Non-typhoidal salmonella invasive infections in China

We read with interest the Article by Christian S Marchello and colleagues.1Marchello CS Birkhold M Crump JA Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis.Lancet Infect Dis. 2022; 22: 692-705Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar The study reported that the most prevalent complications of invasive salmonella infection were septicaemia (171 [57·2%] of 299 participants) and anaemia (580 [47·3%] of 1225 participants), with a case fatality rate of 14·7% (95% CI 12·2–17·3). The pooled case fatality rate varied between different continents: 17·1% (13·6–21·0) in Africa, 14·0% (9·4–19·4) in Asia, 9·9% (6·4–14·0) in Europe, and 9·6% (0·0–25·1) in the Americas. However, data from Asia did not include the case fatality rates in mainland China. To address the absence of data from mainland China in the study,1Marchello CS Birkhold M Crump JA Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis.Lancet Infect Dis. 2022; 22: 692-705Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar we analysed clinical data on salmonella infections collected from 56 tertiary hospitals and 131 secondary hospitals in Henan province, and data from 90 tertiary hospitals and 47 secondary hospitals in Zhejiang province over 3 years from 2018 to 2020. The hospitals included in our analysis serve a population of 65 million people in Henan and 45 million people in Zhejiang. Our data showed that salmonella infections in children (<15 years of age, accounting for 1181 [61·8%] of 1910 cases of infection in Henan and 3224 [52·8%] of 6111 in Zhejiang) were more common than in adult patients. In tertiary hospitals, the overall rate of isolation of Salmonella spp among all bacterial pathogens was 0·64% (1401 of 218 906 isolates) in Henan and 0·55% (4868 of 885 090 isolates) in Zhejiang, which was higher than the isolation rate in secondary hospitals (509 [0·33%] of 154 242 isolates in Henan and 1243 [0·49%] of 253 673 isolates in Zhejiang). 833 (43·6%) of 1910 patients in Henan and 1280 (20·9%) of 6111 patients in Zhejiang had invasive salmonella infections. 566 (67·9%) of 833 people with invasive salmonella infections in Henan and 676 (52·8%) of 1280 people with invasive salmonella infections in Zhejiang had bloodstream infection. For 73 (8·8%) of 833 cases of invasive infection in Henan and 211 (16·5%) of 1280 cases of invasive infection in Zhejiang, Salmonella spp were isolated from different types of drained fluid. 36 (4·3%) of 833 cases in Henan and 107 (8·4%) of 1280 cases in Zhejiang were salmonella-mediated urinary tract infections (appendix pp 1–2). The data on bloodstream infections are consistent with the report of Marchello and colleagues,1Marchello CS Birkhold M Crump JA Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis.Lancet Infect Dis. 2022; 22: 692-705Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar which showed that septicaemia occurred in 171 (57·2%) of 299 participants with invasive infection. Of note, anaemia was not analysed in our study. The most intriguing finding in our study was that none of the cases of invasive infection were fatal—an observation that is in stark contrast with most studies reported in various countries.1Marchello CS Birkhold M Crump JA Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis.Lancet Infect Dis. 2022; 22: 692-705Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar Nevertheless, zero mortality was reported in several countries and regions, such as Taiwan, Vietnam, Malaysia, Israel, and Turkey.1Marchello CS Birkhold M Crump JA Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysis.Lancet Infect Dis. 2022; 22: 692-705Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar In conclusion, our data provide more insight into the clinical outcome of invasive salmonella infections and suggest that mortality rates vary widely between different regions and countries, which needs to be investigated. We declare no competing interests. The research reported here was funded by Guangdong Major Project of Basic and Applied Basic Research (2020B0301030005). Editorial note: The Lancet Group takes a neutral position with respect to territorial claims in published text and institutional affiliations. Download .pdf (.23 MB) Help with pdf files Supplementary appendix Complications and mortality of non-typhoidal salmonella invasive disease: a global systematic review and meta-analysisComplications were frequent among individuals with non-typhoidal salmonella invasive disease and approximately 15% of patients died. Clinicians, especially in African countries, should be aware of non-typhoidal salmonella invasive disease as a cause of severe febrile illness. Prompt diagnoses and management decisions, including empiric antimicrobial therapy, would improve patient outcomes. Additionally, investments in improving clinical microbiology facilities to identify non-typhoidal salmonella and research efforts towards vaccine development and non-vaccine prevention measures would prevent non-typhoidal salmonella invasive disease-associated illness and death. Full-Text PDF Open Access