Respiratory failure linked to mortality in adult invasive Salmonella cohort

Respiratory failure was strongly associated with in-hospital death among adults treated for invasive non-typhoidal Salmonella disease in a single-center observational study in southern Vietnam. The cohort included 106 patients, 74.5% of whom were HIV-positive, and most of the HIV-positive participants had advanced immunosuppression. In an exploratory multivariable analysis, the adjusted prevalence ratio for death among patients with respiratory failure was 9.06, with a 95% confidence interval of 3.65–22.5 and a p-value below 0.001. The association remained similar in a sensitivity analysis that additionally adjusted for pulmonary coinfection, defined as tuberculosis and/or Pneumocystis jirovecii pneumonia.

Researchers at the Hospital for Tropical Diseases used an ambispective design, combining retrospective and prospective data collection from January 2023 through December 2025. Adult patients were consecutively enrolled when non-typhoidal Salmonella was isolated from an extraintestinal specimen. Investigators then analyzed clinical, microbiological, treatment, and outcome data. This approach provided a detailed account of patients receiving care at one tertiary hospital, but the observational design could not determine whether respiratory failure or another measured characteristic caused death. The findings also do not describe the incidence or full clinical profile of invasive non-typhoidal Salmonella disease across Vietnam.

The patient group was distinguished by a high prevalence of advanced HIV infection. HIV was present in 74.5% of the 106 patients, and most had CD4 counts below 200 cells per cubic millimeter, indicating advanced immunosuppression. Gastrointestinal manifestations were relatively uncommon among the patients overall and were particularly uncommon among those who were HIV-positive. The data therefore document how invasive non-typhoidal Salmonella disease presented in a cohort dominated by adults with severely impaired immune systems. This concentration of advanced immunosuppression limits how broadly the results can be applied to adults with invasive disease who do not have HIV or severe immune compromise.

Antimicrobial susceptibility testing showed marked variation among the agents assessed. Resistance to ampicillin was the most frequent, reaching 67.9% of isolates, while 57.5% were resistant to nalidixic acid. In contrast, resistance remained low for ceftriaxone at 2.8% and for ciprofloxacin at 3.8%. Multidrug resistance was identified in 19.8% of isolates. These results show substantial resistance to some antimicrobial agents in the studied population while comparatively low resistance to ceftriaxone and fluoroquinolones. The susceptibility findings describe the isolates collected in this hospital cohort; they do not establish the comparative effectiveness of treatment regimens, and the study did not test such regimens in a randomized comparison.

Respiratory failure was associated with in-hospital mortality in both the main exploratory model and the sensitivity analysis. After adjustment for pulmonary coinfection, the adjusted prevalence ratio was 10.33, with a 95% confidence interval of 4.47–23.88 and p below 0.001. The investigators said respiratory failure may represent an important marker of clinical severity in the studied population, but they cautioned that the association should be interpreted cautiously because the number of deaths was limited. The results are therefore an adjusted association rather than evidence that respiratory failure directly caused the observed deaths. Taken together, the study identifies advanced HIV-associated immunosuppression and multidrug resistance as prominent features of invasive non-typhoidal Salmonella disease among adults treated at a southern Vietnamese tertiary hospital, while identifying respiratory failure as a strong statistical correlate of in-hospital death in this cohort.

Subject of Research: Clinical features, antimicrobial resistance, and mortality in adults with invasive non-typhoidal Salmonella disease in southern Vietnam

Article Title: Clinical characteristics, antimicrobial resistance patterns, and outcomes of invasive non-typhoidal Salmonella disease in adults: a single-center observational study in southern Vietnam

Article References: Le, C. B., Vuong, N. M., Van Dang, T., Ma, N. T., Nguyen, T. L. N., Le, T. M., Gyan, A., & Huynh, G. (2026). Clinical characteristics, antimicrobial resistance patterns, and outcomes of invasive non-typhoidal Salmonella disease in adults: a single-center observational study in southern Vietnam. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14677-6

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DOI: 10.1186/s12879-026-14677-6

Keywords: invasive Salmonella, non-typhoidal Salmonella, antimicrobial resistance, HIV, respiratory failure, in-hospital mortality, Vietnam, observational study, multidrug resistance, Clinical, characteristics, antimicrobial