Statement on Antigen Rapid Tests for Mpox Diagnosis
October 30, 2024
Despite urgent need for decentralized mpox testing in Africa, no antigen rapid diagnostic tests (RDTs) meet minimum requirements for field use. Following the August 2024 public health emergency declarations by Africa CDC and WHO, only three RDTs underwent independent evaluation, showing clinical sensitivity of just 0-10.34%, far below the required 80% minimum. While specificity reached 100%, the poor sensitivity makes these tests unsuitable for current outbreak settings. Africa CDC's Diagnostic Advisory Committee emphasizes the critical need for reliable rapid testing to scale up community-level surveillance, particularly in countries with sustained transmission like DRC and Burundi.
The lack of reliable rapid diagnostic tests for mpox presents a significant challenge in controlling Africa's outbreak, according to a systematic review by the Africa CDC Diagnostic Advisory Committee (DAC).
Current Situation:
1. Emergency Context:
- Africa CDC declared PHECS on August 13, 2024
- WHO declared PHEIC on August 14, 2024
- Countries mobilizing resources for testing and surveillance
- RT-PCR tests recommended but limited in reach
2. Testing Needs:
- Urgent requirement for decentralized testing
- Focus on DRC, Burundi, and other affected states
- Community-level testing capability essential
- Need for rapid results in outbreak settings
3. RDT Evaluation Results:
- Only three RDTs independently evaluated
- Clinical sensitivity: 0-10.34%
- Clinical specificity: 100%
- Poor performance even with high viral loads
- None meet minimum 80% sensitivity requirement
- All meet 97% specificity threshold
4. Implications:
- No suitable rapid tests currently available
- Community testing capacity limited
- Reliance on PCR testing continues
- Scale-up efforts hampered
- Further evaluations ongoing by Africa CDC and FIND
The findings highlight the critical gap between testing needs and available technology, emphasizing the urgent requirement for improved rapid diagnostics to effectively control the mpox outbreak in Africa.