Persistent Detection of Varicella-Zoster Virus DNA in a Previously Healthy Child after Severe Chickenpox

Abstract

In immunocompetent children with primary varicella-zoster virus (VZV) infection, peak viral loads are detected in peripheral blood near the onset of the vesicular rash. VZV DNA concentrations normally diminish and become undetectable within 3 weeks after the appearance of the exanthem. Here, we present a previously healthy, human immunodeficiency virus-negative, 4-year-old boy admitted with severe varicella. High viral loads (>340,000 copies/ml) were found in his blood, and the viral loads remained high for at least 1.5 years. Clinical recovery preceded complete clearance of the virus. General and VZV-specific immune reactivity were intact. NK cells and CD8؉ T cells were activated during acute infection, and VZV-specific CD4 ؉ T cells were detected at high frequencies. VZV DNA was initially detected in B cells, NK cells, and both CD4؉ and CD8 ؉ T cells. In contrast, during the persistent phase of VZV DNA detection, the viral DNA was primarily located in CD8 ؉ T cells. For the first time, we describe the persistent detection of VZV DNA in a previously healthy child.

Prolonged detection of viral DNA in blood following life-threatening chickenpox in an immunocompromised child

“…An alternative explanation is therefore that the virus has established latency in long-lived T cells. As with the case described by Vossen et al, the particularly high initial viral load (>10 5 copies/ml), compared with the typical initial viral load in immunocompetent individuals (10 3 -10 5 copies/ml, 3,8 ), may have resulted in a sufficient number of long-lived T cells becoming latently infected with VZV, such that DNA remained detectable by PCR. If this were correct, the loss of detectable viral DNA would then be dependent upon the clearance of latently infected lymphocytes from the circulation by natural turnover.…”

“…In the only previous report, Vossen et al describe prolonged detection of viral DNA for over eighteen months following recovery from a severe primary VZV infection in an immunocompetent child. 3 …”

Fatal varicella in an immunocompromised adult associated with a European genotype E2 variant of varicella zoster virus

“…Persistent detection of VZV DNA and lesions in liver and spleen have been described previously. 2,3 The disease is often more severe in adults than in children, with more prominent rash, fever and interstitial pneumonitis. Bleeding abnormalities, including increased capillary fragility, disseminated intravascular coagulation, and thrombocytopenia, may also occur.…”

Loss of Varicella Zoster Virus Antibodies Despite Detectable Cell Mediated Immunity after Vaccination

“…The current availability of commercial test kits for the determination of antigen-specific T lymphocytes makes it possible to run these tests on a large scale [21,22]. Some recent studies using such techniques and dealing with VZV underline the importance of this particular topic [17,18,23].…”