Global -Disease -Prevalence _V3

Earlier this week, it was reported that dementia had narrowly overtaken heart disease as the leading cause of death in England and Wales in 2015.

There are thought to be several reasons contributing to this trend, among them: the ageing population; a drop in the number of deaths caused by heart disease; and an increase in overall dementia diagnoses, meaning that doctors are now more equipped to identify the condition as a cause of death than they have been previously.

We might take this news as being indicative of changing health trends we can expect to see over the coming decades.

In 1970, the global population was about 3.7 billion. By the start of 2016, this had doubled to roughly 7.5 billion, and is expected to rise to around:

  • 8.5 billion by 2030
  • 9.2 billion by 2040
  • and 9.7 billion by 2050

This is largely due to better quality of life, and increasing life expectancy:

  • In 2010, global average life expectancy at birth was around 69.
  • By 2050, according to UN estimates, this will have climbed to 76.

Advances in healthcare and better quality of life are the driving factors behind people living longer. However, lifestyles are changing too, partly in response to developing technology, and as we’ll discuss, this means that the prevalence of some illnesses is expected to rise.

In what we expect to be a short series of posts, we’ll explore how these trends may affect the global incidence of certain conditions over the course of the next 35 years, and some of the social factors that may make a difference; but we’ll also look at the worldwide prevalence of communicable illnesses, and how intervention methods may affect these over the coming decades.

How common will diabetes be?

In a recent post, we discussed the future of this condition with the International Diabetes Federation. They estimated the number of those living globally with diabetes in 2015 to be 415 million. By 2040, they estimate that this will have increased to 642 million.

Furthermore, they note that while in 2015 one in eleven adults had diabetes, this will rise to one in ten by 2040.

Type 1 diabetes, as we know, is autoimmune; it occurs when the immune system attacks pancreatic cells and inhibits the body’s ability to make insulin.

Type 2 typically manifests in those aged over 40, or who have one or more risk factors; the most significant of these is being overweight or obese. Type 2 accounts for the majority of cases (about 9 out of 10).

Unhealthy lifestyles, particularly those closely associated with urbanisation, are therefore often attributed to be the main cause of this rise. Calorie and sugar-dense diets, combined with an overall increase in occupations that are sedentary in nature, are major factors behind it.

Luckily awareness of how to reduce the risk of the condition is generally rising thanks to the work of organisations like the IDF, and some governments (such as in Mexico, France, Hungary and now the UK) are responding to calls for sugar levies to be imposed to reduce consumption of sugary products such as fizzy drinks.

But experts argue that more needs to be done to encourage healthy food choices and physical activity in order to curb the escalation of diabetes. Among these are urging supermarkets and producers to make health foods more accessible and affordable, and imposing limitations on the promotion of unhealthy, calorific snack items.

How common will heart disease be?

It is thought by many that cardiovascular conditions will see a rise in prevalence in the coming years, as they tend to be more common in older people and the ageing population is set to increase.

The extent of this rise, however, is subject to discussion.

  • An Icelandic study from 2016 stated that heart failure in those aged 65 and over is set to more than double by 2040, and treble by 2060.
  • One study by researchers Netherlands projected that the number of cardiovascular patients in that country would increase by 65 percent between 2011 and 2040.
  • In 2012 a prominent Hong Kong doctor predicted that heart disease would increase by 50 percent globally by 2040.
  • Figures quoted in a joint report compiled by the World Economic Forum and Harvard School of Public Health estimated that the total global cost of cardiovascular disease (which includes the cost of lost productivity as well as care) is set to increase from $863 billion in 2010 to $1,044 billion in 2030.

WHO baseline scenario projections seem to be somewhat consistent with these findings. They estimate that deaths caused by cardiovascular illnesses will rise from 17.9 million in 2015 to 22.2 million in 2030 (a 24 percent rise); and that globally, ischaemic heart disease will remain the leading cause of death (13.2 percent of global totals in both 2015 and 2030).

As with diabetes, overall awareness of how diet and lifestyle directly affect heart health is growing. But while the projected rise might largely be attributed to the increasing average age of the population, one has to believe that urbanisation and sedentary routines will likely play a role in this too.

To ease the growing burden on healthcare providers, prevention will remain key: once more, campaigning and education on the ramifications of unhealthy lifestyles are going to continue to be essential in the coming decades.

How common will HIV be?

The number of people globally living with human immunodeficiency virus was estimated by UNAIDS in 2015 to be 36.7 million. They also estimated that since the epidemic began, 78 million had become infected with the virus, and 35 million had died from related causes.

In the same report, they noted that new cases of infection had fallen from roughly 3.2 million per year in 2000 to 2.1 million per year in 2015.

The number of people globally receiving treatment for the condition has grown, as accessibility has increased. According to figures published by AVERT, 3 percent of people with HIV globally in 2000 were accessing treatment. By 2015, this had risen to 46 percent.

HIV prevalence has thereby seen an overall rise, because people with the condition are getting the treatment they need and essentially living for longer. Consequently, it is expected that the number of people living with HIV will continue to rise over the coming years, while the number of those dying from related diseases as a percentage of this will likely decrease.

In 2013, WHO projected that HIV/AIDS would be responsible for 1.67 million deaths globally, equivalent to 2.9 percent, in 2015. In 2030, they estimate that the actual number of deaths attributable to HIV/AIDS is expected to rise to 1.79 million, equivalent to 2.6 percent of deaths.

However, how common the condition is years from now largely depends on the measures taken at international level to make testing and treatment accessible to patients.

Research undertaken at the British Columbia Centre for Excellence in HIV/AIDS back in 2006 suggested that the universal provision of antiretroviral therapy could reduce the global presence of the virus to just one million by 2050. While they argued that this provision would obviously come at a considerable financial cost at first, this would decrease with each passing year due to the falling number of new infections.

The economic landscape has changed considerably since then; but the theoretical argument remains that ending the virus is within our scientific means (even if it is not easily within our financial means).

How common will malaria be?

Once again, intervention measures taken at a global level to tackle malaria are going to be crucial in the coming decades. As we’ve seen, the disease is capable of developing a resistance to medicine; which makes total eradication a more practical and economically viable option in the long term, than the perpetual development of new treatments.

Going back to WHO baseline scenario projections, they estimated in 2013 that malaria would cause 447,000 deaths globally in 2015, rising to 457,000 in 2030.

However, since these projections were made, WHO have implemented a ‘major scale-up’ of efforts to drastically reduce the presence of the disease, with the long-term goal of eradication. Their aim is to reduce malaria prevalence by 90 percent by 2030. With cooperation from all countries, total eradication by 2040 is thought to be possible.

You can find more information about malaria and the risk factors present in different countries by consulting our world map.

How common will viral hepatitis be?

Mortality related to hepatitis B and C is on the rise, and a WHO report puts this down to poor access to treatment in some continental regions.

The 2016 publication noted that, globally, an estimated 240 million people are living with chronic hepatitis B, and 130-150 million with hepatitis C. It also noted that 1.46 million people died worldwide from viral hepatitis in 2013.

Without wider access to proper treatment, it went on to project that the disease would be responsible for 19 million further deaths worldwide between 2015 and 2030.

Vaccination and improved blood safety has helped to reduce the overall prevalence of viral hepatitis in recent years; and provided a combined prevention and treatment strategy is implemented, WHO argue that virtual eradication by 2030 is within our power.

Recently, after passing their Hepatitis C Elimination Programme, the Government of Georgia announced that they expected HCV (which affects 6.7 percent of the population in the country) to be ‘practically eradicated’ there by 2020.

As with the other communicable conditions already discussed, where we stand in 30 years time will depend largely on the success of these strategies, and the willingness of nations to cooperate in their implementation.

In the coming weeks, we’ll be returning to this subject to discuss the future of a range of other conditions. Follow us on Twitter and Facebook (icons below) to stay up to date with all the latest posts.