The global burden of non-typhoidal salmonella invasive disease: a systematic analysis for the Global Burden of Disease Study 2017

Background: Non-typhoidal salmonella invasive disease is a major cause of global morbidity and mortality. Malnourished children, those with recent malaria or sickle-cell anaemia, and adults with HIV infection are at particularly high risk of disease. We sought to estimate the burden of disease attributable to non-typhoidal salmonella invasive disease for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017.

Methods: We did a systematic review of scientific databases and grey literature, and estimated non-typhoidal salmonella invasive disease incidence and mortality for the years 1990 to 2017, by age, sex, and geographical location using DisMod-MR, a Bayesian meta-regression tool. We estimated case fatality by age, HIV status, and sociodemographic development. We also calculated the HIV-attributable fraction and estimated health gap metrics, including disability-adjusted life-years (DALYs).

Findings: We estimated that 535 000 (95% uncertainty interval 409 000-705 000) cases of non-typhoidal salmonella invasive disease occurred in 2017, with the highest incidence in sub-Saharan Africa (34·5 [26·6-45·0] cases per 100 000 person-years) and in children younger than 5 years (34·3 [23·2-54·7] cases per 100 000 person-years). 77 500 (46 400-123 000) deaths were estimated in 2017, of which 18 400 (12 000-27 700) were attributable to HIV. The remaining 59 100 (33 300-98 100) deaths not attributable to HIV accounted for 4·26 million (2·38-7·38) DALYs in 2017. Mean all-age case fatality was 14·5% (9·2-21·1), with higher estimates among children younger than 5 years (13·5% [8·4-19·8]) and elderly people (51·2% [30·2-72·9] among those aged ≥70 years), people with HIV infection (41·8% [30·0-54·0]), and in areas of low sociodemographic development (eg, 15·8% [10·0-22·9] in sub-Saharan Africa).

Interpretation: We present the first global estimates of non-typhoidal salmonella invasive disease that have been produced as part of GBD 2017. Given the high disease burden, particularly in children, elderly people, and people with HIV infection, investigating the sources and transmission pathways of non-typhoidal salmonella invasive disease is crucial to implement effective preventive and control measures.

Funding: Bill & Melinda Gates Foundation.