Factors of exacerbation and stimulation of varicella-zoster virus during the incubation period that lead to herpes zoster
Factors of exacerbation and stimulation of varicella-zoster virus during the incubation period that lead to herpes zoster
Seyed Ali Sadr Tabatabaee,1Shaghayegh Yazdani,2,*
1. Bachelor’s student, Microbiology group, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. 2. Department of Microbiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
Introduction: VZV particles, classified as one of the herpes viruses, can undergo retrograde axonal transmission in the dorsal root ganglia and sensory ganglia of the cranial nerve. Following a period of inhibition caused by reactivated factors, it manifests as shingles or herpes zoster. This viral agent commences its replication within the nerve cells and is innervated by the ganglia of the same nerve, wherein it remains concealed, eventually affecting a specific area of the skin or other bodily organs. The intimate association between nerves and the circulatory system facilitates the virus's ability to extend its reach to blood vessels.
Methods: A literature search on PubMed, Google Scholar, and Web of Science databases used the terms herpes zoster and Nervous system immunity. Publications that were not available or were not in the English language were excluded, as were publications that were not related to the topic.
Results: Various studies indicate that viruses are among the most astute microorganisms and, undoubtedly, the most perilous. Consequently, in the case of the varicella-zoster virus, following an encounter with an individual's immune system and subsequent failure, these viruses remain dormant until a suitable opportunity arises.
This opportunity for re-infection, which is significantly more severe and detrimental, is afforded to the virus by a multitude of factors. These factors can be delineated as follows:
1. advancing age is one of the most prevalent risk factors. In fact, statistical evidence indicates that individuals who have previously contracted this virus face a heightened susceptibility to developing shingles after reaching the age of 50. Additionally, other influential factors include the presence of a tumor, as well as viral or bacterial infections. Moreover, both acute and chronic diseases, as well as autoimmune disorders necessitating corticosteroids, can contribute to the increased vulnerability. Furthermore, individuals who have undergone organ or bone marrow transplantation, which results in a reduction in white blood cell count, are also at a heightened risk. Avarand also highlighted the importance of considering asthma, chronic obstructive pulmonary disease, diabetes, depression, and chemotherapy as contributing factors.
2. Occasionally, herpes zoster may manifest in children due to the immaturity of their immune system. To illustrate, children who contract varicella-zoster before reaching 12 months of age have a higher likelihood of developing herpes zoster during their childhood. An example is an 11-year-old girl who exhibited symptoms in the genital area, prompting doctors to suspect sexual abuse. However, further testing revealed that it was indeed an infection, specifically herpes zoster. Additionally, mothers who acquire the varicella-zoster virus (VZV) during pregnancy may experience changes in maternal antibodies, resulting in the conversion of the initial varicella infection into a subclinical form. Consequently, these individuals may initially present with clinical manifestations of herpes zoster. Furthermore, other contributing factors observed in adults, particularly in children, include traumatic injuries that provoke nerve irritation and subsequent shingles symptoms. An instance of this is a 15-year-old boy who experienced a fall while riding a bicycle, leading to the gradual onset of symptoms.
3. One of the most significant precipitants of this virus during its incubation period is certain conditions within the immune system, which are influenced by various factors. For instance, the antibodies produced during the initial infection are virtually ineffective. Varicella-zoster virus (VZV), by impacting the release of active immune substances like cytokines, neurotrophic factors, and chemokines, instigates the suppression of T lymphocytes. The inhibition of JAKi inhibitors and monoclonal antibodies raises the susceptibility to contracting herpes zoster by suppressing the immune system. The existence of specific proteins or defects in the genes responsible for encoding the signal transduction factors of the IFN pathway contributes to the malfunctioning of IFN activity, ultimately yielding ISGs. Specifically, these ISGs restrict the infiltration and replication of the virus in a particular region of the central nervous system. The antiviral response of the dorsal root ganglia relies on the dual functionality of antiviral ISGs and the activation of autophagy.
4. Hypothyroidism, smoking, mental and physical stress, and emotional failures are other factors that provoke and aggravate this virus.
Conclusion: During the research that was conducted, it has been observed that the debilitation of the immune system through various means is the paramount element in the provocation and revival of the virus. With further investigation and many examinations of these factors, it is anticipated that the primary cause will be ascertained. Subsequently, appropriate precautions were taken to avert the occurrence.