Preface

Communicable diseases are prevalent worldwide. In sub-Saharan Africa, communicable diseases cause premature and preventable deaths. Their negative effects are often felt in these poor and inadequate resource settings. Effective implementation of environmental management coupled with community involvement and participation may reduce the burden of communicable diseases, including malaria. Application of simple control and preventable measures that are culturally acceptable, affordable, accessible, and achievable may be the mainstay of dealing with this public health problem in a sustainable manner. The positive effect of successful intervention may be manifested by the reduction of disease burden among women and children, more particularly children under five years of age who die in large numbers. More often than not it is the individual's responsibility to safeguard their own health in all aspects such as positive change in lifestyles, good healthseeking behavior, and where possible control of the environment, hence the effect of climate change.

It is the view of the authors that the readers of this text book will derive maximum benefits from it, use it as a reference manual in their workplaces, and share the knowledge with the communities they serve. It is evident that change is enacted from within the mindset of an individual, then transmitted to families, communities, and eventually nations, who will change thereby create an environment better for everybody.

The book focuses on different types of malaria, more especially *Plasmodium falciparum*, which is detrimental to communities and the cause of death among children, particularly the under-fives, as well as pregnant women, women, and men in general. Preferably, readers may use the book as a bedside reference manual, especially those working in malaria endemic areas, which may contribute to reducing human suffering and unnecessary death. Although the treatment of different forms of malaria, ranging from uncomplicated to complicated malaria, is outlined, users of the book should go beyond bedside medicine to the communities and deal with the root cause of the problem, which is the mainstay of malaria control and prevention. These interventions can facilitate the wellbeing of the communities in the affected countries, thereby economic improvement and meaningful development may be achieved. And we can all jointly acknowledge and accept that "this is our problem" as opposed to "it is their problem." This therefore can help us deal with malaria as a communicable disease.

**II**

**Chapter 8 145**

Commercial Mosquito Repellents and Their Safety Concerns *by Hanem Fathy Khater, Abdelfattah M. Selim, Galal A. Abouelella,* 

*Nour A. Abouelella, Kadarkarai Murugan, Nelissa P. Vaz* 

*and Marimuthu Govindarajan*

**Fyson H. Kasenga, PhD, MPH**

Deputy Vice Chancellor, Malawi Adventist University, Malamulo College of Health of Sciences, Makwasa, Malawi

**1**

**Chapter 1**

**Abstract**

**1. Introduction**

Origin of Two Most Virulent

Agents of Human Malaria:

*Plasmodium falciparum* and

Malaria is a protozoan disease caused by a parasite belonging to *Plasmodium*

**Keywords:** *Plasmodium*, nonhuman primate, human, Africa, origin, host switching

Malaria is a serious infectious disease. It is caused by parasites of the genus *Plasmodium* and transmitted by *Anopheles* mosquitoes to its vertebrate hosts. This disease is an important global health problem, especially in sub-Saharan Africa [1] (**Figure 1**). Indeed, the African region continues to carry a disproportionately high share of the global malaria burden [1, 2]. Among five *Plasmodium* species which infect human, two species *Plasmodium falciparum* and *Plasmodium vivax* pose the greatest threat for human health. For example, *P. falciparum* is the most prevalent malaria parasite on the African continent. It is responsible for most malaria-related deaths globally [3], while *P. vivax* is rare in sub-Saharan Africa, but it is the major

The origin of parasites responsible of human malaria has always been at the center of the debate [5, 6]. Understanding the origin of its infectious agents could open a door in the improvement of strategies to fight against the malaria agents which constantly surprise us by their abilities to adapt to the different means of fight put in place. So then, the questions are as follows: *Where do the pathogens* 

genus. Five species are known to infect humans: *Plasmodium falciparum, Plasmodium vivax, Plasmodium knowlesi, Plasmodium ovale*, *and Plasmodium malariae*. Among these species, *Plasmodium falciparum* and *Plasmodium vivax* account for more than 95% of all human malaria infections and thus pose a serious public health challenge. *Plasmodium falciparum* is highly prevalent in sub-Saharan Africa, while *Plasmodium vivax* is rare in sub-Saharan Africa but endemic in many parts of Asia. The recent studies using the development of molecular tools have shown that a large diversity of malaria parasites circulate among the nonhuman primates and certainly present a similarity with human parasites. For a long time, the question of the origin of its parasites that infect human population has been the subject of much debate. Today, it would seem that both most virulent agents of human malaria would come from African apes. Thus, this chapter tries to review

available data about the origin of these two *Plasmodium* species.

malaria parasite in most countries outside of sub-Saharan Africa [4].

*Plasmodium vivax*

*Boundenga Larson*
