Global deaths from Staphylococcus aureus–associated lower respiratory tract infections (LRTIs) in older adults nearly tripled from 1990 to 2021, according to a study published yesterday in BMC Infectious Diseases.
Using data from the MICROBE (Multidisciplinary Investigation of Clinical Research Outcomes and Burden Estimates) database, Chinese researchers analyzed estimates on deaths and disability-adjusted life years (DALYs) associated with 22 pathogens and 84 drug-pathogen combinations across 204 countries. They focused specifically on S aureus, including deaths and DALYs attributable to methicillin-resistant S aureus (MRSA).
S aureus colonizes skin and mucosal surfaces, and the researchers note that older adults are particularly vulnerable to S aureus LRTIs because of the deterioration of the immune system that accompanies aging, the prevalence of comorbidities, and frequent contact with healthcare facilities. MRSA compounds the problem by limiting treatment options.
“The global spread of antimicrobial resistance (AMR) in S. aureus, especially methicillin resistance (MRSA), represents a critical public health issue,” they wrote.
MRSA contributes significantly to mortality
S aureus–associated LRTI deaths in older adults (age 70 and older) rose from 83,363 in 1990 to 250,347 in 2021, and the mortality rate increased from 41.3 per 100,000 to 50.6. DALYs rose from 1.15 million to 3.29 million. MRSA contributed significantly to mortality. Deaths from MRSA LRTIs in older adults rose from 22,481 in 1990 to 75,038 in 2021, and death rates from 11.1 per 100,000 to 15.2 per 100,000.
In 2021, MRSA mortality among older adults was 6.7 times higher than in adults aged 50 to 69, 9.5-fold higher than in children under 5 years, and more than 70-fold higher than in those aged 5 to 49. DALYs mirrored these trends. The highest mortality burden in 2021 was seen in high-income countries, a finding the study authors attribute in part to rapid demographic aging, while countries in sub-Saharan Africa recorded the highest DALY rate.
“This analysis demonstrates increasing S. aureus LRTIs burden in older adults globally,” the authors concluded. “Our findings underscore the urgent need to prioritize targeted interventions and antimicrobial stewardship to prevent the growing burden of resistant pathogens.”