Laboratorio para el Control Biológico de Aedes aegypti (LCB-UADY), Unidad Colaborativa para Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, México.
Servicios de Salud de Yucatán, Mérida, México.
PLoS Negl Trop Dis. 2022 Apr 26;16(4):e0010324. doi: 10.1371/journal.pntd.0010324. eCollection 2022 Apr.
The combination of Wolbachia-based incompatible insect technique (IIT) and radiation-based sterile insect technique (SIT) can be used for population suppression of Aedes aegypti. Our main objective was to evaluate whether open-field mass-releases of wAlbB-infected Ae. aegypti males, as part of an Integrated Vector Management (IVM) plan led by the Mexican Ministry of Health, could suppress natural populations of Ae. aegypti in urbanized settings in south Mexico.
METHODOLOGY/PRINCIPAL FINDINGS: We implemented a controlled before-and-after quasi-experimental study in two suburban localities of Yucatan (Mexico): San Pedro Chimay (SPC), which received IIT-SIT, and San Antonio Tahdzibichén used as control. Release of wAlbB Ae. aegypti males at SPC extended for 6 months (July-December 2019), covering the period of higher Ae. aegypti abundance. Entomological indicators included egg hatching rates and outdoor/indoor adult females collected at the release and control sites. Approximately 1,270,000 lab-produced wAlbB-infected Ae. aegypti males were released in the 50-ha treatment area (2,000 wAlbB Ae. aegypti males per hectare twice a week in two different release days, totaling 200,000 male mosquitoes per week). The efficacy of IIT-SIT in suppressing indoor female Ae. aegypti density (quantified from a generalized linear mixed model showing a statistically significant reduction in treatment versus control areas) was 90.9% a month after initiation of the suppression phase, 47.7% two months after (when number of released males was reduced in 50% to match local abundance), 61.4% four months after (when initial number of released males was re-established), 88.4% five months after and 89.4% at six months after the initiation of the suppression phase. A proportional, but lower, reduction in outdoor female Ae. aegypti was also quantified (range, 50.0-75.2% suppression).
CONCLUSIONS/SIGNIFICANCE: Our study, the first open-field pilot implementation of Wolbachia IIT-SIT in Mexico and Latin-America, confirms that inundative male releases can significantly reduce natural populations of Ae. aegypti. More importantly, we present successful pilot results of the integration of Wolbachia IIT-SIT within a IVM plan implemented by Ministry of Health personnel.
基于沃尔巴克氏体的不相容昆虫技术（IIT）与辐射不育昆虫技术（SIT）的结合可用于抑制埃及伊蚊种群。我们的主要目标是评估作为墨西哥卫生部主导的综合病媒管理（IVM）计划的一部分，野外大量释放感染 wAlbB 的埃及伊蚊雄性是否可以抑制墨西哥南部城市环境中埃及伊蚊的自然种群。
方法/主要发现：我们在尤卡坦的两个郊区进行了一项对照前后的半实验研究：圣佩德罗奇迈（SPC），该地区实施了 IIT-SIT，而圣安东尼奥塔希兹比肯（San Antonio Tahdzibichén）被用作对照。2019 年 7 月至 12 月期间，SPC 地区进行了为期 6 个月的 wAlbB 埃及伊蚊雄性释放，该阶段覆盖了埃及伊蚊数量较高的时期。昆虫学指标包括在释放点和对照点采集的卵孵化率和户外/室内成年雌性。在 50 公顷的处理区释放了约 127 万只实验室生产的感染 wAlbB 的埃及伊蚊雄性（每公顷每周释放 2,000 只感染 wAlbB 的埃及伊蚊雄性两次，每周释放 200,000 只雄蚊）。IIT-SIT 对抑制室内雌性埃及伊蚊密度的效果（从广义线性混合模型中量化，表明处理区与对照区相比有统计学意义的减少）为抑制阶段开始后一个月为 90.9%，两个月后为 47.7%（此时释放的雄性数量减少了 50%以匹配当地丰度），四个月后为 61.4%（此时重新建立了初始释放的雄性数量），五个月后为 88.4%，六个月后为 89.4%。同时还定量了室外雌性埃及伊蚊的比例降低（范围为 50.0-75.2%）。
结论/意义：我们的研究是沃尔巴克氏体 IIT-SIT 在墨西哥和拉丁美洲的首次野外试点实施，证实了大量释放雄性可以显著降低埃及伊蚊的自然种群数量。更重要的是，我们展示了卫生部人员实施的 IVM 计划中成功整合沃尔巴克氏体 IIT-SIT 的试点结果。
