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Medicinal plant research in Africa pharmacology and chemistry Kuete
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J.C.N. Assob, D.S. Nsagha, A.J. Njouendou, D. Zofou, W.F. Sevidzem, A. Ketchaji, A. Chiara, T.E. Asangbeng, K.O. Dzemo, B.M. Samba, A.C. Wenze, E. Malika, V.B. Penlap, V. Kuete
G.S. Taïwe, V. Kuete
5.
E.U. Nwose, P.T. Bwititi, V.M. Oguoma
3.
4.
6.
R.
D.O. Ochwang’i,
8.
7. Preparation, Standardization, and Quality Control of Medicinal Plants
J.A.K. Noumedem, D.E. Djeussi, L. Hritcu, M. Mihasan, V. Kuete 1.
6.
7.
8.
20. Lactuca sativa
21. Mangifera indica
S. Derese, E.M. Guantai, Y. Souaibou, V. Kuete
1.
3.
4.
5.
6.
7.
8.
4.
5.
7.
24. Passiflora edulis
G.S. Taïwe, V. Kuete
1.
3.
4.
5.
7.
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25. Petroselinum crispum: A Review
C. Agyare, T. Appiah, Y.D. Boakye, J.A. Apenteng
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2.
3.
4.
5.
6.
7.
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Sesamum indicum
S.O. Amoo, A.O.M. Okorogbona, C.P. Du Plooy, S.L. Venter
1.
2.
3.
4.
5.
6.
27. African Medicinal Spices of Genus Piper
I.A. Oyemitan
1.
2. Taxonomy of the genus
3. Diversity in the Piper species
4. Distribution of the genus Piper
5. Ethnobotanical and ethnosocial importance of the genus Piper
6. Ethnomedicinal applications of the genus Piper
7. Economic and commercial prospect of the genus
8. Bioprospecting and conservation status of the genus
9.
10.
11.
12.
1.
2.
3.
4.
5.
A.T. Mbaveng, V. Kuete
1.
2.
4.
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A.T.
3.
5.
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LIST OF CONTRIBUTORS
Sherif Babatunde Adeyemi
Department of Plant Biology, University of Ilorin, Ilorin, Kwara, Nigeria
Christian Agyare
Department of Pharmaceutics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Ketchaji Alice
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Stephen O. Amoo
Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, Pretoria, South Africa
John Antwi Apenteng
Department of Pharmaceutical Sciences, Central University College, Accra, Ghana
Theresa Appiah
Department of Pharmaceutics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Tanue Elvis Asangbeng
Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
Jules Clement Nguedia Assob
Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Nudewhenu O. Avoseh
Natural Products Research Unit, Department of Chemistry, Faculty of Science, Lagos State University, Lagos, Nigeria
Udo Bakowsky
Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Marburg, Germany
Veronique P. Beng
Department of Biochemistry, Faculty of Science, Biotechnology Centre, University of Yaoundé I,Yaoundé, Cameroon
Yaw Duah Boakye
Department of Pharmaceutics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Samba Melvis Bora
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Phillip Taderera Bwititi
Faculty of Science, Charles Sturt University, Bathurst, NSW, Australia
Achangwa Chiara
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Zofou Denis
Department of Biochemistry and Molecular Biology, Faculty of Science, University of Buea, Buea, Cameroon
Solomon Derese
Department of Chemistry, University of Nairobi, Nairobi, Kenya
Doriane E. Djeussi
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
Christian Phillipus Du Plooy
Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, Pretoria, South Africa
Kibu Odette Dzemo
Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
Jean P. Dzoyem
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon; Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Marburg, Germany
Eric M. Guantai
Department of Pharmacology and Pharmacognosy, University of Nairobi, Nairobi, Kenya
Abdulmumeen Amao Hamid
Department of Chemistry, University of Ilorin, Ilorin, Kwara, Nigeria
Lucian Hritcu
Department of Biology, Alexandru Ioan Cuza University, Ias¸i, Romania
Oğuzhan Karaosmanoğlu
Department of Biology, Science Faculty, Anadolu University, Eskis¸ehir; Department of Biology, Kamil Özdag ˘ Science Faculty, Karamanog ˘ lu Mehmetbey University, Karaman, Turkey
Victor Kuete
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
Oladipupo A. Lawal
Natural Products Research Unit, Department of Chemistry, Faculty of Science, Lagos State University, Lagos, Nigeria
Fawzi M. Mahomoodally
Department of Health & Sciences, Faculty of Science, University of Mauritius, Réduit, Mauritius
Tshepiso J. Makhafola
Department of Life and Consumer Sciences, College of Agriculture and Environmental Science, University of South Africa, Pretoria, South Africa
Esembeson Malika
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Armelle T. Mbaveng
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
Lyndy J. McGaw
Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
Jacob O. Midiwo
Department of Chemistry, School of Physical Sciences, University of Nairobi, Nairobi, Kenya
Marius Mihasan
Department of Biology, Alexandru Ioan Cuza University, Ias¸i, Romania
Hamdalat Folake Muritala
Department of Biochemistry, University of Ilorin, Ilorin, Kwara, Nigeria
Mikhail Olugbemiro Nafiu
Department of Biochemistry, University of Ilorin, Ilorin, Kwara, Nigeria
Abdel Jelil Njouendou
Department of Medical Laboratory Sciences, University of Buea, Buea, Cameroon
Jaures A.K. Noumedem
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
Dickson Shey Nsagha
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Ezekiel Uba Nwose
Faculty of Science, Charles Sturt University, Bathurst, NSW, Australia
Dominic O. Ochwang’i
Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya
Jemimah A. Oduma
Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya
Akintayo L. Ogundajo
Natural Products Research Unit, Department of Chemistry, Faculty of Science, Lagos State University, Lagos, Nigeria
Isiaka Ajani Ogunwande
Natural Products Research Unit, Department of Chemistry, Faculty of Science, Lagos State University, Lagos, Nigeria
Victor Maduabuchi Oguoma
School of Psychological and Clinical Science, Charles Darwin University, Darwin, NT, Australia
Alfred Oghode Misaiti Okorogbona
Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, Pretoria, South Africa
Leonidah Kerubo Omosa
Department of Chemistry, School of Physical Sciences, University of Nairobi, Nairobi, Kenya
Idris Ajayi Oyemitan
Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Osun, Nigeria; Division of Academic Affairs & Research, Directorate of Research, Innovation & Development, Walter Sisulu University, Mthatha, South Africa
Roumita Seebaluck-Sandoram
Department of Health & Sciences, Faculty of Science, University of Mauritius, Réduit, Mauritius
Wirsiy Frankline Sevidzem
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Hülya Sivas
Department of Biology, Science Faculty, Anadolu University, Eskis¸ehir, Turkey
Germain Sotoing Taïwe
Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
Jean-de-Dieu Tamokou
Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
Serges Tchatchouang
Department of Biochemistry, Faculty of Science, Biotechnology Centre, University of Yaoundé I,Yaoundé, Cameroon
Sonia L. Venter
Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, Pretoria, South Africa
Ayima Charlotte Wenze
Department of Public Health and Hygiene, Faculty of Health Sciences, University of Buea, Buea, Cameroon
Souaibou Yaouba
Department of Chemistry, University of Nairobi, Nairobi, Kenya
PREFACE
Medicinal plants constitute a good alternative to conventional medicine, considering the rich biodiversity of the continent. They are widely used in Africa to heal various types of health conditions and it has always been stated that about 80% of the population in the continent use traditional healing as primary health care. This could be true, but these are very irregular consultations that cannot be definitively attributed to a class of persons in the population. For example, a person may appeal to traditional therapy in context of a specific disease and unfavorable financial conditions, but used conventional medicine in case of financial ease or another disease. In Africa, traditional medicine is often stigmatized by many people, especially the middle- and high-income people.
Governments in Africa are also providing few incentives to boost traditional medicine including the use of medicinal plants. This position is understandable insofar as there are few studies on the safety of plants used as well as the methods used to obtain various therapeutic preparations. Meanwhile, African populations are disproportionately affected by infectious and cardiovascular diseases, cancers and other illnesses.This remains a contrast if we take into account the exceptional floral biodiversity of the continent and the number of medicinal plants found in each African country. If African countries are endowed with appropriate infrastructure to demonstrate the efficacy and safety of medicinal plants used in the continent, it would be likely that governments would change point of view and encourage not only the use of these plants, but also the production of improved phytodrugs.
Until this is done, and given the fact that the miseries of the people in health matters will not wait, African researchers should propose acceptable alternatives to conventional medicine, which is very expensive for the majority of the population. One of the most acceptable solutions is to propose the use of functional foods and medicinal herbs, such as spices and vegetables, not only as a palliative to the conventional medicine, but as effective therapeutic alternative. This could be more accepted and popularized worldwide.
Given the scarcity of reference updated books adapted to Africa in this theme, I undertook to edit this document, also having an academic purpose. Hence, the background on diverse degenerative diseases in Africa will be discussed from Chapters 1–7. To place African research globally and for a possible academic use, emphasis was put on the methods used in pharmacological surveys in Part II, dealing with the therapeutic potential of African medicinal spices and vegetables (Chapters 8–13). The reviews of the most popular African functional foods, medicinal spices, and vegetables have been discussed in details in Part III (Chapters 14–30). The topics of this book are of interest to scientists of several fields, including Pharmaceutical Science, Pharmacognosy, Complementary and Alternative Medicine, Ethnomedicine, Pharmacology, Medical and Public
Health Sciences, Medicinal Chemistry, Phytochemistry, and Biochemistry. The highlight of this book is an exhaustive compilation of scientific data related to the Pharmacological survey of African medicinal spices and vegetables by top scholars from several countries worldwide. Finally, I would like to thank Molly McLaughlin, the Editorial Project Manager at 50 Hampshire Street Cambridge, Massachusetts 02139, the technical assistant, and Karen East and Kirsty Halterman, the production managers for their help and fruitful collaboration.
Prof. Dr. Victor Kuete
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Diseases in Africa: An Overview
J.C.N. Assob, D.S. Nsagha, A.J. Njouendou, D. Zofou, W.F. Sevidzem, A. Ketchaji, A. Chiara, T.E. Asangbeng, K.O.
Dzemo, B.M. Samba, A.C. Wenze, E. Malika, V.B. Penlap, V. Kuete
1 GENERAL OVERVIEW OF DISEASE BURDEN IN AFRICA
The notion of disease burden refers to the impact of a health problem as measured by financial cost, mortality, morbidity, or other indicators. It is often quantified in terms of quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs), both of which quantify the number of years lost due to disease (YLDs). One DALY can be thought of as 1 year of healthy life lost, and the overall disease burden can be thought of as a measure of the gap between current health status and the ideal health status (where the individual lives to old age free from disease and disability) (David Kay and Carlos, 2000; Prüss-Üstün et al., 2003; Murray et al., 2013).
People around the world are living longer than ever before, and the population is getting older. The number of people in the world is growing because many countries have made remarkable progress in preventing child deaths. As a result, disease burden is increasingly defined by disability instead of premature mortality. The leading causes of deaths and disabilities have changed from communicable diseases in children to noncommunicable diseases in adults; whereas eating too much has overtaken hunger as a leading risk factor for illness (Institute for Health Metrics and Evaluation, 2013). Across the African region, overall progress has been made in decreasing death rates between 1970 and today. Each country has witnessed an increase in its average age of death with some variations; Cape Verde demonstrating the greatest gain (about 28 years) and Chad showing the smallest improvement (1.4 years). Decline in mortality rates largely varied by age, with greatest improvements for young children (Institute for Health Metrics and Evaluation, 2013).
Death rates for children between 1 and 4 years old declined by 65% between 1970 and 2010, whereas mortality rates rose for women and men at different ages (a 39% increase for women aged from 25 to 39 and a 50% increase for men aged from 30 to 34).
Premature death and disability caused by some communicable diseases and newborn conditions have decreased, but they remain leading causes of premature death and illness. Between 1990 and 2010, the African region had succeeded in decreasing premature death and disability, also known as healthy years lost, from lower respiratory infections, diarrheal diseases, and protein-energy malnutrition; however, these conditions are still the
Medicinal Spices and Vegetables from Africa. http://dx.doi.org/10.1016/B978-0-12-809286-6.00001-7
leading causes of disease burden in the region, especially in lower income countries like Niger and Sierra Leone. Malaria and human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) are now the first- and second major causes of premature death and disability (Institute for Health Metrics and Evaluation, 2013).
Noncommunicable diseases are rapidly rising, especially for wealthier countries in the region. Road injuries have taken a growing toll on health in the African region. Healthy years lost from road injuries have increased by 76% between 1990 and 2010, with substantial country variation (ranging from a rise of 9% in Madagascar to 87% in Congo) (Institute for Health Metrics and Evaluation, 2013). To ensure a health system is adequately aligned to a population’s true health challenges, policymakers must be able to compare the effects of different diseases that kill people prematurely and cause ill health. The original Global Burden of Disease (GBD) study’s creators developed a single measurement, DALYs, to quantify the number of years of life lost as a result of both premature death and disability (Institute for Health Metrics and Evaluation, 2013). One DALY equals one lost year of healthy life. DALYs will be referred to by their acronym, as years of healthy life lost, and years lost due to premature death and disability.
Decision-makers can use DALYs to quickly assess the impact caused by conditions, such as cancer versus depression using a comparable metric. Considering the number of DALYs instead of causes of death alone provides a more accurate picture of the main drivers of poor health. GBD provides high-quality estimates of diseases and injuries that are more rigorous than those published by disease-specific advocates. Beyond providing a comparable and comprehensive picture of causes of premature death and disability, GBD also estimates the disease burden attributable to different risk factors (Institute for Health Metrics and Evaluation, 2013). The GBD approach goes beyond risk-factor prevalence, such as the number of smokers or heavy drinkers in a population.With comparative risk assessment, GBD incorporates both the prevalence of a given risk factor and the relative harm caused by that risk factor. It counts premature death and disability attributable to high blood pressure, tobacco and alcohol use, lack of exercise, air pollution, poor diet, and other risk factors that lead to ill health.
According to the World Health Organization (WHO) figures, the Ebola epidemic in West Africa claimed 11,323 lives (WHO, 2003). Although the virulence and rapid spread of the Ebola virus were major causes of concern, it is important to understand the mortality figures in the broader sub-Saharan African context. Deaths in Africa, for example in 2012, fell largely in all the WHO groups. This was such that: • Group 1: (death through communicable diseases, and perinatal, maternal, and nutritional causes): 5.9 million deaths amounting to 61.7% of all deaths in sub-Saharan Africa.
• Group 2: death as a result of noncommunicable diseases accounted for 2.7 million deaths or 28.6% of all deaths. This category includes heart disease (293,000 deaths), various forms of cancer (426,000), and diabetes (175,000).
• Group 3: deaths through injury, amounted to 939,000 deaths, or 9.8% of the total.
Group 3 causes of death include unintentional injuries, such as road accidents (207,000), and intentional injuries, such as interpersonal violence (132,000) and collective violence (14,000).
Noncommunicable and lifestyle diseases are the top killers in high-income countries, accounting for 67.8% of deaths in 2012. In contrast, many of the top killers in subSaharan Africa—lower respiratory tract infections, tuberculosis (TB), diarrheal disease, and malaria—are preventable and treatable, given adequate health care systems and resources. According to WHO’s figures, the five top killers in Africa in 2012 were the following: HIV/AIDS, lower respiratory tract infections, diarrheal diseases, malaria, and strokes.
People living in the African region of the WHO confront the world’s most dramatic public health crisis, with the hope that over time the region can address the health challenges it faces, given sufficient international support (WHO, 2006a). HIV/AIDS continues to devastate the WHO Africa region, which has 11% of the world’s population but 60% of the people with HIV/AIDS. Although HIV/AIDS remains the leading cause of death in adults, more and more people are receiving life-saving treatment. The number of HIV-positive people on antiretroviral medicines increased eightfold, from 100,000 in December 2003 to 810,000 in December 2005 (WHO, 2006a). More than 90% of the estimated 300–500 million malarial cases that occur worldwide every year are in Africans, mainly in children under 5 years, but most countries are moving toward better treatment policies. Of the 42 malaria-endemic countries in the African region, 33 have adopted artemisinin-based combination therapy (ACT)—the most effective antimalarial medicines available today—as first-line treatment (WHO, 2006a). River blindness has been eliminated as a public health problem, and guinea worm control efforts have resulted in a 97% reduction in cases since 1986. Leprosy is close to elimination—which means there is less than one case per 10,000 people in the region (WHO, 2006a).
Most countries are making good progress on preventable childhood illness. Polio is close to eradication, and 37 countries are reaching 60% or more of their children with measles immunization. Overall measles deaths have declined by more than 50% since 1999 (WHO, 2006a). While drawing the world’s attention to recent successes, the report offers a candid appraisal of major hurdles, such as the high rate of maternal and newborn mortality overall in the region. Of the 20 countries with the highest maternal mortality ratios worldwide, 19 are in Africa; and the region has the highest neonatal death rate in the world (WHO, 2006a). Then there is the strain on African health systems imposed by the high burden of life-threatening communicable diseases coupled with increasing rates of noncommunicable diseases, such as hypertension and coronary heart disease. Basic sanitation needs remain unmet for many with only 58% of people living in subSaharan Africa having access to safe water supplies. Noncommunicable diseases, such as hypertension, heart disease, diabetes, are on the rise, and injuries remain among the top causes of death in the region (WHO, 2006a).
2 INFECTIOUS DISEASES
2.1
HIV/AIDS in Africa
HIV, the virus that causes AIDS, “acquired immunodeficiency syndrome” has become one of the world’s most serious health and development challenges. In Canada, and most other western countries, these drugs are readily available and are used by nearly all AIDS patients. These drugs, in addition to effective education and awareness regarding the disease, have helped developed nations get their HIV/AIDS epidemics under control. However, sadly it is not like that everywhere in the world. In Africa particularly, one of the world’s poorest places, AIDS remains a wildly virulent disease that is still killing millions and debilitating entire swaths of the population, mainly a result of people not being able to afford treatment. It is a major public health concern and cause of death in many parts of Africa (Michael, 2014). Although the continent is home to about 15.2% of the world’s population, sub-Saharan Africa alone accounted for an estimated 69% of all people living with HIV and 70% of all AIDS deaths in 2011 (Apps.who.int, 2016).
Countries in North Africa and the Horn of Africa have significantly lower prevalence rates, as their populations typically engage in fewer high-risk cultural patterns that have been implicated in the virus’s spread in sub-Saharan Africa (UNAIDS, 2010). Southern Africa is the most affected region in the continent.
2.1.1 Epidemiology of HIV/AIDS in Africa
There are many reasons why Africa has such a high number of AIDS cases. Between 1999 and 2000 more people died of AIDS in Africa than in all the wars on the continent, as mentioned by the previous UN Secretary General, Kofi Annan (Globalissues. org, 2016). The death toll is expected to have a severe impact on many economies in the region. In some nations, it is already being felt. Life expectancies in some nations are already decreasing rapidly, whereas mortality rates are increasing. Each day, 6000 Africans die from AIDS. Each day, an additional 11,000 are infected (Globalissues.org, 2016). The first cases were reported in 1981 and HIV prevalence rates and the number of people dying from AIDS varied between African countries in 2010 (UNAIDS, 2010): in Somalia and Senegal—HIV prevalence is under 1% of the adult population, whereas in Namibia, Zambia, and Zimbabwe, 10–15% of adults are infected with HIV, in South Africa, the HIV prevalence stands at 17.8%, exceeding 20% in Botswana (24.8%), Lesotho (23.6%), and Swaziland (25.9%). In Cameroon and Gabon, HIV prevalence is 5.3 and 3.6%, respectively, while the prevalence in Nigeria is 4.1%. In East Africa including Uganda, Kenya, and Tanzania the prevalence is above 5%.
2.1.2 Control
2.1.2.1
Prevention
Numerous prevention interventions have been developed to fight HIV, and new tools, such as vaccines, are currently under investigation. Effective prevention strategies include
behavior change programs, condoms, HIV testing, blood supply safety, harm reduction efforts for injecting drug users, and male circumcision. Additionally, recent research has shown that providing HIV treatment to people with HIV significantly reduced the risk of transmission to their negative partners. Preexposure antiretroviral prophylaxis (PrEP) has also been shown to be an effective HIV prevention strategy in individuals at high risk for HIV infection. Experts recommend that prevention be based on “knowing your epidemic,” that is, tailoring prevention to the local context and epidemiology, and using a combination of prevention strategies, bringing programs to scale, and sustaining efforts over time.
2.1.2.2 Treatment
Treatments include the use of combination antiretroviral therapy (ART) to attack the virus itself, and medications to prevent and treat opportunistic infections that can occur when the immune system is compromised by HIV. In light of recent research findings, WHO released a guideline in 2015 recommending starting HIV treatment earlier in the course of illness (UNAIDS, 2015). Approximately 76% of all people receiving ART in sub-Saharan Africa are virally suppressed, which means they are likely healthier and less likely to transmit the virus (WHO, 2013).
2.1.2.3 WHO policies
Since 2002, ART programs have slowly improved in Africa. Initially, HIV-infected people had to wait until they were seriously immunocompromised, with a CD4 T-cell count below 200 mm 3, to begin ART. In 2013, WHO released a guideline that recommends daily oral PrEP as a form of prevention for high-risk individuals in combination with other prevention methods (WHO, 2013). The threshold was raised to 350 and then 500, as the importance of earlier initiation of treatment was recognized. Improved tools and strategies followed, as did consensus on treatment guidelines and international funding. The trajectory toward ending AIDS seemed assured, and international goals grew from “3 by 5” (treating 3 million people by 2005), to “15 by 15,” to a call from the Joint United Nations Programme on HIV/AIDS for “90-90-90” by 2020: 90% of people living with HIV tested, 90% receiving treatment, and 90% with an undetectable 1-viral load.
2.1.2.4 Challenges
Major progress has been made in Africa’s fight against HIV/AIDS but one of the major problems remaining is giving the thousands living with AIDS the drug therapies that can let them live a long life. “In terms of the reality, unfortunately the reality is that while there’s been huge progress made in the fight against AIDS, there still remains important efforts to do” (Ellman, 2015).
In addition, the main reason is because many Africans are having unprotected sex, and many people in Africa are not educated about the dangers of AIDS or unprotected
sex. Recently the President of South Africa made a comment doubting the existence of AIDS. This is one of the other reasons why people in Africa have high cases of AIDS. Many just don’t believe that AIDS exists, and so they don’t take proper precautions to avoid contracting the disease. In most of Africa, despite shortages of health workers, initiating ART in a healthy HIV-positive adult is the begining of monthly queues at clinics and pharmacies to see overburdened medical staff. To obtain treatment, such patients face lots of challenges like long walks to health centers or high transportation costs, hours of queuing, and poor, sometimes stigmatizing, consultation. Unlike symptomatic patients, these patients see no short-term benefit from treatment.
Hence, HIV/AIDS is still a challenge in Africa; providing health care, antiretroviral treatment, and support to people with HIV-related illnesses can help to reduce the annual toll of new HIV infections. As guidelines edge closer to universal treatment for HIV-infected people regardless of CD4 count, more people can choose to receive ART before they develop symptoms. Earlier treatment represents an opportunity not only to prevent illness and transmission but also to inform and empower people living with HIV–AIDS while reducing the burden on health care systems.
2.2 Overview of TB in Africa
TB remains one of the world’s deadliest communicable diseases; it is currently responsible for more years of healthy life lost (2.5% of all DALYs) than any other infectious disease, like AIDS and malaria (Ibrahim et al., 2015). In 2013, an estimated 9.0 million people developed TB and 1.5 million died from the disease, 360,000 of whom were HIV positive (Corbett et al., 2003). TB is slowly declining each year and it is estimated that 37 million lives were saved between 2000 and 2013 through effective diagnosis and treatment (Corbett et al., 2003). TB is present in all regions of the world and the Global Tuberculosis Report 2014 includes data compiled from 202 countries and territories. The report shows higher global totals for new TB cases and deaths in 2013 than previously, reflecting the use of increased and improved national data (Corbett et al., 2003). A special supplement to the 2014 report highlights the progress that has been made in surveillance of drug resistant TB over the last two decades, and the response at global and national levels in recent years (Corbett et al., 2003).
The year 2015 is a watershed moment in the battle against TB. It marks the deadline for global TB targets set in the context of the millennium development goals (MDGs), and is a year of transitions: from the MDGs to a new era of sustainable development goals (SDGs), and from the Stop TB Strategy to the End TB Strategy. It is also two decades since WHO established a global TB monitoring system; since that time, 20 annual rounds of data collection have been completed (WHO, 2015). A decade ago, the problem of TB in Africa attracted little attention, not even meriting a chapter in the first edition of Disease and Mortality in sub-Saharan Africa. Part of the reason was that incidence of TB was low and falling in most parts of the continent (Organization, 2015).The
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[181]
Take the work you want to gild, & in the same way as described above, clean it[182] and gild it, then skilfully dry it; don’t be particular as to drying it too much, only let it be free of all quicksilver, then clean it again lightly and heat it over live embers. Whilst it is in process of heating spread on it a kind of wax which I will describe below
When the wax is spread, let the work cool, then have a fire ready of such nature as shall melt off the wax without heating the metal to redness. When heated in this way, rinse it out in a solution of tartar and water—what among goldsmiths is called grommata. This done, let it stand for such time as you can say an Ave Maria, then clean it with a brush in fresh water, rubbing it well.[183] If your work has been well gilded, you may further colour it with the process I shall tell you of shortly. But as to do so you have first to wax it, I had best tell you to begin with how that wax is made; and ’tis in this wise.
FOOTNOTES:
[181] Che sia abbondantemente carico d’oro.
[182] Cellini refers to the preliminary cleaning with urine described in Chapter xxvii
[183] Ristiara di buon vantaggio.
CHAPTER XXX. HOW TO MAKE THE WAX FOR GILDING.
Take five ounces of new wax, half an ounce of red chalk (that is to say, red stone chalk for drawing[184]), half an ounce of Roman vitriol, [185] three pennyweights[186] of feretto di spagna, [187] that is of the weight of a ducat, or one-eighth of an ounce, or it may be a bit less, half an ounce of verdigris, & three pennyweights of borax. Mix all these things together and melt them with the wax, & apply them as above described. After this, when the wax is cleaned off, you can give it the colouring that follows hereunder.
FOOTNOTES:
[184] Lapis rosso da disegnare; French, ‘sanguine ’
[185] Vitriouolo romano: sulphate of iron.
[186] Denari
[187] Possibly calcined sulphate of iron; French, ‘ferret. ’
CHAPTER XXXI. HOW TO MAKE YET ANOTHER COLOURING.
Take half an ounce of Roman vitriol, half an ounce of saltpetre, six pennyweights of salts of ammonia, half an ounce of verdigris, and pound them upon a stone, do not use iron. Pound the salts of ammonia first very carefully, then all the others together. Then mix them in a glazed vessel[188] with as much water as shall make them have the consistency of a sauce, stir them over the fire with a piece of wood, & let them boil for such space as you can say two Paternosters. Do not give them a strong fire for that would spoil them. Everything in moderation. Let them cool, and use them as is here written in the manner following.
FOOTNOTES:
[188] Pentolino.
CHAPTER XXXII. THE MANNER OF APPLYING
THE SAID
COLOUR.
Let your work be dried with a clean cloth, then by means of a few feathers streak it over with the above concoction in the same way as you did when colouring the gold with the verdigris mixture. Then put it on the fire. When you see it drying and beginning to steam hard (do not let it steam quite dry) dip it in cold water. Then clean it up, & once again let it simmer slowly in the tartar solution[189] for such space as you may say an Ave Maria; yet again clean it in water and polish it where you will. This gives the loveliest gilding and of the most beautiful colour that can be made, and lasts for ever.
FOOTNOTES:
[189] Bollire freddo nella grommata.
CHAPTER XXXIII. WHAT YOU DO WHEN YOU WISH TO LEAVE BARE THE SILVER IN CERTAIN PLACES.
When you have cleaned up the parts where the gold is not to stick, you take some flour dust, such as you may gather on the walls and cornices of mills, & we in Florence call fuscello, and you mix it with water to the consistency of a paste, and with a (camel’s) hair brush lay it thick on the parts not to be gilded, after which you dry it well before a slow fire, and can gild safely.
Another way, too, may be employed where the flour dust is not used. You take gesso in the cake,[190] such as the shoemakers use, pound it up well, and make a paste of it either with stag glue,[191] or better with fish glue,[192] but mind that either glue be well mixed with water, so that it does not get too stiff. And inasmuch as I want to omit nothing, I bid you note that this gesso is best employed when you merely want to gild and leave the silver white, whereas the flour dust method is best used when you want in addition to colour the gold as above described. This is as much as you need know about such matters.
Now though, of a truth, the prime merit of every craft is your being well able to practise it yourself, yet none the less it were better to leave these processes of gilding to those who are specialists, for it is as I said very unhealthy[193] to practise. Know how it’s done, that’s all.
FOOTNOTES: [190] Gesso in pane.
[191] Colla cervona. Probably a glue made of stags’ skins or chippings. In ‘Cennino Cennini’ is a footnote on glues, quoting from ‘Dioscorides’ a glue, colla taurina, hence possibly ‘cervona’ from ‘cervo ’
[192] Colla di pesce.
[193] Perniziossima
CHAPTER XXXIV. HOW TO MAKE TWO KINDS OF AQUAFORTIS,
ONE FOR PARTING,[194] THE OTHER FOR ENGRAVING & ETCHING.
First I will talk of that mixture with which you etch on copper instead of cutting with the graver, this is an easy and a very beautiful method. Aquafortis for etching is made thus: you take half an ounce of sublimate,[195] one ounce of vitriol, half an ounce of rock alum,[196] half an ounce of verdigris, and six lemons; and after having care to pound the first mentioned substances well, you boil them a little in the lemon juice, but not so as to let them get too dry. The boiling should be done in a glazed pot, and if you have no lemons you may take strong vinegar which will give a like result. When you have well smoothed your copper plate you can take any ordinary varnish,[197] such as is used for the lacquering of the ornaments on daggers and other iron work, & heat it gently, putting a little wax with it, this you do to prevent the varnish from cracking when you draw upon it. It must not be too hot when you spread it on your copper plate. When you have etched on your design make a ridge of wax round the plate and pour on the parting water, letting it stand not longer than half an hour. If then it be not bitten deep enough, do it again. Then remove it and clean it well with a sponge. You draw on the varnish with a stylus of well tempered steel, that is an iron needle, which in the craft is termed a stile. You wash the varnish off the plate with a sponge of warm oil, but very softly so as not to destroy the intaglio. Then you use the plate & stamp impressions on to card-board from it in just such a manner as plates done with the graver It is true that this sort of plate is produced very easily, but then, you see, they don’t last near so long as those done with the graver.
FOOTNOTES:
[194] Acqua da partire is the acid into which you put alloys and clippings, filings, etc., to separate gold from silver, or silver from copper, or gold from gilt copper, in other words nitric acid. Partitore is the man who exercises this trade. Hoepli’s Manual, ‘Oreficeria,’ published Milan, gives information about the modern way of using acids for ‘separating or parting.’
[195] Solimato: can this be sublimed sal ammoniac?
[196] Allumi di rôcca.
[197] Vernice ordinaria
CHAPTER XXXV. HOW TO MAKE AQUAFORTIS
FOR PARTING.
Aquafortis for parting[198] is made thus. You take 8 lbs. of burnt rock alum[199] & an equal quantity of the best saltpetre, and 4 lbs. of Roman vitriol, & put them altogether into the alembic,[200] add to these things a little aquafortis that has already been used, exercising your discretion as to the quantity. And in order to give a good luting[201] to your alembic take horse-dung, iron filings & brick dust in equal proportions, and mix them up with the yolk of a hen’s egg, then smear the mixture over the alembic as far as the furnace will allow. Then for the rest put it to a moderate fire, as the wont is.
FOOTNOTES:
[198] Partire.
[199] Allume di rôcca arso. Prof. Church tells me that this is probably sulphate of alumina, from alum shale
[200] Boccia. Biringoccio in the fourth book of his ‘Pirotechnica,’ Venice, 1540, Chap. I., gives an illustrated description both of such an alembic and of how aquafortis for parting is distilled. See also the French edition of the same book translated by ‘Jaques Vincent.’ Rouen, 1627.
[201] Loto: the closing of the joints
CHAPTER XXXVI. HOW TO MAKE ROYAL CEMENT.
Take the gold you wish to refine and beat it thin, cut it into little pieces of the size and the thickness of a golden scudo. Sometimes the scudi themselves are taken and a twenty-four carat cement refined direct from them; and this simple[202] cement has such virtue that it can draw all the alloy[203] out of the scudo itself without destroying the impression on the coin, but drawing from it only what was of base metal.
The cement is made in this wise: Take tartar and brick dust and make a paste of them; construct a round furnace[204] , & into the joints of the furnace between one brick and another spread the paste; put your pieces of gold, or the scudi themselves, if you use them, into the paste, and cover them well up with more of it; then fire for twenty-four hours, at the end of which time they will be refined to twenty-four carats.[205]
Know, gentle reader, that this screed of mine is not writ for the purpose of teaching such as are refiners[206] by profession how to make aquafortis, my only care is to show how & to what end it may serve the art of goldsmithing; for it came about that having made certain golden figures half a cubit high for King Francis, when they were near the ending, during the softening in the fire, it happened they got a film of lead fumes across them, and had I not covered them over with this cement lotion they would have gone brittle as glass.[207] Then I gave them six hours moderate firing, and so in this way freed them from so evil a blemish.
THE END OF THE TREATISE ON GOLDSMITHING.
FOOTNOTES:
[202] Cellini may intend a stronger sense to the word ‘semplice. ’
[203] Lega
[204] See above, furnace construction.
[205] Cellini appears not to have quite understood the process Geber, who gives the oldest description of it, ‘Alchemiae Gebri Arabis Philosophi Solertissimi Libri, etc. Joan: Petreius Nurembergen denuo Bernae excudi faciebat, ’ anno 1545, p. 51, gives the ingredients thus: ‘Vitriol (ferrous sulphate), sal ammoniac, flower of copper (scale of oxide of copper formed by heating the metal with access of air), ground old earthen pot, sulphur in the smallest quantity or none at all, man’s urine, together with similar sharp and penetrating substances,’ etc. See Percy’s ‘Metallurgy,’ Murray, 1880; Part I., p. 385. Prof. RobertsAusten adds that ‘usually the “cement,” and the gold to be purified, were placed together into a porous earthen pot, and not between the joints of the brickwork ’
[206] Partitore.
[207] I am assured that this is a point of considerable scientific interest
THE TREATISE ON SCULPTURE.
The Nymph of
Fontainebleau
THE TREATISE ON SCULPTURE.
CHAPTER I. ON THE ART OF
CASTING IN BRONZE.
As in other places I have done, so now will I do afresh, & in order to give more surety & confidence to him that reads this screed of mine, adduce examples from sundry great works in bronze that I made for King Francis while in the glorious city of Paris. Those bronzes in part I finished, the greater part I left imperfect. One of the completed ones was a lunette about eight cubits across, made for the gateway of Fontainebleau. For this arch I fashioned a statue about seven cubits long in rather more than half relief, it was a figure personifying the fountain. Under its left arm were vases, from which water seemed to flow, and its right arm was posed upon the head of a stag, a great part of whose neck was brought out in full relief. On one side of the lunette were a number of dogs, that is to say setters [208] & greyhounds; on the other side were fashioned stags and wild boar. Above the lunette I made two little angels with torches in their hands as signifying victory, & over the whole was the salamander, the emblem of the King. There was abundance of rich festoonment, and two great satyrs for the pilasters of the gate. These latter were not cast, but were left in a state ready for casting. The lunette, however, was cast in several pieces, & the first and biggest was the nymph of Fontainebleau herself.[209] Her head & other portions of her body stood out in full relief, while the rest were in half relief. The way I fashioned her was as follows. I made a model in clay of just the size the figure was to be; this done, I estimated that the shrinkage would be about one finger’s thickness. So I very carefully went over the whole, touching it up and measuring it as the art directs.[210] Then I gave it a good baking, and after that I spread over the whole an even coat[211] of wax of less than a finger’s thickness, similarly adding wax
where I thought it needed it, or even taking a little away from off the waxen coat that was over the whole. This method I pursued till I had completed it with infinite diligence and care.
After this I pounded up some ox bone, or rather the burnt core of ox horns. It is like a sponge, ignites easily, and is the best bone that you can get anywhere. With this I beat up half a similar quantity of gesso of tripoli,[212] and a fourth part of iron filings, & mixed the three things well together with a moist solution of dung of horses or kine, which I first passed through a fine sieve with fresh water, till the latter took the colour of the dung.
The whole formed a composition which I applied to my model with hog sables, arranging the bristles so that their softer and external ends formed the end of the sable, and were thus tenderer to work with; and so gave the whole figure an equal coating of the composition all over, then I let it dry, and similarly gave it two more coats, each time letting them dry. These coats were every one about the thickness of an ordinary table knife’s back. This done, I gave it a coat[213] of clay about half a finger thick, let it dry, gave it another coat about a finger thick, let that dry too, and finally gave it a third, of the same thickness.
FOOTNOTES:
[208] Bracchi.
[209] See Cellini’s allusion to this in the ‘Vita.’
[210] Misurando come prometta l’arte.
[211] I interpret this to mean that he made measurements with a view to regulating the subsequent wax coat which was in the end to be replaced by the bronze Brinckman interprets it otherwise; according to him the meaning would be that because of the shrinkage Cellini gave the figure another coat of clay, but this appears to me to imply a misunderstanding of the process See also, Symonds’ interpretation of this method in the ‘Vita ’
[212] Gesso di tripolo.
[213] Camicia
CHAPTER II. HOW THE ABOVEMENTIONED CLAY IS MADE.
The clay you use is made thus: You take such clay as is used by the ordnance makers for their moulds. It may be found in many places, but preferably near by rivers, for there it has a certain sandiness,[214] still it must not be too sandy, suffice it if it be thin, for the rich clay is delicate and soft, such as is used for small figures, cups, plates, and so forth, but not good for our purpose. Also you will find it in hills and grottoes, particularly round Rome and Florence, and in France at Paris. The clay from the latter city is the finest I ever saw; but as a rule the clay from grottoes is better than that from rivers.
In order to obtain a good result you must let it dry, and sift it carefully through a rather coarse sieve in order to get rid of any pebbles or bits of root or of glass, & such-like things. Then you mix it with cloth frayings, about half as much of the latter as you have clay; and take note that here is a wondrous mystery of the craft that has never yet been used by any but me. When the clay and the cloth frayings are mixed and bathed with water to the consistency of a dough, you beat the mixture up well with a stout iron rod about two fingers thick; and, for this is the secret, you let it decompose for at least four months or more, the longer the better; for then the cloth frayings rot, and owing to this the clay gets to be like an unguent. To those who have not had experience of this little trade secret of mine the clay will appear too fatty, but this particular kind of fattiness in no wise hinders the accepting of the metal,[215] indeed it accepts it infinitely better, & the clay holds a hundred times more firmly so than if it had not rotted. I have used this kind of clay in ever so many most difficult works, all of which I shall tell of in their proper place.
FOOTNOTES:
[214] Alquanto renosa.
[215] Lo accettare il metallo
CHAPTER III. ANOTHER METHOD OF CASTING FIGURES IN BRONZE OF LIFE SIZE OR A LITTLE UNDER.
Model the figure you wish to cast direct in the clay and rag composition above described. Finish your model most carefully as regards its proportions and its details of design, in fact just as you wish to see it completed. When you have finished your figure, working it part in the fresh & part in the dry clay, as the art may require, and wishing to cast it in bronze, you give it a covering of painter’s foil[216] in order to do which you first take a certain quantity of turps, heat it in a cauldron or pail, and when it is heated to boiling, streak it very carefully all over the figure with a hog’s sable, taking heed not to injure a single muscle, vein or other subtlety, and so very carefully apply your foil. This foil has to be beaten into very fine sheets such as the painters use in many places, as for instance on their canvasses for painting coats of arms; it is well enough known all the world over. Well, you put this foil over the clay figure, and as you have to make a mould of gesso over that, you oil the whole figure well first. Were it not for the foil it would be but ill protected against the humidity and cohesive[217] power of the gesso, but with the foil it is well protected. In this way you work to great advantage, for after the figure is cast in bronze you still have your fine original model before you; and many youths & able workmen can help you clean the bronze figure up, while if you have no model to work to, this cleaning up takes a long time, is little to the poor master’s liking, and has but a sorry result. This was what happened to me when I made the Perseus for the most illustrious Duke Cosimo, and which may still be seen on his Excellency’s piazza. This, which was a figure of more than five cubits high, was made in the first of the two
described methods; that is to say, it was modelled in the clay composition, & finished one finger’s thickness under actual size;[218] then it was well baked, and the coat of wax modelled over it as in the case of the nymph of Fontainebleau. After this it was cast all in one piece. In order to remove the core[219] so that the figure might be lighter, I made through the wax a number of holes in the flanks, shoulders, and legs, and at such places where I required them; the result of this was that the core was kept in its place. Moreover, I put over the wax those unguents which I referred to in the case of the nymph of Fontainebleau, then the two or three coats of clay, next I bound it round with the iron of which I shall tell directly, & then I cast it. This casting was, owing to its size, the most difficult casting ever made. But because I am now minded to tell of the casting of a smaller figure, I will not muddle things too much by leaving my theme. Later on I shall not fail to enter upon a little dissertation about my Perseus.
