The decline in infectious disease mortality as a percentage of total deaths between 1990 and 2017 (source: healthdata). Still responsible for millions of deaths every year in the world, most of these infections are relatively easily curable. Where does this encouraging decrease come from? How could we do even better?

Viruses, bacteria and other micro-organisms

Infectious diseases refer to the diseases caused by a micro-organism. These include a number of very well-known diseases: HIV, cholera, malaria, tuberculosis or the most recent Covid-19. Great scourges of humanity, the great epidemics of history are often due to infectious diseases such as the Black Death in the 14th century, the Spanish flu in 1918 or the Covid-19 pandemic. We also sometimes speak of epidemics of non-infectious diseases such as the epidemics of obesity or depression.

Did you know?

According to Wikipedia, an epidemic is "the rapid increase of a disease in a given place at a given time" while a pandemic is an epidemic that has spread to "a significant part of the planet".

In 2017, infectious diseases accounted for around 15% of deaths worldwide1, far behind the 73% of deaths due to non-infectious diseases such as cancers, which are increasing due to the ageing of the world’s population (source: ONU) and to the increasing exposure to carcinogenic substances (source:

Trends in the incidence of infectious diseases

The histogram below shows the change in the percentage of deaths due to infectious diseases as a percentage of total deaths between 1990 and 2017. Infectious diseases have been grouped here into 5 categories and it can be seen that for 4 of these 5 categories, the percentage of deaths due to infectious diseases has fallen very significantly. Sexually Transmitted Diseases (STDs) are the exception: deaths caused by STDs have increased from 1.3% to 2% of total deaths between 1990 and 2017.

NooS · Trends in deaths from infectious diseases

However, if we look at the evolution of the percentage of deaths caused by STDs, we see that they peaked in 2006 and have been decreasing (in percentage) since then. For example, one of the most infamous respiratory infections, tuberculosis, has been slowly but steadily decreasing over the last 30 years. Other infectious diseases include meningitis, hepatitis, measles and tetanus, all of which have seen significant declines over the period 1990-2017.

NooS · Trends in deaths from STD

Where does this decrease in the incidence of infectious diseases actually come from?

The decline in major infectious diseases can be explained by the mobilization of major health actors financed by governments and individuals, with the World Health Organization at the forefront. With regard to respiratory infections, tuberculosis is the subject of a sub-objective of the UN’s Sustainable Development Objective 3 on Health with the ambition of eradicating this infection by 2030. To achieve this, the WHO recommends mobilising 13 billion dollars per year for access to diagnosis, treatment and care and 22 billion dollars per year for research into this disease. It should be remembered that tuberculosis is an infection that can be treated and cured (source: OMS) .

Also for cholera (diarrheal infection), the WHO has defined an action plan for 2030 to vaccinate and raise hygiene awareness. Once again, this infection is not a mystery to humans, we know its causes and we know how to treat it with oral rehydration solutions (source: OMS) .

International aid has also made it possible, through NGOs, to reduce the impact of neglected tropical diseases, a group of 13 infections affecting the poorest populations in no less than 149 countries. Means of combating these infections include mass deworming campaigns and treatment campaigns that come together with HIV and malaria campaigns, two diseases that attract much more international attention and funding. It has been shown that deworming campaigns have also reduced school absenteeism by 25% (source:

For many other infectious diseases, vaccination campaigns have almost eradicated them in the richest countries. For example, measles killed “only” 26 people in France between 2008 and 2019 (source: but has killed more than 7,000 people in the Democratic Republic of Congo alone in the last two years.

This comparison of measles figures, as there are for many infectious diseases, shows the great inequalities in the face of diseases. Not a biological inequality, but an inequality of resources to fight the disease. The Covid-19 epidemic reminds us that we are all biologically equal in the face of diseases. Nevertheless, the reality of inequalities in wealth and therefore in access to healthcare means that diseases are hitting the poorest harder. To help reduce the impact of these diseases, which are almost non-existent in the so-called developed countries but kill hundreds of thousands in the poorest countries, everyone can support vaccination campaigns, awareness-raising campaigns or the setting up of health infrastructures via NGOs or social enterprises working in this direction.

It is in this sense that NooS has made it its mission to engage companies and individuals in a new paradigm of sustainable development. The projects that you can support through our platform contribute to solving major issues in terms of health, education and the environment.

Photography credits – Cover: Marcelo Leal via Unsplash