50,000 Sterile Mosquitoes Deployed

South Africa's malaria elimination teams are exploring the use of sterile male mosquitoes to control the spread of malaria, with a small-scale field trial in Mamfene, KwaZulu-Natal showing promising results. The trial, conducted by the National Institute for Communicable Diseases (NICD) and Wits University, released approximately 50,000 sterile male mosquitoes biweekly over a 12-week period, resulting in a decline in the target mosquito population.

The Sterile Insect Technique (SIT) method, developed by the NICD and Wits University, exploits the fact that wild Anopheles arabiensis females mate only once in their lifetime. If they mate with sterile decoys, the resulting eggs won't be viable, leading to population collapse. The SIT program is led by Dr. Givemore Munhenga, who stated that the early successes in Mamfene are just the beginning.

The trial was a significant step towards demonstrating the effectiveness of the SIT method in the real world. The NICD and Wits University plan to conduct larger epidemiological trials, a local elimination trial on Grande Glorieuse Island, and eventually cross-border capacity building in neighboring countries. A scoping workshop was hosted by Wits Health Consortium to identify gaps between contained laboratory trials and operational, real-world deployment across the African continent.

## What's at stake Malaria elimination efforts in South Africa have stalled, and the Anopheles arabiensis mosquito may be the culprit. The insect can bypass Indoor Residual Spraying (IRS) and insecticide-treated nets because it bites and rests outdoors. The use of sterile male mosquitoes could be a game-changer in the fight against malaria, potentially supplementing existing IRS efforts and helping to shrink the spread of the disease.

The success of the SIT method has significant implications for the future of malaria control. With millions of decoy mosquitoes specially bred at Africa's first mosquito factory, the potential for large-scale deployment is vast. As the NICD and Wits University continue to develop and refine the SIT method, the hope is that it will become a valuable tool in the fight against malaria, ultimately helping to eliminate the disease in South Africa and beyond.

## Next steps The NICD and Wits University will continue to conduct trials and refine the SIT method, with the goal of eventual deployment across the African continent. The scoping workshop hosted by Wits Health Consortium will help to identify gaps and challenges, and the innovations discussed at the workshop, including examples from Singapore, will inform the development of the SIT method. As the program moves forward, the potential for the SIT method to make a significant impact on malaria control is vast, and the early successes in Mamfene are a promising start.