Neonatal Herpes Simplex Virus Infections.
ABSTRACT Neonatal herpes simplex virus infections are uncommon, but because of the morbidity and mortality associated with the infection they are often considered in the differential diagnosis of ill neonates. The use of polymerase chain reaction for diagnosis of central nervous system infections and the development of safe and effective antiviral therapy has revolutionized the diagnosis and management of these infants. Initiation of long-term antiviral suppressive therapy in these infants has led to significant improvement in morbidity. This article summarizes the epidemiology of neonatal herpes simplex virus infections and discusses clinical presentation, diagnosis, management, and follow up of infants with neonatal herpes disease.
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ABSTRACT: Newborns are more susceptible to severe disease from infection than adults, with maturation of immune responses implicated as a major factor. The type I interferon response delays mortality and limits viral replication in adult mice in a model of herpes simplex virus (HSV) encephalitis. We found that intact type I interferon signaling did not control HSV disease in the neonatal brain. However, the multifunctional HSV protein γ34.5 involved in countering type I interferon responses was important for virulence in the brain in both age groups. To investigate this observation further, we studied a specific function of γ34.5 which contributes to HSV pathogenesis in the adult brain, inhibition of the cellular process of autophagy. Surprisingly, we found that the beclin binding domain of γ34.5 responsible for inhibiting autophagy was dispensable for HSV disease in the neonatal brain, as infection of newborns with the deletion mutant decreased time to mortality compared to the rescue virus. Additionally, a functional beclin binding domain in HSV γ34.5 did not effectively inhibit autophagy in the neonate, unlike in the adult. Type I IFN responses promote autophagy in adult, a finding we confirmed in the adult brain after HSV infection; however, in the newborn brain we observed that autophagy was activated through a type I IFN-independent mechanism. Furthermore, autophagy in the wild-type neonatal mouse was associated with increased apoptosis in infected regions of the brain. Observations in the mouse model were consistent with those in a human case of neonatal HSV encephalitis. Our findings reveal age-dependent differences in autophagy for protection from HSV encephalitis, indicating developmental differences in induction and regulation of this innate defense mechanism after HSV infection in the neonatal brain.PLoS Pathogens 01/2015; 11(1):e1004580. DOI:10.1371/journal.ppat.1004580 · 8.06 Impact Factor
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ABSTRACT: In the field of medical diagnostics, point-of-care (POC) applications are simple to use, portable, easily disposable, and stable under different operating conditions. A high-throughput, automated robotic processing instrument is generally not affordable or feasible in low-resource settings that lack the necessary laboratory infrastructure. Though many methods are already established for medical diagnostics, not aIl of them are suitable for point-of-care diagnostics. Nucleic acid amplification methods are very sensitive and specific due to target amplification and base-pairing interactions. Over polymerase chain reaction (PCR), the isothermal amplification of DNA/RNA has recently drawn interest since it does not require a large thermal cycler. LAMP (100p mediated isothermal amplification) is an isothermal amplification technique and considered as a robust method in terms of sensitivity, tolerance to inhibitory substances present in the real sample, and easy naked eye detection. Therefore, it is a simpler and more energy efficient approach, making it an excellent choice for POC applications. l developed a low cost plastic pouch using a plastic bag (e.g. simple re-sealable zipper storage bag) for the detection of Herpes Simplex Viruses (HSV). The LAMP method was easily incorporated into this plastic pouch and allowed the detection of 6.08 x 101 copies/ill of HSV -1 DNA and 0.598 copies/ill of HSV-2 DNA within 45 minutes. Since the LAMP method is less sensitive to inhibitory substances present in the real sample, we also could detect viral DNA without purifying it. The result was easily evaluated -colorimetrically using the naked eye via the addition of hydroxynaphthol blue (HNB) dye in the reaction mix. Therefore, colorimetric detection by the naked eye makes for easy result analysis. -The lack of need for expensive instruments and its low cost and portability make this invension a perfect candidate for point-of-care (POC) diagnosis both in the laboratory and in low-resource countries.08/2014, Degree: MSc, Supervisor: Fiorenzo Vetrone
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ABSTRACT: Effective viral detection is a key goal in the development of point of care (POC) diagnostic devices. Loop-mediated isothermal amplification (LAMP) could potentially be a valuable tool for rapid viral detection and diagnosis in commercial and hospital laboratories and resource limited settings. Here, we present a novel polypropylene pouch (PP) for detection of HSV-1 and HSV-2. With this plastic pouch we could detect up to 6.08 x 101 copies/µL of HSV-1 DNA and 0.598 copies/µL of HSV-2 DNA within 45 minutes. Since LAMP itself is less sensitive to inhibitory substances present in the real sample, we could also detect viral DNA without the need for viral DNA extraction and purification. The result from LAMP could be evaluated by naked eye due to the addition of hydroxy naphthol blue (HNB) dye in the reaction mixture. Since this proposed device is easy to handle, portable, user friendly and low cost, it offers a tremendous potential to be a perfect candidate for POC diagnostic device for use in resource limited settings.The Analyst 11/2014; DOI:10.1039/C4AN01701C · 3.91 Impact Factor