Treatment and vaccination strategies to control cholera in sub-Saharan refugee settings - A cost-effectiveness analysis

Context.-There is significant controversy about how best to control cholera epidemics in refugee settings. Specifically, there is marked disagreement about whether to use oral cholera vaccines in these settings, despite the improved safety and effectiveness profiles of these vaccines. Objective.-To determine the cost-effectiveness of alternative intervention strategies, including vaccination, to control cholera outbreaks in sub-Saharan refugee camps. Design.-A cost-effectiveness analysis based on probabilities of cholera outcomes derived from epidemiologic data compiled for refugee settings in Malawi from 1987 through 1993; data for costs were obtained from a large relief agency that provides medical care in such settings. Setting and Participants.-A hypothetical refugee camp with 50 000 persons in sub-Saharan Africa evaluated for a 2-year period. Interventions.-We compared the costs and outcomes of alternative strategies in which appropriate rehydration therapy for cholera is introduced preemptively (at the establishment of a camp) or reactively (once an epidemic is recognized) and in which mass immunization with oral B subunit killed whole-cell (BS-WC) cholera vaccine is added to a rehydration program either preemptively or reactively. Main Outcome Measures.-Cost per cholera case prevented and cost per cholera death averted. Results.-In a situation with no available rehydration therapy suitable for the management of severe cholera, a strategy of preemptive therapy ($320 per death averted) costs less and is more effective than a strategy of reactive therapy ($586 per death averted). Adding vaccination to preemptive therapy is expensive: $1745 per additional death averted for preemptive vaccination and $3833 per additional death averted for reactive vaccination. However, if the cost of vaccine falls below $0.22 per dose, strategies combining vaccination and preemptive therapy become more cost-effective than therapy alone. Conclusions.-Provision for managing cholera outbreaks at the inception of a refugee camp (preemptive therapy) is the most cost-effective strategy for controlling cholera outbreaks in sub-Saharan refugee settings. Should the price of BS-WC cholera vaccine fall below $0.22 per dose, however, supplementation of preemptive therapy with mass vaccination will become a cost-effective option.