Scorpion envenomation and serotherapy in Morocco

A clinical and biologic study was conducted in Morocco to assess the effici ency of antivenom therapy for treating victims of scorpion stings. Epidemio logic and clinical data were collected from 275 patients envenomed by Andro ctonus mauretanicus mauretanicus and Buthus occitanus scorpions. Patients r eceived antivenom or other drugs. Blood samples were collected at the time of hospital admission and 1 hr and 3 hr after treatment. Serum venom levels were quantified by using an ELISA. An association was found between clinic al signs of envenoming and the level of venom in serum. Patients classified as grade II (moderate envenoming) had higher serum levels of venom level t han patients classified as grade I (mild envenoming). At admission to the h ospital, the mean venom concentration was not significantly different betwe en the group not treated with antivenom, the group who received 2-5 ml of a ntivenom, and the group who received 10 ml of antivenom. A significant decr ease in serum venom levels and an improvement in the clinical conditions we re observed in patients administered 10 ml of antivenom. The lower decrease in serum venom levels in patients who received 2-5 ml of antivenom was due to lower doses of antivenom. No difference in the venom concentration was observed in patients who were not treated with antivenom. The absence of ad ministration of antivenom increased the risk of developing clinical signs a t the end of the hospitalization period. However, this risk was much higher when more than 1 hr elapsed between the time of the scorpion sting and the time of hospital admission. The results demonstrate that antivenom is effe ctive in decreasing circulating venom and morbidity. Serotherapy is more ef ficient when given as soon as possible after envenomation and with adequate quantities of antivenom.