Cost-effectiveness of outdoor residual spraying, insecticide-treated nets, and their combination for zoonotic malaria control in Sabah, Malaysia: a comparative analysis
摘要
Following the elimination of human malaria, Malaysia has experienced an increasing burden of zoonotic Plasmodium knowlesi malaria, particularly in Sabah. Evidence on the cost-effectiveness of vector control interventions is needed to inform policy decisions and optimise resource allocation. This study assessed the cost-effectiveness of Outdoor Residual Spraying (ORS), Long-Lasting Insecticidal Nets (LLINs), and their combined use for controlling P. knowlesi malaria in Sabah, Malaysian Borneo.
MethodsA cost-effectiveness analysis was conducted from the healthcare provider perspective over a one-year time horizon in three high-endemic districts: Keningau (LLINs), Ranau (ORS), and Kota Marudu (ORS + LLINs). Capital and recurrent components, were estimated using an ingredient-based costing approach. Effectiveness was measured as the number of P. knowlesi cases averted based on routine surveillance data. Incremental cost-effectiveness ratios (ICERs) were calculated relative to a no-intervention scenario, defined as health promotion activities without vector control. One-way sensitivity analyses assessed uncertainty in key parameters. All costs were reported in Malaysian Ringgit (MYR) and adjusted to 2025 values.
ResultsAnnual provider costs ranged from MYR 3912.92 (no intervention) to MYR 39,764.14 (ORS + LLINs). ORS was associated with the highest number of cases averted (n = 13) and the lowest ICER (MYR 2046 per case averted; approximately USD 470). LLINs and the combined strategy were associated with fewer cases averted and higher ICERs. ORS consistently demonstrated the most favourable cost-effectiveness profile across all sensitivity analyses.
ConclusionORS demonstrated the most favourable cost-effectiveness profile under the observed programme conditions for controlling P. knowlesi malaria in Sabah. A stratified approach prioritising ORS, with targeted use of LLINs among high-risk populations, may represent an economically efficient strategy in resource-limited settings.