Bacterial infections caused most deaths in sub-Saharan Africa in 2019: Lancet

The region saw 230 deaths per 100,000 people; Just 5 pathogens caused over half the infection deaths globally

By Susan Chacko
Published: Monday 28 November 2022
Common bacterial infections were the second-leading cause of death in 2019, according to the analysis. Photo: Wikimedia Commons

Sub-Saharan Africa saw the greatest number of deaths due to bacterial infections in 2019, with 230 deaths per 100,000 people, a recent study found. The analysis found that common bacterial infections were the second-leading cause of death in 2019. 

Of the 33 bacterial pathogens studied, five were responsible for more than half of the deaths. However, the deadliest bacterial pathogens and types of infection varied by location and age, the study said. Around 13.7 million infection-related deaths were reported in 2019.

Read more: Steroid misuse in COVID-19 patients can cause life threatening infections

The study was published in the medical journal The Lancet November 21, 2022, by the team of Global Burden of Disease (GBD) 2019 antimicrobial resistance collaborators. This is one of the first studies to present comprehensive global estimates of deaths associated with 33 bacterial pathogens across 11 major infectious syndromes.

Deaths associated with the 33 bacterial pathogens comprised 13.6 per cent of all global deaths and 56.2 per cent of all sepsis-related deaths in 2019. 

The Central African Republic saw the highest age-standardised mortality rate, with 394 deaths per 100,000 people. 

Age-standardised mortality rate is a weighted average of the age-specific mortality rates per 100 000 people, where the weights are the proportions of people in the corresponding age groups of the World Health Organization standard population.

Years of life lost (YLL) is a measure of premature mortality that takes into account both the frequency of deaths and the age at which it occurs. The substantial YLL associated with these bacteria in sub-Saharan Africa magnifies the burden of infections in the region compared with other areas. 

Of 13.7 million infection-related deaths, 7.7 million deaths in 2019 were associated with the 33 bacterial pathogens, both resistant and susceptible to antimicrobials, estimated in this study. 

Meningitis and other bacterial central nervous system infections; cardiac infections; peritoneal and intra-abdominal infections and lower respiratory infections and all related infections in the thorax were some of the infectious syndromes studied.

Read more: Canadian scientists develop new antibiotic that prevents cell division

The study also looked at bacterial infections of the skin and subcutaneous systems; infections of bones, joints, and related organs; typhoid, paratyphoid, and invasive non-typhoidal Salmonella; diarrhoea; urinary tract infections and pyelonephritis; bloodstream infections; and gonorrhoea and chlamydia.

Among the investigated bacteria, five leading pathogens — staphylococcus aureus, escherichia coli, streptococcus pneumoniae, klebsiella pneumoniae and pseudomonas aeruginosa — were responsible for 54.9 per cent of deaths.

The study pointed out that even though more than half of bacterial deaths were caused by one of these five pathogens, only S pneumoniae has been the focus of global surveillance and public health initiatives.

Infectious diseases like human immunodeficiency virus/ acquired immunodeficiency syndrome (HIV/AIDS), tuberculosis and neglected tropical diseases have their own sustainable development goal (SDG) indicators (SDG 3.3). They also have substantial global public health investments like The Global Fund to Fight AIDS, Tuberculosis and Malaria

However, the bacterial pathogens mentioned in the study and with a greater fatal burden were not a major focus of any global public health initiatives.

The deadliest infectious syndromes and pathogens varied by location and age, the study said. Age-standardised mortality rate associated with these bacterial pathogens highest in sub-Saharan Africa. The region sees 230 deaths per 100,000 people, but the number dips to 52.2 deaths per 100,000 population in high-income areas. 

S aureus was the leading bacterial cause of death in 135 countries and was also associated with the most deaths in individuals older than 15 years globally. Among children younger than five years, S pneumoniae was the pathogen associated with the most deaths. 

In 2019, more than 6 million deaths occurred as a result of three bacterial infectious syndromes. Lower respiratory infections and bloodstream infections caused more than 2 million deaths each and peritoneal and intra-abdominal infections caused more than 1 million deaths.

Deaths associated with these bacteria would rank as the second leading cause of death globally in 2019, the study said, when compared with GBD Level 3 underlying causes of death. 

Hence, they should be considered an urgent priority for intervention within the global health community, the study urged. 

Read more: Ineffective magic bullets: Antibiotic resistance is now the leading cause of deaths across the globe

Strategies to address the burden of bacterial infections would include infection prevention, optimised use of antibiotics, improved capacity for microbiological analysis, vaccine development, and improved and more pervasive use of available vaccines.

Every year November 18-24 is observed as World Antimicrobial Awareness Week (WAAW). Global estimates showed that in 2019, nearly five million human deaths worldwide were associated with bacterial antimicrobial resistance, of which 1.3 million human deaths were directly attributable to bacterial AMR.

This year the AMR Multi-stakeholder Partnership Platform was established November 18 to mark the beginning of WAAW.

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