Release of thiotepa sterilized males into caged populations of Aedes aegypti: Life table analysis

BackgroundLong-lasting insecticide-treated net (LLIN) window and door curtains alone or in combination with LLIN water container covers were analysed regarding effectiveness in reducing dengue vector density, and feasibility of the intervention.MethodsA cluster randomised trial was conducted in an urban area of Colombia comparing 10 randomly selected control and 10 intervention clusters. In control clusters, routine vector control activities were performed. The intervention delivered first, LLIN curtains (from July to August 2013) and secondly, water container covers (from October to March 2014). Cross-sectional entomological surveys were carried out at baseline (February 2013 to June 2013), 9 weeks after the first intervention (August to October 2013), and 4–6 weeks after the second intervention (March to April 2014).ResultsCurtains were installed in 922 households and water container covers in 303 households. The Breteau index (BI) fell from 14 to 6 in the intervention group and from 8 to 5 in the control group. The additional intervention with LLIN covers for water containers showed a significant reduction in pupae per person index (PPI) (p=0.01). In the intervention group, the PPI index showed a clear decline of 71% compared with 25% in the control group. Costs were high but options for cost savings were identified.ConclusionsShort term impact evaluation indicates that the intervention package can reduce dengue vector density but sustained effect will depend on multiple factors.

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“…There are also non-chemical strategies that consist of environmental management 7 and, recently, the release of transgenic vectors. 8 …”

Section: Introductionmentioning

confidence: 99%

Effectiveness and feasibility of long-lasting insecticide-treated curtains and water container covers for dengue vector control in Colombia: a cluster randomised trial

Quintero¹,

García-Betancourt²,

Cortés³

et al. 2015

Transactions of the Royal Society of Tropical Medicine and Hygi

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“…Schistosomiasis, caused by trematode worms belonging to the Schistosoma genus [ 1 ], remains a serious public health problem worldwide [ 2 ]. More than 200 million people in approximately 76 countries are affected by the disease with at least a loss of 1.7 to 4.5 million disability-adjusted life years (DALYs) [ 3 ] and probably considerably more [ 4 ]. The true global burden of schistosomiasis japonica alone has been shown to be between four to 30 times greater than previously expected [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Spatio-temporal Transmission and Environmental Determinants of Schistosomiasis Japonica in Anhui Province, China

Bergquist³

et al. 2015

PLoS Negl Trop Dis

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BackgroundSchistosomiasis japonica still remains of public health and economic significance in China, especially in the lake and marshland areas along the Yangtze River Basin, where the control of transmission has proven difficult. In the study, we investigated spatio-temporal variations of S. japonicum infection risk in Anhui Province and assessed the associations of the disease with key environmental factors with the aim of understanding the mechanism of the disease and seeking clues to effective and sustainable schistosomiasis control.Methodology/Principal FindingsInfection data of schistosomiasis from annual conventional surveys were obtained at the village level in Anhui Province, China, from 2000 to 2010 and used in combination with environmental data. The spatio-temporal kriging model was used to assess how these environmental factors affected the spatio-temporal pattern of schistosomiasis risk. Our results suggested that seasonal variation of the normalized difference vegetation index (NDVI), seasonal variation of land surface temperature at daytime (LSTD), and distance to the Yangtze River were negatively significantly associated with risk of schistosomiasis. Predictive maps showed that schistosomiasis prevalence remained at a low level and schistosomiasis risk mainly evolved along the Yangtze River. Schistosomiasis risk also followed a focal spatial pattern, fluctuating temporally with a peak (the largest spatial extent) in 2005 and then contracting gradually but with a scattered distribution until 2010.ConclusionThe fitted spatio-temporal kriging model can capture variations of schistosomiasis risk over space and time. Combined with techniques of geographic information system (GIS) and remote sensing (RS), this approach facilitates and enriches risk modeling of schistosomiasis, which in turn helps to identify prior areas for effective and sustainable control of schistosomiasis in Anhui Province and perhaps elsewhere in China.

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“…aegypti overcomes all the technological, logistical and ecological hurdles described above, as well as successfully addressing regulatory compliance and the public concerns. We developed a treatment that is transient in nature and the active ingredients do not persist in the released adult mosquito [47] (appendix S9). By collecting thousands of local mosquito eggs before the start of the project, we were able to use the ambient mosquito genepool to guarantee that the local climate adaptation and local female seeking capabilities of the released sterile males will be optimal.…”

Section: Discussionmentioning

confidence: 99%

Successful suppression of a field population of Ae. aegypti mosquitoes using a novel biological vector control strategy is associated with significantly lower incidence of dengue

Poncio

Anjos

Oliveira

et al. 2019

Preprint

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Background. Despite extensive efforts to prevent recurrent Aedes-borne arbovirus epidemics, there is a steady rise in their global incidence. Vaccines/treatments show very limited efficacy and together with the emergence of mosquito resistance to insecticides, it has become urgent to develop alternative solutions for efficient, sustainable and environmentally benign mosquito vector control. Here we present a new Sterile Insect Technology (SIT)-based program that uses large-scale releases of sterile male mosquitoes produced by a highly effective, safe and environmentally benign method. Methods and findings. To test the efficacy of this approach, a field trial was conducted in a Brazilian city (Jacarezinho), which presented a history of 3 epidemics of dengue in the past decade. Sterile male mosquitoes were produced from a locally acquired Aedes aegypti colony, and releases were carried out on a weekly basis for seven months in a predefined area. This treated area was matched to a control area, in terms of size, layout, historic mosquito infestation index, socioeconomic patterns and comparable prevalence of dengue cases in past outbreaks. Releases of sterile male mosquitoes resulted in up to 91.4% reduction of live progeny of field Ae. aegypti mosquitoes recorded over time. The reduction in the mosquito population was corroborated by the standard monitoring system (LIRAa index) as determined by the local municipality, which found that our treated neighborhoods were almost free of Ae. aegypti mosquitoes after 5 months of release, whereas neighborhoods adjacent to the treated area and the control neighborhoods were highly infested. Importantly, when a dengue outbreak started in Jacarezinho in March 2019, the effective mosquito population suppression was shown to be associated with a far lower incidence of dengue in the treated area (16 cases corresponding to 264 cases per 100,000 inhabitants) almost 16 times lower than the dengue incidence in the control area (198 cases corresponding to 4,360 dengue cases per 100,000 inhabitants). Conclusions. Our data present the first demonstration that a SIT-based intervention has the potential to prevent the spread of dengue, opening exciting new opportunities for preventing mosquito-borne disease.

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Release of thiotepa sterilized males into caged populations of Aedes aegypti: Life table analysis

Cited by 13 publications

References 36 publications

Effectiveness and feasibility of long-lasting insecticide-treated curtains and water container covers for dengue vector control in Colombia: a cluster randomised trial

Effectiveness and feasibility of long-lasting insecticide-treated curtains and water container covers for dengue vector control in Colombia: a cluster randomised trial

Spatio-temporal Transmission and Environmental Determinants of Schistosomiasis Japonica in Anhui Province, China

Successful suppression of a field population of Ae. aegypti mosquitoes using a novel biological vector control strategy is associated with significantly lower incidence of dengue

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