A regional One Health approach to the risk of invasion by Anopheles stephensi in Mauritius

PLoS Negl Trop Dis. 2024 Sep 11;18(9):e0011827. doi: 10.1371/journal.pntd.0011827. eCollection 2024 Sep.

Abstract

Background: Anopheles stephensi is an invasive malaria vector in Africa that threatens to put an additional 126 million people at risk of malaria if it continues to spread. The island nation of Mauritius is highly connected to Asia and Africa and is at risk of introduction due to this connectivity. For early detection of An. stephensi, the Vector Biology and Control Division under the Ministry of Health in Mauritius, leveraged a well-established Aedes program, as An. stephensi is known to share Aedes habitats. These efforts triggered multisectoral coordination and cascading benefits of integrated vector and One Health approaches.

Methods: Beginning June 2021, entomological surveys were conducted at points of entry (seaport, airport) and on ships transporting livestock in collaboration with the Civil Aviation Department, the Mauritian Port Authority and National Veterinary Services. A total of 18, 39, 723 mosquito larval surveys were respectively conducted in the airport, seaport, and other localities in Mauritius while two, 20, and 26 adult mosquito surveys were respectively conducted in the airport, seaport, and twenty-six animal assembly points. Alongside adult mosquito surveys, surveillance of vectors of veterinary importance (e.g.- Culicoides spp.) was also carried out in collaboration with National Parks and Conservation Service and land owners.

Results: A total of 8,428 adult mosquitoes were collected and 1,844 larval habitats were positive for mosquitoes. All collected mosquitoes were morphologically identified and 151 Anopheles and 339 Aedes mosquitoes were also molecularly characterized. Mosquito species detected were Aedes albopictus, Anopheles arabiensis, An. coustani, An. merus, Culex quinquefasciatus, Cx. thalassius and Lutzia tigripes. Anopheles stephensi was not detected. The One Health approach was shared with the French Agricultural Research Centre for International Development (CIRAD), strengthening collaboration between Mauritius and Réunion Island on vector surveillance at entry points and insecticide resistance monitoring. The Indian Ocean Commission (IOC) was also alerted to the risk of An. stephensi, leading to regional efforts supporting trainings and development of a response strategy to An. stephensi bringing together stakeholders from Comoros, Madagascar, Mauritius, Réunion Island and Seychelles.

Conclusions: Mauritius is a model system showing how existing public health entomology capabilities can be used to enhance vector surveillance and control and create multisectoral networks to respond to any emerging public and veterinary health vector-borne disease threat.

MeSH terms

  • Aedes / classification
  • Aedes / physiology
  • Animals
  • Anopheles* / classification
  • Anopheles* / physiology
  • Ecosystem
  • Humans
  • Introduced Species
  • Larva / physiology
  • Malaria* / epidemiology
  • Malaria* / prevention & control
  • Malaria* / transmission
  • Mauritius
  • Mosquito Control* / methods
  • Mosquito Vectors* / classification
  • Mosquito Vectors* / physiology
  • One Health*

Grants and funding

Funding for this work was provided by the Ministry of Health and Wellness in Mauritius, the Indian Ocean Commission, the US Centers for Disease Control and Prevention (grant support to TEC), and the US President's Malaria Initiative (salary support to SZ). This work was funded by the Ministry of Health and Wellness, Mauritius, as part of its endeavor to improve the national mosquito surveillance system in Mauritius. Molecular analysis was funded through Baylor University and the US Centers for Disease Control and Prevention contract with TEC. No funders played a role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript, with the exception of the Ministry of Health and Wellness within the Government of Mauritius which supported staff and data collection where in line with routine public health activities.