As with every outbreak, Zika can potentially involve costs for the society and economy is essential to estimate all those costs but also for a better understanding of how the disease is transmitted. What will be the role of the economists ? We already know that the people lifestyle and behaviour can lead to either accelerate or slow down the dynamic of the disease. The first task of the economist will be to outline the ins and outs of the outbreak. Poverty and lifestyles, can be one of those main determinants. The second task of the economist is probably to estimate the costs of the disease and therefore the social costs and the systemic costs of these outbreaks. We evaluate the economic loss of Latin America GDP due to Zika outbreak at 0,06%, GDP is the Gross Domestic Product. It represents significant amounts, around 3,5 billion dollars, this cost has been estimated in a study of the World Bank, which you can retrieve in the references of this short presentation. How does the World Bank estimate costs ? First, it takes the costs directly linked to the disease, treatment, prevention, then there are also costs linked to the loss of productivity at work, therefore linked to absenteeism at work and also the decreased productivity of workers. With Zika, as many cases do not show symptoms, we therefore can assume that those costs will be quite limited. There are also intangible costs, linked to human loss and also linked to people trying to avoid the disease, for example a loss of tourism activity because tourists will avoid the areas infected by the disease, there are also costs linked to policies of public prevention of the disease and not individual private household spendings. Those costs in terms of preventive behaviours to avoid the disease are directly linked to the number of cases and communications of the number of cases. The effect on productivity is around one week of absence out of 5 Zika cases and the cost of symptoms is quite low from that score. The Public Health expenses and the costs of public prevention will mainly be costs to avoid the disease and the loss of tourism, so in the 3,5 billion dollars estimated by the World Bank for the last Latin American Zika outbreak, reflect the loss of revenue. We can add to those the demographic costs of the outbreak, meaning that some people will change their decision of having a baby due to the disease. As it has been said, without a vaccine, vector control is central and costly, for instance, Brazil has called on the army, the World Bank has invested 150 million dollars in the fight against Zika, these are some aspects among others. So, firstly the task of the economists will be to evaluate the cost of the disease. Secondly, he will have to establish the disease transmission considering individual behaviours in the epidemiological patterns. How does it works with those patterns ? Economists start from classic epidemiological models, that is to say with a disease transmission dynamic, and they add human behaviours, human decisions on treatment and prevention linked to the disease. Those patterns are called economic epidemiology and their main feature is that there is a kind of prevalence- elasticity, when there is an increase of risks, people protect themselves more, and when the risk decreases, they protect themselves less, therefore, if protection is proportional to the rise of risks, there is a good chance to eradicate the disease. But it is not always the case. Therefore, we can explain why some diseases are never completely eradicated because when the risk is decreasing prevention releases itself and then the disease can restart for a new cycle of epidemic transmission. The role of economic epidemiology is also to establish the link between public policies and individual behaviour, to do so we implant utility feature in the epidemiological patterns, and with my colleague, Yves Dumont, we have achieved studies showing that public policies of prevention and vector control can sometime have disincentive effects on people, meaning that people at home who benefit from public intervention of mosquito eradication can release prevention actions during an outbreak, and so it can lead to a resurgence of risks if there are new sources of infection. This is something we resume in a paper you can also find it in the references, which constituted a backup for the economy : try to anticipate a bit more of the so-called rational outbreak supervision, in which we introduce individual behaviours called rational behaviours. The third point on which the economy has an impact is the organisation of systems as a whole, we see that with Zika as we did with Ebola, those two major outbreaks probably lead to a paradigm shift. You know that in numerous poor areas, the approach for years was to focus on specific infectious diseases, the Ebola outbreak, highly expensive for West Africa, also lead to these new paradigms and to changes in health systems with a focus on primary health care, and in the efficiency of those health systems and the quality of care, this is how the economy can participate in terms of evaluation of public policies about outbreaks. In terms of recommendations for sustainable development objectives, these new changes, have been included in those objectives. It is also important to take into account that when international help is recquired in a good way, as it was in the case of HIV, diseases can be contained and this is a very optimistic message in order to reduce the number of cases, of deaths within the major outbreaks. The economists contribution is then threefold : the disease impact on economic development and on the various factors of economic growth and dynamic, secondly, the socioeconomic ins and outs of the disease, which is mainly the people behaviours towards vectorial diseases and prevention, thirdly and last, the systemic organisation in terms of various stakeholders public but also private, in the fight against Zika.