“They were undone, destroyed, after all of man's weapons and devices had failed, by the tiniest creatures that God in his wisdom put upon this earth.”⁽²⁾ This quote from H.G Wells’ ‘War of the Worlds’ refers to how invading aliens were not able to survive in our atmosphere with the countless number of viruses, bacteria and fungi present on earth. These hypothetical aliens were new to our environment and therefore were unable to survive, but what about the human race that has been around for centuries? Why are we still riddled with numerous diseases and infections that we are unable to cure or control?

Disease is defined as ‘a particular quality or disposition regarded as adversely affecting a person or group of people’.⁽³⁾ Examples of common diseases in the 21st century include HIV&AIDS, malaria, influenza and colds. These diseases may be caused by a number of agents, including bacteria, viruses and fungi which may be transferred through various ways, including airborne droplets (usually respiratory diseases), ingesting contaminated food (gastrointestinal illnesses), sexual contact (sexually transmitted diseases) or insects (as in the case of malaria. Furthermore, diseases that cannot be transmitted, referred to as non-communicable diseases, such as cancer and heart disease, are ever-present in today’s society. Diseases have been, and still are, a major concern for human health and despite modern advances in medical technology and healthcare, disease is still the greatest historical killer.⁽⁴⁾

This paper discusses the most prevalent diseases in Africa and the reasons why Africa, and the world, continue to battle disease.

African case studies: Most prevalent diseases afflicting the continent

This section provides a description of leading diseases affecting humankind throughout the world and particularly in Africa. There are a number of examples of current and most concerning African diseases and the most prevalent ones will be discussed here as specific cases. These cases include tuberculosis (TB), cholera, HIV&AIDS, malaria and cancer. The listed cases represent all the transmission pathways mentioned above; as well as cancer, a non-communicable disease.

TB is highly infectious and may be contracted by simply being in the same room as an infected person. The infectious nature of this disease has resulted in it becoming widespread in Africa.⁽⁵⁾ Furthermore, based on data from 2000-2008, the incidence of TB, as well as the related death rate, is increasing.⁽⁶⁾ The countries with the highest incidence of TB are Swaziland, Zimbabwe, South Africa, Lesotho and Botswana.⁽⁷⁾ TB is preventable and curable,⁽⁸⁾ yet one person reportedly dies from it every 20 seconds. Although relatively inexpensive cures have been around for 50 years,⁽⁹⁾ the medical treatment required is often inaccessible. Furthermore, certain strains of TB have developed immunity to some drugs and often multi-drug treatments are required. As such, constant research into new methods and treatments is needed.⁽¹⁰⁾

Cholera is a disease contracted through consuming contaminated food or water. This disease is usually related to poverty, as rural areas typically lack access to clean water or are unable to boil unsanitary water – two conditions in which cholera thrives.⁽¹¹⁾ There has been an increasing spread of cholera cases in 31 African countries,⁽¹²⁾ with the highest incidence rates in the same countries as identified for TB above. However, these increases have been accompanied by a decrease in the mortality rate, which is likely due to improved treatment and sanitation. Cholera is easily treatable usually with oral rehydration salts and, in more severe cases, with antibiotics to reduce the adverse effects.⁽¹³⁾

HIV&AIDS is a sexually transmitted disease contracted through intercourse, or from contact with bodily fluids. Interestingly, the number of people between the ages of 15 and 49 living with HIV&AIDS in Africa has decreased during the years between 2001 and 2007.⁽¹⁴⁾ The countries with the largest number of HIV&AIDS infected individuals are the same as for cholera and TB. Despite the decrease however, the prevalence of HIV&AIDS and the associated mortality rate are much larger for African regions than anywhere else in the world.⁽¹⁵⁾ HIV&AIDS is preventable with the correct use of prophylactics in the form of condoms; and there is currently medication to significally reduce the chances of an individual contracting HIV&AIDS if taken immediately after fluid contact. HIV&AIDS-suppressing drugs (or antiretrovirals) are also available to slow the symptoms of the disease.

Malaria is a vector-borne disease carried by mosquitoes, which bite and infect humans. The mosquito is merely a carrier of the infectious disease. This disease is prevalent in the tropical areas of Africa extending into some subtropical countries. Countries with the highest number of malaria cases are Uganda, the Democratic Republic of Congo (DRC), Malawi and Mozambique. These countries have more than 4.5 million reported cases per annum. This equates to the African region having more than 10 times the number of cases compared to the Eastern Mediterranean; and more than 6 times the global average.⁽¹⁶⁾ However, malaria is also preventable and treatable. Prevention methods include mosquito nets and the use of insecticides, as well as oral prophylactics before entering a malaria-prone area. Treatment is required immediately after contraction of the disease; otherwise it may quickly become life-threatening.⁽¹⁷⁾

Cancer is a non-communicable disease, the incidence of which continues to increase globally.⁽¹⁸⁾ Cancer is the uncontrollable growth of abnormal cells in the body. Besides commonly being a hereditary disease, other common causes of cancer are smoking, poor diet, excessive alcohol consumption, sun exposure, environmental pollutants, infections, stress, obesity and a lack of exercise.⁽¹⁹⁾ Of these, smoking, diet and infections are considered the greatest threats.⁽²⁰⁾ Therefore, with appropriate lifestyle changes, cancer can be avoided and is therefore possibly preventable. Treatments for cancer vary according to the stage of development and include surgical removal of the cancerous cells, radiation and/or chemotherapy.⁽²¹⁾

Why is there an increase in occurrence of disease?

Pathology, or the study of disease, has been around for at least 1,000 years.⁽²²⁾ Modern advancements and novel understandings of the functioning and effects of diseases have shed much needed light on methods for treating disease. Some diseases have even been eradicated due to modern vaccines, antibiotics and new treatments. A good example of this is smallpox which was eradicated by mass vaccination.⁽²³⁾ However, there are several articles investigating new strains of diseases or epidemics of certain diseases, and often it appears that very little is being done to actually develop cures or preventative measures for these diseases. This sections aims to explain the dynamic nature of diseases and why they are nearly impossible to eradicate.

Firstly, infectious or communicable diseases are spread by infected individuals. The risk of infection is seen as a density-dependent factor which means that the larger the number of individuals, and the more crowded the environment is, the easier and more likely disease is to spread.⁽²⁴⁾ If one avoids coming into contact with an infected person or their environment, then there is a lower risk of person-to-person infection. However, airborne diseases are often able to withstand exposure to the environment as they develop protective shells and may remain dormant in the environment for long periods of time before becoming infectious once again; and thus can spread over large distances on air currents.⁽²⁵⁾

The global population has been increasing at such a high rate that living density has subsequently increased, thereby resulting in an increased rate of disease transmission. Furthermore, the modern transport infrastructure systems that enable people to reach the other side of the world in a single day have facilitated the spread of diseases that were previously isolated to a single population or continent.

Secondly, poor and unsanitary living conditions facilitate the growth and spread of disease.⁽²⁶⁾ Africa is predominantly a poor continent with a large proportion of the population living in rural areas – a contributing factor to the large number of cases and deaths resulting from leading diseases. Often rural communities do not have running water and this necessity must be obtained from a nearby river. According to the data published by the World Health Organisation in 2008, only 61% of Africa’s population is using improved drinking water sources such as piped water into dwellings; a public tap; a tube well or borehole; or a protected dug well, spring and rainwater collection.⁽²⁷⁾ Unfortunately, the other 39% are using unsafe water sources such as river systems, which often harbour cholera and where contamination often occurs.⁽²⁸⁾ Furthermore, poor health systems in developing countries, situated few and far between, are often inadequately equipped to deal with complicated stages of infections, and often multiple-disease patients do not get the required treatments.⁽²⁹⁾

Emerging global climate change has also played a key role in the increase and pervasion of disease. The negative effects of climate change and the increasing human population have resulted in land loss and the subsequent loss of biodiversity. This loss of biodiversity has been found to increase the incidence and distribution of infectious diseases through the homogenisation of ecosystems.⁽³⁰⁾ It is estimated that climate change alone is responsible for an additional 150,000 deaths and five million illnesses per year, with the greatest number of mortalities and incidences in Africa.⁽³¹⁾ Climate-driven diseases are among the largest global killers, and include malaria and diarrhoeal-related diseases such as cholera.⁽³²⁾ The increasing temperatures associated with climate change have increased the area that the disease covers, resulting in more infections and deaths.⁽³³⁾

Developing countries are often ill-equipped, physically, scientifically and technologically, for the treatment of diseases. For example, a survey of 11 doctors in the KwaZulu-Natal region of South Africa found that 8 of these doctors either prescribed the wrong treatment, or dose and duration were incorrect for the most common diseases.⁽³⁴⁾ This is as a result of incorrect knowledge of the current diseases. Furthermore, in multiple-disease cases such as individuals with both TB and HIV&AIDS, different doctors are used for the separate treatments. However, it is much more beneficial for a single doctor, with an up-to-date understanding of integrated treatments, to deal with these patients.

Impoverished areas are prone to contracting easily transmitted diseases and they often have limited supplies and technology to deal with the increase of disease resulting in worse situations. Another factor exacerbating the situation is that many diseases have become immune to certain treatments, and more advanced diagnostic equipment is required with the prescription of multiple treatments. Disease has been very difficult to eradicate and, with so many factors that facilitate the spread of disease, especially in impoverished countries, little headway appears to have been made.

Health securities: Are diseases better at surviving than humankind?

Both diseases and humankind have survived each other for decades. There are hypotheses suggesting that disease wiped out the dinosaurs and because humans have not experienced a similar fate to dinosaurs, it could be inferred that the human race is co-existing with diseases. Diseases are better at adapting to changing environments, as is the case with drug-resistance strains and, in so doing, are the largest killers of humans in history, even surpassing war.⁽³⁵⁾ Communicable diseases are the largest killers in Africa while non-communicable diseases are the top causes of deaths for all other regions.⁽³⁶⁾ However, despite the fact that humankind is unable to develop immunities like diseases do, we use our environment and knowledge to develop vaccines, drugs and treatments, which can be considered as a form of artificial adaptation. In the end, there is a never-ending race between diseases’ infectious ability and humans’ ability to fight off disease with immunity and artificial adaptation.

Even in this age of technological quantum leaps, it appears that disease is here to stay, for now at least. But surely there is hope with globally and locally improving health security and the massive amount of research going into cures and medication? Efforts from global corporations and organisations have had great benefits, especially where efforts have been focused on more disease-prone countries such as those in Africa.⁽³⁷⁾ However, the impoverished nature of the African continent is the reason why it is still struggling with even less-serious diseases. When considering the above-mentioned diseases in a global context, it is evident that Africa is far more affected by these diseases than any other region in the world.⁽³⁸⁾ There may be better health security globally, but Africa is more than 5% below the global average Gross Domestic Product (GDP) expenditure on health.⁽³⁹⁾

Concluding comment: What is in store for the future?

This paper has looked at the continuing spread of diseases afflicting the human race. Moreover, the discussion has delved into why we continue to stage war with these diseases. The reasons for the continued occurrences of disease include poverty, continued person-to-person infections, environmental considerations such as climate change, and under-developed technological and scientific resources, especially in developing countries. Mankind has made major strides in creating various elixirs and treatment options for common and complex human diseases. However, more needs to be done in order to combat the spread of disease. This will involve knowledge- and technology-sharing, associated funding for developing countries, and a greater understanding of the physical environment as well as anthropogenic activities, which negatively impact on the environment.

There are two ways of looking at the future. In the first scenario, recent increases in new diseases and their incredibly infectious nature, even across borders, will eventually lead to a new ‘super-disease’. This ‘super disease’ will simply be too infectious and spread too quickly for adequate treatment to develop and become available to the masses, resulting in mass extinction. Assumedly this will be similar to the hypothesis regarding the dinosaur extinction. Alternatively, future advances in drugs and research in medical fields may allow for the complete immunity of human’s from the majority of diseases as is the case in the few vaccinations that are present today. This would then increase the average lifespan of the human race and potentially increase the threats associated with overpopulation leading to new problems.

NOTES:

(1) Contact Wayne Brazier through Consultancy Africa Intelligence’s Enviro Africa Unit (enviro.africa@consultancyafrica.com).
(2) Wells, H.G., 1898. The war of the worlds. London: William Heineman.
(3) ‘Disease’, Oxford dictionaries, 2011, http://oxforddictionaries.com.
(4) Sara Reardon, ‘Preventable chronic diseases are now the world’s biggest killers’, ScienceMag, 27 April 2011, http://news.sciencemag.org.
(5) WHO, ‘Health situation analysis in the African region: Atlas of health statistics 2011’, 2011, http://www.afro.who.int.
(6) Ibid.
(7) Ibid.
(8) WHO, ‘Tuberculosis’, 2011, http://www.who.int.
(9) ‘Tackling tuberculosis in Africa’, The World Bank, 21 March 2008, http://go.worldbank.org.
(10) WHO, ‘Guidelines for the programmatic management of drug-resistant tuberculosis’, 2011, http://whqlibdoc.who.int.
(11) WHO, ‘Resurgence of cholera in the WHO African region: Current situation and way forward’, Regional committee for Africa, http://www.afro.who.int.
(12) Ibid.
(13) Ibid.
(14) WHO, ‘Health situation analysis in the African region: Atlas of health statistics 2011’, 2011, http://www.afro.who.int.
(15) Ibid.
(16) Ibid.
(17) WHO, ‘Malaria’, http://www.who.int.
(18) WHO, ‘Are the number of cancer cases increasing or decreasing in the world?’, 1 April 2008, http://www.who.int.
(19) Anand, P. et al., 2008. Cancer is a preventable disease that requires major lifestyle changes. Pharmaceutical Research, 25(9), pp.2097-2116.
(20) Ibid.
(21) ‘Cancer’, PubMed Health, 14 August 2010, http://www.ncbi.nlm.nih.gov.
(22) Wiltse, L.L. and Pait, T.G., 1998. Herophilus of Alexandria (325-255 B.C.). The father of anatomy. Spine, 23(17), p.1904-1914.
(23) WHO, ‘The end of the line for some infectious diseases’, 1999, http://www.who.int.
(24) Wilson, K. et al., 2002. Coping with crowds: Density-dependent disease resistance in desert locusts. Proceedings of the National Academy of Sciences of the United States of America, 99(8), pp.5471-5475; Leader-Williams, N., 1982. Relationship between a disease, hot density and mortality in a free-living deer population. Journal of Animal Ecology, 51, pp.235-240.
(25) Barton, L.L. and Northup, D.E., 2011. Microbial ecology. Hoboken, NJ: John Wiley & Sons.
(26) WHO, ‘Resurgence of cholera in the WHO African region: Current situation and way forward’, Regional committee for Africa, http://www.afro.who.int.
(27) WHO, ‘Health situation analysis in the African region: Atlas of health statistics 2011’, 2011, http://www.afro.who.int.
(28) Miriam Mannack, ‘Cholera spreads to river systems of South Africa’s Kruger Park’, Now Public, 29 January 2009, http://www.nowpublic.com; Madoroba, E. and Momba, M.N.B., 2010. Prevalence of Vibrio cholerae in rivers of Mpumalanga province, South Africa as revealed by polyphasic characterization. African Journal of Biotechnology, 9(43), pp.7295-7301; Lynne Altenroxel and Anna Cox, ‘Girl dies after baptism in cholera river’, IOLNews, 19January 2001, http://www.iol.co.za.
(29) ‘Tackling tuberculosis in Africa’, The World Bank, 21 March 2008, http://go.worldbank.org.
(30) Pongsiri, M.J. et al., 2009. Biodiversity loss affects global disease ecology. BioScience, 59(11), pp.945-954.
(31) Climate Institute, ‘Human health’, 2010, http://www.climate.org.
(32) Ibid.; ‘Predicting future spread of infectious-disease vectors’, ScienceDaily, 2 February 2009, http://www.sciencedaily.com.
(33) Ibid.
(34) Connolly, A.M. et al., 1999. Inadequate treatment for sexually transmitted diseases in the South African private health sector. International Journal of STD & AIDS, 10(5), pp.324-327.
(35) Sara Reardon, ‘Preventable chronic diseases are now the world’s biggest killers’, ScienceMag, 27 April 2011, http://news.sciencemag.org.
(36) Ibid.
(37) WHO, ‘WHO in the African region’, 2009, http://www.afro.who.int.
(38) WHO, ‘Health situation analysis in the African region: Atlas of health statistics 2011’, 2011, http://www.afro.who.int.
(39) Ibid.

Written by Wayne Brazier ⁽¹⁾