This 'hidden killer' is responsible for one in five deaths, and you might never have heard of it

It’s preventable and treatable, and yet it kills more people every year than cancer. That’s one of the conclusions of a new study of sepsis, an often hard-to-spot condition that many people have never heard about.

The research, led by scientists from the University of Pittsburgh and the University of Washington, has found that sepsis kills 11 million people every year – more than double previous estimates. It says sepsis is responsible for one in every five deaths worldwide.

Sepsis, also known as blood poisoning, occurs when a person’s immune system overreacts to an infection and starts to damage the body's tissues and organs. It can lead to further health complications, organ failure and death, and survivors can be left with lifelong health problems or disability.

Because there are lots of possible symptoms, and these can be vague, sepsis can be difficult to identify – which has led to it being called a "hidden killer".

Anyone affected by an infection could develop sepsis, according to the World Health Organization (WHO). But some vulnerable populations such as elderly people, pregnant women, people in hospital, and those with conditions like HIV/AIDS, liver cirrhosis, cancer, and kidney disease are at higher risk.

The scale of the problem

The majority of cases affect patients in low or middle-income countries, although wealthy countries are also impacted, the new report says. Sub-Saharan Africa is one of the worst affected regions, along with some South Pacific islands and parts of Asia.

More than 40% of cases occur in children under 5 years old, and the study highlights the disproportionately high death rate among children from poor areas.

While previous estimates of the disease’s global spread were based on hospital data from some middle and high-income countries, the recent study includes cases occurring outside of hospitals, especially in low-income regions.

"We are alarmed to find sepsis deaths are much higher than previously estimated, especially as the condition is both preventable and treatable," explains study senior author, Mohsen Naghavi, Professor of Health Metrics Sciences at IHME at the University of Washington School of Medicine.

"We need renewed focus on sepsis prevention amongnewborns and on tackling antimicrobial resistance, an important driver of the condition."

While the scale of the problem is bigger than first thought, the number of cases is decreasing over time.

The incidence of sepsis per 100,000 of the population for both males and females has been on a downward trajectory over the past three decades. In 1990, there were an estimated 60.2 million cases leading to 15.7 million deaths. By 2017, total cases of sepsis had fallen 19% and there were 30% fewer deaths.

The next steps

While this trend is encouraging, more can be done to reduce the impact of this deadly condition.

Tackling the underlying causes that lead to sepsis is part of the solution, which involves improving sanitation, access to clean water and promoting vaccination programmes, particularly in poorer regions.

Initiatives like Gavi, the Vaccine Alliance, launched at the World Economic Forum Annual Meeting in 2000, helps promote immunization programmes in poorer countries through public-private partnerships. The programme brings together world bodies like UNICEF and the WHO, the Bill & Melinda Gates Foundation, government and research agencies, the vaccine industry and many other organizations to help protect the world’s children from infectious diseases.

Marking its 20th anniversary at Davos 2020, the alliance has contributed to the immunization of nearly 700 million children and saved an estimated 10 million lives.

Kristina E. Rudd, a lead author of the new study and assistant professor in Pitt's Department of Critical Care Medicine, sums up the solution. "To start with it's basic public health infrastructure. Vaccines, making sure everyone has access to a toilet and clean drinking water, adequate nutrition for children and maternal healthcare would address a lot of these cases."