Varicella Cases Research Articles

Monkeypox: Cutaneous clues to clinical diagnosis

Monkeypox: Cutaneous clues to clinical diagnosis

Vaccine Coverage and Effectiveness in a School-Based Varicella Outbreak in Jinan Prefecture, Shandong Province.

Background: Licheng District of Jinan Prefecture reported a school-based varicella outbreak. We conducted an investigation to analyze the epidemiology and scope of the outbreak, determine varicella vaccine coverage on the school campus, and estimate varicella vaccine effectiveness (VE). Methods: In the epidemiological investigation, we determined the attack rate, the clinical manifestations of varicella cases, and histories of prior varicella disease and varicella vaccination. We tested students for presence of serum IgM antibodies, and we attempted to isolate the varicella virus from vesicular fluid samples. We used chi-square to compare incidences between classes and floors. VE was estimated using a retrospective cohort study. Results: There were 13 varicella cases in the outbreak. All were among fourth grade students - twelve in Class 7 and one in Class 6. The attack rate in the two classrooms was 14.3% (13/91). Clinical symptoms were rash (100%) and fever (46.15%). All cases were reported within one average incubation period, and the epidemic curve suggested common exposure. Six of the 13 cases previously received one dose of varicella vaccine with a median time between vaccination and infection of 9 years; the other seven cases had not been vaccinated. Varicella vaccine coverage with one or more doses was 81.31%; 2-dose coverage was 38.15%. The median age of receipt of dose 1 was 1.18 years, and median age for receiving dose 2 was 5.12 years. One-dose varicella VE was 73.2% (95% confidence interval: 37.0%, 88.6%), and two-dose VE was 100%. Conclusions: Varicella vaccine coverage has been gradually increasing in recent years, as ≥1-dose and 2-dose coverage rates are higher in younger children than older children. High one-dose vaccination coverage limited the outbreak scope and led to the breakthrough cases being mild. Mild cases were difficult to detect in a timely manner. Varicella vaccine was highly effective, with 1-dose VE of 73% nine years after vaccination and 2-dose VE of 100%. We strongly recommended that all school students receive two doses of varicella vaccine.

Varicella vaccination in India's universal immunisation program –is it time?

We report two representative cases of complicated varicella in immunocompetent children highlighting the significant vaccine preventable varicella burden in the Indian population. A robust surveillance programme followed by incorporation of varicella vaccine in routine immunization would be the way forward to mitigate this illness.

The impact of universal varicella vaccination on the clinical burden of varicella in Colombia: A National database Analysis, 2008–2019

In 2015, one-dose universal varicella vaccination (UVV) was introduced in the Colombian National Immunization Program targeting children aged 12 months, expanding to a two-dose program in 2019. This study aimed to examine the effect of one-dose UVV on the burden of varicella in Colombia. A retrospective study was conducted using national databases to estimate incidence and mortality for the target (1–4 years old), non-target (less than 1 and 5 years and older) and overall (all age groups) populations from the pre-UVV period (January 2008–June 2015) to the post-UVV period (July 2015-December 2019). A time-series analyses with ARIMA modeling was used to project expected varicella incidence and mortality in the absence of UVV in the post-UVV period. UVV impact was estimated by comparing predicted and observed values, providing point estimates and prediction intervals (PI). Overall vaccination coverage rate was over 90 % from 2016-2019. Following UVV introduction, mean annual incidence rates reduced from 743.6 to 676.8 per 100,000 in the target population and from 203.2 to 198.1 per 100,000 in the overall population. Our study estimated a reduction in varicella incidence from 2017, with the highest reduction of 70.5 % (95 % PI: 78.2-54.2) and 54.8 % (95 % PI: 65.0-36.4) observed in 2019 for the target and the overall populations, respectively. The ARIMA model estimated UVV in Colombia to have prevented 198,236 varicella cases from 2015 to 2019. Mortality reduced in the overall population from 0.8 per 1,000,000 to 0.5 per 1,000,000 and from 1.3 per 1,000,000 to 0.5 per 1,000,000 in the target population, in the pre-UVV and post-UVV periods, respectively. However, these differences were not statistically significant. Our study showed a significant reduction in varicella incidence after implementation of a one-dose UVV program in Colombia, increasing over time. Further assessment is needed to evaluate the impact of a two-dose UVV program in Colombia.

Varicella outbreaks in schools and kindergartens in Shanghai, China from 2011 to 2020.

Varicella is a contagious disease caused by varicella-zoster virus and varicella vaccine (VarV) is the most effective way to prevent and control varicella. Despite high VarV coverage there were still varicella outbreaks in schools and kindergartens. We aim to analyze the epidemiological characteristics of varicella outbreaks in Huangpu District, Shanghai, China from 2011 to 2020. For varicella outbreaks, case information and vaccination history were collected. Mann-Kendall test and descriptive methods were used to analyzed the trend and epidemiological catachrestic of varicella outbreaks. A total of 57 varicella outbreaks were reported from 2011 to 2020, including 30 outbreaks (52.6%) in primary schools. The results of the Mann-Kendall trend test (z = 1.97, p = 0.049) showed an upward trend in the number of cases during the study period, but the trend change was not statistically significant. Emergency vaccination was carried out in 42 (73.7%) outbreaks which influenced the duration of the epidemic (F = 4.53, p = 0.0379). A total of 573 varicella cases were reported, including 357 cases (62.3%) who had received at least one dose of varicella vaccine. The number of varicella outbreaks has not changed significantly in the decade from 2011 to 2020. The strategy of varicella vaccination, the development and application of varicella vaccine, and the control measures after the occurrence of varicella outbreaks need to be optimized. In addition to vaccination, as a disease transmitted by contact, quarantine measures, good personal hygiene, environmental disinfection, and ventilation are also important.

An Epidemiological Study of Outbreak Investigation of Chickenpox in Remote Hamlets of a Tribal State in India.

Background: Chickenpox is a benign, self-limiting disease caused by the varicella-zoster virus (VZV) that is transmitted from person to person with direct contact or airborne spread, which usually lasts for five to seven days. There was a sudden increase in the number of cases of fever along with rashes at two sites in Jharkhand, India. We aimed to survey and establish the etiology and investigate the extent of the disease.Methods: We defined the case of chickenpox as a person with acute onset of diffuse maculo-papulovesicular rash. From the clinically suspected cases, blood samples were collected and tested for anti-VZV immunoglobulin M and immunoglobulin G antibodies (depending on the clinical features) with an enzyme-linked immunosorbent assay (ELISA) kit (Novatec Immundiagnostica GmbH, Dietzenbach, Germany). A detailed history was collected from each case including the history of contacts and immunization status.Results: The outbreak investigations were done at two villages of the two different blocks and one school in the Bharno block. According to the case definition, 16 persons were found affected by the varicella-zoster/chickenpox infection who belonged to five different households of Itkhori village in Chatra district. The age group varied from four to 45 years. The mean age was 20.28 years. Out of 16 cases, 10 (62.5%) cases complained of fever, rashes, and itching, two (12.5%) reported rashes and fever, and four (25%) complained of itching along with rashes. While at the Bharno block of Gumla district, out of 62 cases that fulfilled the case definition, 55 (88.7%) cases complained of fever, rashes, and itching, two (3.2%) reported itching and rashes, one (1.6%) reported vomiting along with fever and rashes, one (1.6%) complained about pain and rashes, one (1.6%) complained of cough with rashes, and four (25%) complained of itching along with rashes. There was neither any death nor any serious complication noted due to varicella.Conclusion: Chickenpox is still widespread in Northern parts of India like Jharkhand. Most of the cases were self-limiting and recovered at the Itkhori block, while at the Bharno block, there were 20 active cases and the rest were either recovered or were still in the recovery phase.

Silent Reactivation of Varicella Zoster Virus in Pregnancy: Implications for Maintenance of Immunity to Varicella.

We encountered two cases of varicella occurring in newborn infants. Because the time between birth and the onset of the illness was much shorter than the varicella incubation period, the cases suggested that the infection was maternally acquired, despite the fact that neither mother experienced clinical zoster. Thus, we tested the hypothesis that VZV frequently reactivates asymptomatically in late pregnancy. The appearance of DNA-encoding VZV genes in saliva was used as an indicator of reactivation. Saliva was collected from 5 women in the first and 14 women in the third trimesters of pregnancy and analyzed at two different sites, at one using nested PCR and at the other using quantitative PCR (qPCR). No VZV DNA was detected at either site in the saliva of women during the first trimester; however, VZV DNA was detected in the majority of samples of saliva (11/12 examined by nested PCR; 7/10 examined by qPCR) during the third trimester. These observations suggest that VZV reactivation occurs commonly during the third trimester of pregnancy. It is possible that this phenomenon, which remains in most patients below the clinical threshold, provides an endogenous boost to immunity and, thus, is beneficial.

Recognition & management of varicella infections and accuracy of antimicrobial recommendations: Case vignettes study in the US.

In 1995, the CDC recommended one-dose routine varicella immunization for children <12 years of age, expanding its recommendation to two doses in 2006. Today, with widespread varicella vaccination coverage, an estimated 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented annually in the United States. Since varicella infections are now uncommon, health care providers (HCPs) may not recognize varicella infections and may prescribe inappropriate treatment. An online survey of HCPs was conducted to assess recognition and management of varicella infections. Responses to eight varicella vignettes describing patients with varying varicella symptoms were analyzed and descriptive analyses performed. Stratified analysis comparing responses of those licensed before and in/after 1996 was also performed. 153 HCPs (50 nurse practitioners, 103 doctors) completed the survey. Mean age of respondents was 44 years. 62% were female, and 82% were licensed before 1996. Varicella infection was correctly diagnosed 79% of the time. HCPs correctly recognized uncomplicated varicella vignettes 85% of the time versus 61% of the time for complicated varicella vignettes. Antibiotics were recommended 17% of the time and antivirals 18% of the time, of which 25% and 69% (respectively) were not appropriate per guidelines. HCPs licensed before 1996 were better able to recognize varicella compared to those licensed later, but prescribed more antimicrobials medications to treat varicella. Although most HCPs recognized varicella infection, a sizable proportion could not recognize cases with complications, and some of the varicella cases were inappropriately treated with antibiotics and/or antivirals. Additional HCP training and high vaccination coverage are important strategies to avoid inaccurate diagnoses and minimize unnecessary exposure to antimicrobial/antiviral therapies.

Impact of universal varicella vaccination on the use and cost of antibiotics and antivirals for varicella management in the United States.

Our objective was to estimate the impact of universal varicella vaccination (UVV) on the use and costs of antibiotics and antivirals for the management of varicella among children in the United States (US). A decision tree model of varicella vaccination, infections and treatment decisions was developed. Results were extrapolated to the 2017 population of 73.5 million US children. Model parameters were populated from published sources. Treatment decisions were derived from a survey of health care professionals' recommendations. The base case modelled current vaccination coverage rates in the US with additional scenarios analyses conducted for 0%, 20%, and 80% coverage and did not account for herd immunity benefits. Our model estimated that 551,434 varicella cases occurred annually among children ≤ 18 years in 2017. Antivirals or antibiotics were prescribed in 23.9% of cases, with unvaccinated children receiving the majority for base case. The annual cost for varicella antiviral and antibiotic treatment was approximately $14 million ($26 per case), with cases with no complications accounting for $12 million. Compared with the no vaccination scenario, the current vaccination rates resulted in savings of $181 million (94.7%) for antivirals and $78 million (95.0%) for antibiotics annually. Scenario analyses showed that higher vaccination coverage (from 0% to 80%) resulted in reduced annual expenditures for antivirals (from $191 million to $41 million), and antibiotics ($82 million to $17 million). UVV was associated with significant reductions in the use of antibiotics and antivirals and their associated costs in the US. Higher vaccination coverage was associated with lower use and costs of antibiotics and antivirals for varicella management.

Vaccine Strain and Wild-Type Clades of Varicella-Zoster Virus in Central Nervous System and Non-CNS Disease, New York State, 2004-2019.

Since the introduction of the varicella-zoster virus (VZV) vaccine in the United States in 1995, there has been a dramatic decrease in both the number and severity of varicella cases. However, VZV surveillance data and information on the VZV clade distribution in central nervous system (CNS) disease and non-CNS disease in New York State is not available. To investigate this, cerebrospinal fluid (CSF) samples from patients with encephalitis or meningitis and non-CSF samples from patients with non-CNS disease manifestations consistent with VZV, collected from 2004 to 2019, were tested with molecular VZV assays. A total of 341 CSF and 1,398 non-CSF samples that tested positive by a VZV-specific real-time PCR assay were further characterized as wild-type or vaccine strain by 3 biallelic real-time PCR assays targeting single nucleotide polymorphism (SNP) markers in open reading frame (ORF) 62. Genotyping was then performed on wild-type strains by conventional PCR and sequencing of 500-bp regions in ORFs 21, 22, and 50. Sequence analysis identified clades 1 to 5 in both sample types with a virtually identical clade distribution between CSF and non-CSF samples. In addition, 19 clade 6 and 13 clade 9 samples were detected in non-CSF samples after implementation of an expanded genotyping scheme, including ORF 29, 38, and 67. These clades were not detected in any CSF samples. Finally, a total of 28 vaccine strains were detected, 25 in the non-CSF samples and 3 in the CSF samples. All three cases of vaccine strain with CNS involvement experienced relatively minor symptoms of aseptic meningitis and fully recovered. These results support the evidence that while the VZV vaccine is capable of causing CNS disease, it is still a rare event and symptoms are typically less severe than those caused by wild-type infection.

Assessment of the economic damage caused by varicella disease in children aged 0–17 years in the Altai Territory

Introduction. In modern conditions, the economic analysis of the damage caused by varicella (chickenpox) is of particular importance, as it contributes to the adoption of management decisions aimed to achieve the maximum medical preventive effect.Purpose: to assess the economic damage caused by the varicella disease in children aged 0–17 years in the Altai Territory.Materials and methods. To estimate the costs, we used data on the incidence of varicella obtained in our previous studies, tariffs of the Territorial Compulsory Health Insurance Fund for the Altai Territory, data on the gross regional product, as well as data from a survey of parents of patients with varicella. The study was conducted based on two polyclinics in Barnaul (for outpatient patients) and the children's infectious diseases department of the Barnaul City Clinical Hospital (for hospitalized patients) for one calendar year (July 2019 – June 2020).Results. The estimated damage caused by varicella per one year in the Altai Territory amounted to 31,527,294.87 rubles, of which 42% are expenses from the own funds of citizens (parents of children with varicella). The cost of parents' personal funds for the treatment of one outpatient case of varicella averaged 3125.4 rubles, and of inpatient case — 2705.4 rubles.Conclusions. The expenses of the government and citizens of the Altai Territory for the treatment of varicella are very large and the disease cannot be controlled by existing preventive measures, as evidenced by consistently high incidence rates. In this regard, an accurate assessment of economic damage is necessary for proper management decisions on the introduction of new preventive measures, including vaccination.

Cost effectiveness and budget impact of universal varicella vaccination in Russia

ABSTRACT This economic evaluation assesses the cost-effectiveness and budget impact of introducing a two-dose varicella vaccine in the Russian national immunization program. A static Markov model followed a simulated 2019 Russian cohort over its lifetime and compared outcomes and costs of three varicella vaccination strategies: strategy I (doses given at 12 and 15 months of age), strategy II (doses given at 1 year and 6 years of age), and a no vaccination scenario. Inputs on age-dependent clinical pathways, associated costs, and related health outcomes were collected from national sources and published literature. Results are presented as incremental cost-effectiveness ratio (ICER) from the healthcare payer and societal perspective over the lifetime of the birth cohort and the budget impact over a 10 years’ time horizon. Vaccination strategies I and II resulted in an ICER of approximately 1.7 million rubles per quality-adjusted life years gained from the healthcare payer perspective and were cost-saving from the societal perspective. From the healthcare payer perspective, the costs per varicella case averted were 5,989 and 7,140 rubles per case for strategies I and II, respectively. However, from the societal perspective, vaccination is a dominant strategy and the budget impact analysis shows significant healthcare savings over 10 years, with strategy I realizing savings of ~2 billion rubles more than strategy II. From a public health impact perspective, varicella vaccination of children at 12 and 15 months of age through the Russian NIP is expected to be cost-effective with an affordable budget impact compared to no vaccination.

Association between ambient temperature and varicella among adults in Qingdao, China during 2008-2019

ABSTRACT Little concern has been paid to the relationship between temperature and varicella among adults. Daily meteorological data and varicella cases in Qingdao among adults from 1 January 2008 to 31 December 2019 were collected. A combination of quasi-Poisson generalized additive model (GAM) and distributed lag non-linear model (DLNM) was conducted to assess the temperature-lag-varicella relationship. We also estimated the lag-response curves for different temperatures and the exposure-response relationships for different lag days. The number of varicella cases was 10,296. Compared with the minimum-varicella temperature (25°C), we found the largest effect of temperature on varicella within 21 lag days was at 1°C (RR, 6.72; 95% CI, 2.90–15.57), and then the effect declined as the temperature increased. A similar trend of rising first and then falling was found in temperature-response curves for different lag days. A reverse U-shape lag pattern was found for different levels of temperatures. Temperature may affect varicella.

Atypical primary varicella rash: Systematic literature review.

AimIn previously healthy subjects, primary varicella presents with a distinctive vesicular rash that is more intense on the trunk and head than on the extremities. However, an atypical presentation may occasionally develop. We aimed at systematically assessing the characteristics of cases affected by atypical primary varicella rash.MethodsThe United States National Library of Medicine, Excerpta Medica and Web of Science databases were reviewed, without date or language restrictions. Articles were eligible if reporting previously healthy and immunocompetent subjects with a primary varicella rash (i.e., a photo‐localised primary varicella or skin inflammation‐associated primary varicella).ResultsThirty‐eight reports providing information on 59 cases of atypical primary varicella were identified. Twenty‐four cases (median 8.5 years of age, 19 females) were photo‐localised and 35 (median 4.8 years of age, 15 females) were associated with pre‐existing skin inflammation (including cast occlusion, diaper irritation, operative sites, burns, insect bites, vaccinations or pre‐existing skin disease). The skin rash was monomorphic and without a “starry sky” appearance.ConclusionPrimary varicella may have a modified presentation in areas of irritation such as sun exposure or pre‐existing inflammation. There is a need for a wider awareness of these modulators of varicella rash.

Ospa wietrzna w Polsce w 2019 roku

Chickenpox is a common disease in Poland, which is usually mild, but can lead to serious complications. Vaccination is an effective form of prevention. Prior to universal vaccination against chickenpox, high incidence was recorded in many countries. In Poland, since 2003, vaccinations have been carried out recommended for people who did not suffer from chickenpox and, since 2009, obligatory vaccinations for children up to 12 years of age particularly vulnerable to infection and children around them. To assess epidemiological situation of chickenpox in Poland in 2019, including vaccination coverage in Polish population, in comparison to previous years. Assessment of the epidemiological situation of chickenpox in Poland in 2019 was based on the results of the analysis of aggregate data published in the annual bulletins: "Infectious diseases and poisoning in Poland in 2019" and "Protective Vaccination in Poland in 2019." In addition, the recommendations from the Protective Vaccine Program for 2019 were used. In 2019, 180 641 cases of chickenpox were registered in Poland, i.e. 17.2% more than in the previous year. The incidence of chickenpox in 2019 was 470.6 per 100 thousand and was higer than in 2018. The lowest incidence was registered in the Dolnośląskie Voivodeship - 297.9/100 thousand, the highest in the Śląskie Voivodeship - 555.9/100 thousand. Children aged 0-4 years became ill the most (89 611). The incidence of chickenpox in men was higher than in women, and in rural areas it was higher than in urban areas. Hospitalization due to chickenpox in 2019 covered 1 156 people, which accounted for 0.64% of the total number of registered cases. In 2019, there was a growth in the number of chickenpox cases compared to the previous year, the incidence remains lower than in 2012-2014. An effective method of disease prevention is vaccination against chickenpox, which, despite the lack of common funding, is carried out in a growing population. Further improvement of the epidemiological situation requires health education of the society in the field of primary prevention, which is based on vaccinations. As recommended, the chickenpox vaccination course consists of two doses of the vaccine separated by at least 6 weeks from the previous dose.

Trend of Chickenpox in Jordan (2013-2020)

Background Chickenpox is the primary infection of varicella-zoster virus (VZV), which is a highly contagious disease. Objective The main goal of this epidemiological descriptive study was to analyze the medical chickenpox data from 2013 to 2020 in Jordan. The aim of the study was to obtain in-depth statistics for all Jordan cities comparing the year semesters for these years, with comparisons of gender and age categories. In addition, we aimed to determine the status of the epidemiological situation in Jordan with concern of the effects of Syrian refugees and the COVID-19 epidemic. Methods This was an epidemiological descriptive study focusing on children under 15 years old. Data were collected based on a clinical diagnosis by doctors. Chickenpox data were obtained from the Ministry of Health as computerized and manual weekly reports from public and private health centers and hospitals. SPSS was used to statistically analyze the data. Results The total number of chickenpox cases reported from 2013 to 2020 in Jordan was 40,988. There was an obvious rise in cases in 2014 (19.24%) with possible outbreaks due to the influx of Syrian refugees, whereas the lowest number of cases (2.44%) was reported in 2020 due to the COVID-19 pandemic and associated quarantine that occurred in Jordan, especially because of closing schools and clinics. Although the total number of chickenpox cases varied from 2013 to 2020, all years showed the same seasonal distribution, with the highest numbers in the spring (especially May), at 16.12%. Geographic distribution analysis showed that the highest numbers of cases were reported in the cities of Amman and Zarqa, with 18.15% and 12.81%, respectively, according to the highest population and gatherings. In gender distribution, there was a sustained preponderance for males over females with 54.48% of the cases reported in males. The age category of 5-9 years was the most likely to be affected by this disease, accounting for 43.34% of cases. This is because these younger children are newly entering school and starting to interact with others. However, the age category of over 20 years showed the lowest number of cases, accounting for 3.98%. There is more concern in Mafraq city (which has the greatest number of Syrian refugees), and we found that children in the age categories of 1-4 years and less than 1 year were more likely to be infected than others. Conclusions Our analysis showed a possible outbreak of chickenpox in 2014, and the lowest number of cases occurred in 2020. In addition, the spring season is the time with the highest number of infected cases. Chickenpox is a highly transmissible childhood disease that becomes more severe with age, and is especially prevalent in children 5-9 years of age in Jordan. Moreover, the gender distribution of cases throughout the years showed a sustained preponderance for males over females. Due to the high populations in Amman and Zarqa cities, these areas had the highest numbers of people infected with chickenpox.

Decreased Pediatric Viral Burden and Increased Rhinovirus Infection During The COVID-19 Pandemic

Objective: Primary preventive nonpharmaceutical interventions were introduced to reduce viral transmission and disease spread at the beginning of the COVID-19 pandemic. Therefore, herein, we aimed to determine and assess the impact of the nonpharmaceutical interventions on bronchiolitis and varicella infection rates in the pediatric population during the pandemic compared to the previous four years. We also aimed to evaluate which viruses cause viral respiratory tract infections during the pandemic period. Material and Methods: Diagnosis and laboratory data of the patients who were one month to 18 years of age were retrospectively retrieved from hospital records. The distribution of the number of patients with bronchiolitis and chickenpox diagnoses was shown monthly between January 2016 and December 2020. Viral agents detected by polymerase chain reaction (PCR) in the nasopharyngeal aspirate samples obtained at the first application of the patients during the pandemic period were investigated. Results: The data of 2.254.877 pediatric patients admitted to our hospital from January 2016 to December 2020 were examined. There were 38.458 bronchiolitis and 954 chickenpox cases reported both as inpatients and outpatients. There was a 85.6% decrease in the rate of bronchiolitis compared to previous years, and chickenpox peak was not observed in the pandemic period. Rhinovirus was found to be the most common etiologic agent of bronchiolitis during the pandemic period and Respiratory Syncytial Virus (RSV) came second. A significant decrease in the frequency of influenza was also observed. Conclusion: Our study reveals that the measures which curtail social life and prioritize social distancing prevent the spread of viral infections. It has also shown that there is an increase in the frequency of Rhinovirus infection during the pandemic period.

Elderly Male: An Immune-Compromise Sufficient Enough to Have Hemorrhagic Varicella.

Elderly Male: An Immune-Compromise Sufficient Enough to Have Hemorrhagic Varicella.

Varicella Outbreak at a Boarding School, Chikomba District, Mashonaland East Province, Zimbabwe, 2019

Background: Varicella is a contagious illness, caused by varicella zoster virus (VZV). It is transmitted via the respiratory route and through contact with the infected person. Fourteen cases of varicella from a boarding school in Chikomba District, Zimbabwe were reported on 14 February 2019. We investigated the outbreak to determine its scope, identify risk factors for transmission and recommend evidence-based control measures. Methods: A 1:2 unmatched case-control study was conducted. A case was a form one student at a boarding school in Chikomba District who developed acute onset of diffuse maculopapulovesicular rash without other apparent cause from 22 January 2019 to 24 February 2019. A control was a form one student at the same boarding school who did not develop the signs and symptoms of varicella during the same period. The diagnosis was based on clinical signs and symptoms. An interviewer-administered questionnaire was used to collect data. Epi info 7TM was used to calculate frequencies, odds ratios and perform logistic regression to control for confounding variables. Results: We recruited 31 cases and 62 controls. Independent risk factors for contracting varicella were classmate contact [AOR 24; (95% CI 4.4 - 83), p < 0.01], dormitory contact [AOR 14; (95% CI 2.7 - 75), p < 0.01] and previous history of varicella like illness [AOR 0.08; (95% CI 0.02 - 0.30), p < 0.01]. Only 35% (11/31) of cases and the majority 58 % (36/62) of controls, knew at least three signs and symptoms of varicella (p = 0.04). All cases were reported to the health facility within two days of onset of illness but were not managed according to guidelines. Conclusion: A perfect setting for the spread of infection was available in the form of students in a naive community living in close proximity both at class and at dormitories, which lead to the rapid transmission of the virus. Screening and isolation of the infected students controlled the outbreak.

POSC195 What Is the Burden of Varicella-Associated Complications: A Systematic Literature Review

Economic evaluations of varicella vaccination typically consider only outpatient varicella cases. However, varicella complications can occur, requiring additional diagnostic procedures or hospitalizations. Therefore, their inclusion in such models should be considered. This systematic literature review aimed at identifying the prevalence and duration of complications, and case-fatality rates among patients with primary varicella.