Risk factors for fatal scorpion envenoming among Brazilian children: a case–control study

Abstract

Scorpion envenoming is relatively frequent in tropical and subtropical regions and potentially fatal. We aimed to identify risk factors for fatal scorpion envenoming among Brazilian children. A case-control study investigated all fatal cases of scorpion envenoming among children up to 10y old, reported to the Brazilian Diseases Surveillance System between 1 January 2007 and 18 July 2016. Controls were randomly sampled from children who survived the envenoming over this period. Data were analysed using logistic regression. Of the 254 cases and 1083 controls investigated, the identified risk factors were age ≤5y, occurred in a rural area, time-to-treatment ≥3h, treatment with scorpion antivenom (SAV) but either excessive or insufficient number of vials, treatment with antivenom that was neither SAV nor anti-spider and no antivenom administered compared with the standard recommended treatment. Treatment effectiveness at preventing fatal scorpion envenoming was 77.0% when time-to-treatment was <3h and 75% in children 9-10y of age. SAV was 63% effective at preventing death when administered early at the recommended dosage. Fatal scorpion envenoming was associated with younger age, incident occurring in a rural area, late treatment and inadequate antivenom treatment. SAV was effective at preventing death when administered early.