Herpes simplex virus type 1 and respiratory disease in critically-ill patients: real pathogen or innocent bystander?

Abstract

Herpes simplex virus type 1 (HSV-1) has been associated with pulmonary disease, mostly in severely immunocompromised patients. After reactivation and shedding in the oropharynx, the virus may reach the lower respiratory tract by aspiration or by contiguous spread. HSV-1 can be detected in clinical specimens by virus culture or quantitatively by nucleic acid amplification techniques. With these techniques, HSV-1 is often detected in the respiratory secretions of critically-ill patients. However, a clear diagnosis of HSV-1 pneumonia is difficult to establish because clinical criteria, radiological features and laboratory findings all lack specificity. Lower respiratory tract HSV-1 infections have not been associated with specific risk-factors. There is also an absence of consistent data concerning the effect of antiviral treatment on the outcome of critically-ill patients. Further studies are needed to better define the pathogenic role of HSV-1 in the lower respiratory tract of these patients, to improve the diagnosis, and, especially, to assess the need for antiviral treatment in the individual patient.

Detection of herpes viruses in respiratory secretions of patients undergoing artificial ventilation

“…Blood samples to determine the HSV IgG status of patients on admission to ITU were not available. No overt case of HSV pneumonia was diagnosed in any patient in whom HSV was detected although the diagnosis of this condition is easily missed [Simoons-Smit et al, 2006]. This has been noted in studies in which HSV has been detected in tracheal or bronchial secretions without there being evidence of classical HSV pneumonia such as HSV inclusions demonstrated histologically [Verheij et al, 2004;Daubin et al, 2005].…”

Cytological recognition of herpes simplex virus infection in bronchoscopic samples from the respiratory tract

“…The clinical significance of detecting evidence of HSV in patients presenting with pneumonia remains controversial. 9 It is likely that in most patients it represents evidence of reactivation of latent HSV infection rather than evidence of a true viral pneumonitis. Studies in ventilated patients with pneumonia have shown a high incidence of PCR-detectable HSV in respiratory samples and it is unclear whether there is any specific benefit in initiating treatment in the absence of other features to suggest a true viral pneumonitis.…”

Herpes Simplex Virus Presenting with Pneumonia in an Infant

“…Primer enfeksiyondan sonra virüsün latent enfeksiyonları tükürükle asemptomatik atılım, ağız içi mukozal ülserler veya oro-labial lezyonlar gibi basit reaktivasyonlarla karşımıza çıka-bildiği gibi, immünyetmezliği olan hastalarda herpetik özofa-jit, trakeo-bronşit ve pnömoni gibi ciddi hastalıklara yol aça-bilir. Primer enfeksiyon genellikle asemptomatik olduğu için reaktivasyon HSV enfeksiyonunun ilk görülme şekli olabilir 4,5 .…”

“…Bu yolla yayılım diffüz interstisyel pnömoniye yol açar. Üçüncü yol ise vagal gangliondaki latent infeksiyonun reaktivasyonu ile nervus vagus aracılığı ile akciğer epiteline yayılımdır (4). Orta ve alt solunum yolunun HSV enfeksiyonları nadir görülür ve genellikle immünyetmezliği olan hastalardır.…”

“…Ateş, dispne, prodüktif öksürük, göğüs ağrısı, bronkospazm HSV'nin neden olduğu pnömonide en sık görülen semptomlardır. Herpes labialis veya orofaringeal lezyonlar pnömoniye eşlik edebilir 4,7 . Herpes virüsleri ile meydana gelen klinik sendromlar tablo 1' de özet-lenmiştir (Tablo 1) 8,9 .…”