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Will Zika return to the ‘Old World’?
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MODEL
Microbes and Infection xx (2016) 1e2 www.elsevier.com/locate/micinf
Editorial
Will Zika return to the ‘Old World’?
Zika virus infection is now rapidly disseminating throughout Latin American and the Caribbean, and possibly soon into the Gulf Coast of the United States. The World Health Organization estimates that up to four million people could be infected in the Western Hemisphere by the end of 2016. In the coming months could Zika virus infection travel across the Atlantic Ocean and begin causing infections (and microcephaly cases) in Europe, the Middle East, and Africa? The Zika virus was first described in the Zika Forest of Uganda during the late 1940s and isolated in 1952 [1]. The first human case was described in Nigeria in 1954 [2], and it is believed that Zika caused localized epidemics of Zika virus infection before it migrated from Africa and across Asia in the ensuing decades. In the 21st century molecular genetic comparisons suggest that Zika mutated to a pandemic strain that resulted in high virus attack rates in Micronesia and French Polynesia, before causing widespread infections in the ‘New World’ of the Americas [3]. There are several reasons to believe that Zika could complete its trip around the planet by spreading to vulnerable areas of the ‘Old World’ e Europe, the Middle East, and Africa. This is true particularly in urban areas that meet the major criteria responsible for current Zika outbreaks in the Americas, especially crowding and human migrations, poverty, and the presence of Aedes mosquitoes. 1. Southern Europe It has been noted that Southern Europe, including Portugal, Spain, Southern France, Italy, Corsica and Greece, has experienced resurgence in vector borne diseases over the last decade [4]. In terms of virus infections transmitted by Aedes mosquitoes, these diseases include dengue virus infection in Madeira off the coast of Portugal in 2012e13, and chikungunya in Italy, Spain, France, and Italy beginning in 2007 [4]. Although the major Aedes species found in Southern Europe, the Asian tiger mosquito Aedes albopictus, is believed to be less efficient than Ae. aegypti in transmitting Zika virus infection, the fact remains that Ae. albopictus successfully ignited dengue and chikungunya outbreaks. This finding portends a real possibility that we could start seeing Zika cases soon in Southern Europe. The adjoining Black Sea region
(where both Ae. albopictus and Ae. aegypti are found), is also at risk [5]. Among the major external factors that could promote Zika in Southern Europe include recent and sharp economic downturns and climate change now producing unprecedented warming in the region [4]. 2. The Middle East Ae. aegypti is found in the western area of the Arabian Peninsula that includes Saudi Arabia and Yemen [6,7] (Fig. 1). Beginning in 1992 human migrations during the Hajj and Umrah pilgrimages from Asia introduced dengue fever through Jeddah and from there into the region [8]. As a result, dengue fever remains endemic to Saudi Arabia and Yemen [9]. Could the Hajj or Umrah pilgrimages also introduce Zika into the Middle East? This is a real possibility that needs to be seriously considered. In my role as US Science Envoy focusing on the Middle East and North African region, I have had some sobering discussions with the Saudi Ministry of Health regarding steps required to conduct surveillance activities beginning this summer and into the September 2016 Hajj season. 3. Africa One of the big unknowns about Zika virus infection is the current extent of the African strain that was first isolated from Uganda more than 60 years ago. If indeed the African strain was widespread and induced protective immunity to the pandemic strain of Zika, the possibility remains that parts of the African continent could be partially protected against Zika virus introduction. However, it is equally likely that Zika could affect Africa, much as yellow fever is now causing a serious epidemic in West Africa [10], while dengue is also affecting large populations [9]. The poverty and depleted health systems found in many Sub-Saharan African countries make the region vulnerable Zika and microcephaly epidemics such as those in northeastern Brazil beginning last year. 4. Asia and beyond Just as India and Indonesia are experiencing some of the worst dengue problems anywhere in the world [9], we will
http://dx.doi.org/10.1016/j.micinf.2016.05.003 1286-4579/© 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved. Please cite this article in press as: Hotez PJ, Will Zika return to the ‘Old World’?, Microbes and Infection (2016), http://dx.doi.org/10.1016/j.micinf.2016.05.003
2
Editorial / Microbes and Infection xx (2016) 1e2
Fig. 1. Distribution of Aedes aegypti. Reproduced from Reference [6], Kraemer et al.
need to assume the possibility that these and neighboring countries could also be at risk for Zika virus infection. As in Africa, a big unknown is the extent to which the African strain previously affected these nations resulting in an immunized population. Zika virus will need to become front and center of the Global Health Security Agenda that was established as an international collaboration by the US Government together with the World Health Organization and other United Nations agencies in 2014 [11]. There is much to learn about this virus and the conditions responsible for its epidemic and pandemic potential. As we brace for Zika to strike the continental US, it's important to consider where Zika will spread next, and the implications of seeing clusters of microcephaly cases appear in Europe, the Middle East, Asia Minor, Africa, and Asia. Conflict of interest
[6]
[7] [8]
[9]
[10]
[11]
Sea region increases risk of Chikungunya, Dengue, and Zika outbreaks in Europe. PLoS Negl Trop Dis 2016 Apr;10(4):e0004664. Kraemer MU, Sinka ME, Duda KA, Mylne A, Shearer FM, Brady OJ, et al. The global compendium of Aedes aegypti and Ae. albopictus occurrence. Sci Data 2015 Jul 7;2:150035. http://dx.doi.org/10.1038/ sdata.2015.35. Alikhan M, Al Ghamdi K, Mahyoub JA. Aedes mosquito species in western Saudi Arabia. J Insect Sci 2014 May 20;14:69. El-Kafrawy SA, Sohrab SS, Abol Ela S, Abd-Alla AM, Alhabbab R, Farraj SA, et al. Multiple introductions of dengue 2 virus strains into Saudi Arabia from 1992 to 2014. Vector Borne Zoonotic Dis 2016 May 2;16(6):391e9 [Epub ahead of print]. Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al. The global distribution and burden of dengue. Nature 2013 Apr 25;496(7446):504e7. Woodall JP, Yuill TM. Why is the yellow fever outbreak in Angola a 'threat to the entire world'? Int J Infect Dis 2016 May 6. pii: S1201e9712(16)31044-X. doi: 10.1016/j.ijid.2016.05.001. [Epub ahead of print]. Global Health Security Agenda. https://ghsagenda.org. [accessed 18.05.16].
The author declares no conflicts of interest. References [1] Dick GW, Kitchen SF, Haddow AJ. Zika virus. I. Isolations and serological specificity. Trans R Soc Trop Med Hyg 1952 Sep;46(5):509e20. [2] MacNamara FN. Zika virus: a report on three cases of human infection during an epidemic of jaundice in Nigeria. Trans R Soc Trop Med Hyg 1954 Mar;48(2):139e45. [3] Wang L, Valderramos SG, Wu A, Ouyang S, Li C, Brasil P, et al. From mosquitos to humans: genetic evolution of Zika virus. Cell Host Microbe 2016 May 11;19(5):561e5. [4] Hotez PJ. Southern Europe's coming plagues: vector-borne neglected tropical diseases. PLoS Negl Trop Dis 2016 (in press). [5] Akiner MM, Demirci B, Babuadze G, Robert V, Schaffner F. Spread of the invasive mosquitoes Aedes aegypti and Aedes albopictus in the Black
Peter J. Hotez* Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA Department of Biology, Baylor University, Houston, TX, USA James A Baker III Institute of Public Policy, Rice University, Houston, TX, USA *1 Baylor Plaza, Houston, TX, 77030, USA. E-mail address: [email protected]. 18 May 2016 Available online ▪ ▪ ▪
Please cite this article in press as: Hotez PJ, Will Zika return to the ‘Old World’?, Microbes and Infection (2016), http://dx.doi.org/10.1016/j.micinf.2016.05.003
MODEL
Microbes and Infection xx (2016) 1e2 www.elsevier.com/locate/micinf
Editorial
Will Zika return to the ‘Old World’?
Zika virus infection is now rapidly disseminating throughout Latin American and the Caribbean, and possibly soon into the Gulf Coast of the United States. The World Health Organization estimates that up to four million people could be infected in the Western Hemisphere by the end of 2016. In the coming months could Zika virus infection travel across the Atlantic Ocean and begin causing infections (and microcephaly cases) in Europe, the Middle East, and Africa? The Zika virus was first described in the Zika Forest of Uganda during the late 1940s and isolated in 1952 [1]. The first human case was described in Nigeria in 1954 [2], and it is believed that Zika caused localized epidemics of Zika virus infection before it migrated from Africa and across Asia in the ensuing decades. In the 21st century molecular genetic comparisons suggest that Zika mutated to a pandemic strain that resulted in high virus attack rates in Micronesia and French Polynesia, before causing widespread infections in the ‘New World’ of the Americas [3]. There are several reasons to believe that Zika could complete its trip around the planet by spreading to vulnerable areas of the ‘Old World’ e Europe, the Middle East, and Africa. This is true particularly in urban areas that meet the major criteria responsible for current Zika outbreaks in the Americas, especially crowding and human migrations, poverty, and the presence of Aedes mosquitoes. 1. Southern Europe It has been noted that Southern Europe, including Portugal, Spain, Southern France, Italy, Corsica and Greece, has experienced resurgence in vector borne diseases over the last decade [4]. In terms of virus infections transmitted by Aedes mosquitoes, these diseases include dengue virus infection in Madeira off the coast of Portugal in 2012e13, and chikungunya in Italy, Spain, France, and Italy beginning in 2007 [4]. Although the major Aedes species found in Southern Europe, the Asian tiger mosquito Aedes albopictus, is believed to be less efficient than Ae. aegypti in transmitting Zika virus infection, the fact remains that Ae. albopictus successfully ignited dengue and chikungunya outbreaks. This finding portends a real possibility that we could start seeing Zika cases soon in Southern Europe. The adjoining Black Sea region
(where both Ae. albopictus and Ae. aegypti are found), is also at risk [5]. Among the major external factors that could promote Zika in Southern Europe include recent and sharp economic downturns and climate change now producing unprecedented warming in the region [4]. 2. The Middle East Ae. aegypti is found in the western area of the Arabian Peninsula that includes Saudi Arabia and Yemen [6,7] (Fig. 1). Beginning in 1992 human migrations during the Hajj and Umrah pilgrimages from Asia introduced dengue fever through Jeddah and from there into the region [8]. As a result, dengue fever remains endemic to Saudi Arabia and Yemen [9]. Could the Hajj or Umrah pilgrimages also introduce Zika into the Middle East? This is a real possibility that needs to be seriously considered. In my role as US Science Envoy focusing on the Middle East and North African region, I have had some sobering discussions with the Saudi Ministry of Health regarding steps required to conduct surveillance activities beginning this summer and into the September 2016 Hajj season. 3. Africa One of the big unknowns about Zika virus infection is the current extent of the African strain that was first isolated from Uganda more than 60 years ago. If indeed the African strain was widespread and induced protective immunity to the pandemic strain of Zika, the possibility remains that parts of the African continent could be partially protected against Zika virus introduction. However, it is equally likely that Zika could affect Africa, much as yellow fever is now causing a serious epidemic in West Africa [10], while dengue is also affecting large populations [9]. The poverty and depleted health systems found in many Sub-Saharan African countries make the region vulnerable Zika and microcephaly epidemics such as those in northeastern Brazil beginning last year. 4. Asia and beyond Just as India and Indonesia are experiencing some of the worst dengue problems anywhere in the world [9], we will
http://dx.doi.org/10.1016/j.micinf.2016.05.003 1286-4579/© 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved. Please cite this article in press as: Hotez PJ, Will Zika return to the ‘Old World’?, Microbes and Infection (2016), http://dx.doi.org/10.1016/j.micinf.2016.05.003
2
Editorial / Microbes and Infection xx (2016) 1e2
Fig. 1. Distribution of Aedes aegypti. Reproduced from Reference [6], Kraemer et al.
need to assume the possibility that these and neighboring countries could also be at risk for Zika virus infection. As in Africa, a big unknown is the extent to which the African strain previously affected these nations resulting in an immunized population. Zika virus will need to become front and center of the Global Health Security Agenda that was established as an international collaboration by the US Government together with the World Health Organization and other United Nations agencies in 2014 [11]. There is much to learn about this virus and the conditions responsible for its epidemic and pandemic potential. As we brace for Zika to strike the continental US, it's important to consider where Zika will spread next, and the implications of seeing clusters of microcephaly cases appear in Europe, the Middle East, Asia Minor, Africa, and Asia. Conflict of interest
[6]
[7] [8]
[9]
[10]
[11]
Sea region increases risk of Chikungunya, Dengue, and Zika outbreaks in Europe. PLoS Negl Trop Dis 2016 Apr;10(4):e0004664. Kraemer MU, Sinka ME, Duda KA, Mylne A, Shearer FM, Brady OJ, et al. The global compendium of Aedes aegypti and Ae. albopictus occurrence. Sci Data 2015 Jul 7;2:150035. http://dx.doi.org/10.1038/ sdata.2015.35. Alikhan M, Al Ghamdi K, Mahyoub JA. Aedes mosquito species in western Saudi Arabia. J Insect Sci 2014 May 20;14:69. El-Kafrawy SA, Sohrab SS, Abol Ela S, Abd-Alla AM, Alhabbab R, Farraj SA, et al. Multiple introductions of dengue 2 virus strains into Saudi Arabia from 1992 to 2014. Vector Borne Zoonotic Dis 2016 May 2;16(6):391e9 [Epub ahead of print]. Bhatt S, Gething PW, Brady OJ, Messina JP, Farlow AW, Moyes CL, et al. The global distribution and burden of dengue. Nature 2013 Apr 25;496(7446):504e7. Woodall JP, Yuill TM. Why is the yellow fever outbreak in Angola a 'threat to the entire world'? Int J Infect Dis 2016 May 6. pii: S1201e9712(16)31044-X. doi: 10.1016/j.ijid.2016.05.001. [Epub ahead of print]. Global Health Security Agenda. https://ghsagenda.org. [accessed 18.05.16].
The author declares no conflicts of interest. References [1] Dick GW, Kitchen SF, Haddow AJ. Zika virus. I. Isolations and serological specificity. Trans R Soc Trop Med Hyg 1952 Sep;46(5):509e20. [2] MacNamara FN. Zika virus: a report on three cases of human infection during an epidemic of jaundice in Nigeria. Trans R Soc Trop Med Hyg 1954 Mar;48(2):139e45. [3] Wang L, Valderramos SG, Wu A, Ouyang S, Li C, Brasil P, et al. From mosquitos to humans: genetic evolution of Zika virus. Cell Host Microbe 2016 May 11;19(5):561e5. [4] Hotez PJ. Southern Europe's coming plagues: vector-borne neglected tropical diseases. PLoS Negl Trop Dis 2016 (in press). [5] Akiner MM, Demirci B, Babuadze G, Robert V, Schaffner F. Spread of the invasive mosquitoes Aedes aegypti and Aedes albopictus in the Black
Peter J. Hotez* Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA Department of Biology, Baylor University, Houston, TX, USA James A Baker III Institute of Public Policy, Rice University, Houston, TX, USA *1 Baylor Plaza, Houston, TX, 77030, USA. E-mail address: [email protected]. 18 May 2016 Available online ▪ ▪ ▪
Please cite this article in press as: Hotez PJ, Will Zika return to the ‘Old World’?, Microbes and Infection (2016), http://dx.doi.org/10.1016/j.micinf.2016.05.003