Neglected tropical diseases (NTDs) are a diverse group of tropical infections which are common in low-income populations in developing regions of Africa, Asia, and the Americas. They are caused by a variety of pathogens such as viruses, bacteria, protozoa and helminths. These diseases are ((common in 149 countries, affecting more than 1.4 billion people (including more than 500 million children) and costing developing economies billions of dollars every year. In addition to their impact on health, NTDs contribute to an immense social and economic burden resulting from social stigma, physical disabilities, disfigurement, blindness, discrimination, loss of social status, malnutrition, growth failure, and impaired cognitive development. Preventive chemotherapy, innovative and intensified disease management (IDM), effective vector control, the provision of safe drinking-water, basic sanitation and hygiene as well as involvement of veterinary public health will help with the prevention and control of neglected tropical diseases. Some challenges inherent in sustaining the drive to overcome the global impact of neglected tropical diseases include global economic constraints, lack of expertise in prevention and control of individual neglected tropical disease, hindrances to the availability of adequate quantities of essential medicines, lack of proper estimate of the actual cost of expanding implementation activities. To sustain the drive to overcome the global impact, it is essential to among others; prioritize prevention, control, elimination and eradication of neglected tropical diseases in national health, political and development agendas as well as sustain the development and updating of evidence-based norms, standards, policies, guidelines and strategies for prevention, control and elimination of neglected tropical diseases
TABLE OF CONTENTS
Title page i
Approval Page ii
CHAPTER ONE: INTRODUCTION 1
CHAPTER TWO: NEGLECTED TROPICAL DISEASE 2
2.1 Distribution 5
2.1.1 Lymphatic filariasis 5
2.1.2 Onchocerciasis 6
2.1.3 Schistosomiasis 6
2.2 Life Cycles and Modes of Infection 7
2.2.1 Life Cycle of Lymphatic filariasis 7
2.2.2 Life Cycle of Onchocerca volvulus 8
2.2.3 Life Cycle of Schistosomes 8
2.3 Symptoms 9
2.3.1 Symptoms of Lymphatic filariasis 9
2.3.2 Symptoms of Onchocerciasis 10
2.3.3 Symptoms of Schistosomiasis 10
2.4 Diagnosis 11
2.4.1 Diagnosis of Lymphatic filariasis 11
2.4.2 Diagnosis of Onchocerciasis 12
2.4.3 Diagnosis of Schistosomiasis 12
CHAPTER THREE: CHALLENGES MILITATING THE SUSTENANCE OF THE DRIVE TO OVERCOME THE GLOBAL IMPACT OF NTDs 13
3.1 Prevention, Treatment and Control 14
3.1.1 Prevention of NTDs 14
3.2 Control 18
3.2.1 Effective Vector Control 18
3.2.2 The Provision of safe Drinking-water, Basic Sanitation and Hygiene 18
3.2.3 Involvement of Veterinary Public Health 21
3.3 Treatment of Neglected Tropical diseases 22
3.3.1 Treatments for lymphatic filariasis 22
3.3.2Treatments for Onchocerciasis 23
3.3.2 Treatments for Schistosomiasis 24
3.2 Conclusion 24
Neglected tropical diseases (NTDs) are a group of bacterial, parasitic, viral, and fungal infections that are prevalent in many of the tropical and sub-tropical developing countries where poverty is rampant. According to a World Bank study, 51% of the population of sub-Saharan Africa, a major focus for NTDs, lives on less than US$1.25 per day, and 73% of the population lives on less than US$2 per day (Hotez and Kamath, 2009).
The World Health Organization (WHO) prioritizes 17 neglected tropical diseases (NTDs) that affect over a billion of the world’s poorest people and pose a significant economic burden to developing economies (scabies was just added to the list in June of 2014, bringing the count to 18). NTDs are a heterogeneous group of infections caused by parasites, viruses, and bacteria. What makes NTDs different from non-neglected diseases is that these diseases are disablers rather than killers. Indeed, these infections are co-endemic: an individual may be infected with more than one NTD in addition to other well-known diseases such as HIV, tuberculosis, and malaria. (Hotezet al., 2014)
For example, the parasite infection schistosomiasis can make women and girls more susceptible to HIV infection, saps micronutrients and iron from developing children to stunt their growth, and renders children less likely to attend school. A chronic helminth parasite infection known as lymphatic filariasis (LF) may reduce vaccine efficacy by broadly modulating the immune system. LF causes severe swelling (lymphedema) in 40 million people rendering them socially stigmatized and largely unable to work. In addition to schistosomiasis and LF, many more NTDs are characterized by chronic disabilities, increased susceptibility to infectious and non-infectious diseases, social stigma, and an economic burden on the individual, the family, and the country (World Health Organization. 2017).
In the 2010 Global Burden of Disease Study, NTDs accounted for 26.06 million disability-adjusted life years (DALYs) (95% confidence interval: 20.30, 35.12) (Hotez, 2014). In addition to their impact on health, NTDs contribute to an immense social and economic burden resulting from social stigma, physical disabilities, disfigurement, blindness, discrimination, loss of social status, malnutrition, growth failure, and impaired cognitive development. All of these interrelated outcomes perpetuate the cycle of poverty by preventing individuals from leading productive lives, and by adversely affecting families, communities, and countries as a whole. However, many of these diseases are preventable, and could be eliminated with improved sanitation, vector control, available treatments, and mass drug administration (MDA) campaigns.
The World Health Organization (WHO) classified NTDs into two groups: preventive chemotherapy and transmission control (PCT) NTDs, and innovative and intensified disease management (IDM) NTDs (World Health Organization, 2017). The most prominent examples of NTDs that have been allocated to the PCT group are lymphatic filariasis, onchocerciasis, schistosomiasis, and soil-transmitted helminthiasis; the main tool for their control is the periodic administration of efficacious, safe, and inexpensive (usually donated) drugs to entire at-risk populations. IDM, on the other hand, focuses on those NTDs that currently lack appropriate tools for large-scale use. These diseases include Buruli ulcer, Chagas disease, human African trypanosomiasis, and leishmaniasis (Rosenberg, Utzingerand Addiss, 2016).
Climate change and global warming are increasing the likelihood and spread of many vector-borne diseases, including malaria, dengue fever, Chagas disease, leishmaniasis, filariasis, onchocerciasis, schistosomiasis, and trypanosomiasis (Githekoet al., 2000). At the 70th World Health Assembly (WHA) held in Geneva, Switzerland in May 2017, a resolution was adopted on a Global Vector Control Response for 2017–2030 that aims to prevent, detect, report and respond to outbreaks of vector-borne diseases worldwide through an integrated, comprehensive approach (Alonso, 2017).
This seminar dwells on the epidemiology, health challenges, and global burden of major NTDs, and suggests public health measures.
This seminar reviews the distribution, lifecycles, symptoms, diagnosis, prevention, treatment and control of neglected tropical disease with emphasis on Lymphatic filariasis, Onchocerciasis and schistosomiasis.