Infectious Disease · Medical Literature
[Corrections] Correction to Lancet Infect Dis 2026; published online June 3. https://doi.org/10.1016/S1473-3099(26)00285-9
Abstract
Tortosa F, Santamaría G, Bustamante R, et al. Use of tocilizumab for severe hantavirus pulmonary syndrome: a MEURI case series with contextual comparisons. Lancet Infect Dis 2026; published online June 3. https://doi.org/10.1016/S1473-3099(26)00285-9—In this Article, Ariel Izcovich's affiliation should have been “Universidad del Salvador, Buenos Aires, Argentina” and “Department of Internal Medicine, Hospital Alemán of Buenos Aires, Buenos Aires, Argentina”. This correction has been made to the online version as of June 15, 2026, and will be made to the printed version.
Clinical relevance
In patients with laboratory-confirmed severe hantavirus pulmonary syndrome (HPS) requiring ICU-level care, does the addition of tocilizumab (IL-6 receptor inhibitor) to standard supportive therapy improve survival to ICU discharge compared with standard supportive care alone, under a MEURI (Monitored Emergency Use of Unregistered and Investigational Interventions) expanded-access framework? __SNAPSHOT__ {"studyDesign":"Prospective MEURI expanded-access case series with contextual (non-randomized) comparisons; described as an early interim report from an ongoing, larger pre–post study (ISRCTN72088243)","setting":"Single center: Hospital Zonal de Bariloche Dr Ramón Carrillo, San Carlos de Bariloche, Argentina. Conducted in the context of a cruise-associated hantavirus outbreak.","sampleSize":"n=10 eligible patients (tocilizumab-treated: n=5; eligible but untreated comparator: n=5); 13 total evaluated for inclusion","population":"Adults with laboratory-confirmed severe hantavirus pulmonary syndrome requiring ICU admission or ICU-level assessment. Three of 13 screened were ineligible (2 with refractory shock at presentation precluding timely administration; 3 did not receive tocilizumab due to drug unavailability). The untreated comparator group was reported to be older and more severely ill than the treated group.","intervention":"Tocilizumab 8 mg/kg IV (single dose; maximum 800 mg) administered within 24 hours of ICU admission or ICU-level evaluation, added to standard supportive care","comparator":"Eligible patients who did not receive tocilizumab due to drug unavailability or presentation with refractory shock, managed with standard supportive care alone. NOTE: The comparator group was NOT randomly assigned; baseline imbalances in age and illness severity were acknowledged by the authors.","primaryOutcome":"Survival to ICU discharge (descriptive; no formal statistical hypothesis testing reported)","followUp":"ICU discharge (duration of follow-up beyond ICU discharge not reported)","fundingSource":"None (as reported by Scimex/journal metadata)"}
Key findings
Among the five tocilizumab-treated patients, four (80%) survived to ICU discharge; one died after rapid progression to refractory shock. Among the five eligible but untreated patients, zero (0%) survived to ICU discharge; all five died following ICU admission. The absolute difference in ICU survival was 80 percentage points (80% vs. 0%) (calculated), yielding a number needed to treat (NNT) of 1.25 (calculated) — a figure that must be interpreted with extreme caution given the tiny, non-randomized sample and severe baseline imbalance between groups. No p-values, confidence intervals, or formal inferential statistics were reported, consistent with the descriptive intent of the study. Adverse events related to tocilizumab were not separately reported in the available abstract.
Practice implications
This early, interim MEURI case series provides hypothesis-generating signal that IL-6 inhibition with tocilizumab may reduce mortality in severe HPS, a disease for which no proven specific therapy currently exists. However, the study establishes no causal inference: the comparator group was not randomly assigned, was acknowledged to be older and more severely ill, and the reasons for non-treatment (refractory shock, drug unavailability) are themselves surrogates of worse prognosis. The apparent survival benefit may be substantially or entirely confounded by severity imbalance. The sample size (n=10) is insufficient to draw reliable conclusions about efficacy or safety. Findings apply only to patients with laboratory-confirmed HPS at the ICU threshold in a resource-limited setting during an outbreak; they are not generalizable to milder disease, pediatric populations, or other hantavirus species/geographies. The correction notice that prompted this submission was administrative in nature (author affiliation correction for Ariel Izcovich) and does not alter any clinical data or conclusions. Because only the abstract was available for review, full methods, baseline characteristics, clinical details, and safety data could not be independently assessed — a meaningful limitation of this summary. __LIMITATIONS__ Extremely small sample size (n=5 per group); severely underpowered for any inferential conclusion,Non-randomized, non-blinded contextual comparator: the untreated group was older and more severely ill, introducing profound confounding by indication and severity,The mechanism of non-treatment (refractory shock at diagnosis, drug unavailability) is itself a marker of worse prognosis, biasing the comparison in favor of the treated group,No formal statistical testing; no confidence intervals or p-values reported — the study is explicitly descriptive,Single-center design from a highly specialized outbreak context limits generalizability,Follow-up limited to ICU discharge; longer-term outcomes not reported,Potential ascertainment and reporting biases inherent to MEURI expanded-access frameworks,Safety and adverse event profile of tocilizumab in HPS not systematically characterized,No funding conflicts reported, but the outbreak context and absence of a control arm may have introduced selection pressures,Only abstract-level data were available for this summary; full study methods, tables, and patient-level data were not independently reviewable __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ This MEURI case series reports that 4 of 5 tocilizumab-treated patients with severe HPS survived to ICU discharge, versus 0 of 5 untreated eligible controls — a striking signal in a disease with no proven therapy. However, critical confounding by severity and illness acuity, the absence of randomization, and the very small sample make any efficacy conclusion premature. Tocilizumab should not yet be adopted as standard of care for HPS; the authors appropriately call for collaborative randomized studies, and clinicians should await results of the ongoing pre–post study (ISRCTN72088243) before changing practice.