Quantitation of viral load in neonatal herpes simplex virus infection and comparison between type 1 and type 2

Abstract

Neonatal herpes simplex virus (HSV) infection is a severe disease with high mortality and morbidity in spite of the development of effective anti-viral therapies. The viral load in neonatal herpes simplex virus (HSV) infection was measured retrospectively in 37 patients. HSV DNA copy numbers in serum and cerebrospinal fluid (CSF) were quantified using a real-time PCR assay. Patients with disseminated infection had a higher viral load in their sera. whereas patients with central nervous system (CNS) infection exhibited a higher viral load in the CSF. The viral load was significantly higher in the serum of patients who died later. Interestingly, patients with HSV type-2 infection exhibited more CNS involvement and neurological impairment, together with a high viral load in the CSF, than did HSV type-1 patients. These results suggest that quantitation of HSV viral load may be useful for assessing the prognosis, and may provide additional information for the management of neonatal HSV infection.

Novel Technique of Quantitative Nested Real-Time PCR Assay for Mycobacterium tuberculosis DNA

“…Although many previous studies have used a conventional single-step real-time PCR assay to quantitatively detect various infectious pathogens in different clinical samples, few have been able to describe accurate copy numbers of the causative pathogens (3,4,5,6,9,15,19,21,23). In many previous studies, even though various internal controls have been used for monitoring PCR assay conditions, they have regrettably never been used for correctly determining the copy numbers of the causative pathogens (5,6,9,15,19,21,23).…”

“…Recently, real-time PCR assays have been applied in routine diagnostic laboratory testing (1,10,14,16,22). In addition to conventional qualitative analysis, real-time PCR assays make it possible to perform accurate quantitative analyses with a high degree of reproducibility (3,4,5,6,9,15,19,21,23).…”

Persistence of herpes simplex virus DNA in cerebrospinal fluid of neonates with herpes simplex virus encephalitis

“…It is possible that the persistently positive PCR reflects an initially high CSF viral load that is reflective of a greater degree of CNS injury and results in a longer time for achievement of an undetectable concentration. 21 Domingues et al 22 found that among 16 patients with HSV-1 encephalitis who had a mean age of 37 ± 21 years, greater than 100 copies of HSV DNA per ml in CSF was associated with decreased level of consciousness, presence of lesions detected by CT scan of brain and poor neurological outcomes. Similar studies that assess the contribution of HSV viral load to neurodevelopmental outcome or antiviral response are needed in neonates.…”

Polymerase chain reaction in neonatal HSV encephalitis: an assay to count on?

“…3,11 Although presumed to reflect persistent viral replication, it is unclear whether the detected PCR products after therapy represent active infection, residual DNA fragments after successful treatment, or a point along a continuum between the two states. Quantitative real-time PCR, which can provide rapid detection of HSV DNA and documentation of viral load, 21 has been used successfully in pediatric 22,23 and neonatal [22][23][24] patients with known HSV CNS infections. Kimura et al 24 applied quantitative real-time PCR in a small population of neonates with HSV, showing an association between HSV-2 infection and higher neurological morbidity, CNS involvement and CSF viral load.…”

“…Quantitative real-time PCR, which can provide rapid detection of HSV DNA and documentation of viral load, 21 has been used successfully in pediatric 22,23 and neonatal [22][23][24] patients with known HSV CNS infections. Kimura et al 24 applied quantitative real-time PCR in a small population of neonates with HSV, showing an association between HSV-2 infection and higher neurological morbidity, CNS involvement and CSF viral load. Quantitative PCR may be useful in determining the efficacy of antiviral therapy in neonatal HSV encephalitis by documenting HSV DNA levels in serial CSF samples from infected infants.…”