[Evaluation of a new polyvalent antivenom against snakebite envenomation (Inoserp® Panafricain) in two different epidemiological settings: Northern Benin and Maritime Guinea]

Abstract

Objectives: The authors evaluated the safety and efficacy of Inoserp(®) Pan Africa, a new polyvalent antivenom composed of highly purified and lyophilized fragments of F(ab')2 immunoglobulins, recently registered in Benin and Guinea.

Methods: We treated 100 patients in northern Benin (Atacora) and 109 in Maritime Guinea (Kindia) with confirmed envenomation. Treatment consisted of intravenous administration of 1 vial for uncomplicated envenomation, and 2 vials for hemorrhagic or neurotoxic envenomation. The dose was repeated when bleeding or signs of neurotoxicity persisted or appeared.

Results: In Atacora, on arrival at the hospital, 90% of patients had incoagulable blood, and 50% were bleeding. The resolution of these bleeding disorders was obtained in less than 3 hours for 50% of the patients and in less than 24 hours for 98%. Four patients died. In Kindia, 96 patients (88%) presented viper bites with pain + edema and 13 (12 %) others showed elapid (ptosis, dyspnea) envenomation. One patient bitten by a member of the Elapidae family, died despite early treatment. In Benin, protocol deviations for 60% of patients led to significant underdosing of the antivenom; the proportion was much lower (2%) in Guinea. Signs of intolerance after Inoserp(®) Pan Africa administration were reported in 8% of patients. All these symptoms were mild and disappeared rapidly after an antihistamine or corticosteroid treatment.

Conclusion: Treatment using intravenous Inoserp(®) Pan Africa appeared to be well tolerated and effective against snakebite envenomation in both epidemiological settings.

Keywords: Africa; Benin; Guinea; antivenom; envenomation; snakes.