Zika is now in the U.S. in a bigger than thought way. The virus was detected in 279 pregnant women, according to health officials. Here are the details of OX513: OX513A is a bisex RIDL strain. Males are released to mate with wild females. The progeny of such matings die as late larvae or pupae. Continual releases of sufficient numbers of RIDL males will reduce the target population to below the level needed to transmit disease. The late lethality means that RIDL larvae compete with wild-type larvae for resources,adding to the overall effectiveness of control. Before release, male and female pupae are separated mechanically, exploiting the fact that they are naturally significantly different in size. The strain contains the DsRed marker which is clearly visible in larvae, a useful tool for quality control in production and effective monitoring in the field. OX513A is available in Asian and Latin American genetic backgrounds.StatusOX513A has regulatory approvals for import and contained testing in Brazil, Cayman Islands, France, India, Malaysia, Singapore, Thailand, USA and Vietnam. Open field trials have taken place in both Grand Cayman and Malaysia, and are currently also underway in Brazil.Performance in evaluationOX513A has been successfully evaluated at a number of laboratories including at the Institut Pasteur in Paris and at the WHO Collaborating Centre for Vectors at the Institute for Medical Research (IMR) in Malaysia. OX513A has demonstrated stable performance over 60 generations.The key indicator of success is competitiveness against local males to achieve mating with wild females. Mating competitiveness trials by the IMR in a purpose-built field house showed that OX513A males competed effectively with wild-type local males for matings with local wild-type females, a critical indicator of success in the field. The IMR also conducted a series of binomial studies on parameters such as longevity, development times and egg-laying, none of which showed any significant difference between the OX513A and the wild-type strain.--- Reference - Phuc et al BMC Biology 2007, 5:11 In the latest quarterly report, XON said: The U.S. Food and Drug Administration (FDA) Center for Veterinary Medicine published a preliminary finding of no significant impact (FONSI) on Oxitec's self-limiting OX513A Ae. aegypti mosquito for an investigational trial in the Florida Keys. Related drug firms: Inovio Pharmaceuticals