Microbiology laboratory and the management of mother-child varicella-zoster virus infection

Abstract

Varicella-zoster virus, which is responsible for varicella (chickenpox) and herpes zoster (shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella (particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times: (1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection; (2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear (atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation; (3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and (4) when the baby is born and it is necessary to confirm a diagnosis of varicella (and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn. Core tip: Although varicella during pregnancy is infrequent and congenital varicella syndrome (CVS) is rare, every available means should be used to prevent and diagnose them. Microbiology laboratories can be crucial in these situations: Evaluating a mother's immune status with sensitive and specific tests for the detection of antibodies; allowing a rapid diagnosis with molecular biology tests when a clinical manifestation may be due to different etiologies; following pregnant women with varicella for the prenatal diagnosis of CVS with close collaboration between molecular biology investigators and specialists in imaging diagnostics.De Paschale M, Clerici P. Microbiology laboratory and the management of mother-child varicella-zoster virus infection. World

Herpes Zoster and Immunogenicity and Safety of Zoster Vaccines in Transplant Patients: A Narrative Review of the Literature

“…FAMA is highly sensitive and considered the gold standard test for VZV antibodies, but is labor intensive and not automated ( 36 ). ELISA is widely used because of its simplicity and the possibility of automation, but still lacks sufficient sensitivity of detecting vaccine seroconversion ( 37 ). Combination of serology testing and real-time PCR on paired serum and CSF/intraocular fluid can be used for diagnosing HZ with cerebral and ocular complications ( 38 ).…”

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“…Varicella-zoster virus is a DNA virus from the order of of Herpesvirales, the Herpesviridae family, the Alphaherpesvirinae subfamily, Varicellovirus genus (7). It is exclusive to humans, with a diameter of approximately 175 nm (8,9).…”

Advances in pharmacotherapeutic management of common skin diseases in neonates and infants

“…VZV infection is rare in infancy; when encountered in pregnant women, it can lead to serious complication both of the mother and of the fetus or newborn: the transmission of VZV occurs in 8-24% of cases of maternal infections and may be responsible for congenital varicella syndrome (CVS), neonatal varicella, or herpes zoster in the early years of life [34].…”

“…The most severe presentations verify when the mother develops varicella in the period between five days before and two days after delivery, because the fetus cannot benefit from passive maternal immunization [34]. In this case, the rate of neonatal mortality is up to 7% and 30%, respectively, with and in absence of treatment, caused by a fulminant course, with disseminated visceral and central nervous system disease.…”

“…In infancy, its use reduces severity and complications. In infants with varicella, the use of acyclovir may reduce the severity of the disease and the risk for complications and also block the neurologic and ophthalmic involvement in CVS [34].…”