L I L I A N A V . R I O S , M . D .
I N F E C T I O U S D I S E A S E C O N S U L T A N T S
ZIKA VIRUSWHAT IS IT? WHERE DID IT COME FROM?
HOW DID IT GET HERE?
EPIDEMIOLOGY
• A single stranded RNA
virus
• Genus: Flavivirus
• Classified amongst
better known :
Dengue Virus (DEN),
West Nile Virus
(WNV), Yellow Fever
(YF) Virus, Japanese
encephalitis (JE) virus
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EPIDEMIOLOGY
• Vector: spread by the
bite of an infected
female Aedes mosquito.
• Distinctive black &
white markings
• Usually bites during the
daytime
• Breeds in standing
water, particularly
manmade containers [1]
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ZIKA VIRUS DISEASE
• Presents similarly to Dengue and Chikungunya
• Asymptomatic infection 80%
• Or a mild febrile illness 20%
• Symptoms include:
• Fever
• Rash
• Joint pains
• Red eyes
• In less than 1%, neurologic syndromes can occur
• Guillain-Barré syndrome
• Microcephaly In the developing fetus[2]
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THE ORIGIN OF THE VIRUS
• Discovered: 1947
• As scientists worked on
YF transmission.
• A. J. Haddow, MD
• Aedes Africanis
• Rhesus monkey
• Officially named
in1948, after the Zika
Forest in Uganda.[3]
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ZIKA VIRUS :AN EMERGING VIRUS
• Between 1947 and 2006
• Only 14 reports of human cases documented
• First native case in 1954
• A 10 yr old girl in Nigeria who had a mild febrile
illness and recovered completely.[4]
• First experimental infection in a human volunteer
in 1956
• Experienced a mild febrile illness and recovered
completely.[5]
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ZIKA VIRUS :AN EMERGING VIRUS
• In 2007
• An outbreak occurred on the island of Yap
(Federal States of Micronesia).
• 49 confirmed and 59 probable cases of Zika
virus disease
• An estimated 73% of Yap residents >3 years of
age had been recently infected with Zika virus
• Aedes hensilli was the mosquito identified[6]
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ZIKA VIRUS :AN EMERGING VIRUS
• In 2013
• An epidemic of Zika virus emerged in French
Polynesia where Dengue is endemic.
• A larger scale of people were exposed at an
estimated 28,000 cases; approximately 11% of the
population.
• And yet the true incidence of exposure was
likely under reported as infection is most
commonly asymptomatic.
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ZIKA VIRUS :AN EMERGING VIRUS
• In contrast to YAP, serious effects become obvious
when the virus affects a lot of people in French
Polynesia.
• Correlations to the more uncommon clinical
neurologic manifestations of Guillain-Barré
syndrome are unmasked and first associated to
Zika virus. [7]
• Smaller outbreaks then followed from French
Polynesia to the cook islands, Easter Island and the
Solomon Islands.[8]
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ZIKA VIRUS :AN EMERGING VIRUS
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RACE TO THE AMERICAS
• Northeastern Brazil, 2015
• The Aedes mosquito is endemic here as is Dengue fever.
• However, up to 60,000 cases with non-Dengue and non-Chikungunya began accumulating.
• Thus, scientists take note at the Oswaldo Cruz foundation and began investigating.
• On June 2015, the first domestic transmission of Zika virus was confirmed and documented in Brazil.• They used phylogenetic analysis and traced the virus to the
Asian clade of Zika virus
• confirmed by PCR DNA sequencing[9]
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RACE TO THE AMERICAS
• The precise means by which Zika Virus was introduced to the Western Hemisphere is unknown.
• Brazil reported 1.5 million cases, and more than 4,000 suspected cases of microcephaly in babies.• The predominant incidence however was in the poorer
northeast.
• Zika rapidly spread throughout Latin America and the Caribbean, such that within 1 year most countries in the region reported local transmission. [10]
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HOW IT GOT TO THE AMERICAS
• Postulates from Journal of Virology and Scientific
American:
• The viremic traveler from the French Polynesia via:
• FIFA Confederations Cup, which was held in
Brazil from 15 June to 30 June 2013
• World cup soccer competition July 2014
(what an upset!)
• Va’a world sprint Championship canoe race in
Rio de Janeiro Brazil in August 2014
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THE ZIKAVIRUS, CLASS DIVIDE, AND CLIMATE CLASH
• In our current scholarly articles; Asian Pac J Trop Biomed and New England Journal of Medicine:
• Emergence of the world as a global village.
• Climate change • summer heat waves, drought, and heavy rains with flash
floods.
• Human factors• many inhabitants in large cities
• Lack of : electricity, running water, garbage collection, sewers and drains for rain.
• Inadequate health service
• Dev of vector resistance to insecticides[11 -12]
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AN ESTABLISHED GLOBAL THREAT
• On Nov 1, 2015 the Brazil Ministry of Health declared a
public health emergency as the number of cases of
microcephaly continued to increase.
• On February 1, 2016 The World Health Organization
(WHO) declared the cluster of microcephaly cases and
other neurological disorders a health emergency.
• On February 8, 2016, the Centers for Disease Control
(CDC) elevated its response efforts to a Level 1
activation.
• The WHO launched the global Strategic Response Framework
to encompass surveillance, response activities and research.
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HOW IT GOT TO THE US*? FLORIDA DEPT. OF HEALTH
• Local transmission via domestic mosquito vector has
been reported in Puerto Rico (*US territory), but not
elsewhere in the United States.
• Cases of Zika fever have been reported in travelers
returning to the United States.
-secondary transmission is possible via sex.
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CDC UPDATE JANUARY 1, 2015 – JUNE 1, 2016.
US States
• Travel-associated cases reported: 618
• Florida cases – 128
• Locally acquired vector-borne cases reported: 0
• Total: 618
• Sexually transmitted: 11
• Guillain-Barré syndrome: 1
US Territories
• Travel-associated cases reported: 4
• Locally acquired cases reported: 1,110
• Total: 1,114
• Guillain-Barré syndrome: 8
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THE ZIKA VIRUS TIME LINE
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R E P O R T S 6 0 C O U N T R I E S A N D T E R R I T O R I E S R E P O R T C O N T I N U I N G M O S Q U I T O - B O R N E T R A N S M I S S I O N .
AS OF 1 JUNE 2016, THE WHO
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INFECTIOUS DISEASE CONSULTANTS
• We specialize in
Infectious Diseases &
Travel Health.
• For an appointment
call: 407.830.5577
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CITATIONS
1. http://www.floridahealth.gov/diseases-and-conditions/zika-virus/index.html
2. CDC.gov
3. Zika Virus (I). Isolations and serological specificity. G.W. A. Dick, S.F. Kitchen, A. J. Haddow. Trans R Soc Trop Med Hyg (1952)46 (5): 509-520.doi: 10.1016/0035-9203(52)90042-4.
4. MacNamara, F.N. (March 1954). "Zika virus: a report on three cases of human infection during an epidemic of jaundice in Nigeria.". Transactions of the Royal Society of Tropical Medicine and Hygiene 48 (2): 139–45.
5. Bearcroft, W.G. (September 1956). "Zika virus infection experimentally induced in a human volunteer." Transactions of the Royal Society of Tropical Medicine and Hygiene 50 (5): 442–8.
6. Tai-Ho Chen, M.D., W. et al. Zika Virus Outbreak on Yap Island, Federated States of Micronesia. Mark R. Duffy, D.V.M., M.P.H., N Engl J Med 2009; 360:2536-2543
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CITATIONS
7. Search and one will find: Zika virus everywhere Trans R Soc Trop Med Hyg (2016)110 (4): 207-208.doi: 10.1093/trstmh/trw020.
8. Musso D. Zika virus transmission from French Polynesia to Brazil. Emerg Infect Dis. 2015;21(10):1887.
9. Camila Zanluca et al. Mem. Inst. Oswaldo Cruz vol.110 no.4 Rio de Janeiro June 2015 Epub June 09, 2015.
10. Zika Virus: New Clinical Syndromes and Its Emergence in the Western Hemisphere. Helen M. Lazear and Michael S. Diamond. J. Virol. May 2016 vol. 90 no. 104864-4875
11. Troncoso A, Zika threatens to become a huge worldwide pandemic. Asian Pac J Trop Biomed (2016)
12. Anthony S. Fauci, M.D., and David M. Morens, M.D. Zika Virus in the Americas — Yet Another Arbovirus Threat. N Engl J Med 2016; 374:601-604.
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