A new analysis of global foodborne illness data published in Foodborne Pathogens and Disease has found that the number of invasive non-typhoidal (iNT) Salmonella cases has risen by 46 percent since 1990, along with a 27 percent increase in mortality. Significant regional disparities were noted.

The researchers, associated with Guangdong Medical University and Jiangmen Central Hospital in China, obtained data on the incidence and mortality of iNT Salmonella infections from the Global Burden of Disease Study (2021), in which an international network of more than 10,000 collaborators from more than 150 countries and territories provided, reviewed, or analyzed data to produce burden estimates for hundreds of important diseases for the years 1990–2021. Data included in the burden estimates included national and international surveillance programs, hospital and clinical data, and literature reviews.

Cases Rise by Almost Half, Deaths by More Than a Quarter

Based on the Global Burden of Disease study data, iNT Salmonella cases rose from 348,244 in 1990 to 509,976 in 2021 (46.44 percent increase). Mortality also rose from 48,941 deaths in 1990 to 62,018 deaths in 2021 (26.72 percent increase). At the same time, the global age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) exhibited relatively modest annual increases, suggesting that population growth and demographic shifts may be contributing to the rising burden of iNT Salmonella.

Lower-Income Regions Disproportionately Burdened

The regional distribution of iNT Salmonella burden revealed striking disparities, with Sub-Saharan Africa continuing to bear the highest incidence and mortality rates. Notably, Western Sub-Saharan Africa exhibited the highest ASIR and ASMR in 2021, with more than a twofold increase in both cases and deaths since 1990. Conversely, high-income regions experienced relatively lower iNT Salmonella burden.

Surprisingly Substantial Burden Growth in Western Europe

Interestingly, despite having a lower overall iNT Salmonella burden, Western Europe—especially the UK—exhibited the most substantial increase in ASIR between 1990 and 2021, potentially due to increased international travel, migration, and the globalization of food supply chains contributing to the introduction and dissemination of Salmonella strains previously uncommon in these regions. Additionally, improvements in disease surveillance, reporting, and diagnostics have likely increased the number of iNT Salmonella cases detected. Still, the researchers say this trend in higher-income countries underscores the importance of vigilance and global cooperation in food safety monitoring and foodborne illness response.

The Need for Vaccines and Antibiotic Alternatives

Unfortunately, the researchers hypothesize that the global burden of iNT Salmonella is likely to continue rising as antimicrobial resistance (AMR) continues to grow. Investment in effective antimicrobial stewardship programs and the development of alternative treatment and control strategies for Salmonella are necessary.

The researchers call for the urgent development and deployment of effective iNT Salmonella vaccines in regions where the burden is high, such as Sub-Saharan Africa, as well as improving access to rapid, affordable, and decentralized diagnostic platforms in these regions. In a recent development addressing this need, a new vaccine targeting both typhoid fever and non-typhoidal Salmonella infections recently completed a successful Phase 1 clinical trial with promising results.