Since 1993, the Australian Paediatric Surveillance Unit (APSU) has been conducting prospective national surveillance of rare conditions in Australian children, including communicable diseases and complications of communicable diseases. In 2024, fifteen communicable diseases and complications were under APSU surveillance: acute flaccid paralysis (AFP); congenital cytomegalovirus (cCMV) infection; dengue; severe acute hepatitis; neonatal/infant herpes simplex virus (HSV) infection; perinatal exposure to human immunodeficiency virus (HIV); paediatric HIV infection, juvenile-onset recurrent respiratory papillomatosis (JoRRP); severe complications of influenza (Flu); Japanese encephalitis virus infection; paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS); Q fever; congenital rubella infection/syndrome; congenital varicella syndrome; and neonatal varicella infection. A total of 1,350 paediatricians and other child health specialists received the monthly APSU report card (97% electronically) in 2024. A total of 237 notifications were received, with 174 confirmed as incident cases after excluding duplicates, errors and prevalent (historic) cases not previously reported. The incident cases included: Flu (n = 34) - one child died and only two children had received influenza vaccination; JoRRP (n = 1); NVI (n = 1); cCMV (n = 26); HSV (n = 8) - neurological sequelae were common; perinatal exposure to HIV (n = 15) - no cases of mother-to-child transmission identified; and rare emerging diseases dengue (n = 4) and PIMS-TS (n = 2). The non-polio AFP rate of ≥ 1 case per 100,000 children aged < 15 years was again achieved. The APSU continues to be an important mechanism for obtaining enriched data on rare communicable diseases and their complications in Australian children, to better understand disease burden, and the effects of health interventions, over time.

Congenital varicella syndrome (CVS) is a rare consequence of maternal varicella infection during early pregnancy and is characterized by cicatricial skin lesions, neurological impairment, limb hypoplasia, and ocular abnormalities. Renal anomalies are not classical features but may occur. We report a term male neonate, born to a primigravida mother with a history of varicella infection at 12 weeks of gestation. The neonate presented with perinatal asphyxia, seizures, cicatricial skin lesions, and a rare renal anomaly - crossed nonfused renal ectopia (CNRE). The neonate required resuscitation at birth, developed hypoxic-ischemic encephalopathy, and was managed with therapeutic hypothermia and antiepileptics. Radiological imaging revealed CNRE. Both maternal and neonatal varicella IgG serology were positive. The baby improved with supportive management and was discharged in stable condition. To the best of our knowledge, CVS and CNRE are not correlated and represent coincidental, unrelated findings in our case.

Primary varicella-zoster virus (VZV) infection during pregnancy poses significant risks to both mother and fetus, including congenital varicella syndrome (CVS) and serious maternal complications. In Iran, the absence of varicella vaccination in the national immunization program leaves many women susceptible. This systematic review and meta-analysis aimed to determine the overall seroprevalence of VZV antibodies among reproductive-age women in Iran. A comprehensive search was conducted in both international and Iranian databases for studies published up to November 15, 2024. Eligible studies reporting VZV seroprevalence among Iranian women aged 15-49 years were identified. Screening, data extraction, and risk of bias assessment were independently performed by two reviewers. Pooled seroprevalence was estimated using a random-effects meta-analysis in STATA version 18. Heterogeneity was evaluated with the Cochrane Q test and I² statistic. Subgroup analyses and meta-regression explored sources of heterogeneity. Sensitivity analyses (leave-one-out) and publication bias (Doi plot, LFK index) were also performed. The protocol was registered in PROSPERO (CRD42025647813). Data from 20 studies, including 5,629 participants, were analyzed. A pooled VZV seroprevalence of 81% (95% CI: 77-85%) was found, indicating that approximately 19% of reproductive-age women in Iran remain susceptible. Higher seroprevalence was observed in pregnant women (88%) compared with non-pregnant women (79%), with the lowest rates among medical students (74%). Despite subgroup and meta-regression analyses, substantial heterogeneity remained unexplained. Sensitivity analyses supported the robustness of the results, while possible publication bias was suggested. Nearly one in five reproductive-age women in Iran lack immunity to VZV. Targeted vaccination, especially among non-pregnant women and students, may reduce susceptibility. Preconception screening for VZV immunity could help prevent maternal and fetal complications. However, given the high unexplained heterogeneity, results should be interpreted with caution.

The Australian Paediatric Surveillance Unit (APSU) has been conducting prospective national surveillance of rare communicable diseases, and complications of communicable diseases, of childhood and infancy for more than three decades. In 2023, there were 15 communicable diseases and complications of communicable diseases under APSU surveillance, which included: acute flaccid paralysis (AFP), congenital cytomegalovirus (cCMV), dengue, severe acute hepatitis (SAH), neonatal and infant herpes simplex virus (HSV) infection, perinatal exposure to human immunodeficiency virus (HIV) and paediatric HIV infection, severe complications of influenza, juvenile-onset recurrent respiratory papillomatosis (JoRRP), Q fever, congenital rubella infection/syndrome, congenital varicella syndrome (CVS) and neonatal varicella infection (NVI), as well as two new communicable diseases, which were paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and Japanese encephalitis virus (JEV) infection. The results of 2023 APSU surveillance show a marked increase in severe influenza cases for the first time in five years, with more complications associated with influenza type B. Moreover, one child died and only 6% of children received a seasonal influenza vaccine. The APSU also received reports of cases of rare emerging diseases: dengue, Q fever and PIMS-TS. Furthermore, our results show a persistence of vaccine-preventable JoRRP, mother-to-child transmission of HIV, and deaths from neonatal HSV.

Varicella-zoster virus is an α-herpes virus with a double-stranded DNA genome, which causes two main clinical pictures: varicella or chickenpox and herpes zoster. Chickenpox is the primary infection, predominantly affecting children, and it presents with fever and a cutaneous eruption consisting of a vesicular, pruritic, and painful rash. Herpes zoster is a viral infection that typically develops in adulthood as a result of the reactivation of the varicella-zoster virus. If acquired during pregnancy, chickenpox may be responsible for serious complications for the mother, the fetus, or the newborn. The most frequent complication of primary varicella-zoster virus infection in mothers is varicella pneumonia, while encephalitis and hepatitis are rare. The effects on the fetus due to chickenpox infection depend on the stage of pregnancy when the mother becomes infected. If the infection occurs during the first trimester, it does not increase the risk of miscarriage. However, if the infection occurs during the first or second trimester, it may cause fetal varicella syndrome or congenital varicella syndrome. During pregnancy, if the varicella-zoster virus reactivates, it usually does not cause harm to the fetus or lead to any birth defects. However, it may increase maternal morbidity due to herpes zoster and its complications. In the case of primary varicella-zoster virus infection in pregnant women, about 20% of newborns may get neonatal or infantile herpes zoster without any complications. However, it is recommended to start early treatment of herpes zoster in pregnant women as it is believed to accelerate the healing process of skin lesions and alleviate pain, reducing both its duration and severity. Through this narrative review, we discuss the approach to the optimal management of varicella-zoster virus infection during pregnancy.