Burden of Varicella in Latin America: A Systematic Review and Critical Analysis

PIN3 BurdeN of VarIcella IN latIN amerIca: a SyStematIc reVIew aNd crItIcal aNalySIS Yang H.K.1, Liaw K.L.2, Manoff S.2, Kuter B.1 1Merck & Co, Inc., West Point, PA, USA, 2Merck & Co, Inc., Upper Gwynedd, PA, USA Objectives: Varicella is a common, vaccine-preventable illness with significant public health impact in Latin America (LA). This study aimed to review the epidemiology and economic burden of varicella, and to perform a critical analysis of available data in LA. MethOds: A comprehensive literature review was conducted in major databases and government websites to identify published data on epidemiology and economic burden of varicella in LA. Study data were extracted systematically including incidence rates, lifetime prevalence, mortality, type and rates of complications, as well as use of health care resources (hospitalizations, physician office visits, others) and both direct and indirect costs associated with varicella. Critical analyses of study quality and data availability are performed for each country. Results: Published studies were identified from ten countries including Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, Paraguay, Uruguay, and Venezuela. Annual incidence rates ranged from 20 per 100,000 in Uruguay up to 381 per 100,000 in Mexico. Incidence was highest among children < 10 years of age, bearing increased utilization of healt health care resources. Bimodal seasonal patterns of varicella were reported in Argentina, Mexico and Uruguay. Most frequent complications among hospitalized patients were skin and soft tissue infections, respiratory infections and neurological complications. Patients hospitalized for varicella stayed generally between 1-5 days. Critical analysis suggested that most published studies had limitations including data representativeness and study design issues. Data gaps in the epidemiology and economic burden of varicella were also found on the country level. cOnclusiOns: Currently there is limited information available on burden of varicella in Latin America, potentially due to the lack of mandatory reporting and active surveillance systems for varicella in the region. Country-specific epidemiological information and varicella-related health care resource utilization data are needed to elucidate the disease burden for developing appropriate immunization recommendations and informing decision makers about the value of varicella vaccination.