Cost-effectiveness of Antivenoms for Snakebite Envenoming in Nigeria

Abstract

BackgroundSnakebite envenoming is a major public health problem throughout the rural tropics. Antivenom is effective in reducing mortality and remains the mainstay of therapy. This study aimed to determine the cost-effectiveness of using effective antivenoms for Snakebite envenoming in Nigeria.MethodologyEconomic analysis was conducted from a public healthcare system perspective. Estimates of model inputs were obtained from the literature. Incremental Cost Effectiveness Ratios (ICERs) were quantified as deaths and Disability-Adjusted-Life-Years (DALY) averted from antivenom therapy. A decision analytic model was developed and analyzed with the following model base-case parameter estimates: type of snakes causing bites, antivenom effectiveness to prevent death, untreated mortality, risk of Early Adverse Reactions (EAR), mortality risk from EAR, mean age at bite and remaining life expectancy, and disability risk (amputation). End-user costs applied included: costs of diagnosing and monitoring envenoming, antivenom drug cost, supportive care, shipping/freezing antivenom, transportation to-and-from hospital and feeding costs while on admission, management of antivenom EAR and free alternative snakebite care for ineffective antivenom.Principal FindingsWe calculated a cost/death averted of ($2330.16) and cost/DALY averted of $99.61 discounted and $56.88 undiscounted. Varying antivenom effectiveness through the 95% confidence interval from 55% to 86% yield a cost/DALY averted of $137.02 to $86.61 respectively. Similarly, varying the prevalence of envenoming caused by carpet viper from 0% to 96% yield a cost/DALY averted of $254.18 to $78.25 respectively. More effective antivenoms and carpet viper envenoming rather than non-carpet viper envenoming were associated with lower cost/DALY averted.Conclusions/SignificanceTreatment of snakebite envenoming in Nigeria is cost-effective with a cost/death averted of $2330.16 and cost/DALY averted of $99.61 discounted, lower than the country's gross domestic product per capita of $1555 (2013). Expanding access to effective antivenoms to larger segments of the Nigerian population should be a considered a priority.

Snakebite is Under Appreciated: Appraisal of Burden from West Africa

“…As a condition affecting poor vulnerable rural dwellers, it is not only a major health problem but also a major impediment to economic prosperity from loss of income following initial incapacitation, hospitalization, long-term disabilities and premature deaths [ 7 ]. It is preventable and treatable with antivenom which has been shown to be cost effective [ 8 ]. In this analysis, we estimated the impact of snakebite mortality and morbidity using the Disability Adjusted Life Years (DALYs) metrics for 16 countries in Western Africa (WA).…”

Management of snakebite victims using low dose antisnake venom in a tertiary hospital in Southern Nigeria: A 5-year Retrospective study

“…Studies of snake bite that are hospital based are 3 to 5 times lower in prevalence compared to household or community based studies (11). A previous study showed that only 8.5% of snake bite victims present to hospital facilities in Nigeria (12), as most victims patronize traditional healers. This may be a reflection of the number of cases that reported in our facility during this period of study.…”

“…Traditional medical practitioners make use of concoctions which are administered either orally or applied topically. In Nigeria, certain herbs such as Aristollchia albida,Guiera senegalensis, were found to act on snake venoms in experimental animals but findings were not conclusive (12). Prior visits for traditional treatment should be highly discouraged because it delays presentation, may distort the clinical picture, with the increased risk of other complications such as bleeding, infection and gangrene.…”

Priority Actions and Progress to Substantially and Sustainably Reduce the Mortality, Morbidity and Socioeconomic Burden of Tropical Snakebite

“…Data from studies conducted in India [11,14], Bangladesh [15], Sri Lanka [16,17], Nigeria [12,18], Burkina Faso [19], Kenya [20] and Senegal [21], amongst others, provide evidence of an increasing capability of acquiring snakebite epidemiology data that need to be adopted and promoted more widely. The workshop was informed of hospital-based and community survey projects being undertaken or planned in several countries represented by the recently established African Society of Venimology and in Southeast Asia.…”