Herpes simplex virus in the bronchoalveolar lavage of immunocompromised patients with LRTI – results of a prospective study

Human herpes simplex virus (HSV) infections are prevalent and pose significant risk for immunocompromised (IC) individuals. This study aimed to evaluate the impact of lower respiratory infections (LRTIs) with HSV diagnosed via PCR in bronchoalveolar lavage fluid (BALF) in immunocompromised patients. 2,666 visits of 1,301 patients undergoing bronchoscopy for suspicion of LRTI were included in this study. Of these, 119 cases tested positive for HSV1 and/or HSV2 in BAL (haematological disease (n=43), solid organ transplantation (n=24) and other causes (n=52)). The primary outcome assessed was predefined modifications in patient management with follow-up conducted for up to 30 days. BAL findings prompted therapeutic adjustments in 69.19% (n=82) of HSV-infected cases. Among the 119 HSV-positive cases, 63.87% (n=76) demonstrated coinfections with viral, fungal or bacterial pathogens. Mixed infections were associate to higher neutrophil counts in BALF (42% CI 7.5-84.3% vs. 9% CI 2-59.5%). Unadjusted 30-day mortality rates were nummerically higher in those with positive HSV-PCR in BALF (9.4% vs 5.7%, p=0.0961). Respiratory infections with HSV are in the majority of cases associated with coinfection with bacterial, viral or fungal pathogens. Fiberoptic bronchoscopy, including BAL, emerges as a valuable tool facilitating treatment modifications in immunocompromised patients with LRTIs associated with HSV.