Correspondence www.thelancet.com Vol 388 July 2, 2016 25 Is Zika a substantial risk for visitors to the Rio de Janeiro Olympic Games? On May 20, 2016, 150 physicians, bioethicists, and scientists from several countries (including Brazil) posted an open letter suggesting WHO Director-General Margaret Chan exert pressure on Olympics authorities to delay or relocate the Rio de Janeiro Games because of public health concerns over the risk of Zika virus infection for tourists and athletes. The same concern was raised in 2013 about the risk of dengue infection for tourists and athletes intending to travel to Brazil during the 2014 World Cup. At the time we estimated that the individual risk of dengue for visitors would vary from around 6 × 10 – ⁵ to around 4 × 10 – ⁴, 1 which represented an expected number of infections among tourists between three and 59 cases. The reported number of dengue cases among tourists after the Games was three. 2 Here we provide a risk estimation for tourists and athletes intending to visit Rio de Janeiro during the summer Olympics in August. Aedes mosquitoes have a strong seasonal pattern with highest abundance in the summer months (from January to February in Rio de Janeiro) and lowest in the winter (from July to August), and Burattini and colleagues 3 estimated the individual risk of being bitten by an Aedes egypti mosquito in Rio de Janeiro during the 3 weeks of the Olympic Games at 3·5 × 10 – ². The individual risk of dengue infection for tourists in the same period was estimated by Ximenes and colleagues 4 to be about 5 × 10 – ⁴. Although the actual numbers of Zika virus infection in Brazil are still unknown, it is estimated between 500 000 and 1·5 million cases of infection; 5 with these estimates, we calculated the risk of infection in August to be between 9 × 10 – ⁶ and 3 × 10 – ⁵. 6 The risk of Zika virus infection is therefore more than 15 times less than that for dengue. Although the risk of Zika virus infection during the time of the Olympic Games is extremely low, we think that pregnant women should avoid visiting any region of the world where Zika virus circulation has been reported, including Rio de Janeiro, a recommendation in line with international and national public health guidelines. 7,8 We declare no competing interests. *Eduardo Massad, Francisco Antonio Bezerra Coutinho, Annelies Wilder-Smith edmassad@usp.br School of Medicine, University of São Paulo, São Paulo, Brazil (EM, FABC); London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK (EM); and Lee Kong Chian School of Medicine, Singapore (AW-S) 1 Massad E, Wilder-Smith A, Ximenes R, et al. Risk of symptomatic dengue for foreign visitors to the 2014 FIFA World Cup in Brazil. Mem Inst Oswaldo Cruz 2014; 109: 394–97. 2 Aguiar M, Rocha F, Pessanha JEM, Mateus L, Stollenwerk N. Carnival or football, is there a real risk for acquiring dengue fever in Brazil during holidays seasons? Sci Rep 2015; 5: 8462. 3 Burattini MN, Coutinho FA, Lopez LF, et al. Potential exposure to Zika virus for foreign tourists during the 2016 Carnival and Olympic Games in Rio de Janeiro, Brazil. Epidemiol Infect 2016; 144: 1904–06. 4 Ximenes R, Amaku M, Lopez LF, et al. The risk of dengue for non-immune foreign visitors to the 2016 summer olympic games in Rio de Janeiro, Brazil. BMC Infect Dis 2016; 16: 186. 5 ECDC. Rapid risk assessment: Zika virus disease epidemic potential association with microcephaly and Guillain–Barré syndrome. Stockholm: European Centre for Disease Prevention and Control, 2016. 6 Massad E, Tan SH, Khan K, Wilder-Smith A. Estimated Zika virus importations to Europe by travellers from Brazil. Glob Health Action 2016; 9: 31669. 7 WHO. Pregnancy management in the context of Zika virus infection. Interim guidance update May 13, 2016. http://www.who.int/csr/ resources/publications/zika/pregnancy- management/en/ (accessed June 10, 2016). 8 Public Health England. Zika virus: updated travel advice for pregnaÛnt women. https:// www.gov.uk/government/news/zika-virus- updated-travel-advice-for-pregnant-women (accessed June 10, 2016). For the open letter see https:// www.washingtonpost.com/ news/to-your-health/wp- content/uploads/sites/ 26/2016/05/Zika-Olympics- Open-Letter-to-WHO-current2. pdf?tid=a_inl%22open%20letter Published Online June 17, 2016 http://dx.doi.org/10.1016/ S0140-6736(16)30842-X The Hajj health requirements: changing a mindset In response to our Correspondence on the Hajj health requirements, 1 the statement by Ziad Memish and colleagues (April 23, p 1719) 2 that we called to “restrict the Hajj pilgrimage based on non-communicable diseases (NCDs)” is extremely misleading. We would like to clarify that we called for a global discussion, to include all Hajj stakeholders nationally and internationally, on whether seriously ill pilgrims should be allowed to attend Hajj and not for a unilateral action from the Saudi authorities to prevent pilgrims with any form of NCD or chronic illness from doing the pilgrimage. Hajj health screenings are not a new concept, nor are the calls for screening, including exclusion of severely ill individuals. 1,3,4 Many Muslim countries routinely do such screenings and some even exclude pilgrims on the basis of their health status. 3–6 Hence, we believe the time has come for this topic to be discussed in an open and frank manner among all Hajj stakeholders. Introduction of health screening as a requirement for Hajj would only be considered after a global consultation and an international consensus including all Hajj stakeholders. A consensus on not only the concept and practicalities of a Hajj health screening but also the criteria for exclusion if it was to be introduced. The consensus on the criteria for exclusion is important to ensure that the process of exclusion would not be misused and the current Hajj eligibility criteria imposed by some countries would be harmonised and fair. Education about prevention of NCDs via Hajj-related health-care contact of pilgrims, as advocated by Memish and colleagues, 2 although important, will do little to deter severely ill individuals from risking their own lives attempting to do the Hajj pilgrimage in the belief that they are religiously obligated regardless of their financial or health status. What is needed, therefore, is a concerted effort to change this mindset by instilling in prospective pilgrims the key Islamic message that Hajj is only mandatory for those financially and physically capable to do T photography