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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