Early HTA of Cholera Rapid Diagnostic Test

Principal investigator: Carlo Federici (CeRGAS)

Team UB/Cergas: Ludovica Borsoi

Partners: Mantel Malvolti Global Health Consulting – MMGH (Switzerland);

Sponsor: Wellcome Trust (UK)

Duration: Jan 2024- Nov 2024

Abstract: 
Cholera, caused by Vibrio cholerae bacteria is a severe diarrheal disease and a significant health threat in low- and middle-income countries (LMICs) with inadequate water, sanitation, and hygiene (WaSH). The World Health Organization (WHO) estimates 1.4–4.0 million cases and 21,000–143,000 deaths annually, with transmission occurring through contaminated food, water, or direct contact. Cholera outbreaks, often unpredictable, impose substantial clinical and economic burdens, especially in endemic areas. Efforts to combat cholera focus on improving WaSH, vaccination campaigns, and early detection, which helps limit outbreak severity and spread. Rapid diagnostic tests (RDTs) have been developed for quicker patient screening, but existing RDTs fall short of sensitivity and specificity standards set by the Global Task Force on Cholera Control (GTFCC). A new RDT with enhanced performance for stool samples is under development.

To support this RDT's development, we conducted a development-focused Health Technology Assessment (DF-HTA) to:
1) determine minimum performance for cost-effectiveness; 2) estimate the technology’s headroom (maximum cost-effective incremental cost); and 3) identify evidence gaps affecting cost-effectiveness uncertainty.

Emerging Insights

  • This early-stage economic evaluation suggested that scenarios where RDTs are systematically employed for outbreak response are likely to be either highly cost-effective or even cost-saving compared to standard outbreak response approaches that rely only on culture tests for confirmation.
  • The cost-effectiveness results hold for both the scenario with and without considering the potential impact of RDTs on Oral Vaccination costs (although in the former the cost-saving effect was more pronounced).
  • When assuming a 47% reduction in cases averted compared to the No RDT scenario, the cost per case averted in Bangladesh and the DRC was estimated at -$15.9 and -$8.2, respectively, without considering OCV cost reductions. When OCV cost reductions were included, the cost per case averted was -$268 and -$112, respectively.

Recommendations

Once the RDT has been developed and tested, an analysis should be performed to better understand the cost to produce the RDT to determine the unit selling price. A better understand of costs and unit selling price will also inform the calculation of the financial investment required for the business case.  
A full cost effectiveness analysis and the business case would be greatly informed by further research in the following topic areas:

  • Understanding the extent to which more RDT-driven response approaches (e.g. Case Area Targeted Interventions- CATI) might affect vaccine delivery and the impact on vaccination campaign costs.
  • Assessing the implementation costs of more targeted response approaches (e.g. CATIs) and investigating how the improved performance of the new RDT would affect current guidelines and ultimately impact both the costs and efficacy of outbreak response activities as opposed to similar strategies with current RDTs.
  • In-depth analysis of how RDTs will be actually used for outbreak response strategies.
  • Exploring the links between improved outbreak response activities and their costs and outcomes.