Severe pneumonia is a leading cause of death in the intensive care unit (ICU) and it is frequently accompanied by viral reactivation during treatment. Nevertheless, there have been limited studies that have assessed the viral reactivation patterns in the lower respiratory tract and its impact on the mortality of ICU patients with severe pneumonia.

In January 2023, Dr. FANG Xueling and Dr. CAI Hongliu from the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZU) co-published an article entitled "Viral reactivation in the lungs of patients with severe pneumonia is associated with increased mortality, a multicenter, retrospective study" in the Journal of Medical Virology (If=20.69). This study investigated the landscape of viral reactivation in the lungs of patients with severe pneumonia and found that herpesviridae reactivation in the lungs was associated with an increased risk of mortality among these patients.

In this multicenter study, Dr. HUANG et al. measured bronchoalveolar lavage fluid from patients with severe pneumonia who were transferred to the ICU using metagenomic next-generation sequencing (mNGS). The results showed that, unlike the widespread detection of bacteria and fungi, the most common viruses in the lungs were CMV, EBV, and HSV-1, and about half of the patients had herpesviridae reactivation in their lungs.

The team then analyzed the clinical features of these patients. There were no differences in SOFA score, APACHE II score, sex, or age between patients with and without reactivation, and the time to transfer to the ICU for mNGS testing was similar. However, the proportion of patients in the reactivation group had a higher proportion of immunosuppressive states upon admission. The patients were divided into immunosuppressed and non-immunosuppressed groups, and survival curves were plotted. Patients in the reactivation group showed a higher mortality rate regardless of the group. In terms of overall mortality, the 28-day mortality rate in the non-viral reactivation group was only 53% (p<0.05) of the reactivation group. They then adjusted for confounding factors such as sex, age, SOFA score, APACHE II score, and immunosuppressive status, and showed that the reactivation of herpesviridae in the lungs was an independent risk factor for death.

This study is the first to comprehensively describe the reactivation of viruses in the lungs of people with severe pneumonia. The study findings indicate that CMV, HSV-1, and EBV were the most commonly reactivated viruses in the lungs of patients with severe pneumonia. Notably, the presence of herpesviridae reactivation was found to be associated with an increased risk of mortality. Moreover, the simultaneous reactivation of multiple viruses highlights the need to consider this factor in the design of future clinical trials.

More information: Dr. FANG Xueling and Dr. CAI Hongliu are the co-corresponding authors of the article and Dr. HUANG Lingtong is the first author.

Source: the First Affiliated Hospital, Zhejiang University School of Medicine

Photo credit: Department of Critical Care Medicine of FAHZU