Estimating the health economic impact of the universal varicella vaccination in Argentina from 2015 to 2019.

Since the introduction of Universal Varicella Vaccination (UVV) in the Argentinean National Immunization Program in 2015, a significant decline in the incidence of varicella has been reported. This study aimed to estimate the economic impact of single-dose UVV in Argentina from 2015 to 2019. The economic impact was assessed based on the observed incidence of varicella in the post-UVV period and the number of cases avoided, obtained from a previously published study that used an Autoregressive Integrated Moving Average (ARIMA) model. The weighted average cost per case was calculated using local studies. The post-UVV cost reductions were calculated by multiplying the number of cases avoided from 2015 -2019 by the weighted average cost per case. Data were summarized yearly and by peak (September-November) periods for the target (1-4 years) and overall populations. We estimated avoided costs of United States dollars (USD) $65 million in the target population and $112 million in the overall population over 4 years following UVV introduction. We observed a trend toward greater reductions in costs over time, with substantial differences observed in peak periods. We estimated that the single-dose UVV program considerably reduced the economic burden of varicella in Argentina by avoiding direct and indirect costs associated with varicella management.

Impacto clínico y epidemiológico de las infecciones por varicela en niños previo a la introducción de la vacuna al Calendario Nacional de Argentina / Clinical and epidemiological impact of varicella infection in children prior to the introduction of the varicella vaccine in the national immunization schedule of Argentina

Introducción. En Argentina, se estiman 400 000 casos anuales de varicela. Dado el subregistro de casos existentes, la carga de enfermedad real se desconoce. Objetivo. Evaluar la carga de enfermedad por varicela antes de la introducción de la vacuna al Calendario Nacional. Materiales y métodos. Estudio retrospectivo, analítico, observacional, realizado en tres centros asistenciales del país. Revisión de los registros de consultas ambulatorias a los Servicios de Urgencias y de las historias clínicas de las internaciones por varicela en pacientes < 18 años. Período: 1/2011-12/2013. Resultados. Fueron asistidas un total de 382782 consultas ambulatorias; 3367 (0,88 %) correspondieron a consultas por varicela; el 57,6 %, < 4 años. Requirieron internación 164 (4,9 %) con una tasa de hospitalización global de 65,3/10000 hospitalizados/año (IC 95 %: 55,4-76,5); tasa de hospitalización en niños sanos: 57,2/10 000 (IC 95 %: 67,7-48,0); mediana de edad: 31,5 meses. Las causas de internación más frecuentes fueron infecciones de piel y/o partes blandas (61,1 %) y respiratorias (10,1 %). El 54,3 % recibió tratamiento con aciclovir, y el 73,1 %, con antibióticos. Presentaron bacteriemia 5/67 (7,5 %), todas por cocos Gram(+) y en inmunocompetentes. De los 19 pacientes inmunocomprometidos, el 36,8 % tuvo complicaciones (5 infecciones de piel y/o partes blandas y 2 neumonías). La mediana de días de internación fue 4, significativamente más prolongada en pacientes inmunocomprometidos. Un paciente requirió cuidados intensivos. No hubo fallecidos. Conclusión. La carga de enfermedad registrada fue significativa, con impacto considerable en pacientes sin patología de base.

Introduction. In Argentina, an estimated 400 000 varicella cases occur annually. Given the under-recording of existing cases, the actual burden of disease is unknown. Objective. To assess the burden of varicella before the introduction of the varicella vaccine in the national immunization schedule. Materials and methods. Retrospective, analytical, observational study carried out in three hospitals of Argentina. Review of medical records from outpatient visits to the Emergency Department and from patients younger than 18 years hospitalized for varicella. Period: 1/2011-12/2013. Results. A total of 382 782 outpatients were seen; 3367(0.88%) corresponded to visits due to varicella; 57.6 % were < 4 years old. A total of 164 (4.9 %) patients required hospitalization, with an overall hospitalization rate of 65.3/10 000 hospitalized patients/year (95 % confidence interval -#91;CI-#93;: 55.4-76.5); hospitalization rate in healthy children: 57.2/10 000 (95 % CI: 67.7-48.0); median age: 31.5 months. The most common causes of hospitalization were skin and/or soft tissue infections (61.1 %) and respiratory infections (10.1 %). Also, 54.3 % were treated with acyclovir and 73.1 %, with antibiotics. Bacteremia developed in 5/67 patients (7.5 %), all cases were caused by Gram-positive cocci and occurred in immunocompetent patients. Out of 19 immunocompromised patients, 36.8 % had complications (5 skin and/or soft tissue infection and 2 pneumonia cases). The median length of stay was 4 days, which is significantly more prolonged in immunocompromised patients. One patient required intensive care. No patient died. Conclusion. The burden of disease was significant, with a considerable impact in patients without an underlying disease.