• Pediatric Infection and Vaccine
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• v.5 no.1
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• pp.88-95
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• 1998

Purpose : Varicella is a common contagious illness and vaccine against it has been used in healthy Korean children. We studied clinical and epidemiologic features of varicella and the effect of vaccination. Methods : We analyzed clinical and epidemiologic features of varicella and vaccination effect against it in children treated in Hangang Sacred Heart Hospital from March 1994 to December 1996. Results : 1) Total 73 cases of varicella, 46 male and 27 female patients were included. Annual incidence was 31, 20 and 22 cases from '94 to '96 respectively, with an increase during the period June to July and December to January. 2) Mean age was $46{\pm}37.2$ months and 84.9% of the patients were younger than 7 years old including 16.4% of infants. 3) Varicella occurred after a contact with varicella patients in 40(54.8%) patients. 4) Fever developed in 44(60%) patients with mean $38.4{\pm}0.8^{\circ}C$ and persisted for mean $3{\pm}2.4$ days. Nine(12.3%) patients had complications and eighteen(25%) patients were admitted for mean $4{\pm}2.1$ days but all recovered. 5) Twenty(27.8%) patients were affected despite preceding vaccination against varicella but the number of vesicles decreased significantly in vaccinees(P<0.01). 6) The rate of secondary cases in healthy siblings was 27 out of 35(77.1%) and was not affected by preceding vaccination. Conclusion : Varicella occurred mainly in children younger than 7 years old and showed seasonality. Because 27.8% of cases developed despite preceding vaccination and the rate of secondary cases was not affected by vaccination, further study for vaccine efficacy is necessary.

• Pediatric Infection and Vaccine
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• v.23 no.3
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• pp.180-187
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• 2016

Purpose: This study described the post-exposure prophylaxis (PEP) and secondary varicella infection in children inadvertently exposed to varicella zoster virus (VZV) in the hospital. Methods: We retrospectively analyzed data from patients with VZV infection who were initially not properly isolated, as well as children exposed to VZV at the Seoul National University Children's Hospital between January 2010 and December 2015. The PEP measures were determined by the presence of immunity to VZV and immunocompromising conditions. Patient clinical information was reviewed via medical records. Results: Among 147 children hospitalized between 2010 and 2015, 13 inadvertent exposures were notified due to VZV infection. Five index children had a history of VZV vaccination. Eighty-six children were exposed in multi-occupancy rooms and 62.8% (54/86) were immune to VZV. The PEP measures administered to 27 exposed patients included varicella zoster immunoglobulin and VZV vaccination. Four children developed secondary varicella, which was linked to a single index patient, including one child who did not receive PEP and three of the 27 children who received PEP. The rates of secondary varicella and prophylaxis failure were 4.7% (4/85) and 11.1% (3/27), respectively. The secondary varicella rates were 1.9% (1/54) and 9.7% (3/31) among immunocompetent and immunocompromised children, respectively. Conclusions: Delayed diagnosis of VZV infection can lead to unexpected exposure and place susceptible children and immunocompromised patients at risk for developing varicella. The appropriateness of the current PEP strategy based on VZV immunity may require re-evaluation.

• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.61-70
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• 2000

Standard plaque assay using agarose-overlay has long been used for titration of many infectious virus particle. Plaque assay for the titration of varicella-zoster virus and its live vaccine requires three intermittent agarose overlay to visualize plaques. Overall procedure of the assay takes at least nine days from virus inoculation and microbe contamination including fungi is frequently accompanied during incubation period. We studied whether an immunofocus assay in conjunction with peroxidase-mediated immunohistochemical reaction may replace the standard plaque assay for the virus titration by comparing the two methods. A linear relationship was observed between number of foci and virus dilution. The number of foci in a given dilution of virus appeared a little higher than counted plaques formed in standard plaque assay. Independent titration results obtained from two assay methods for a given dilution of virus demonstrated a strong correlation ($r^2=0.99$). Foci of virus infected cells as revealed by the enzyme reaction could be counted either 4 days post-infection (p.i.) under low magnification (40X) microscopy, or 6 days p.i. by naked eye observation. Larger size of cell cuture plate, virus adsorption at $35^{\circ}C$, and 10% FBS in diluent appeared to be better conditions for the assay. Immunofocus assay will be an effective and dependable titration method for varicella-zoster virus and its live vaccine in place of the standard plaque assay in respect to accuracy, costs, and experimental convenience.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.230-235
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• 2002

We experienced a case of herpes zoster in a 9-months aged infant as followings; The patient had no history of chickenpox or varicella vaccination. Also, her mother had no history of varicella infection and no contact history with varicella during pregnancy. The patient had only a history of exposure to chickenpox patient at 7th days after birth, but fortunately chickenpox was not developed. Sequentially, symptoms of cough with fever and tachypnea were developed on admission date(7 days had passed already after development of the initial skin lesion). On physical examination, multiple grouped painless erythematous papulovesicles with small crusts were observed on the right lower back, flank and abdomen along the T11 dermatome. Coarse breathing sound was osculated, and increased linear infiltrations on both parahilar areas were seen on chest radiography. Liver enzymes were slightly elevated. Tzanck test was negative. The initial titers of anti-VZV IgM and IgG on admission were negative, but the following titers of anti-VZV IgM and IgG were positive. The patient received treatment of acyclovir for 7 days, and healed completely without sequelae. We report this case with brief review of related literatures.

• Pediatric Infection and Vaccine
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• v.20 no.3
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• pp.161-167
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• 2013

Purpose: This study was performed to describe the clinical manifestations of hospitalized children due to varicella-zoster virus (VZV) infection Methods: This study included 40 children who were hospitalized for varicella or herpes zoster at Seoul National University Children's Hospital, 2009-2012. Diagnosis of VZV infection was confirmed by VZV PCR or culture from vesicular fluid. Medical records were reviewed to collect clinical features and outcome, antiviral treatment, history of varicella vaccination, and underlying diseases. Results: Sixteen patients with varicella and 24 patients with herpes zoster were included. Their median age was 10.5 years (16 days-19 years). Thirty-five (87.5%) patients had underlying diseases. Among 24 patients with herpes zoster, 11 patients had previous history of varicella and 1 had herpes zoster. Twenty patients (50%) had a history of varicella vaccination, and 19 immunocompromised patients had VZV infection despite of vaccination. Most (95%) patients were treated by intravenous or oral acyclovir, and no treatment failure of intravenous acyclovir was found. The median duration of fever was 4.4 days (1-10 days), and that of antiviral treatment was 12 days (7-23 days) in immunocompromised patients. Immunocompromised patients received longer duration of antiviral treatment than imunocompetent patients (P=0.014). Eleven (27.5 %) immunocompromised patients had postherpetic neuralgia, 2 (5%) had proven co-infection by Streptococcus pyogenes and Klebsiella oxytoca, and 1 (2.5%) complicated with pneumonia. Conclusion: Immunocompromised children require longer duration of treatment and are at risk of severe complication associated with VZV infection. Early initiation of antiviral therapy and close monitoring are necessary for those in immunocompromised conditions.

• Pediatric Infection and Vaccine
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• v.9 no.1
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• pp.61-66
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• 2002

Purpose : To determine wether varicella can be prevented by administration of oral acyclovir(ACV) during the incubation period of the disease. Methods : Starting 9 days after exposure to the index case in their families, ACV(40 mg/kg/day in four divided doses) was given orally to 20 exposed children for 5 days. Their clinical features was compared with those of 20 control subjects. Antibody titers to VZV were measured in both group 1 week and 4 weeks after finishing the oral ACV administration. Results : The mean age of family members with varicella(51.4 months) were significantly high compared to that of ACV prophylaxis group(28.5 months) and control group(31 months) (P<0.05). Among the 12 children with ACV prophylaxis who completed follow up blood sampling, nine children were diagnosed as VZV infection on the serologic test(75%). Among them six children showed positive VZV IgM on the first blood sample and two children showed serocoversion to positive IgM on the second test after ACV prophylaxis. One child who was negative on both IgM and IgG, showed positive IgG on the second test. The incidence of fever and severity of skin rashes were significantly low in children received oral ACV than in the control group. No or reduced number of maculopapular eruption were observed in the oral ACV group compared to multiple vesicles of the control group. Conclusion : In the present study, we observed that oral ACV prophylaxis to the family contacts is effective in reducing severity of skin lesion. It is likely that oral ACV 9 days after contact prevents or reduces blood dissemination of VZV. Little is known about clinical effect and immunity to the virus in exposed children with no varicella symptom after treatment. We propose the checking up antibody to VZV some period after oral ACV, and considering vaccination to whom with no antibody. But further more studies are needed to practical application of oral ACV for the postexposure prophylaxis of varicella.

• Natural Product Sciences
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• v.5 no.2
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• pp.107-111
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• 1999

To investigate less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was isolated from the carpophores of Elfvingia applanata (pers.) Karst. Anti-varicella zoster virus (Oka strain; anti-VZV/Oka) activity of EA was examined in MRC-5 cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with nucleoside anti-VZV agents, acyclovir and vidarabine, were examined on the multiplication of VZV/Oka. EA exhibited a concentration-dependent reduction in the plaque formation of VZV/Oka with a 50% effective concentration $(EC_{50})$ of $464.14\;{\mu}g/ml$. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combination of EA with acyclovir showed more potent synergism with CI values of $0.18{\sim}0.62$ for $50{\sim}90%$ effective levels than that of EA with vidarabine with CI values of $0.67{\sim}1.04$.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.705-709
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• 2009

Herpes zoster is caused by the varicella-zoster virus (VZV), which affects nerve ganglions. VZV infection may be associated with neurologic complications, which are usually observed after vesicular exanthem. Acute aseptic meningitis is a rare complication of VZV reactivation. We report the case of a previously healthy 14-year-old boy who suffered from aseptic meningitis that was attributed to reactivated VZV infection with exanthem; the patient had undergone vaccination against varicella. This condition can be confirmed by the detection of VZV DNA in the cerebrospinal fluid. The patient was treated with acyclovir and recovered fully.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.268-273
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• 2015

The fluorescent-antibody-to-membrane-antigen (FAMA) test is regarded as the "gold standard" to detect protective antibodies to varicella-zoster virus (VZV) because of its high sensitivity and specificity. Because the classic FAMA test uses an infectious virus for detection of antibodies to VZV, it is labor-intensive, and also requires special equipment for handling the virus. For this reason, we attempted to develop a simple and safe FAMA assay. Because VZV glycoprotein E (gE) is one of the major VZV glycoproteins, we used the gE protein for the FAMA test (gE FAMA). Here, we demonstrate that overexpression of gE in HEK293T cells can be used to measure antibodies in human serum, and that gE FAMA titers are closely correlated with gpEIA ELISA data. These results indicate that our gE FAMA test has the potential to measure antibodies to VZV.

• Korean Journal of Bronchoesophagology
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• v.5 no.2
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• pp.222-230
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• 1999

Varicella-zoster virus(VZV) becomes latent in the sensory ganglia after primary infection and emerges from latency to cause zoster in adults. After primary infection, VZV remains latent in the dorsal spinal ganglia. The mechanisms responsible for its reactivation and the clinical entity of herpes zoster are poorly understood. Reactivation of VZV is commonly known to manifest as Ramsay Hunt syndrome which is one of the VZV-associated neurologic diseases with facial paralysis, ear pain, and a characteristic herpetic auricular rash. It is now known that lesions of this syndrome can affect all cranial nerves. Central, cervical and peripheral effects of this syndrome is polyneuropathic in nature. VZV usually involves the 5th and 7th cranial nerves and less commonly the lower cranial nerves such as 9th and 10th. We report a treated case of healthy 40 years old male with VZV infection of the 5th, 9th and 10th cranial nerves. The patient typically showed herpetic vesicles in the auricle and temporal bone area without facial paralysis.