Herpes zoster of posterior division of mandibular branch of trigeminal nerve.

Herpes zoster is a disease caused by the reactivation of dormant varicella zoster virus present in the sensory root ganglion. It presents with a vesicular rash on an erythematous base similar to that seen in classical varicella, however, with only a single dermatomal distribution. The rash is usually seen throughout the affected dermatome as the dorsal root ganglia for each dermatome are clustered together. We present a case of an otherwise healthy male who developed a vesicular rash confined to the distribution of the posterior division of the mandibular nerve. Though the entire mandibular nerve arises from a single ganglion, the skin area supplied by the anterior division of the mandibular nerve was spared. This case provides evidence to show that there is anatomic segregation of cell bodies of nerves traversing anterior and posterior divisions of mandibular division in the trigeminal ganglion and that partial involvement of a sensory root ganglion is possible in immunocompetent patients.

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.

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.

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.

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 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.

Expanded spectrum of varicella disease and the need for vaccination in India.

Varicella vaccine was first licensed in Japan and South Korea in 1989 for use in healthy children and was introduced in US in 1995. So far, 29 countries have adopted varicella vaccine in their universal immunization program (UIP). No Asian country, India included, has adopted the varicella vaccine as part of their UIP. The extra-cutaneous sites for VZV diseases are central nervous system and gastrointestinal tract, the expanded disease spectrum includes vasculopathy, myelitis, inflammatory bowel disease, perforated ulcers, and gastritis. The actual disease burden of varicella is not known as most of the infected individuals may not visit the physician. The amplifiable VZV DNA will not always be detectable in cerebrospinal fluid (CSF) samples in protracted illnesses such as vasculopathies, but demonstrable anti-VZV IgG in CSF has diagnostic value. The World Health Organization (WHO) position paper 2014 recommends two doses of varicella and zoster vaccines in targeted population. In India, varicella vaccine is not included in the UIP due to the cost and the belief that lifelong immunity occurs following primary infection. The expanded spectrum of VZV disease and the mounting body of evidence, however, suggest the need for both varicella and zoster vaccines in routine immunization schedule.

A hidden dilemma; post COVID-19 first detection of Varicella zoster M4 genotype from Pakistan.

OBJECTIVES: During the COVID-19 pandemic, the risk of childhood infectious diseases was increased. Post-COVID-19 escalation of chickenpox cases, becoming an emerging public health concern. Thus, the study was designed to compare chickenpox prevalence and Varicella zoster virus (VZV) genotypes circulating before, during, and post-COVID-19 in Pakistan. METHODS: A total of 267 lesion specimens collected from tertiary care hospitals, and chickenpox outbreaks from Pakistan were analysed by a two-amplicon approach with phylogenetic analysis. RESULTS: Among suspected cases, overall 178/267 were VZV positive. Majority (84.2 %; 150/178) cases were of post-COVID-19 pandemic time. Small outbreaks occurred soon after COVID-19 in Rawalpindi and Islamabad (Pakistan), 40 positive cases out of 178 cases were outbreak cases. There was first time detection of the M4 genotype, which was significantly associated with disease severity (p = 0.0006) and post-COVID-19 chickenpox outbreaks in 2021 (77.9 %; 46/59; p < 0.00001). However, in pre-COVID-19 only M2 genotype was detected. The M2 prevalence varied from 2019 (100 %; 19/19) to 2022 (3.2 %; 3/91). However, the most prevalent strain of 2022 belonged to the M1 genotype (64.8 %; 59/91). CONCLUSION: A significant rise in chickenpox cases detected soon after COVID-19 in Pakistan, and oscillation of different VZV genotypes with first time detection of M4 genotype is an alarming situation. This demands further detailed genotypic studies on transmission dynamics of a rare M4 with other genotypes to protect the local population and restrict spread in other regions.

Genetic causal association between varicella-zoster virus infection and psychiatric disorders: A 2-sample Mendelian randomization study.

BACKGROUND: Psychiatric disorders, such as schizophrenia (SCZ), major depressive (MDD), and bipolar disorder (BD) have a profound impact on millions of individuals worldwide. The critical step toward developing effective preventive and treatment strategies lies in comprehending the causal mechanisms behind these diseases and identifying modifiable risk factors associated with them. METHODS: In this study, we conducted a 2-sample Mendelian randomization analysis to explore the potential links between chickenpox(varicella-zoster virus infection) and three major psychiatric disorders(SCZ, MDD, BD). RESULTS: In our MR study, among the three major psychiatric disorders, chickenpox was shown to be causally related to BD, indicating that infection with chickenpox may increase the risk of developing BD (IVW: OR = 1.064, 95% CI =1.025-1.104, P=0.001; RAPS: OR=1.066, 95% CI=1.024-1.110, P=0.002), while there was no causal relationship between SCZ and MDD. Similar estimated causal effects were observed consistently across the various MR models. The robustness of the identified causal relationship between chickenpox and BD holds true regardless of the statistical methods employed, as confirmed by extensive sensitivity analyses that address violations in model assumptions. The MR-Egger regression test failed to reveal any signs of directional pleiotropy (intercept = -0.042, standard error (SE) = 0.029, p = 0.236). Similarly, the MR-PRESSO analysis revealed no evidence of directional pleiotropy or outliers among the chickenpox-related instrumental variables (global test p = 0.653). Furthermore, a leave-one-out sensitivity analysis yielded consistent results, further underscoring the credibility and stability of the causal relationship. CONCLUSIONS: Our findings provide compelling evidence of a causal effect of chickenpox on the risk of BD. To gain a more comprehensive understanding of this association and its underlying mechanisms, additional research is needed. Such investigations are pivotal in identifying effective interventions for promoting BD prevention.

Nanopore sequencing in distinguishing between wild-type and vaccine strains of Varicella-Zoster virus.

BACKGROUND: The introduction of varicella vaccines into routine pediatric immunization programs has led to a considerable reduction in varicella incidence. However, there have been reports of varicella, herpes zoster, and meningitis caused by the vaccine strain of varicella-zoster virus (VZV), raising concerns. Establishing the relationship between the wild-type and vaccine strains in VZV infections among previously vaccinated individuals is crucial. Differences in the single nucleotide polymorphisms (SNPs) among vaccine strains can be utilized to identify the strain. In this study, we employed nanopore sequencing to identify VZV strains and analyzed clinical samples. METHODS: We retrospectively examined vesicle and cerebrospinal fluid samples from patients with VZV infections. One sample each of the wild-type and vaccine strains, previously identified using allelic discrimination real-time PCR and direct sequencing, served as controls. Ten samples with undetermined VZV strains were included. After DNA extraction, a long PCR targeting the VZV ORF62 region was executed. Nanopore sequencing identified SNPs, allowing discrimination between the vaccine and wild-type strains. RESULTS: Nanopore sequencing confirmed SNPs at previously reported sites (105,705, 106,262, 107,136, and 107,252), aiding in distinguishing between wild-type and vaccine strains. Among the ten unknown samples, nine were characterized as wild strains and one as a vaccine strain. Even in samples with low VZV DNA levels, nanopore sequencing was effective in strain identification. CONCLUSION: This study validates that nanopore sequencing is a reliable method for differentiating between the wild-type and vaccine strains of VZV. Its ability to produce long-read sequences is remarkable, allowing simultaneous confirmation of known SNPs and the detection of new mutations. Nanopore sequencing can serve as a valuable tool for the swift and precise identification of wild-type and vaccine strains and has potential applications in future VZV surveillance.

Rapid identification of A29L antibodies based on mRNA immunization and high-throughput single B cell sequencing to detect Monkeypox virus.

With the large number of atypical cases in the mpox outbreak, which was classified as a global health emergency by the World Health Organization (WHO) on 23 July 2022, rapid diagnosis of mpox and diseases with similar symptoms to mpox such as chickenpox and respiratory infectious diseases in the early stages of viral infection is key to controlling the spread of the outbreak. In this study, antibodies against the monkeypox virus A29L protein were efficiently and rapidly identified by combining rapid mRNA immunization with high-throughput sequencing of individual B cells. We obtained eight antibodies with a high affinity for A29L validated by ELISA, which were was used as the basis for developing an ultrasensitive fluorescent immunochromatographic assay based on multilayer quantum dot nanobeads (SiTQD-ICA). The SiTQD-ICA biosensor utilizing M53 and M78 antibodies showed high sensitivity and stability of detection: A29L was detected within 20 min, with a minimum detection limit of 5 pg/mL. A specificity test showed that the method was non-cross-reactive with chickenpox or common respiratory pathogens and can be used for early and rapid diagnosis of monkeypox virus infection by antigen detection. This antibody identification method can also be used for rapid acquisition of monoclonal antibodies in early outbreaks of other infectious diseases for various studies.

Clinical and Economic Burden of Antibiotic Use Among Pediatric Patients With Varicella Infection in the Outpatient Setting: A Retrospective Cohort Analysis of Real-world Data in France.

BACKGROUND: Varicella infects 90% of children before age 9. Though varicella is self-limiting, its complications may require antibiotics, though how antibiotics are utilized for varicella in France is not well known. This study assessed antibiotic use and costs associated with varicella and its complications in pediatric patients managed in the outpatient setting in France. METHODS: A retrospective cohort study using the Cegedim Strategic Data-Longitudinal Patient Database, an electronic medical record database from general practitioners and office-based specialists in France, was conducted. Children <18 years old diagnosed with varicella between January 2014 and December 2018 with 3-month follow-up available were included. We used descriptive analysis to assess varicella-related complications, medication use, healthcare resource utilization and costs. RESULTS: Overall, 48,027 patients were diagnosed with varicella; 15.3% (n = 7369) had ≥1 varicella-related complication. Antibiotics were prescribed in up to 25.1% (n = 12,045/48,027) of cases with greater use in patients with complications (68.1%, n = 5018/7369) compared with those without (17.3%, n = 7027/40,658). Mean medication and outpatient varicella-related costs were €32.82 per patient with medications costing a mean of €5.84 per patient; antibiotics contributed ~23% to total costs annually. CONCLUSION: This study showed high antibiotic use for the management of varicella and its complications. A universal varicella vaccination program could be considered to alleviate complications and associated costs in France.

Burden of chickenpox complications in Poland, 2006 to 2021: A comprehensive registry-based study.

BackgroundChickenpox, a vaccine-preventable disease caused by the varicella zoster virus, generally presents with mild symptoms but can cause complications necessitating hospitalisation. In Poland, since 2009, vaccination has been obligatory for children up to 12 years of age who are particularly vulnerable to infection and for children in their vicinity.AimTo examine the burden of chickenpox complications and the trends of hospitalisation arising from these complications over time in the Polish population.MethodsData spanning 2006-21 were sourced from the Polish Infectious Diseases Surveillance System, the Nationwide General Hospital Morbidity Study and the Statistics Poland death registry. Standardised and age-specific incidence rates, hospital discharge rates and number of deaths because of chickenpox were calculated. Moreover, the joinpoint regression model was used to analyse trends of annual hospital discharge rates.ResultsOver the analysed timeframe, 25,804 hospitalisations and 52 deaths attributable to chickenpox complications were documented, and 1.0% of chickenpox cases required hospitalisation because of chickenpox. Age-standardised hospitalisation rates varied between 2.3 and 9.6 per 100,000 population. The analysis revealed no statistically significant trend in overall hospital discharge rates from chickenpox complications. However, a notable increase in hospitalisation rates was observed in children aged 0-4 and among inhabitants of rural areas, with annual percentage changes of 4.9% and 3.4% respectively.ConclusionsOur findings suggest that the implementation of a universal chickenpox immunisation programme, supported by health education, should be considered to reduce the number of hospitalisations and nearly eliminate deaths because of chickenpox.

A mathematical model for varicella-zoster and HIV co-dynamic supported by numerical simulations.

The prevalence of the varicella-zoster virus (VZV) and its correlation underscore its impact on a significant segment of the population. Notably contagious, VZV serves as a risk factor for the manifestation of HIV/AIDS, with its reactivation often signaling the onset of immunodeficiency. Recognizing the concurrent existence of these two diseases, this study focuses on the co-infection dynamics through a deterministic mathematical model. The population is categorized into seven exclusive groups, considering the complexities arising from the interplay of HIV and Zoster. We establish the non-negativity and boundedness of solutions, examine equilibrium points, calculate basic reproduction numbers via the next-generation matrix approach, and analyze the existence and local stabilities of equilibriums using the Routh-Hurwitz stability criteria. The numerical simulations reveal that the model converges to an endemic equilibrium point when the reproduction number exceeds unity. The primary objectives of this study are to comprehensively understand the transmission dynamics of HIV and Zoster in a co-infected population and to provide valuable insights for developing effective intervention strategies. The findings emphasize the importance of addressing these co-infections to mitigate their impact on public health.

Herpes zoster infection in pregnancy: features and consequences.

Herpes (varicella) zoster (HZ) infection occurs in 4 people per 1000 in the general US population (irrespective of prior varicella infection and vaccination status) each year and has been the subject of scientific inquiry for decades. The consequences of infection are myriad and may depend on the dermatome of involvement as well as host factors such as age, comorbidities, prior treatment or immunization, and immunologic status. Pregnancy is associated with an altered immune and hormonal status in the mother. While maternal HZ infection during pregnancy is not uncommon, the implications for both mother and child are not well established, although multiple studies of perinatal maternal HZ infection suggest no intrauterine transmission to the fetus. We review the current literature on herpes zoster infection in pregnancy, including epidemiology, diagnosis, potential immunologic sequelae, and strategies for prevention and treatment.

Varicella outbreak at nursery school under routine immunization in Japan in 2017 and 2018 and vaccine effectiveness.

BACKGROUND: In Japan, routine administration to one-year-old children of two-dose immunization for varicella was introduced in October 2014. Object The object of this study was to report outbreaks of varicella under routine immunization at a nursery school and in its surrounding area using data of surrounding areas from the (Nursery) School Absenteeism Surveillance System. Then, we measured the effectiveness of routine two-dose immunization for varicella to onset. We tentatively assessed its severity in a nursery school. METHOD: The study period extended from April 2017 through March 2018. The study area comprised Nursery school B and other nursery schools, and elementary and junior high schools in City A. Subjects in Nursery school B were 120 children. We analyzed vaccine effectiveness (VE) as an observational study and assessed severity using Fisher's exact test. We also assessed VE for severity using linear regression. Severity was defined as the length of nursery school absence attributable to varicella infection. RESULTS: During the one month preceding a period of two weeks before the initial case at Nursery school B, there were 16 cases of varicella infection in nursery schools, 45 cases in elementary schools, and one case in junior high schools in City A. For children who had received one vaccine dose or more, VE was 48.1% for all ages and 49.2% among children three years old and older. No significant VE against infection was found. Vaccination using one dose or more can reduce severity significantly. DISCUSSION AND CONCLUSION: Because many nursery school children who had received two doses of vaccine were infected, VE was estimated as low in the nursery school and not significant. Although VE for severity with more than one dose was confirmed, a second dose might not reduce severity compared to one dose.

UK healthcare professionals' attitudes towards the introduction of varicella vaccine into the routine childhood vaccination schedule and their preferences for administration.

BACKGROUND: Varicella (chickenpox) is a highly contagious disease caused by the varicella-zoster virus. Although typically mild, varicella can cause complications leading to severe illness and even death. Safe and effective varicella vaccines are available. The Joint Committee on Vaccination and Immunisation has reviewed the evidence and recommended the introduction of varicella vaccine into the UK's routine childhood immunisation schedule. OBJECTIVES: To explore UK healthcare professionals' (HCPs) knowledge and attitudes towards varicella vaccination, its introduction to the UK routine childhood immunisation schedule, and their preferences for how it should be delivered. DESIGN: We conducted an online cross-sectional survey exploring HCPs' attitudes towards varicella, varicella vaccine, and their preferences for delivery of the vaccine between August and September 2022 prior to the recommendation that varicella vaccine should be introduced. PARTICIPANTS: 91 HCPs working in the UK (81 % nurses/health visitors, 9 % doctors, 10 % researcher/other, mean age 48.7 years). RESULTS: All respondents agreed or strongly agreed that vaccines are important for a child's health. However, only 58% agreed or strongly agreed that chicken pox was a disease serious enough to warrant vaccination. Gaps in knowledge about varicella were revealed: 21.0% of respondents disagreed or were unsure that chickenpox can cause serious complications, while 41.8% were unsure or did not believe chickenpox was serious enough to vaccinate against. After receiving some basic information about chickenpox and the vaccine, almost half of the HCPs (47.3%) in our survey would prefer to administer the varicella vaccine combined with MMR. CONCLUSIONS: Given the positive influence of HCPs on parents' decisions to vaccinate their children, it is important to understand HCPs' views regarding the introduction of varicella vaccine into the routine schedule. Our findings highlighted areas for training and HCPs' preferences which will have implications for policy and practice when the vaccine is introduced.

Prevalence and progression of pneumonia in immunocompetent adults with varicella.

Pneumonia is the most common complication of varicella infections. Although previous studies have tended to focus mainly on immunocompromised patients, varicella pneumonia can also occur in healthy adults. Therefore, in this study, we aimed to assess the progression of varicella pneumonia in immunocompetent hosts. This retrospective study involved immunocompetent adult outpatients with varicella who attended the adult Fever Emergency facility of Peking University Third Hospital from April 1, 2020, to October 31, 2022. Varicella pneumonia was defined as a classic chickenpox-type rash in patients with infiltrates on chest computed tomography. The study included 186 patients, 57 of whom had a contact history of chickenpox exposure. Antiviral pneumonia therapy was administered to 175 patients by treating physicians. Computed tomography identified pneumonia in 132 patients, although no deaths from respiratory failure occurred. Seventy of the discharged patients were subsequently contacted, all of whom reported being well. Follow-up information, including computed tomography findings, was available for 37 patients with pneumonia, among whom 24 reported complete resolution whereas the remaining 13 developed persistent calcifications. Notably, we established that the true incidence of varicella pneumonia is higher than that previously reported, although the prognosis for immunocompetent hosts is generally good.