Number Of Varicella Cases Research Articles

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.

Role of Climatic Conditions on the Incidence of Varicella in an Out-patient Clinic of a Tertiary Care Pediatric Hospital at Dhaka

Background & objective : Chicken pox or varicella is a disease of both tropical and temperate zones bearing a complex-relationship with climatic variables, like temperature, rainfall and relative humidity, wind velocity and so on. As no study has, by far, been conducted to relate its occurrence with these climatic variables in Bangladesh, this study was intended to explore the effect of weather conditions on the incidence of varicella in Dhaka city of Bangladesh.
 Methods: The present cross-sectional study obtained data of 172 varicella cases from the records of the daily register of Out-patient Department of Dhaka Shisu Hospital, Dhaka between January 2018 to December 2019. According to the study protocol a child was diagnosed as having varicella or chicken pox who had a history of short febrile illness accompanied by a pruritic vesicular eruption (on the face and trunk)) of the skin and mucous membranes which ultimate weeps out and crusts. Total number of cases treated monthly at Out-patient Department (OPD) during the period was also recorded. Climatic data were provided by Bangladesh Meteorological Department, which among others, included monthly average temperature, relative humidity (RH) and amount of rainfall or precipitation. While the outcome variable was monthly number of varicella cases, the predictive variables were average temperature, humidity and rainfall during the study period.
 Result: Over 70% of children were 1-10 years old with median age of the children being 5.5 years (range: < 1 month -14 years). Boys were a bit higher (54%) than the girls (46%). A seasonal pattern of chicken pox was seen with clustering of cases between mid-February to mid-April (spring season) with two peaks – one in February and another in April, when monthly average temperature, total rainfall and humidity all were at their optimum. The peak incidences of chicken pox cases during the spring both in 2018 and 2019 as correlated with climatic data of the same period, it is seen that the prevailing weather then was optimum-average temperature was 23°C, average precipitation was 20-25% of the total annual precipitation and relative humidity was around 65%.
 Conclusion: The study concluded that majority of the varicella cases occur under ten years of age and boys are a little more susceptible to have the infection than the girls. A seasonal pattern of chicken pox is clearly seen with clustering of cases between mid-February to mid-April (spring season) with two peaks when monthly average temperature, total rainfall and humidity all are optimally favorable for the multiplication of varicella zoster virus.
 Ibrahim Card Med J 2020; 10 (1&2): 11-17

1389. Economic Evaluation of Universal Varicella Vaccination in Mexico

BackgroundUniversal varicella vaccination (UVV) has proven to be cost-effective in countries where implemented. However, this has not yet been evaluated for Mexico. We assessed the cost-effectiveness of UVV in the Mexican Immunization Program from both healthcare and societal perspectives.MethodsThe annual disease burden (varicella cases/deaths, outpatient visits, and hospitalizations) were derived from Mexican seroprevalence-published data adjusted to the 2020 country’s population. The annual economic burden was calculated by combining disease with Mexican published unit cost data. Four different vaccination strategies were evaluated: 1. One dose of a single varicella vaccine at 1 year old; 2. Two doses of single varicella vaccine at 1 and 6 years; 3. One dose of a single varicella vaccine at 1 year, and quadrivalent measles-mumps-rubella-varicella vaccine (MMRV) at 6 years; 4. Two doses of MMRV at 1 and 6 years.We developed an economic model for each vaccination strategy where 20 consecutive birth cohorts were simulated. The impact of vaccination (number of avoided cases/deaths) was evaluated for a 20 years follow-up period based on vaccine effectiveness (87% and 97.4%), and assuming a 95% coverage. Subsequently, we estimated net vaccination costs, benefit-cost ratio (BCR), annual costs saved, cost-effectiveness ratio.ResultsFrom annual disease burden estimation, avoided cases with one dose, and two doses were of 20,570,722 and 23,029,751, respectively. From the 20 years cohort, the yearly number of varicella cases was estimated at 2,041,296, and total costs at $115,565,315 (USD) (healthcare perspective) and $165,372,061 (healthcare and societal perspectives). Strategies 1 and 2 were found to be cost-saving (BCR >1) (Figure 1), and strategy 3 to be cost-effective (CE) ($1539 per Life Year Gained). Strategy 4 was not CE. Strategies 1 and 2 would allow saving annually $53.16 million and $34.41 million, respectively, to the Mexican society.FIGURE 1 Conclusion1.The disease and economic burden of varicella in Mexico are high.2.UVV with four different vaccination strategies results in a high reduction of cases.3.From healthcare and societal perspectives, UVV was shown to be cost-effective (with strategy 3), and cost-saving (with strategies using one dose or two doses separately).Disclosures All Authors: No reported disclosures

Descriptive epidemiology of varicella based on national surveillance data before and after the introduction of routine varicella vaccination with two doses in Japan, 2000–2017

Routine childhood immunization using two doses of the varicella vaccine was introduced in Japan in October 2014. In this study, we analyzed the data extracted from national varicella surveillance, including pediatric sentinel surveillance from 2000 to 2017 and hospitalized varicella surveillance from the 38th week of 2014 to the 37th week of 2017. Compared with the 2000–2011 baseline data, the number of varicella cases per sentinel decreased substantially by 76.6% overall and by 88.2% among children aged 1–4 years in 2017. Of 997 hospitalized patients, we found a decreasing trend in the number of cases among children aged <5 years. We also found a decreasing trend in the number of cases with complications among children aged 1–4 years. Data on the self-reported transmission sites in 35.5% (354/997) of the hospitalized varicella patients showed that transmission of varicella zoster virus (VZV) occurred frequently in household, at school for young children, in the workplace for adults, and at hospital for all age groups. Data from 29.0% (289/997) of the hospitalized patients with a self-reported source of infection showed that transmission of VZV occurred from a patient with herpes zoster (HZ) in 30.4% (88/289) of cases. Our data demonstrate a substantial decrease in the number of varicella cases in young children following introduction of routine childhood vaccination program with two-dose varicella vaccination in Japan. These data highlight the unique aspects of transmission sites across age groups and the important role of HZ cases in disease circulation.

Influence of demographic changes on the impact of vaccination against varicella and herpes zoster in Germany \u2013 a mathematical modelling study

BackgroundEpidemiological studies suggest that reduced exposure to varicella might lead to an increased risk for herpes zoster (HZ). Reduction of exposure to varicella is a consequence of varicella vaccination but also of demographic changes. We analyzed how the combination of vaccination programs and demographic dynamics will affect the epidemiology of varicella and HZ in Germany over the next 50 years.MethodsWe used a deterministic dynamic compartmental model to assess the impact of different varicella and HZ vaccination strategies on varicella and HZ epidemiology in three demographic scenarios, namely the projected population for Germany, the projected population additionally accounting for increased immigration as observed in 2015/2016, and a stationary population.ResultsProjected demographic changes alone result in an increase of annual HZ cases by 18.3% and a decrease of varicella cases by 45.7% between 1990 and 2060. Independently of the demographic scenario, varicella vaccination reduces the cumulative number of varicella cases until 2060 by approximately 70%, but also increases HZ cases by 10%. Unlike the currently licensed live attenuated HZ vaccine, the new subunit vaccine candidate might completely counteract this effect. Relative vaccine effects were consistent across all demographic scenarios.ConclusionDemographic dynamics will be a major determinant of HZ epidemiology in the next 50 years. While stationary population models are appropriate for assessing vaccination impact, models incorporating realistic population structures allow a direct comparison to surveillance data and can thus provide additional input for immunization decision-making and resource planning.

One-dose vaccination associated with attenuated disease severity of adolescent and adult varicella cases in Beijing’s Fengtai District

Background In recent years, the number of varicella cases in adults has significantly increased in Beijing. However, the effect of the vaccination on varicella-related characteristics among adults has not been studied.Methods and Results: Using data from the Infectious Disease Reporting System and the Immunization Information System, we compared the epidemiology and disease severity in breakthrough and unvaccinated varicella cases in adolescents and adults (≥ 15 year-old) from 2008 to 2011 in Beijing’s Fengtai district, China. The results showed that the age (P = 0.003),contact history (90% vs. 73%, P = 0.019) and outbreak cases (10% vs. 1%, P < 0.0001) were significantly differently distributed between the two groups and that both the incidence of moderate-to-severe cases (26% vs. 45%, P = 0.035, OR = 0.446) and varicella-associated fever (49% vs. 66%, P = 0.068, OR = 0.534) were either significantly lower or trended to be lower in the breakthrough group than in the unvaccinated group. Additionally,vaccine effectiveness against moderate-to-severe cases of varicella was 55.4%.Conclusion: Altogether, these results indicate that vaccination against varicella among adolescents and adults affected the epidemiology and attenuated the disease severity of the cases. The Results from this study will provide useful information for the prevention of varicella in adolescents and adults.

Economic evaluation of varicella vaccination in Spain—Results from a dynamic model

Varicella is a universal childhood disease in Spain, causing approximately 400,000 cases, 1500 hospitalizations and 15 deaths every year. The aim of this study is to determine the economic impact of childhood varicella vaccination on the burden of disease and associated costs by using a dynamic model. The analysis is based on the varicella transmission model developed by Halloran and adapted to the Spanish context. Cost data (€, 2004) were derived from previous studies and official tariffs. Two vaccination scenarios were analysed: (1) routine vaccination program for children aged 1–2 years, and (2) routine vaccination program for children aged 1–2 years completed by a catch-up program during the first year of vaccine marketing for children aged 2–11 years. The analysis considers that a similar coverage rate to the MMR one would be achieved (97.15%). A societal perspective, including direct and indirect costs, and a health care payor perspective were adopted. A probabilistic sensitivity analysis was performed. A routine vaccination program has a positive impact on varicella-related morbidity: the number of varicella cases is estimated to be reduced by 89%, and 1230 hospitalizations are prevented. From the societal perspective, scenario (1) is cost-saving whether or not indirect costs are considered (−51 and −4%, respectively). From the Health Care System the strategy is cost-effective, with a cost-effectiveness ratio estimated at €3982 per life-year gained, although it leads to a small increase in the costs. Considering the impact of vaccination on morbidity and costs, a routine childhood vaccination program against varicella is worth while in Spain without taking into account the potential impact on HZ.

Epidemiology of varicella in Slovenia over a 20-year period (1979-98).

Varicella is one of the most common childhood diseases. The course of the disease is usually mild and uncomplicated. In Slovenia, varicella is a notifiable communicable disease which must be reported. Data collected from 1979-98 were analysed. Over the 20-year period the number of varicella cases reported ranged from a low of 11,086 (in 1994) to a maximum of 21,141 (in 1987). During the last 10 years, the highest incidence of varicella was reported in children aged from 12 months to 2 years. In adults over 20, incidence has slightly but steadily increased over the 20 year period. Overall, the number of males with varicella exceeded that of females. The proportion of females was higher only in the 20-30-year age group, probably as a consequence of more frequent and closer contact with infected children by mothers. The highest number of reported cases was during winter and early spring.

Varicella: Complications and Costs

Varicella (chickenpox) has long been considered a benign, inevitable disease of childhood. Complications are generally mild and rarely severe, and virtually every individual is infected by adulthood. Infection is associated, however, with a high risk of serious complications in certain high-risk groups, such as leukemic children. Concerns about the severity of varicella in this population have led to the development and testing of a live, attenuated vaccine. Because of the favorable results thus far available, the vaccine may soon be licensed for use in high-risk individuals. The fact that a vaccine may soon be available has led to an increased interest in the potential benefits of a childhood varicella vaccine program. The costs associated with varicella infection in normal persons without a varicella vaccination program have been estimated to be approximately $400 million, 95% of which is the cost of caring for a child at home. Vaccination of normal 15-month-old children with a safe and effective vaccine with long-lasting immunity could reduce the cost by 66% and result in a savings of $7 for every dollar spent on the vaccination program. This assumes that vaccine would be administered only once with measles, mumps, and rubella vaccine, that there would be no increase in the number of varicella cases in older persons who are at increased risk for complications, and that there would be no deleterious effect on the occurrence and severity of herpes zoster.(ABSTRACT TRUNCATED AT 250 WORDS)