They represent one in eight deaths recorded in 2019.
One in eight deaths recorded in 2019 is linked to bacterial infections, which were the second leading cause of death worldwide that year, reveals a study published in the scientific journal Lancet.
That year, 7.7 million deaths (13.6% of the total) were linked to 33 common bacterial infections, with more than half of the cases linked to just five bacteria (S. aureus, E. coli, S. pneumoniae, K. pneumoniae and P. aeruginosa), shows the survey.
“These new data reveal, for the first time, the magnitude of the challenge bacterial infections pose to public health around the world,” said study co-author Christopher Murray, director of the Institute for Health. Metrics and Evaluation (IHME) from the University of Washington, quoted in the publication of the report.
The calculations were made “for all ages and genders” in 204 countries and territories, with researchers using 343 million “individual and isolated pathogen records to estimate deaths associated with each pathogen and disease type. ‘responsible infection’.
The new study “provides the first global estimates of mortality associated with 33 common bacterial pathogens and the 11 major types of infection – known as infectious syndromes – that lead to death from sepsis”.
More than 75% of these 7.7 million deaths were due to three syndromes: lower respiratory tract infections, bloodstream infections, and peritoneal and intra-abdominal infections.
Regarding the five bacteria responsible for more than half of the deaths, the main one is S. aureus (1.1 million deaths), followed by E. coli (950,000 deaths), S. pneumoniae (829,000), K. pneumoniae (790,000) and P. aeruginosa (559,000). These pathogens caused “a similar number of deaths of women and men”.
But death rates based on age and the type of deadliest pathogens vary by location.
Sub-Saharan Africa had the highest mortality rate (230 deaths per 100,000 population), while the highest income super-region (which includes countries in Western Europe, North America and Australasia) had the lowest (52 deaths per 100,000 population).
By country, the Central African Republic had the highest rate (394 deaths per 100,000 population) and Iceland the lowest (35.7 per 100,000).
According to the study, S. aureus was the leading bacterial cause of death in 135 countries, followed by E. coli (37 countries), S. pneumoniae (24 countries) and K. pneumoniae and Acinetobacter baumannii (4 countries each).
The pathogens associated with most deaths also differ by age.
S. aureus was associated with most deaths in adults over 15 years of age and Salmonella enterica serovar Typhi was associated with most deaths in children aged five to 14 years.
The pathogen associated with the highest number of neonatal deaths was K. pneumoniae, while S. pneumoniae was the deadliest in children under five, excluding newborns, the study showed.
The researchers point out that while many estimates exist for pathogens such as tuberculosis, malaria and HIV (human immunodeficiency virus), calculations of the disease burden of bacterial pathogens have so far been limited to a handful of specificities and types of infection or have focused only on certain populations.
In 2019, S. aureus and E. coli were associated with more deaths than HIV/AIDS, but analyzes show that 42 billion dollars (around 41 billion euros) have been allocated to researching this virus, while that relating to E. coli received 800 million (781.4 million euros).
The study admits that the differences may be due to a lack of data on the global significance of these infections.
“So far, there has been a clear lack of country-level estimates for regions of the world where people are most affected by bacterial infections,” said study co-author Authia Gray. and researcher at IHME.
“These new data can be used as a guide to help tackle the disproportionately high burden of bacterial infections in lower-middle-income countries and may ultimately help save lives and prevent people from losing years of their lives to disease,” he added. .
Reducing bacterial infections should become a global public health priority, the study points out, considering that to reduce the burden of the diseases they cause, it is essential to build stronger health systems, with greater laboratory diagnostic capacity, the application of control measures and the optimization of the use of antibiotics.
“Effective antimicrobials exist for all 33 bacteria studied,” he says, adding that “much of the disproportionately high burden (of infections) in lower-middle-income countries can be attributed to insufficient access to effective antimicrobials, weak health systems and prevention programs”.
For the researchers, “essential prevention strategies” include “better access to clean water and sanitation facilities, increased vaccination rates, development of new vaccines”, and it is also important to improve the access to the appropriate antibiotic for each infection. .
For bacteria for which there is no vaccine, their development is crucial, they insist, also noting the importance of developing effective new antibiotics to deal with “the growing threat” of antimicrobial resistance and infections. bacteria in general.