, Cairo University, Cairo, Egypt

**Epidemiology**

**Section 1**

**Section 1**
