Essentials for Practice of Medicine in the Frontline: From Tropical Africa; Pleasantly Different

By Dr. Inyang Ukot

Essentials for Practice of Medicine in the Frontline: From Tropical Africa; Pleasantly Different, Volume 1 of this two-volume unusual textbook of medicine is the product of a long-time yearning that I have had for authoring a multi-specialty textbook that goes straight to the point in addressing the need

• Language: English
• Publisher: Dr. Inyang Ukot
• Release date: Jan 28, 2023
• ISBN: 9781958518861

Dr. Inyang Ukot

Inyang Ukot is a Chief Consultant in Family Medicine. He is the Medical Director of RST Clinics Ltd., Uyo, Nigeria. Inyang is a 1981 alumnus of College of Medicine of the University of Lagos. He holds the Fellowship in Family Medicine of the National Postgraduate Medical College of Nigeria, 1991, and the West African College of Physicians, 1995. Between 1996 and 1999 he was on the Faculty Board in his specialty in the National Postgraduate Medical College of Nigeria where he has served as coordinator of training and examiner. He is also an examiner with the West African College of Physicians. He is the author of the following books: Medicine in the Frontline: 1000 MCQs and Answers with Comments (1996) A Companion to Medical Students and Doctors (2018) Our Hospitals: Making Things Work - Perspectives from a Developing Country (2021) MCQs for Medical Students and Doctors - 1200 Multiple-choice Questions and Answers with Comments (2022) Inyang is also an author of non-medical books. He is married and has four adult daughters and a granddaughter.

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ABOUT AUTHORS

Udeme Asibong

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Udeme Asibong is an Associate Professor in Family Medicine at the University of Calabar and an honorary Chief Consultant to the University of Calabar Teaching Hospital, Calabar, both in Nigeria. He is also the Medical Director of the Calabar Women and Children Hospital. Udeme is also the Research and Training Coordinator in Family Medicine, and an Examiner in Family Medicine with the West African College of Physicians. He was the Head, Department of Family Medicine at both the aforementioned University and its Teaching Hospital between 2014 and 2016.

Mayen Egbe

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Mayen Egbe (Nee´ Ecoma), MBBS, FRCP (UK), MSc., MMEd., PGDip., is a 1981 alumnus of College of Medicine of the University of Lagos, Nigeria, and a Fellow of the Royal College of Physicians of London. She is a Consultant Physician and Geriatrician with the National Health Service of the United Kingdom. She is also Director of Medical Education, Acute Adult Care Division, Bolton NHS Foundation Trust. Mayen works mainly in Internal Medicine, has subspecialty interests in care of older persons with multiple comorbidities and stroke medicine, and has an enduring passion for medical education. Her current research interests include predictive modeling of outcomes in clinical practice. She is married to Mark Egbe, and they have two adult children.

Saturday Etuk

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Professor Saturday Etuk graduated from the College of Medical Sciences of the University of Calabar with MB.BCh degree in 1985. He obtained the Fellowship of the West African College of Surgeons (FWACS) in 1995 and the Fellowship of the Medical College in Obstetrics and Gynecology (FMCOG) in 1997 with prizes as the best graduating fellow in these examinations. His Fellowship of the International College of Surgeons (FICS) came in 2002. He also obtained the Certificate of Good Clinical Practice (CGCP) from London School of Hygiene and Tropical Medicine in 2010 and Doctor of Medicine Degree (MD) from the National Postgraduate Medical College of Nigeria in 2020.

Professor Etuk has been Consultant Obstetrician and Gynecologist at the University of Calabar Teaching Hospital from 1996 till date. He became a Professor of Obstetrics and Gynecology in 2005. He has held multiple professional and academic positions in the above hospital and university culminating in Provost,

College of Medical Sciences of the University of Calabar. Prof. Etuk has been External Examiner to many Universities in Nigeria; Examiner to the West African College of Surgeons and also to the National Postgraduate Medical College of Nigeria.  He has been adjunct professor, sessional consultant and visiting professor to a couple of tertiary institutions in Nigeria.

Professor Etuk has been member Boards of Management of the following : a) Federal Neuropsychiatric Hospital, Calabar; b) Faculty of Obstetrics and Gynecology of the National Postgraduate Medical College of Nigeria; c) College of Medical Sciences and Teaching Hospital – both of University of Calabar; d) University of Calabar. He is currently a member of Council of the West African College of Surgeons. He holds the award of Distinguished Goodwill Ambassador of the University of Calabar..

Professor Etuk has 100 scientific publications in international and local journals with 6 book chapters to his credit. He is a Christian and is happily married to Professor (Mrs.) Imaobong S. Etuk and the marriage is blessed with four children.

Olubunmi Lapido

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Olubunmi LADIPO, Chief Consultant Obstetrician and Gynecologist, was formerly head of Obstetrics and Gynecology department and head of the IVF center of the National Hospital, Abuja, Nigeria. He has worked as a consultant in the hospital for over 20 years. He has been involved in training of medical students, resident doctors, and sub-specialty training of gynecologists. He graduated from the College of Medicine, University of Lagos in 1985, and has been practicing obstetrics and gynecology since 1988, first as a resident doctor in Obstetrics and Gynecology and later appointed a consultant in 1998. He is a Fellow of the West African College of Surgeons, Fellow of the International College of Surgeons, and a member of many professional associations.

Olusegun Ojo

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Dr. Olusegun Sylvester Ojo, MB; BS, FMCPath, is a Professor of Pathology at the Obafemi Awolowo University’s College of Health Science, Ife, Nigeria. Professor Ojo obtained his Bachelor of Medicine and Surgery from the College of Medicine of the University of Lagos in 1983 and undertook Postgraduate Training in Pathology, achieving the Fellowship of the National Postgraduate Medical College of Nigeria in 1989. Professor Ojo also has research interest in liver and digestive tract diseases.

Professor Olusegun Ojo was the pioneer Editor-in-Chief of the Annals of Tropical Pathology, the premier Journal of Pathology in Africa, until recently.

Among other duties, he continues to serve in a busy Surgical Pathology Service at Ife, where many undergraduate and postgraduate students are under his tutelage.

Obasi Onwuka Okorie

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Obasi Onwuka Okorie is a pediatrician with an avowed interest in pediatric endocrinology currently employed in the Department of Pediatrics at the West Cumberland Hospital, Whitehaven, Cumbria, UK. He had his undergraduate medical training at the College of Medical Sciences, University of Calabar, Calabar, Nigeria (2001). He has a postgraduate Pediatrics fellowship of the National Postgraduate Medical College of Nigeria (2017), and another Fellowship from the Pediatric Endocrinology Training Center for West Africa (2015), both situate in Lagos, Nigeria. He worked for four years as a pediatric endocrine specialist at the Endocrine and Diabetes Centre in Al Jouf, King Abdulaziz Specialist Hospital, Sakaka, Jouf, Saudi Arabia. He has over 15 years of practical experience in pediatrics both within and outside Nigeria and seeks to contribute to the growth of pediatric endocrinology in Nigeria and the African continent. He has five articles to his credit in both international and local peer-reviewed journals. He is happily married with two children.

Taiwo Sogunle

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Dr Taiwo Sogunle is a Chief Consultant and pioneer Head of Department of Family Medicine at Federal Medical Center, Abeokuta, Nigeria. He is the African representative on WONCA board on Ethics. He has been in active Family Medicine practice and postgraduate training since 1998. His academic qualifications include Fellowship of the West African College of Physicians in Family Medicine, Diploma in Family Medicine, MMed Family Medicine, MSc Clinical Epidemiology, PhD Medicine (option in Family Medicine). He is an examiner at the fellowship examinations of the West African College of Physicians and National Postgraduate Medical College of Nigeria. He has 22 publications in both local and international peer-reviewed journals. He is on the editorial board of three scientific journals.

Emilia Udofia

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Dr. Emilia Udofia has over 20 years of medical practice and nearly 17 years of research experience. She possesses a Bachelor degree in Medicine and Surgery (M.B.B.S) from the University of Nigeria, Nsukka, Nigeria, a Masters degree in Public Health (MPH) from the University of Lagos, Nigeria, and a PhD from the University of Ghana. She is a Fellow of the West African College of Physicians (Community Health) and a Fellow of the National Postgraduate Medical College of Nigeria (Public Health). Dr. Udofia is a University of Michigan African Presidential Scholar (2012–2013 cohort) and a member of the American Public Health Association. She is a Senior Lecturer at the Department of Community Health, University of Ghana Medical School, Korle Bu.

Owoidoho Udofia

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Professor Owoidoho Udofia is a seasoned psychiatrist with over 40 years of clinical experience and several publications in national and international journals. He is a past Registrar of the National Postgraduate Medical College of Nigeria. He has taught medical students and resident doctors in internal medicine, family medicine and psychiatry for over three decades. He served in numerous positions which include former Faculty Chairman and Chief Examiner (Psychiatry) in the National Postgraduate Medical College of Nigeria, former President of the Association of Psychiatrists in Nigeria, and represents Central and West Africa on the board of the World Psychiatric Association (WPA). Happily married, he is blessed with a few sons and holds a Black Belt in the Martial Arts of Taekwondo.

Inyang Ukot

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Inyang Ukot is a Chief Consultant in Family Medicine. He is the Medical Director of RST Clinics Ltd., Uyo, Nigeria. Inyang is a 1981 alumnus of College of Medicine of the University of Lagos. He holds the Fellowship in Family Medicine of the National Postgraduate Medical College of Nigeria, 1991, and the West African College of Physicians, 1995. Between 1996 and 1999 he was on the Faculty Board in his specialty in the National Postgraduate Medical College of Nigeria where he has served as coordinator of training and examiner. He is also an examiner with the West African College of Physicians. He is the author of the following books: a) Medicine in the Frontline: 1000 MCQs and Answers with Comments (1996); b) A Companion to Medical Students and Doctors (2018); c) Our Hospitals: Making Things Work – Perspectives from a Developing Country (2021); and d) MCQs for Medical Students and Doctors – 1200 Multiple-choice Questions and Answers with Comments (2022).

DEDICATION

This book is dedicated to all medical students and practicing

doctors who, like me, have always wished to have their lives

simplified with material that they could readily find guidance

in abridged presentation and compressed format.

Inyang Ukot

ACKNOWLEDGMENTS

I acknowledge both the divine and the human.

With respect to God my acknowledgment is principally because of keeping me alive and in good health to achieve this dream eventually.

As far as the human is concerned my gratitude goes to two sets of people:

Family: Sarah Ukot, my wife. She has been amazing. She kept me company during the approximately 24 months in the making of this book. This is apart from the years of also encouraging me with other medical book projects and the non-medical books – the latter are already on Amazon, etc. My daughters Grace, Elor, Sarah Jr., and Joy need special mention; this is because this book project (and previous ones) have almost made them suffer relegation. I pray that the time will soon come that I shall be as available as my family deserves.

Colleagues: I hereby express my gratitude to the colleagues who, in spite of their choked-up schedules, agreed to join me in executing this onerous and unusual project. They are the ones who weathered the storm to the end by graciously enduring my critique of each chapter of their submissions. I really congratulate them because others who originally accepted could not withstand the challenges and had to give up.

Inyang Ukot

INTRODUCTION

Essentials for Practice of Medicine in the Frontline is a paradigm shift. It is so, principally because every physician and medical student knows that textbooks of medicine usually concentrate on the major specialties e.g. Medicine, Surgery, Pediatrics, Obstetrics and gynecology, Public health, Family medicine, etc. Others concentrate on sub-specialties in these broad specialties, providing us with standard textbooks in Cardiology, Neurology, Dermatology, Otorhinolaryngology, Ophthalmology, Urology, Pediatric cardiology, Tropical medicine, Parasitology, and countless others. To produce Essentials for Practice of Medicine in the Frontline is, indeed, a bold attempt at the unusual.

This book is far from being comprehensive – it includes much less than it excludes. It is a book that covers only the essentials for practicing medicine in the frontline confidently. And what is the frontline, in this context? It should be seen as the frontier of practice whereby the physician is the first doctor to attend to patients who present with all manner of ailments. Medical practitioners in the frontline are, therefore, doctors who render services to clients who present with cases that are not only unpredictable but also common and various in nature.

Any humble doctor who has found themselves in this circumstance will acknowledge that the work exposes them to peculiarities which include the following: (a) They have no clear idea of the type of actual cases they would encounter in any day of work; (b) They frequently attend to many patients on an average day at work, and are prone to making errors due to limited time for clerking, examination, etc.; (c) Even if they are specialists, and they are exposed to such situations for one reason or another, they find themselves attending to or giving advice on cases that are outside their areas of specialization; (d) Depending on the part of the world they work in, or find themselves having to work in because of circumstances beyond their control, they may not be able to carry with them all the books they know could cover the clinical cases they reasonably expect to attend to during medical mission work to foreign countries, medical rescue or support work during disasters that accompany social disruptions, etc.

Doctors who practice in countries that are classified as advanced economies know that some clinical conditions in medicine are ones that they have only heard of, or had direct exposure in management only infrequently or many years prior. These doctors know that the world is a global village.

Because of the large number of travelers, and high rate of international travel for all sorts of reasons, no doctor should consider themselves cut out for only certain cases – even when they work in reference centers. There are the usual diseases as well as emerging and re-emerging disease conditions. While it is good to make allowance for emerging clinical entities, the re-emerging ones could be an embarrassment, if a doctor encounters them and does not have a reliable book to readily refer to – and those conditions may deserve only little space in recent editions of standard medical textbooks. Such an encounter can be as a result of the doctor traveling to another location on the globe, while in-flight, and sometimes as a result of the patient traveling from a completely different practice zone, medically, to meet the doctor who practices in the patient’s destination. Whatever be the scenario, a single book that covers essentials of conditions that are common for some doctors, yet uncommon (or even unusual) for others, should be a welcome addition to the plethora of books on medicine.

This book does not (because it cannot) cover every pertinent area of practice of medicine. It does not even cover all major specialties. What the editor did was to select well-grounded specialists in a few areas of medicine and create 10 sections that cover 10 chapters each. This book, therefore, is a compilation of 100 titles on topics that would find relevance in any area of the world, as long as the physician is the doctor of first contact. The areas selected include: Internal medicine, Public health, Pediatrics, Family medicine, Obstetrics and gynecology, Pathology and two miscellaneous sections on sundry topics with one emphasizing photographs, short comments, and clinical scenarios. Each of the major sections has multiple-choice questions that enable the reader to self-test. Each of the questions has answers, and some of them that deserve explanations have short comments also; the answers appear toward the tail end of the book.

This unique book was designed to be different from most medical textbooks and most of the chapters do not have the number of references that medical textbooks have. The co-authors were required to write in a simple format to meet the needs of everybody, for the target audience for this book ranges from first-year clinical students up to retired medical practitioners who still want to read on certain topics. The main audience remains the doctor who is described in earlier paragraphs of this Introduction. Each section of the book has a different character; this is because the editor allowed the co-authors to write using their individual styles. This has yielded the anticipated variety in flair for this publication. The editor and co-authors desire that the reader should be able to carry one or both volumes of this book around; they certainly wish that, for once, a medical student, or practicing doctor can read a book in a relaxed atmosphere, like when lying on the bed; that is why this book comes as flat 8.5 x 11 volumes with each volume just about 500 pages.

You are welcome to Essentials for Practice of Medicine in the Frontline.

Inyang Ukot

PREFACE

If, as a practicing physician or a medical student, you were asked to identify about one hundred topics that represent the conditions that most doctors would encounter in most of their patients most of the time in most out-patient and in-patient settings, what would you choose?

From my first year in the medical school in Nigeria in the mid-1970s I noticed that neither I nor some of my classmates could afford all the books that we needed to buy and read. This went on to the final year. This situation may, or may not, apply till today in developing countries. Many medical students do not come from wealthy backgrounds – they just happen to be intelligent young people who have the desire to make impact on other people’s lives using the medical profession as a vehicle.

When I eventually started medical practice, still in a developing country setting, I had the opportunity of working in one of the busiest hospitals in the southern part of my country; it was run by missionaries. In the second year, which is devoted to national service by every graduate of a tertiary institution, I was exposed to a secondary care hospital in the northern part of the same country. These first two years of practice opened my eyes to two realities: a young doctor could work in a hospital and get so inundated with work that though books are available in the library, there is virtually no time to identify the particular book of interest and when the book is found, to identify that small or particular point of interest at the time; the second reality is that a doctor may not be able to move with heavy books from place to place, especially if the journey is by air.

During residency, which was in general medical practice (now family medicine) things became worse. The books we needed were either unaffordable or unavailable. Things got so bad that the leadership of the young specialty had to obtain a book parcel consisting of a set of essential books which the post-graduate trainee doctor gladly paid for.

The above, and more, created a longing in me to write an atypical book. It was difficult to attempt this project because medical books have their peculiarity which is not limited to a combination of bulk, detailed presentation, and restriction of contents to specialty. I was too young to endeavor something unusual and could not convince anyone of, or enlist anybody into, a project that could be roundly criticized by experienced doctors in the academia. This became worse as I made a detour from the academic field many years ago.

I actually started writing a miscellaneous book the year after my fellowship; five years later, in 1996, Medicine in the frontline – 1000 multiple-choice questions and answers (with comments) was published. This book covered many areas, was of an acceptable size, and many readers accepted it. A companion to medical students and doctors followed in 2018.

It is a thing of personal satisfaction and joy that I was able to convince and enlist colleagues who are experienced specialists in their various fields and work in diverse practice settings. Essentials for practice of medicine in the frontline is a dream of many years come true. It consists of ten chapters in every section. To meet my original desire of making the book light enough for ease of carrying around and also make it affordable, it is in two volumes.

Inyang Ukot

SECTION 1

PUBLIC HEALTH

INTRODUCTION

This section highlights ten topics of public health importance. In the first chapter, climate change is discussed in terms of relevant terms, global limits, key concepts of global warming and greenhouse effect, greenhouse gases, health effects and evidence for the effects of climate change. Notable points are morbidity associated with climate change and key points for clinicians. The second chapter focuses on zoonoses and health and describes a one health approach to zoonoses, ante-mortem and post-mortem inspection of animals as a control measure and discusses specific zoonoses including yellow fever, plague, rabies, brucellosis, zoonotic tuberculosis, Ebola hemorrhagic fever, toxoplasmosis and anthrax. For each disease, the etiology, clinical features, diagnosis, management, and prevention are discussed briefly. The third chapter addresses food markets and health based on the WHO healthy food markets initiative. It describes the environment of the food market, potential hazards and foodborne pathogens commonly encountered in the tropics. The fourth chapter opens with approaches to school health services, components of the whole community, whole child conceptual model and describes the characteristics of green schools. School health services are described by components and requirements and ends with examples of indicators to assess service provision.

Housing and health are the focus of the fifth chapter which addresses common terms used in housing, types of houses, and characteristics of slums. The principles of healthy housing are discussed in relation to satisfaction of physiological and psychosocial needs, and protection against accidents and communicable diseases. Hazards associated with sub-standard housing are outlined and briefly discussed with supporting evidence. The sixth chapter focuses on water and health and begins with global targets, availability, uses, physiological requirements, sources, and later outlines properties of a sanitary well, water quality, parameters of assessment, and diseases associated with water. The chapter concludes with a brief discussion of potential contaminants such as metals, pharmaceuticals, polyaromatic hydrocarbons, and potential health outcomes. The seventh chapter focuses on liquid waste and health and opens with the global challenge of liquid waste disposal, and follows with a discussion of sanitation, methods of excreta disposal, sewage treatment, and common occupational hazards associated with liquid waste management.

Solid waste management and health is the subject of the eighth chapter which details sources of solid waste, activities of waste management, groups at risk, potential hazards associated with occupational exposure, and human pathogens associated with solid waste. The ninth chapter addresses medical waste management, focusing on solids. Detailed within the chapter is the classification of solid medical waste, characteristics and preferred treatment options, sources, waste management activities and standards, and hazards associated with solid medical waste. The final chapter addresses noise and health in which sources of noise, auditory and non-auditory effects of noise, risk groups, and preventive measures are discussed in brief.

The pictures used in the chapters are the output of student field trips at the University of Ghana, while some others were taken personally during the early phase of this work. Other sources are duly referenced. It is hoped that these photographs will enrich your journey through each chapter. Finally, these chapters provide highlights mostly from a developing country perspective but readily find application anywhere. Notably, public health is a rapidly-evolving discipline and readers are encouraged to keep this in mind as they navigate each page.

CHAPTER 1

CLIMATE CHANGE AND HEALTH

Emilia Udofia

Definitions

Weather refers to the state of the atmosphere at a given time in a specific location. It is often experienced as changes in temperature, humidity, precipitation, cloudiness, and wind (Uejio, Tamerius, Wertz, Konchar, 2015). Weather patterns tend to vary according to the latitude, proximity to seas and oceans, and terrain types e.g. mountains. On the other hand, climate has been defined as the long-term average weather pattern for a place or region, usually obtained over a range of thirty to fifty years (Uejio, Tamerius, Wertz, Konchar, 2015). When there is a natural variation in climate spanning decades or longer, this is referred to as climate variability. Climate change is a systematic change in the long-term conditions of climate spanning multiples of decades and longer (Rudolph, Harrison, Buckley & North, 2018). Climate change can result from natural and anthropogenic activities, or only the latter.

Global limits set for climate change

Between the 1950s and the present, significant changes have occurred outside the natural variability in weather patterns. For instance, global temperatures have risen by 0.9oC (Barrett, Charles, Temte, 2015). The agreed UN target is to keep temperatures well below 2oC (International Energy Agency, 2015). This is expected to prevent the catastrophic consequences to life on earth should greenhouse gas emissions continue unabated. Consequently, policies have focused on limiting warming effects to this limit (Ramanathan and Xu, 2010). The need to reduce emission of greenhouse gases lies in its potential impacts: anticipated rises may accelerate extinction of animal and plant species with nearly 3 species disappearing each hour and a third of all vertebrates disappearing in less than 50 years (Barrett et al., 2015). Above 2oC, ice glaciers have been projected to cause a rise in sea levels by 200–600cm by 2100 (IPC Working Group 1, 2014). In order to remain below a limit of 1.5oC, the total global emissions should not exceed 240,000 billion tons of carbon (Rudolph et al., 2018). Current predictions indicate that burning coal, oil, and gas reserves would produce 2800 gigatons, potentially producing rises in temperature between 3oC and 6oC, thus intensifying atmospheric and ocean impacts (Barret et al., 2015).

Global warming and Greenhouse effect

Studies indicate that humans have contributed significantly to global warming, which has in turn increased global temperature in the past 50 years. Global warming describes the phenomenon of the earth’s surface heating up. Gases such as water vapor, carbon dioxide, nitrous oxide, and methane, which are also known as greenhouse gases, trap heat and light from the sun, and increase earth surface temperatures. This ability of greenhouse gases to capture solar energy and increase average temperatures on earth is referred to as the greenhouse effect. Reports of greenhouse gas emissions contributing to global warming and climate change date back to the 1970s (Benton 1970; Gast 1971). With increased warming of the earth’s surface and atmosphere, increased evaporation, humidity, and average rainfall occur in some places. Drought might also occur in extreme heat conditions. It has been reported that at the recent climate summit for local leaders held in Paris during COP21, 440 mayors and sub-national level leaders pledged to reduce greenhouse gas emissions significantly by 2030 (ISOCARP 2018; Choudhury et al., 2019).

Typically, solar energy radiates to the earth and a fraction of it radiates from the earth’s surface back into space. This fraction which radiates back into space keeps the earth at a relatively constant temperature by preventing accumulation of energy on the earth. The rest of this energy is absorbed in the atmosphere, oceans and other water bodies, and land surfaces. The natural greenhouse effect is considered beneficial as it ensures favorable conditions for existence. However, human activities have increased the concentrations of carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and other fluorinated gases. These have an increased warming effect.

Greenhouse gases

Carbon dioxide

Every living human and animal exhales carbon dioxide, which is absorbed from the atmosphere through the process of plant photosynthesis. Carbon dioxide is also emitted during volcanic eruptions and is involved in interactions between the water bodies and the atmosphere. The discharge of carbon dioxide from human activities such as combustion of fossil fuels, industrial activities, and transportation contributes more than 80% of carbon dioxide released into the atmosphere (Rudolph, Harrison, Buckley, & North, 2018). Activities such as deforestation contribute to increased concentrations of carbon dioxide in the atmosphere as they remove trees; trees are useful in absorbing carbon dioxide from the atmosphere.

Methane

Methane is generated by organic decomposition and use of fossil fuels. It is removed naturally in soil and chemical reactions. Activities involving organic decomposition include decay of food waste in landfills, creation of manure from animal husbandry, and compost from night soil. Since it has a short half-life, its effects are likely to be felt earlier, compared to carbon dioxide.

Nitrous oxide

Nitrous oxide is a by-product of denitrification. Denitrification is one of the processes in the nitrogen cycle where bacteria living in nearly oxygen-free areas close to the water table reduce nitrates in soil to gaseous nitrogen. Gaseous nitrogen is returned to the atmosphere, where it interacts with water vapor to form nitrous oxide. Its removal from the atmosphere occurs by bacterial action or decomposition by ultraviolet radiation. Emissions are found in agriculture through the use of fertilizers or compost used as soil conditioners. Waste management and combustion of fossil fuels are other known sources.

Fluorinated gases

Fluorinated gases have been used as refrigerants in air-conditioning systems for vehicles and buildings. Hydrofluorocarbons (HFC) are potent greenhouse gases. Perfluorocarbons are by-products of aluminum production industry and sulfur hexafluoride is produced during transmission of electricity.

Global warming potential (GWP) is the ability of each greenhouse gas to absorb energy emitted from the earth’s surface and atmosphere. Therefore, gases with a higher GWP absorb more energy and contribute to global warming. Carbon dioxide is used as the standard with a GWP of 1 and others are compared with it: methane (21), nitrous oxide (300) and HFCs (140 to 11,700) (Environmental Protection Agency 2013).

Health effects of climate change

The projected health effects (Costello et al., 2009) discussed six categories of effects which exhibit some degree of overlap. They include: (i) Changing disease patterns, (ii) food insecurity, (iii) water and sanitation, (iv) shelter and human settlements, (v) extreme weather events, (vi) migration. Examples are found in Table 1 below.

Evidence for effects of climate change on health

Food security

The annual number of food emergencies is reported to have risen from 15 per year in the 1980s to 30 per year by 2009 (Schneider & Garrett as cited in Barret et al., 2015). Food insecurity affects 1 in 7 of the global population and more than a billion people suffer malnutrition per day (Barret et al., 2015). Studies conducted by the International Food Policy Research Institute project increases in food prices due to climate change. For instance, in Ghana the projected increase in the price of rice is expected to double due to climate change (from 60% to 121%) (Kankam-Yeboah, Amisigo and Obuobi, 2011). Such increases when transferred to consumers can limit the purchasing ability of households in low- and middle-income settings. Drought and floods have adversely affected crop yields further decreasing availability and quantity of alternative staples.

Mortality

The 2003 heat wave in Europe was reported to have accounted for 60,000 deaths (Filleul et al., 2006; Analitis et al., 2013; Orru et al., 2013 as cited in Barret et al., 2015). Persons with mental illness have triple risk of mortality in a heat wave (Rudolph, Harrison, Buckley, & North, 2018). Death, suicide, violence, aggression, and increased hospitalization of persons with psychiatric conditions have been noted with extreme heat (Rudolph et al., 2018). Heat waves tend to increase the severity of drought. This increases the intensity of wild fires; wild fires release toxic air pollutants which affect respiratory health adversely (IPCC, 2014). Drought-related deaths account for 59% of total deaths due to extreme weather events and Africa is home to more drought disasters and mortality than elsewhere (Kallis, 2008). In West Africa, heavy precipitation led to mudslides in Sierra Leone contributing to the submergence of over 300 houses along River Juba. It left 5905 people displaced and 1141 were reported dead or missing (World Bank, 2017; Musoke, Chimbaru, Jambai et al., 2019). This event called for an emergency response, including the surveillance of waterborne diseases from healthcare facilities in the affected areas, and administration of the cholera vaccine to high-risk groups to prevent cholera outbreak (Musoke, Chimbaru, Jambai et al., 2019).

Flood which occurred in Ghana in 2007 was reported to have affected the lives of 332,600 people and led to 56 deaths in the Upper East, Upper West, Northern, and Western regions of the country. Studies conducted at the Council for Scientific and Industrial Research – Water Research Institute indicate that even without climate change considerations, Ghana is predicted to become a water-stressed country by 2025 (Kankam-Yeboah, Amisigo and Obuobi, 2011). Floods also account for a significant proportion of vehicle-related fatalities as reported in Greece (Salvati, Petrucci, Rosi et al., 2018). Overall, floods account for 40–50% of all disasters and disaster-related deaths globally (Du, Fitzgerals, Clark & Hou, 2010). Low-income countries are worst hit as demonstrated by the ratio of deaths when compared to high income-countries, 23:1. Mortality rates tend to increase up to 50% in the first year after flood has occurred (Alderman, Turner & Tong, 2012).

Waterborne diseases

Flooding has been associated with waterborne disease outbreaks in Finland (Miettinen et al., 2001) and Sweden (Ebi, 2006). Hospitalizations from gastroenteritis in Spain were significantly related to hot temperature (Morral-Puigmal, Martinez-Solanas, Villanueva and Basagana, 2018). Vibrios abound in warm coastal waters, where their growth depends on temperature and salinity. In tropical areas where the daytime temperature exceeds 15oC, the growth of the organism is enhanced. Therefore, warm temperatures promote the growth of Vibrios which are mostly concentrated in shellfish. Eating raw or inadequately-cooked seafood could result in transmission and disease outbreaks. In Puerto Rico, one study demonstrated that gastrointestinal illnesses spike after rain events. (Crespo, Wu, Myer & Fulford, 2019).

Water-based diseases

During floods people may have to wade through dirty water to have access to their homes. This action may predispose them to eggs of Schistosoma in areas where the disease is prevalent, snail hosts are present, and improved latrines are lacking. Eggs of Schistosoma hatch in water liberating larval forms called miracidia. The miracidia penetrate the snail hosts, undergo asexual reproduction, and emerge as cercaria – the infective form. Cercaria penetrate human skin, develop into adult forms which cause damage to the vesical plexus or mesenteric veins where they are shed in urine or feces respectively, depending on the species. It is the penetration by cercaria which places humans at risk when they pass through flood waters.

Vector-borne diseases

Temperatures 4oC to 6oC higher than ambient air temperatures have been demonstrated to promote higher larval development and population growth rates of mosquitoes under laboratory conditions. Thresholds for survival of Plasmodium falciparum, the predominant species in West Africa, has been reported to have a minimum temperature threshold for survival of 18oC. This favors the spread of malaria in addition to host and other environmental characteristics (Dasgupta, 2018). Therefore, malaria can be expected to increase as previously colder climates become warmer and hotter climates remain so for extended periods, due to global warming effects. Warm temperature accelerates replication of viruses in vectors and prolongs breeding seasons. Examples of other diseases include dengue, West Nile fever, and onchocerciasis (Semenza, 2015).

Respiratory diseases

Cerebrospinal meningitis caused by Neisseria meningitidis is important due to its potential to occur in epidemic proportions. It has been associated with climatic conditions including dry winds, dust storms, low humidity, and cold nights which impair the local immunity of the pharynx (Codjoe and Nabie, 2014). The meningitis belt is extending southward. Countries affected by outbreaks include Burkina Faso, Chad, Ethiopia, and Niger.

In 2002, it spread in villages and refugee camps in East Africa causing 2200 cases, including 200 deaths (WHO, 2005). In Ghana, as in most countries in the West African Region, it tends to peak at the harmattan season (December–January) and decline around April. In temperate regions, the seasons for allergies and asthma have become longer and more intense. Additionally, temperature, humidity, and rainfall affect the concentration of air pollutants (particulates, ozone, and aeroallergens) which, in turn, negatively affect respiratory health (Tong and Ebi, 2019).

Foodborne diseases

A break in the cold chain in food processing industry can promote the growth of Staphylococcus aureus, Clostridium perfringens, and Listeria. Elevated temperatures encourage multiplication of organisms which cause food spoilage. A recent study conducted in South Korea indicated that the combination of temperature, relative humidity, insolation, precipitation, and cloudiness are associated with monthly incidence of hospitalizations due to salmonellosis, enterohemorrhagic Escherichia coli O157:H7 and vibriosis. These climatic factors accounted for 54% to 58% of the variation in incidence (Park et al., 2018). In particular, a strong correlation between temperature (and relative humidity) and foodborne diseases including Escherichia coli, Vibrio parahaemolyticus, Campylobacter jejuni, Salmonella spp., and Bacillus cereus has been demonstrated (Kim et al., 2015).

Wind speed during a storm event was reported to be positively associated with density changes in Vibrio spp. (Shaw et al., 2014), and in South Korea wind speed was negatively associated with the incidences of salmonellosis, vibrioses and Campylobacterioses (Park et al., 2018). The consumption of crops in lands inundated by floods and contaminated by feces (where open defecation exists) or wastewater can also predispose individuals to foodborne diseases (Alderman, Turner & Tong, 2012).

Malnutrition

Periods of drought affect food crop harvest and market supplies. These result in increases in food prices and limit household food security. Poorer households are at most risk as they are unable to afford prices of food and may resort to less nutritious alternatives. Poor intake, nutrient deficiencies, and comorbidity singly, but more often in combination, result in undernutrition in these households. Flood-related destruction of crops can worsen existing malnutrition by reducing availability of foods and intake. A longitudinal study conducted in Bangladesh following the 1998 floods showed that children in households affected by floods were smaller than those that were not affected (del Ninno and Lundberg, 2005).

Rashes

Rashes have been reported as a common post-flood complaint. For instance, 40% of workers repairing buildings damaged by floods following Hurricane Katrina were confirmed to have skin rashes. It was suggested that mites associated with flood-impacted buildings may have played a role (Noe et al., 2007).

Leptospirosis

This an acute febrile illness resulting from contact with the urine of infected rodents. It tends to occur in areas of poor drainage and dense population (Alderman, Turner & Tong, 2012). In Argentina, most of the incident cases from 1999 to 2005 tended to occur during the rains; contact with contaminated water increased the risk of infection four-fold (Vanasco, Schmeling, Lottersberger et al., 2008). The causative agent is found in urine, placental tissue, and amniotic fluid of infected rodents or other animal reservoirs (swine, cattle, dogs). Contamination of moist soil and water makes leptospires remain viable for weeks or months at favorable temperatures (28°C–32°C) (Heymann & APHA, 2015). Transmission is through contact with skin or mucous membranes while wading in flood waters. Table 2 outlines physical hazards, morbidity, and notable points for physicians.

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CHAPTER 2

ZOONOSES AND HEALTH

Emilia Udofia

Zoonoses refer to infectious diseases which are transmitted from vertebrate animals to humans under natural conditions. More than 200 diseases in this category are caused by microbial organisms including prions, bacteria, viruses, protozoa, fungi, and helminths. As has been reported, nearly 80% of viruses, 50% of bacteria, 40% of fungi, 70% of protozoa, and 95% of helminths that infect humans are zoonotic (Morse, Mazet, Woolhouse et al., 2012). Pathogens shared with animal hosts have been reported to cause more than 60% of infectious diseases in humans (Karesh, Dobson, Lloyd-Smith et al., 2012). Wars, natural disasters, and overpopulation are conditions that have led to the displacement of people into conditions that are favorable for transmission. Transmission of pathogens to humans is often a product of human-animal-environment interactions (Karesh, Dobson, Lloyd-Smith et al., 2012). Additionally, certain occupations or hobbies (by entomologists, farmers, uniformed service men, veterinarians, tanners, campers or hikers) and research may expose people to reservoirs of infection.

Informal, unplanned settlements situated in close proximity to refuse dumps may result in humans becoming accidental hosts in the life cycles of parasites and victims of stray animals. Alterations to the environment such as creation of artificial lakes, waste stabilization ponds, and irrigation systems may offer breeding sites for mosquitoes, especially in warm temperatures enhanced by climate change. Importation, breeding, and slaughter of infected animals may lead to zoonoses, especially where they escape veterinary inspection and border control of imported food items. Preparation and consumption of wild animals, handling of infected animals, changes in land use and increase in trade and travel are other factors contributing to transmission of zoonoses (Karesh, Dobson, Lloyd-Smith et al., 2012; Kilpatrick and Randolph, 2012).

To prevent zoonoses, veterinary officers take steps to conduct an antemortem inspection of animals for slaughter. The animals are observed in motion and at rest in the lairage and examined 24 hours before slaughter. The following are examined: respiration, gait, posture, behavior, anatomical structure, color, odor, and abnormal discharges from orifices (Herenda, Chambers, Ettriqui, Seneviratna & da Silva, 2002). Animals found to exhibit abnormal features and behavior may be separated from the herd as suspect and managed as per protocol. In cases of highly infectious diseases, the herd may be culled. Healthy animals are declared fit for slaughter.

The animals are shot, bled, and singed using a gas gun in more advanced settings, but many local abattoirs tend to use old automobile tires for the fire. Burning with tires typically releases large clouds of smoke that place both the abattoir workers and others in the environs at risk. Thereafter, the animals are divided into quarters and evisceration carried out to remove the internal organs for processing.

The animal parts are examined for pathological features indicative of zoonoses e.g. inflamed lymph nodes and joints, abscesses, edema, lesions in the liver, spleen, kidneys, and heart (Herenda et al., 2002). This is done by inspection, palpation, incision, and olfaction techniques in a post-mortem examination carried out by the veterinary officer, a district environmental health officer, or their equivalent. Findings on ante-mortem and post-mortem examination of animals with selected zoonoses are listed in Table 1.

[Sources: Herenda, Chambers & Ettriqui, 1994; Heymann & APHA, 2015; Bauerfeind, et al., (2016)]

Where signs of pathology are absent, the meat is stamped fit for sale and packaged for transportation to the market. Conveyance should take place in a cooling van to maintain appropriate temperature and prevent spoilage during transport. However, in communities, meat meant for sale is transported in the back of trucks, taxis, and motorcycles. Dead or diseased animals are totally condemned and are given a sanitary burial in a dug-out pit lined with clay and lime. Such pits when covered must be demarcated and fenced to prevent the carcass from being dug out by scavengers. If the disease is localized to only part(s) of the animal, these can be removed and the rest of the animal passed if duly considered not to pose a risk to consumers. At the butchery, the meat should be sold in a screened shelter to keep out flies; this may not always happen.

One health approach to zoonoses

Clinicians play a key role among other professionals including ecologists, epidemiologists, and public health practitioners in limiting local disease outbreaks and global pandemics. They do this by rapid identification of cases and notification to enable public health authorities respond with appropriate management and control measures (Kilpatrick and Randolph, 2012). Occupational health physicians and industrial hygienists play a specific role in identification of workplace hazards and providing guidance to responsible authorities to put safety measures in place for workers. The veterinary officer plays an important role at the animal interface ensuring that animals are reared under healthy conditions, diseased animals are identified and not passed on for slaughter, and that animals slaughtered are fit for consumption. They also ensure that surveillance for diseases detected in animals is effective. Environmental health practitioners have a role to play in ensuring that animal husbandry, slaughter, and sale of meat occur under sanitary conditions. The actions at the human, animal, and environmental interface underlie the concept of one health.

It is essential that all stakeholders in the food chain complement the efforts of the aforementioned groups to ensure that food consumed is wholesome.

Zoonoses

The following sub-sections are on selected zoonoses of international importance for the attention of frontline medical practitioners. They are yellow fever, plague, rabies, brucellosis, zoonotic tuberculosis, Ebola hemorrhagic fever, toxoplasmosis, and anthrax.

Yellow fever: This is a vector-borne disease caused by an RNA virus of the family Flaviviridae. It is endemic in Africa and Latin America. The yellow fever belt stretches from 15°N to 10°S. Vaccination efforts have largely brought it under control. Now it occurs mostly in outbreaks in tropical forest areas where non-human primates serve as a reservoir. Sub-optimal vaccination coverage (<80%) in affected areas implies that herd immunity is not attained, leaving susceptible groups in which infection can occur. There are three known cycles. The sylvatic cycle involves monkeys and mosquitoes (Stegomyia [Aedes] africanus and Hemagogus). The intermediate or savannah cycle involves Stegomyia (Aedes) simpsoni and other Aedes species, humans, and non-human primates. The urban cycle involves mosquitoes (Stegomyia [Aeges] aegypti) and humans.

Yellow fever has an incubation period of 3–6 days. Clinical features include: Febrile illness, headache, backache, myalgia, nausea, and vomiting. The pulse is often slow in contrast to the elevated temperature. This is referred to as Paget’s sign. In about 15% of cases remission, recurrence of symptoms, and progression to jaundice, epistaxis, hematemesis or melaena are features . There is also asymptomatic presentation. Risk groups include unvaccinated travelers to endemic areas and people engaged in outdoor activities in forest areas where vectors are prevalent. Vaccination provides lifelong immunity. Transient passive immunity lasting up to six months has been reported in infants of immune mothers. All persons aged 9 months or older considered to be at risk are eligible for vaccination with a single subcutaneous injection with live attenuated 17D vaccine. Hypersensitivity to egg and egg products is a contraindication.

Plague: The causative organism of this rodent-borne disease is Yersinia pestis, transmitted by the bite of an ectoparasite, Xenopsylla cheopis. The vector, Xenopsylla cheopis, is a flea. Wild rodents are natural vertebrate hosts and contact with domestic rodents is usually a precedent to human infections. Infested rodents may be forced from their habitats through bush burning and wild fires and move closer to, or into, human dwellings where infestations may be introduced through local house rats and their fleas. Domestic pets such as cats and dogs may introduce infected fleas into dwelling areas and handling these pets exposes susceptible hosts to bites by parasites. Transmission by Pulex irritans facilitates person-to-person spread; such spread occurs in conditions of overcrowding, poor sanitation, and poverty.

Yersinia pestis can persist in soil and it tends to be more common in areas where people sleep on dirt floors of mud huts which might be flea-infested. Plague may also be transmitted from consumption of uncooked, contaminated meat (https://www.ecdc.europa.eu/en/plague/facts).

There are three main clinical manifestations based on the route of infection: bubonic plague, pneumonic plague, and septicemic plague. Early symptoms include fever, chills, myalgia, nausea, sore throat, and headache (Stenseth, Atshabar, Begon et al., 2008). Bubonic plague manifests as a febrile lymphadenitis affecting lymph nodes which drain the site of the flea bite. It produces a tense tender swelling referred to as a bubo. Typically, inguinal lymph nodes are affected; axillary, cervical, crural, and sub-maxillary buboes occur. Cervical and axillary buboes are more common in children. The buboes are often inflamed and later suppurate.

Secondary to a bubonic plague, a secondary septicemic plague may occur. In 10–25% of cases, it may also occur without a bubo and spread to other parts of the body presenting with shock and, in some cases, disseminated intravascular coagulopathyy (Prentice and Rahalison, 2007). Spread to the lungs can lead to a secondary pneumonic plague which can be transmitted by the spread of respiratory droplets to a susceptible host, resulting in primary pneumonic plague. Symptoms of pneumonic plague include sudden onset of fever, dyspnea, cough with bloody sputum, and chest pain, following a short incubation period of a few hours to 3 days (Prentice and Rahalison, 2007). There may also be diarrhea, agitation, and prostration. Spread to the central nervous system results in