Failure of a new antivenom to treat Echis ocellatus snake bite in rural Ghana: the importance of quality surveillance

Abstract

This study compares two antivenoms used to treat Echis ocellatus snake bite patients at Mathias Hospital, Yeji, central Ghana. FAV-Afrique antivenom (Aventis Pasteur) was given to 278 patients during 2001--2003, whilst Asna Antivenom C (Bharat Serum and Vaccines Ltd) was used in 2004 to treat 66 patients. The two groups had comparable patient attributes, time from snake bite to treatment and staff adherence to the tested treatment protocol. The antivenom C group required more repeat doses and twice the amount of antivenom to treat coagulopathy. Of greater concern, the antivenom C mortality rate was 12.1%, a marked rise from the 1.8% rate in the earlier FAV-Afrique antivenom group. In this study, antivenom C was ineffective as treatment for West African E. ocellatus snake venom. This illustrates the absolute need for regional pilot tests to assess the effectiveness of a new antivenom against local snake venoms before its sole and general distribution in a region is initiated.

The paraspecific neutralisation of snake venom induced coagulopathy by antivenoms

“…The results of the plasma assay were somewhat unexpected because the toxin composition of snake venoms are known to vary extensively at every taxonomic level due to a variety of processes 2–4,26–28 , and these are well known to undermine the paraspecific efficacy of antivenom 8,9,29 .…”

A multicomponent strategy to improve the availability of antivenom for treating snakebite envenoming

“…Carrying out independent in vitro or animal experiments to test the efficacy of antivenoms is a task belonging to national regulatory agencies and should be done routinely on a batch-by-batch basis, even if data on neutralizing potency have been provided by manufacturers seeking product registration. 13,14 Strengthening manufacturing and quality control…”

Snakebite Envenoming: A Public Health Perspective

“…This issue of low cross-reactivity of some antivenoms may have potentially serious implications, when some products are used in the treatment of envenomings by species whose venoms are immunologically different from the ones used in immunization. One example has been the use of antivenoms manufactured in India for the treatment of envenomings in sub-Saharan Africa (Visser et al, 2008). This problem is complicated by the frequent lack of regulation and quality control of imported antivenoms in many countries, thus precluding the proper assessment of their neutralizing ability.…”