Challenges in clinical diagnosis of Clade I Mpox: Highlighting the need for enhanced diagnostic approaches.

BACKGROUND: Due to limited diagnostic capacity and availability of point-of-care tests, diagnosis of Clade I mpox in the geographical regions most affected is usually on clinical grounds. This may be complicated due to the similarity between mpox and varicella (chickenpox) lesions. Visual assessment of lesions is also used for determining clinical progress and to assess patient outcomes in clinical trials. However, there has been no investigation into whether clinicians can (i) identify Clade I mpox compared to other viral lesions (ii) differentiate between Clade I mpox lesion stages. METHODOLOGY/PRINCIPLE FINDINGS: The objective of this study was to evaluate inter-rater reliability and agreement between clinicians assessing lesions in patients with Clade I mpox. We presented experienced clinicians with 17 images of Clade I mpox or varicella and asked them to independently indicate the most likely diagnosis-mpox or varicella-and to categorise the lesions according to their stage. When selecting the most likely diagnosis, accuracy varied across all images, the inter-rater reliability was poor (κ = 0.223; z = 10.1) and agreement was moderate (Po = 68%). When categorising lesions according to their type, if a single lesion type was present in the image, inter-rater reliability was moderate (κ = 0.671, z = 40.6) and agreement was good (Po = 78%), but when multiple lesion types were shown in an image, both inter-rater reliability (κ = 0.153, z = 10.5) and agreement (Po = 29%) decreased substantially. CONCLUSIONS: This study demonstrates that there are presently limitations in using visual assessment to diagnose Clade I mpox and evaluate lesion stage and treatment outcomes, which have an impact on clinical practice, public health and clinical trials. More robust indicators and tools are required to inform clinical, public-health, and research priorities, but these must be implementable in countries affected by mpox.

Effectiveness of two-dose vs. one-dose varicella vaccine in children in Shanghai, China: a prospective cohort study.

Objective: Varicella, a highly contagious viral disease caused by the varicella-zoster virus (VZV), affects millions globally, with a higher prevalence among children. After the initial infection, VZV lies dormant in sensory ganglia and has the potential to reactivate much later, causing herpes zoster (HZ). Vaccination is one of the most effective methods to prevent varicella, and the two-dose varicella vaccine (VarV) regimen is widely used around the world. In China, the VarV has been included in the national immunization programme with a recommended single-dose regimen. This study aimed to compare the effectiveness of the two-dose vs. one-dose VarV regimen in children in Shanghai, China. Materials and methods: A prospective cohort study was conducted in Shanghai, China, from September 2018 to December 2022. The study enrolled children aged 3-18 years who had received either the one-dose, two-dose, or 0-dose VarV regimen. Vaccination history, varicella infection status, and relevant variables, including demographic information (name, date of birth and sex) and medical history (clinical features of varicella and illness duration) were collected through medical record review and parental interviews. Results: A total of 3,838 children were included in the study, with 407 in the 0-dose regimen group, 2,107 in the one-dose regimen group and 1,324 in the two-dose regimen group. The corresponding incidence density in these groups was 0.13, 0.05 and 0.03 cases per 1,000 person-days, respectively. The adjusted vaccine effectiveness (VE) was 81.7% (95%CI: 59.3-91.8%) for the two-dose regimen and 60.3% (95%CI: 29.3-77.7%) for the one-dose regimen, compared to the 0-dose regimen. The two-dose VarV regimen showed a protective effectiveness of 47.6% (95%CI: 2.5-71.9%) compared to the one-dose VarV regimen. Conclusion: This study provides evidence supporting the greater effectiveness of the two-dose VarV regimen in preventing varicella infection compared to the one-dose regimen.

Varicella-zoster virus-related neurological complications: From infection to immunomodulatory therapies.

The Varicella-zoster virus (VZV), classified as a neurotropic member of the Herpesviridae family, exhibits a characteristic pathogenicity, predominantly inducing varicella, commonly known as chickenpox, during the initial infectious phase, and triggering the reactivation of herpes zoster, more commonly recognized as shingles, following its emergence from a latent state. The pathogenesis of VZV-associated neuroinflammation involves a complex interplay between viral replication within sensory ganglia and immune-mediated responses that contribute to tissue damage and dysfunction. Upon primary infection, VZV gains access to sensory ganglia, establishing latent infection within neurons. During reactivation, the virus can spread along sensory nerves, triggering a cascade of inflammatory mediators, chemokines, and immune cell infiltration in the affected neural tissues. The role of both adaptive and innate immune reactions, including the contributions of T and B cells, macrophages, and dendritic cells, in orchestrating the immune-mediated damage in the central nervous system is elucidated. Furthermore, the aberrant activation of the natural defence mechanism, characterised by the dysregulated production of immunomodulatory proteins and chemokines, has been implicated in the pathogenesis of VZV-induced neurological disorders, such as encephalitis, myelitis, and vasculopathy. The intricate balance between protective and detrimental immune responses in the context of VZV infection emphasises the necessity for an exhaustive comprehension of the immunopathogenic mechanisms propelling neuroinflammatory processes. Despite the availability of vaccines and antiviral therapies, VZV-related neurological complications remain a significant concern, particularly in immunocompromised individuals and the elderly. Elucidating these mechanisms might facilitate the emergence of innovative immunomodulatory strategies and targeted therapies aimed at mitigating VZV-induced neuroinflammatory damage and improving clinical outcomes. This comprehensive understanding enhances our grasp of viral pathogenesis and holds promise for pioneering therapeutic strategies designed to mitigate the neurological ramifications of VZV infections.

Safety and Immunogenicity of the Live Attenuated Varicella Vaccine in Vietnamese Children Aged 12 Months to 12 Years: An Open-Label, Single-Arm Bridging Study.

OBJECTIVE: This study aims to evaluate the safety and immunogenicity of the SKYVaricella vaccine in healthy Vietnamese children aged 12 months to 12 years. METHODS: This open-label, single-arm study involved 201 children divided into two groups: 60 children aged 12 months to 5 years and 141 children aged 6 to 12 years. Safety was assessed through immediate reactions, solicited adverse events within 7 days, and unsolicited events up to Day 42. Immunogenicity was evaluated by seroconversion rates (SCR) and geometric mean titer (GMT) increments using fluorescent antibody-to-membrane antigen (FAMA) on the day of vaccination (D0) and 42 days after vaccination (D42). RESULTS: All participants completed the follow-up. Immediate adverse events included pain (8.0%), redness (8.0%), and swelling (20.9%) at the injection site. Within 7 days, pain (17.9%) and swelling (12.4%) were mild and self-resolving. Unsolicited adverse events were infrequent and mild. Both age groups achieved 100% SCR. GMT of varicella-zoster virus antibodies increased from 1.37 (SD 1.97) at D0 to 18.02 (SD 2.22) at D42, a 13.12-fold rise. No Grade 3 adverse events were observed. CONCLUSION: The SKYVaricella vaccine shows a robust immunogenic response and favorable safety profile in Vietnamese children aged 12 months to 12 years. These findings endorse its potential inclusion in pediatric vaccination programs as a reliable preventive option against varicella.

Immunity against measles, mumps, rubella, and varicella among homeless individuals in Germany - A nationwide multi-center cross-sectional study.

Introduction: Homeless individuals suffer a high burden of vaccine-preventable infectious diseases. Moreover, they are particularly susceptible to adverse infection outcomes with limited access to the health care system. Data on the seroprevalence of measles, mumps, rubella, and varicella within this cohort are missing. Methods: The seroprevalence of measles, mumps, rubella, and varicella was determined within the homeless population in Germany. Predictors of lacking immune protection were determined using multivariable logistic regression analysis. Results: Homeless individuals in Germany (n = 611) showed a seroprevalence of 88.5% (95% CI: 85.8-91.0) for measles, 83.8% (95% CI: 80.6-86.6) for mumps, 86.1% (95% CI: 83.1-88.7) for rubella, and 95.7% (95% CI 93.8-97.2) for varicella. Measles seroprevalences declined from individuals born in 1965 to individuals born in 1993, with seroprevalences not compatible with a 95% threshold in individuals born after 1980. For mumps, seroprevalences declined from individuals born in 1950 to individuals born in 1984. Here, seroprevalences were not compatible with a 92% threshold for individuals born after 1975. Seronegativity for measles, mumps and rubella was associated with age but not with gender or country of origin. Discussion: Herd immunity for measles and mumps is not achieved in this homeless cohort, while there was sufficient immune protection for rubella and varicella. Declining immune protection rates in younger individuals warrant immunization campaigns also targeting marginalized groups such as homeless individuals. Given that herd immunity thresholds are not reached for individuals born after 1980 for measles, and after 1975 for mumps, vaccination campaigns should prioritize individuals within these age groups.

Association between emphysema and other pulmonary computed tomography patterns in primary varicella pneumonia: A retrospective cohort study.

This study aims to evaluate chest computed tomography (CT) findings in hospital patients with primary varicella pneumonia (PVP). We retrospectively analyzed CT images of 77 PVP patients using 3D Slicer, an open-source software, to model lesions and lungs. This retrospective cohort study was approved by the Institutional Review Board (Ethical Committee, Renmin Hospital, Hubei University of Medicine, Shiyan, China) and waived the requirement for written informed consent. The left lung was more frequently and severely affected in PVP, with significant differences between the 2 groups in CT involvement percentage of each lung region, except for total lung inflation. Group A showed higher median percentages of lung collapse compared to Group B. The extent of left lung involvement is a critical predictor of emphysema in PVP patients, highlighting the importance of also monitoring the right lung for more severe cases. Lower emphysema levels correspond to more collapsed and infiltrated lung segments, suggesting a more severe clinical presentation.

Varicella zoster virus outbreak in a long-term care unit of a tertiary care hospital in northern India.

Nosocomial outbreak of varicella zoster virus (VZV) has been reported when susceptible individuals encounter a case of chicken pox or shingles. A suspected VZV outbreak was investigated in a 50-bedded in-patient facility of Physical Medicine and Rehabilitation in a tertiary care multispecialty hospital. A 30-year-old female patient admitted with Pott's spine was clinically diagnosed with chicken pox on 31 December 2022. The following week, four more cases were identified in the same ward. All cases were diagnosed as laboratory-confirmed varicella zoster infection by PCR. Primary case was a housekeeping staff who was clinically diagnosed with chicken pox 3 weeks prior (9 December 2022). He returned to work on eighth day of infection (17 December 2022) after apparent clinical recovery but before the lesions had crusted over. Thirty-one HCWs were identified as contacts a and three had no evidence of immunity. Two of these susceptible HCWs had onset of chickenpox shortly after first dose of VZV vaccination was inoculated. All cases recovered after treatment with no reported complications. VZV infection is highly contagious in healthcare settings with susceptible populations. Prompt identification of cases and implementation of infection prevention and control measures like patient isolation and vaccination are essential for the containment of outbreaks.

The clinical and economic costs associated with regional disparities in varicella vaccine coverage in Italy over 50 years (2020-2070).

Italy implemented two-dose universal varicella vaccination (UVV) regionally from 2003 to 2013 and nationally from 2017 onwards. Our objective was to analyze regional disparities in varicella outcomes resulting from disparities in vaccine coverage rates (VCRs) projected over a 50-year time-horizon (2020-2070). A previously published dynamic transmission model was updated to quantify the potential public health impact of the UVV program in Italy at the national and regional levels. Four 2-dose vaccine strategies utilizing monovalent (V) and quadrivalent (MMRV) vaccines were evaluated for each region: (A) MMRV-MSD/MMRV-MSD, (B) MMRV-GSK/MMRV-GSK, (C) V-MSD/MMRV-MSD, and (D) V-GSK/MMRV-GSK. Costs were reported in 2022 Euros. Costs and quality-adjusted life-years (QALYs) were discounted 3% annually. Under strategy A, the three regions with the lowest first-dose VCR reported increased varicella cases (+ 34.3%), hospitalizations (+ 20.0%), QALYs lost (+ 5.9%), payer costs (+ 22.2%), and societal costs (+ 14.6%) over the 50-year time-horizon compared to the three regions with highest first-dose VCR. Regions with low first-dose VCR were more sensitive to changes in VCR than high first-dose VCR regions. Results with respect to second-dose VCR were qualitatively similar, although smaller in magnitude. Results were similar across all vaccine strategies.

Chickenpox in Poland in 2021. / Ospa wietrzna w Polsce w 2021 roku.

INTRODUCTION: Chickenpox is a highly contagious disease, but one that can be effectively prevented by vaccination. In Poland, vaccination against the disease is recommended, paid for, and chickenpox remains very common. In recent years, starting in 2002, the upward trend in the incidence of chickenpox has continued, except in 2020. In 2020, there was a decrease in incidence. OBJECTIVES: The aim of this study was to evaluate epidemiological indicators of chickenpox in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic. MATERIAL AND METHODS: The evaluation of the epidemiological situation of chickenpox in Poland in 2021 was carried out based on the results of the analysis of aggregate data published in the annual bulletins: "Infectious Diseases and Poisons in Poland in 2021" and "Immunization in Poland in 2021". In addition, recommendations from the 2021 Immunization Program are described. RESULTS: 57,669 cases of chickenpox were registered in Poland in 2021, 42% less than in the previous year. The incidence of chickenpox in 2021 was 151.1 per 100,000, which was lower than in 2020, as well as in 2019, when it was 470.6/100,000. The lowest incidence was registered in Lower Silesia Province - 99.2/100,000, while the highest in Silesia Province - 215.8/100,000. The highest incidence was in children aged 0-4 years (18,028). The incidence of chickenpox in males was higher than in females (159.5 vs. 143.3/100 thousand), and urban residents were higher than rural residents (152.1 vs. 149.6/100 thousand). Hospitalization due to chickenpox in 2021 included 210 people, which accounted for 0.36% of the total number of registered cases. CONCLUSIONS: In 2021, there was a decrease in the number of chickenpox cases compared to the previous year. The lower incidence may have been the result of a decrease in the transmission of the chickenpox virus, the decrease in the number of cases has to do with, among other things, the restrictions put in place in connection with the COVID-19 pandemic, which result in, among other things, reduced human contact, the wearing of masks and increased social distance.

Coletânea de Respostas Rápidas-Turma 1: programa educacional em vigilância em saúde no enfrentamento da COVID-19 e de outras doenças virais VigiEpidemia / Collection of Rapid Responses-Class 1: educational program in health surveillance in coping with COVID-19 and other viral diseases VigiEpidemia

Coletânea dedicada aos estudos das respostas rápidas do Programa Educacional em Vigilância em Saúde no enfrentamento da COVID-19 e outras Doenças Virais (VigiEpidemia). Esse tema é de extrema relevância e atualidade em nosso contexto da saúde global e na resposta as emergências em saúde pública (ESP) de forma geral. As ESP, que englobam surtos e epidemias, desastres e desassistência à população, representam desafios complexos que exigem respostas ágeis e eficazes por parte das autoridades sanitárias, profissionais da saúde e comunidades como um todo. Até o momento, a pandemia de COVID-19 foi a maior ESP do Século XXI. Ela serviu como um lembrete doloroso da vulnerabilidade da humanidade diante da ameaça de doenças virais. Esta ESP, que teve resposta catastrófica em diversos momentos, evidenciou a importância do investimento em preparação, vigilância e resposta, destacando a necessidade de sistemas de vigilância robustos, colaboração internacional, Inteligência epidemiológica e comunicação transparente para mitigar o impacto devastador das doenças infecciosas na sociedade. As lições aprendidas com a pandemia de COVID-19 são vastas e multifacetadas. A importância da pesquisa, da educação em saúde e do desenvolvimento de vacinas foi evidenciada como uma prioridade crucial na proteção da saúde pública mundial. O investimento em pesquisas e em cursos para formação de profissionais que possam estar atentos as mudanças nos padrões e comportamentos das doenças infecciosas, além de atuar na resposta rápida quando necessário, é fundamental para estarmos preparados para as futuras pandemias. A vacinação, por exemplo, sempre foi uma das ferramentas mais poderosas para evitar surtos e epidemias e, durante a pandemia de COVID-19, ajudou a controlar os óbitos pela doença e possibilitou que voltássemos a ter uma vida normal. Além da vacina contra COVID-19, as vacinas de influenza e dengue também são exemplos notáveis de avanços científicos que desempenham um papel fundamental na prevenção de futuras ESP. Ao explorar os diversos aspectos da resposta, monitoramento e controle de surtos, epidemias e pandemias, esta coletânea visa fornecer uma compreensão abrangente dos desafios enfrentados, das melhores práticas e das estratégias eficazes para mitigar os impactos adversos desses eventos. Espera-se que este trabalho não apenas informe e eduque, mas também inspire ações concretas para fortalecer a recuperação e resiliência dos sistemas de saúde e proteger o bem-estar das comunidades mais vulneráveis do nosso pais.

A collection dedicated to the study of rapid responses by the Educational Program in Health Surveillance in addressing COVID-19 and other Viral Diseases (VigiEpidemia). This theme is of utmost relevance and timeliness in our context of global health and in responding to public health emergencies (PHE) in general. PHEs, which encompass outbreaks and epidemics, disasters, and neglect of the population, represent complex challenges that require swift and effective responses from health authorities, healthcare professionals, and communities as a whole. To date, the COVID-19 pandemic has been the largest PHE of the 21st century. It served as a painful reminder of humanity's vulnerability in the face of viral disease threats. This PHE, which had catastrophic responses at various times, highlighted the importance of investing in preparedness, surveillance, and response, underscoring the need for robust surveillance systems, international collaboration, epidemiological intelligence, and transparent communication to mitigate the devastating impact of infectious diseases on society. The lessons learned from the COVID-19 pandemic are vast and multifaceted. The importance of research, health education, and vaccine development was highlighted as a crucial priority in protecting global public health. Investing in research and training courses to prepare professionals who can be attentive to changes in the patterns and behaviors of infectious diseases and act quickly when needed is essential to be prepared for future pandemics. Vaccination, for example, has always been one of the most powerful tools to prevent outbreaks and epidemics, and during the COVID-19 pandemic, it helped control disease-related deaths and allowed us to return to a normal life. In addition to the COVID-19 vaccine, influenza and dengue vaccines are also notable examples of scientific advancements that play a key role in preventing future PHEs. By exploring the various aspects of response, monitoring, and control of outbreaks, epidemics, and pandemics, this collection aims to provide a comprehensive understanding of the challenges faced, best practices, and effective strategies to mitigate the adverse impacts of these events. It is hoped that this work will not only inform and educate but also inspire concrete actions to strengthen the recovery and resilience of health systems and protect the well-being of the most vulnerable communities in our country.

Varicela neonatal tardía: presentación en un paciente pediátrico / Late neonatalchickenpox: presentation in a pediatric patient

La varicela es una infección poco frecuente durante la gestación, el riesgo para el feto y las manifestaciones clínicas, variarán en función del momento del embarazo en que se produce la infección materna, cuando la erupción maculopapular materna se produce entre los 5 días previos al parto y las 48 horas posteriores, se habla de varicela neonatal tardía. La clínica es grave, con afectación visceral (pulmonar, cerebral, hepática, hemorragias cutáneas, etc.) y un 30 % de los casos desarrollarán una varicela fulminante. Se presenta el caso de neonato masculino que consultó por lesiones en piel, tipo pápulas eritematosas y vesiculares pleomorfas, de distribución dispersa. Con evolución clínica tórpida, permaneció 24 horas en la institución, con franco deterioro respiratorio y neurológico, compatible con cuadro de varicela neonatal tardía fulminante(AU)

Chickenpox is considered a rare infection during pregnancy, the risk to the fetus and the clinical manifestations will vary depending on the time of pregnancy when the maternal infection occurs, when the maternal maculo-papular injuries occurs within the previous 5 days after delivery and 48 hours after, there is talk of late neonatal chickenpox. The symptoms are severe with visceral involvement (lung, brain, liver, skin bleeding, etc.) and 30% of cases will develop fulminant chickenpox. We present the case of a male neonate who consults due to skin lesions, such as erythematous papules and pleomorphic vesicles, with scattered distribution. With a torpid clinical course, who remains in the institution for 24 hours, with frank respiratory and neurological deterioration compatible with late-neonatal fulminant varicella symptoms(AU)

Detection of intrathecal IgG antibody for varicella and measles diagnosis by evaluation and comparison of a commercial IgG chemiluminescent immunoassay with two ELISAs.

OBJECTIVES: Analyse alternative methods of intrathecal antibody detection by comparing chemiluminescent immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) techniques to determine if CLIA can replace ELISA in the diagnosis of CNS infections. METHODS: A panel of 280 paired samples-cerebrospinal fluid (CSF) and serum-with known antibody reactivities (Varicella, n = 60; Measles, n = 120) and negative samples (n = 100) were used to evaluate the performance of six serological test kits (Enzygnost, VirClia®, and Serion ELISA (Measles and Variella). RESULTS: For Measles virus IgG, the VirClia® IgG monotest revealed 97% and 94% positive and negative agreement to the Enzygnost as reference test, respectively. In contrast, Serion ELISA kits yielded values of 18% and 90%. For the Varicella Zoster virus (VZV) IgG, the VirClia® IgG monotest showed 97% and 90% positive and negative agreement compared to Enzygnost. The Serion ELISA kits showed values of 55% and 86%, respectively. ROC analysis revealed that the areas under the curve for Measles and VZV IgGs were 0.7 and 0.852, respectively, using the Serion kit, and 0.963 and 0.955, for Vircell S.L CLIA technique. VirClia® monotest values were calculated using an antibody index cut-off of 1.3. CONCLUSION: The findings indicate that CLIA testing can improve antibody detection in CSF samples, aiding the diagnosis of infectious neurological impairments.

Serious neurological adverse events in immunocompetent children and adolescents caused by viral reactivation in the years following varicella vaccination.

Serious adverse events following vaccination include medical complications that require hospitalisation. The live varicella vaccine that was approved by the Food and Drug Administration in the United States in 1995 has an excellent safety record. Since the vaccine is a live virus, adverse events are more common in immunocompromised children who are vaccinated inadvertently. This review includes only serious adverse events in children considered to be immunocompetent. The serious adverse event called varicella vaccine meningitis was first reported in a hospitalised immunocompetent child in 2008. When we carried out a literature search, we found 15 cases of immunocompetent children and adolescents with varicella vaccine meningitis; the median age was 11 years. Eight of the children had received two varicella vaccinations. Most of the children also had a concomitant herpes zoster rash, although three did not. The children lived in the United States, Greece, Germany, Switzerland, and Japan. During our literature search, we found five additional cases of serious neurological events in immunocompetent children; these included 4 cases of progressive herpes zoster and one case of acute retinitis. Pulses of enteral corticosteroids as well as a lack of herpes simplex virus antibody may be risk factors for reactivation in immunocompetent children. All 20 children with adverse events were treated with acyclovir and recovered; 19 were hospitalised and one child was managed as an outpatient. Even though the number of neurological adverse events remains exceedingly low following varicella vaccination, we recommend documentation of those caused by the vaccine virus.

Varicella mimicking complications of acute rhinosinusitis in an infant.

Varicella is the manifestation of primary infection with the varicella-zoster virus, mainly affecting preschool and school-aged children. The children suffer from a generalised, vesicular rash and fever. Despite the infection's typically non-threatening course, a variety of severe complications have been described.The authors present the case of a female infant suffering from varicella and developing preseptal cellulitis with a frontal abscess while being treated with intravenous antibiotics. Otorhinolaryngology consultation was sought since the clinical image was highly suggestive for sinusitis complications, namely orbital cellulitis and frontal bone osteomyelitis (Pott's puffy tumour). However, the child was below the age of frontal sinus development and there was no other apparent sign of sinonasal involvement. Ultrasonography revealed a mid-frontal collection without signs of abscess formation preseptally or postseptally, leading to the diagnosis of cutaneous superinfection of varicella lesions. The frontal abscess was drained, and the child fully recovered under antibiotic treatment.

Low vaccine coverage and varicella outbreaks in Brazil - 2019-2022.

The persistence of varicella outbreaks in Brazil has underscored the high concern with the low vaccine coverage in the last 4 years. Using publicly available data from the Brazilian Health System (SUS), this study analyzed varicella vaccine coverage and incidence trends from 2019 to 2022 in Brazilian States. Vaccine coverage decreased nationally in 2020, possibly influenced by the COVID-19 pandemic's initial phase. In Bahia State, we have the persistence of varicella with an incidence rate of 3.0 cases per 100,000 inhabitants (higher incidence compared to other States) in 2023. Under 15 months children and young children (4-6 Years old) faced the highest risk, urging the importance of vaccination. Despite a monovalent varicella vaccine being available through Brazil's National Immunization Program (NIP), Bahia fell short of achieving the ≥95 % disease control target for coverage. The study highlight the importance of vaccines to prevent some infectious diseases, as varicella, in poor tropical regions. Addressing vaccine hesitancy and misinformation, and augmenting awareness campaigns, are important to achieve and sustain high vaccine coverage over 80% as WHO guidelines to obtain a safe rate of protection for Brazilian population (Brazil's national immunization program has a target of 95% coverage).

Varicella in the 21st Century.

Varicella is a highly contagious disease caused by the varicella-zoster virus and has a wide range of clinical presentations. Varicella can cause mild disease in infants born to infected persons who are immunized as a result of previous vaccination or previous clinical or subclinical infection. However, varicella can also lead to severe life-threatening disease in infants, particularly for those born to nonimmunized persons. In this review, we will summarize the natural history of varicella-zoster infection in pregnant persons, infants with congenital varicella syndrome, and infants with postnatal varicella infection. We will also provide guidance about isolation recommendations and chemoprophylaxis for exposed hospitalized infants. Finally, we will describe risk factors for developing disseminated disease and review the approach to treatment of infected infants.

Epidemiological Characteristics of Varicella in Anhui Province, China, 2012-2021: Surveillance Study.

BACKGROUND: Varicella is a mild, self-limited disease caused by varicella-zoster virus (VZV) infection. Recently, the disease burden of varicella has been gradually increasing in China; however, the epidemiological characteristics of varicella have not been reported for Anhui Province. OBJECTIVE: The aim of this study was to analyze the epidemiology of varicella in Anhui from 2012 to 2021, which can provide a basis for the future study and formulation of varicella prevention and control policies in the province. METHODS: Surveillance data were used to characterize the epidemiology of varicella in Anhui from 2012 to 2021 in terms of population, time, and space. Spatial autocorrelation of varicella was explored using the Moran index (Moran I). The Kulldorff space-time scan statistic was used to analyze the spatiotemporal aggregation of varicella. RESULTS: A total of 276,115 cases of varicella were reported from 2012 to 2021 in Anhui, with an average annual incidence of 44.8 per 100,000, and the highest incidence was 81.2 per 100,000 in 2019. The male-to-female ratio of cases was approximately 1.26, which has been gradually decreasing in recent years. The population aged 5-14 years comprised the high-incidence group, although the incidence in the population 30 years and older has gradually increased. Students accounted for the majority of cases, and the proportion of cases in both home-reared children (aged 0-7 years who are not sent to nurseries, daycare centers, or school) and kindergarten children (aged 3-6 years) has changed slightly in recent years. There were two peaks of varicella incidence annually, except for 2020, and the incidence was typically higher in the winter peak than in summer. The incidence of varicella in southern Anhui was higher than that in northern Anhui. The average annual incidence at the county level ranged from 6.61 to 152.14 per 100,000, and the varicella epidemics in 2018-2021 were relatively severe. The spatial and temporal distribution of varicella in Anhui was not random, with a positive spatial autocorrelation found at the county level (Moran I=0.412). There were 11 districts or counties with high-high clusters, mainly distributed in the south of Anhui, and 3 districts or counties with high-low or low-high clusters. Space-time scan analysis identified five possible clusters of areas, and the most likely cluster was distributed in the southeastern region of Anhui. CONCLUSIONS: This study comprehensively describes the epidemiology and changing trend of varicella in Anhui from 2012 to 2021. In the future, preventive and control measures should be strengthened for the key populations and regions of varicella.

An economic evaluation and incremental analysis of the cost effectiveness of three universal childhood varicella vaccination strategies for Ireland.

BACKGROUND: The cost effectiveness of childhood varicella vaccination is uncertain, as evidenced by variation in national health policies. Within the European Economic Area (EEA), only 10 of 30 countries offer universally funded childhood varicella vaccination. This study estimates the cost effectiveness of universal childhood varicella vaccination for one EEA country (Ireland), highlighting the difference in cost effectiveness between alternative vaccination strategies. METHODS: An age-structured dynamic transmission model, simulating varicella zoster virus transmission, was developed to analyse the impact of three vaccination strategies; one-dose at 12 months old, two-dose at 12 and 15 months old (short-interval), and two-dose at 12 months and five years old (long-interval). The analysis adopted an 80-year time horizon and considered payer and societal perspectives. Clinical effectiveness was based on cases of varicella and subsequently herpes zoster and post-herpetic neuralgia avoided, and outcomes were expressed in quality-adjusted life-years (QALYs). Costs were presented in 2022 Irish Euro and cost effectiveness was interpreted with reference to a willingness-to-pay threshold of €20,000 per QALY gained. RESULTS: From the payer perspective, the incremental cost-effectiveness ratio (ICER) for a one-dose strategy, compared with no vaccination, was estimated at €8,712 per QALY gained. The ICER for the next least expensive strategy, two-dose long-interval, compared with one-dose, was estimated at €45,090 per QALY gained. From a societal perspective, all three strategies were cost-saving compared with no vaccination; the two-dose short-interval strategy dominated, yielding the largest cost savings and health benefits. Results were stable across a range of sensitivity and scenario analyses. CONCLUSION: A one-dose strategy was highly cost effective from the payer perspective, driven by a reduction in hospitalisations. Two-dose strategies were cost saving from the societal perspective. These results should be considered alongside other factors such as acceptability of a new vaccine within the overall childhood immunisation schedule, programme objectives and budget impact.