Use of transgenicAedes aegyptiin Brazil: risk perception and assessment

Abstract

The OX513A strain of Aedes aegypti, which was developed by the British company Oxitec, expresses a self-limiting transgene that prevents larvae from developing to adulthood. In April 2014, the Brazilian National Technical Commission on Biosafety completed a risk assessment of OX513A and concluded that the strain did not present new biological risks to humans or the environment and could be released in Brazil. At that point, Brazil became the first country to approve the unconstrained release of a genetically modified mosquito. During the assessment, the commission produced a comprehensive list of – and systematically analysed – the perceived hazards. Such hazards included the potential survival to adulthood of immature stages carrying the transgene – should the transgene fail to be expressed or be turned off by exposure to sufficient environmental tetracycline. Other perceived hazards included the potential allergenicity and/or toxicity of the proteins expressed by the gene, the potential for gene flow or increased transmission of human pathogens and the occupation of vacant breeding sites by other vector species. The Zika epidemic both elevated the perceived importance of Ae. aegypti as a vector – among policy-makers and regulators as well as the general public – and increased concerns over the release of males of the OX513A strain. We have therefore reassessed the potential hazards. We found that release of the transgenic mosquitoes would still be both safe and of great potential value in the control of diseases spread by Ae. aegypti, such as chikungunya, dengue and Zika.

Simple framework for real-time forecast in a data-limited situation: the Zika virus (ZIKV) outbreaks in Brazil from 2015 to 2016 as an example

“…For instance, the Zika fever in this work is a disease whose transmission depends largely on the activity of mosquitoes, which has strong seasonality. Local mosquito abundance drops to a sufficiently low level from May each year [64], which could largely reduce the ZIKV spread. Hence, τ is probably before May 2016.…”

“…Alternatively, for Zika disease, one may gain knowledge of τ from the mosquito vectors' activities. Since the mosquito abundance in Brazil decreases around May each year [64], we attempted to project the final size (K) with τ fixed at three dates prior to May, namely the first days of February, March and April 2016. Similarly, for the real-time projection, we used the data from time 0 to T 1 , where 0 < T 1 < T, to train the model.…”

Aedes aegypti e sociedade: o impacto econômico das arboviroses no Brasil

“…No entanto, em vista do grande registro de casos de arboviroses nos últimos anos no Brasil, é possível concluir pela baixa efetividade do programa em reduzir as populações de vetores em níveis que poderiam interromper a transmissão das doenças (Araújo et al, 2015;Paes de Andrade et al, 2016).…”

Transcriptional activities of two newly identified Haemaphysalis longicornis tick‐derived promoter regions in the Ixodes scapularis tick cell line (ISE6)

“…By contrast, gene manipulation methods, such as gene knockout or gene knock‐in, have already been conducted in mosquitoes (Gratz, ; Kokoza et al ., ; Yamamoto et al ., ; Dong et al ., ). The gene manipulation leads to a decrease not only in the number of mosquitoes but also in the transmission of mosquito‐borne pathogens such as dengue virus (Paes de Andrade et al ., ). Therefore, gene manipulation methods could be useful for controlling ticks and tick‐borne pathogens and also for understanding the biological features of ticks.…”