**Epidemiology**

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

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

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

products and Type 2 cytokines, such as interleukin-25 and 33, as adjuvants.

this section.

VIII Preface

**Chapter 1**

**Multiple Regression for the Schistosomiasis Positivity**

Schistosomiasis, caused by *Schistosoma mansoni*, is an endemic disease conditional on the

In Brazil, there are eleven species and one subspecies of *Biomphalaria* genus mollusks that have been identified: *B. glabrata* (Say, 1818), *B. tenagophila* (Orbigny, 1835), *B. straminea* (Dunker, 1848), *B. peregrina* (Orbigny, 1835), *B. schrammi* (Crosse, 1864), *B. kuhniana* (Clessin, 1883), *B. intermedia* (Paraense & Deslandes 1962), *B. amazonica* (Paraense 1966), *B. oligoza* (Paraense 1974), *B. occidentalis* (Paraense 1981), *B. cousini* (Paraense, 1966) and *B. tenagophila*

In Minas Gerais state, the presence of seven species: *B. straminea*, *B. tenagophila*, *B. peregrina*, *B. schrammi*, *B. intermedia* and *B. occidentalis* was reported [1]. Among these, there are three *Biomphalaria* species (*B. glabrata*, *B. tenagophila* and *B. straminea*) that have been found to be naturally infected with *S. mansoni*. Other three species, *B. amazonica*, *B. peregrina* and *B. cous‐ ini*, were experimentally infected, being considered as potential hosts of this trematode [2-4]. *B. glabrata* is of great importance, due to its extensive geographic distribution, high infection indices and efficiency in the schistosomiasis transmission. In endemic areas, large concentra‐ tions of these snails, together with other risk factors, favor the existence of localities with

and reproduction in any medium, provided the original work is properly cited.

© 2013 Guimarães et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

**Index Estimates in the Minas Gerais State - Brazil at**

**Small Communities and Cities Levels**

Ricardo J.P.S. Guimarães, Corina C. Freitas, Luciano V. Dutra, Guilherme Oliveira and

Additional information is available at the end of the chapter

presence of snails of aquatic habits of the genus *Biomphalaria*.

Omar S. Carvalho

**1. Introduction**

http://dx.doi.org/10.5772/53500

*guaibensis* (Paraense 1984) [1].

high prevalence [5-7].
