Cost-effectiveness modelling to optimise active screening strategy for gambiense human African trypanosomiasis in endemic areas of the Democratic Republic of Congo

Christopher N Davis,Matt J Keeling,Marina Antillón,Kat S Rock,Erick Mwamba Miaka

doi:10.1186/s12916-021-01943-4

Abstract

BackgroundGambiense human African trypanosomiasis (gHAT) has been brought under control recently with village-based active screening playing a major role in case reduction. In the approach to elimination, we investigate how to optimise active screening in villages in the Democratic Republic of Congo, such that the expenses of screening programmes can be efficiently allocated whilst continuing to avert morbidity and mortality.MethodsWe implement a cost-effectiveness analysis using a stochastic gHAT infection model for a range of active screening strategies and, in conjunction with a cost model, we calculate the net monetary benefit (NMB) of each strategy. We focus on the high-endemicity health zone of Kwamouth in the Democratic Republic of Congo.ResultsHigh-coverage active screening strategies, occurring approximately annually, attain the highest NMB. For realistic screening at 55% coverage, annual screening is cost-effective at very low willingness-to-pay thresholds (<DOLLAR/>20.4 per disability adjusted life year (DALY) averted), only marginally higher than biennial screening (<DOLLAR/>14.6 per DALY averted). We find that, for strategies stopping after 1, 2 or 3 years of zero case reporting, the expected cost-benefits are very similar.ConclusionsWe highlight the current recommended strategy—annual screening with three years of zero case reporting before stopping active screening—is likely cost-effective, in addition to providing valuable information on whether transmission has been interrupted.

Highlights

Gambiense human African trypanosomiasis has been brought under control recently with village-based active screening playing a major role in case reduction
The time-horizon of 30 years is sufficient in the village context to capture the dynamics; when we expanded the horizon to 100 years, we found that roughly 99.1% of costs and 99.8% of Disability-adjusted life year (DALY) are attributable to the first 30 years
Using a dynamic cost-effectiveness framework we have performed analysis to examine the optimal use of medical resources for strategies against Gambiense human African trypanosomiasis (gHAT) as it approaches the end-game

Summary

Introduction

Gambiense human African trypanosomiasis (gHAT) has been brought under control recently with village-based active screening playing a major role in case reduction. Despite the continued decline in the annual number of reported cases of gambiense human African trypanosomiasis (gHAT), accounting for fewer than 1000 new cases reported in 2019 [1, 2], the disease persists in many of the historically endemic sites in Western and Central Africa. This vector-borne disease, transmitted by a bite from a tsetse infected with the parasite Trypanosoma brucei gambiense, is typically— not always—fatal when untreated [3]. Screening and treating infected individuals both allows the infected people to be saved from a potentially fatal disease, but it prevents further spread of infection via tsetse

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