current understanding of zika virus epidemiology · brian d. foy, kevin c. kobylinski, joy l....
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Pedro F. C. Vasconcelos, MD, PhD Director, Evandro Chagas Institute /SVS/MoH
Department of Arbovirology and Hemorrhagic Fevers
National Reference Laboratory for Arboviruses
National Institute of Science & Technology for Viral Hemorrhagic Fevers
PAHO/WHO CC for Arboviruses – Member of RELDA
Current Understanding of Zika Virus Epidemiology
1947 – Prototype strain isolated in Zika Forest near the Lake Victoria in Entebe, Uganda, from a febrile sentinel rhesus monkey
ZIKV is endemic eastern and western Africa
1952 – First human cases
1960’s ZIKV spillover to Asia and became endemic
2007 – Epidemic at Yap island (Micronesia)
2013-2014 – Epidemic in French Polynesia
2014 – Chile (Easter Island)
2015 – Identification of ZIKV in Brazil (introduction occurred in 2013)
ZIKA VIRUS (ZIKV) - Milestones
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ZIKV introduction in Brazil
Data from 08/DEC/2015
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Epidemiology
Source: WHO, 2 June 2016
Source: WHO, 2 Juneil 2016
Proposed schedule to ZIKV specific laboratory diagnosis by virus isolation, real-time RT-PCR and serology (IgM/IgG) by the IEC.
Infection
Onset of disease (symptoms/signs)
Incubation period
Time in days
Viral RNA
Blood Urine
Laboratory diagnosis by RT-PCR and serology (IgM/IgG) to Zika virus Source: Adapted from Sullivan, Nicolaides, Pathology 2014
Sperm: > 2 months
INCUBATION PERIOD
Humans: 3-6 days
Mosquitoes: 7-14 days
Aedes aegypti, the ZIKV vector
MODES OF TRANSMISSION
Vectors (Aedes spp – Aedes aegpty)
Sexual
Perinatal
Congenital
Blood transfusion and organ transplants
Saliva and urine (?)
Potential Sexual Transmission of Zika Virus Didier Musso, Claudine Roche, Emilie Robin, Tuxuan Nhan, Anita Teissier, Van-Mai Cao-Lormeau
In December 2013, during a Zika virus (ZIKV) outbreak in French Polynesia, a patient in Tahiti sought treatment for hematospermia, and ZIKV was isolated from his semen. ZIKV transmission by sexual intercourse has been previously suspected. This observation supports the possibility that ZIKV could be transmitted sexually.
Emerging Infectious Diseases • Vol. 21, No. 2, February 2015
Probable Non–Vector-borne Transmission of Zika Virus Colorado, USA Brian D. Foy, Kevin C. Kobylinski, Joy L. Chilson Foy, Bradley J. Blitvich, Amelia Travassos da Rosa, Andrew D. Haddow, Robert S. Lanciotti, and Robert B. Tesh
Clinical and serologic evidence indicate that 2 American scientists contracted Zika virus infections while working in Senegal in 2008. One of the scientists transmitted this arbovirus to his wife after his return home. Direct contact is implicated as the transmission route, most likely as a sexually transmitted infection.
Emerging Infectious Diseases • Vol. 10, No. 2, May 2011
Source: WHO, 13 April 2016
Since October 2013, French Polynesia has experienced the largest documented outbreak
of Zika virus (ZIKAV) infection. To prevent transmission of ZIKAV by blood transfusion,
specific nucleic acid testing of blood donors was implemented. From November 2013 to
February 2014: 42 (3%) of 1,505 blood donors, although asymptomatic at the time of
blood donation, were found positive for ZIKAV by PCR. Our results serve to alert blood
safety authorities about the risk of post-transfusion Zika fever.
Euro Surveill. 2014;19(14):pii=20761. Available online: http://www.eurosurveillance.org/
Transplantation, February 2016
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ZIKV - causal agent of microcephaly and CNS congenital
malformations (Zika congenital syndrome?)
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States
Average
microcephaly birth
rate per 100,000
live births. Brazil,
2010-2014 (*)
Microcephaly birth
rate per 100,000
live births. Brazil,
2015(**)
Distrito Federal 2.2 2.2
Goiás 3.2 2.1
Mato Grosso do Sul 1.9 2.4
Alagoas 6.5 112.4
Bahia 5.2 18.2
Ceará 5.3 20.0
Maranhao 2.6 10.4
Paraíba 7.4 436.2
Pernambuco 6.1 456.7
Piauí 6.5 77.6
Rio Grande do Norte 3.8 168.8
Sergipe 4.7 225.0
Tocantins 5.0 49.8
Rio de Janeiro 5.5 5.8
Total 4.9 99.7
Microcephaly birth rates per 100,000 live births.
Brazil 2010-2014 and 2015
Central West Region
Northeast Region
Northern Region
Southeast Region
(*) Calculated using the average number of Microcephaly cases that occurred between 2010 and 2014 in the numerator, and the number of live births per mother's state of residency from 2013 in the denominator. (**) Calculated using the number of Microcephaly cases that occured up until EW 47, 2015, and the number of live births per state of the mother's residency from 2013 in the denominator.
Lancet, 387: 719-721, 2016.
Mlakar et a., NEJM 374: 951-958, 2016
Brasil et al., 2016 NEJM
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A total of 301 cases of microcephaly associated to ZIKV were laboratorially confirmed (Real-time RT-PCR and IgM ELISA) in Brazil, EW 21, 2016
MICROCEPHALY IN BRAZIL
Source: WHO, Zika - Epidemiological Update Jun 02 2016
MICROCEPHALY AND MALFORMATIONS IN THE CNS
Microcephaly History Cases
114 120
162
137
168
140
0
20
40
60
80
100
120
140
160
180
1 2 3 4 5 6
Cas
es
2010 - 2015
Reference: RIPS-SISPRO Minsalud. Preliminar data October 2015
Microcephaly cases reported in Colombia, 2010-2015
IMAGENS AUTORIZADAS DE CRIANÇAS COM MICROCEFALIA. REGIÃO METROPOLITANA DE RECIFE, 01/08 A 31/10/2015.
Microcephaly cases
Other patterns
Photos: Courtesy of Dr. Adiana Melo
Freitas et al., JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2016.0267 Published online February 9, 2016.
A
D
B C
E
Azevedo et al., 2016 - submitted
G
H I
F
Azevedo et al., 2016 - submitted
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ZIKV - causal agent of GBS
GUILLAIN-BARRÉ SYNDROME (GBS)
13 countries and territories have reported increase inthe incidence of GBS or confirmed by laboratory results infection by ZIKV in patients with GBS.
Source: WHO, 2 June 2016
Reference: Sivigila – National Institut of Health
Zika cases notification of virus infection and the infection report of Guillain-Barré Syndrome, Epidemiological weeks 07 of 2016 in Colombia
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Conclusion remarks
• Although actually dengue is the most important and widespread infectious diseases (many times more reported cases than malaria), the emergence of other Aedes-borne viruses especially ZIKV with its new, explosive and severe presentation is of concern;
• Air transportation and large sportive events are important mechanisms for spreading of arboviruses from one place to another facilitating virus introduction and local transmission;
• The specific serologic diagnostic of exanthematic viral disease including DENV, CHIKV and ZIKV is a big challenger and is a problem to epidemiologic studies;
• The occurrence of microcephaly and other CNS malformations, abortion, stillbirth, cases of GBS and deaths of adults with autoimmune disorders by ZIKV are of concern, and today there are consensus of the ZIKV causality, but need studies to support incidence/case fatality rates;
• The fast spread of ZIKV in the Americas is of concern; the simultaneous occurrence of three different Aedes-borne viruses (DENV, CHIKV, ZIKV) in the region is noteworthy; and the risk of spread to other countries is seriously considered in the next years, during the rainy season;
• It is urgent to strenghth the Aedes aegypti control programs in the Americas, including using of new technologies, in order to stop the spread of ZIKV in the region;
• The occurrence of atypical severe (some fatal) cases of both CHIKV and ZIKV needs special investigation and is an opportunity to scientific studies on molecular/molecular epidemiology, clinical, diagnostic and pathogenesis , etc.;
• The development of vaccine against ZIKV is an international emergency;
Acknowledgements
IEC, Ananindeua
Bruno Tardelli
Consuelo Oliveira
Daniele Medeiros
Eliana Silva
Socorro Azevedo
Sueli Rodrigues - and all other people at IEC
SVS -MoH, Brasília
Wanderson Oliveira and all people of CIEVS
Giovanini Coelho and all people of PNCD
Alexander Vargas and people of EPI-SUS
• Dominican Republic MoH
• CDC
• SMS de São Luís
• WHO
Financial support
CNPq, CAPES, FAPESPA, EU, MoH-SVS, TDR, PAHO/WHO
UFPE/IMIP, Recife
Carlos Brito
FIOCRUZ, Recife
Rafael Dhalia
Rafael França
SMS/Instituto Elpidio de Almeida,
Campina Grande
Adriana Melo
PAHO, Washington
Sylvain Aldighieri
MoH, Bogota
Fernando Ruiz Goméz
INSTITUTO EVANDRO CHAGAS 1936-2011
www.iec.pa.gov.br
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
Arbovirology and Hemorrhagic Fevers INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
www.iec.pa.gov.br
Thank you!
New Campus of Instituto Evandro Chagas in Ananindeua/Pará.
INSTITUTO EVANDRO CHAGAS 1936-2011
Arbovirology and Hemorrhagic Fevers
www.iec.pa.gov.br
INSTITUTO EVANDRO CHAGAS 1936-2016
Arbovirology and Hemorrhagic Fevers