Monitoring of herpes simplex virus in the lower respiratory tract of critically ill patients using real-time PCR: a prospective study.
Herpes simplex virus (HSV) has increasingly been associated with pulmonary disease in critically ill patients. However, the clinical relevance of HSV is still a topic of debate. Monitoring of HSV in a quantitative way could potentially give relevant information on its role in the pathogenesis of lower respiratory tract infection. A fast and reliable quantitative real-time PCR (Q-PCR) for the quantitative detection of HSV-1 and HSV-2 DNA was developed. A prospective observational study was performed in an intensive-care unit (ICU) to monitor the HSV viral load in lower respiratory tract aspirates of long-term mechanically ventilated patients. HSV was common in the lower respiratory tract (LRT) of critically ill patients with mechanical ventilation for at least 48 h (62%, n = 65/105). Detection of HSV was significantly associated with prolonged mechanical ventilation (p <0.01), prolonged ICU stay (p <0.01), and development of ventilator-associated pneumonia (p = 0.02). Corticosteroid administration (p <0.01) in the ICU and anti-HSV IgG seropositivity (p <0.01) were risk factors for the occurrence of HSV in the LRT. The fact that no HSV-seronegative patient became positive suggests that all HSV DNA-positive patients had HSV reactivations. Monitoring the HSV viral load in the LRT of critically ill patients showed a typical homogeneous pattern of HSV kinetics. HSV emerged in tracheal and bronchial aspirates after a median of 7 days of intubation (5-11 days), and this was followed by an exponential increase (c. 1 log copies/mL/day) to reach very high HSV peaks (10(6)-10(10) copies/mL) in 78% of the HSV DNA-positive patients.
De Vos
N
N
Laboratory of Clinical Biology, Department of Microbiology and Molecular Biology, Onze Lieve Vrouw Hospital, Aalst, Belgium.
Van Hoovels
L
L
Vankeerberghen
A
A
Van Vaerenbergh
K
K
Boel
A
A
Demeyer
I
I
Creemers
L
L
De Beenhouwer
H
H
D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness; D004279:DNA, Viral / Q000302:isolation & purification; D005260:Female; D006561:Herpes Simplex / Q000821:virology*; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000302:isolation & purification*; D018258:Herpesvirus 2, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000821:virology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D012137:Respiratory System / Q000821:virology*
D004279:DNA, Viral