Research Partnership with Developing Countries
A Programme funded by Swiss National Science Foundation (SNSF) and Swiss Agency for Development and Cooperation (SDC)

A randomized, double-blind, multi-centre clinical trial of two dose regimens of polyvalent Anti Snake Venom Serum (ASVS) for the treatment of snake bite envenoming in Nepal

Snake bites are considered as one of the major neglected public health issues of our times. They occur chiefly in developing countries and mainly affect poor rural communities. Besides the inadequate supply, distribution and accessibility of antivenom, a major problem is the absence of standardized and adequate treatment protocol. There is a significant diversity in clinical practices, in particular concerning the dose of antivenom given. Additionally, antivenom is often given even in the absence of a clear indication for envenoming. Altogether, this leads to an incredible waste of a scarce and costly resource. In Nepal there are gross disparities in the management and outcomes of snake bite envenomings. The country's national guidelines, issued in 2004, prescribe an initial antivenom dose that is 5 times less than the one advocated by most experts. The dosage recommended by the National guidelines is not based on scientific or clinical evidence, and currently, there is confusion about the adequate dose to be administered. Some physicians follow recommendations published by experts, others follow the National guidelines, but for most, dosage is arbitrary. These discrepancies directly impact on morbidity and mortality and lead to wastage of a costly treatment that few can afford. Our principal objective is to establish unequivocally which dosage regimen is the most appropriate for the treatment of snake bite neurotoxic envenoming. We plan to conduct a randomized, double-blind, clinical trial comparing high and low initial doses of snake polyvalent antivenom. 250 snake bite victims showing signs of neurotoxic envenoming will be enrolled over 2 years in three health centres of Southern Nepal. Each participant will initially receive either 2 vials or 10 vials of snake polyvalent antivenom. In both arms we will compare mortality, the proportion of patients needing assisted respiration, and the percentage of patients who show worsening of neurotoxic signs and therefore require additional doses of antivenom. We will also measure the kinetics of recovery and the total consumption of antivenom. Finally, we also intend to assess the incidence and severity of early and late adverse reactions to antivenom. The economical impact of snake bite envenoming will also be determined by measuring direct and indirect costs to both health services and individual victims. Because they chiefly affect agricultural workers and children, snake bites have serious socio-economic consequences, a fact that is frequently overlooked by national authorities. Our hope is that the scientific evidence and economical arguments produced will prompt the revision of Nepal's national guidelines.

Contacts:

Dr. François Chappuis
Unité de Médecine des Voyages
Département de Médecine Communautaire et de
Hôpital Cantonal Universitaire de Genève
Rue Micheli-du-Crest 24
CH-1211 Genève 4
Francois.Chappuis(at)hcuge.ch

Sanjib Kumar Sharma
Department of Medicine
B. P. Koirala Institute of Health Sciences
NP- Dharan
drsanjib(at)yahoo.com