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5/17/2017
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Zika Virus: What We Know and Don’t Know
Meg Fisher, MDMedical Director
Disclosures
• I have no financial disclosures.
• I do not plan to discuss off label uses of medications.
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Objectives• Discuss the epidemiology of Zika virus
• Advise a parent or teen regarding travel to Zika areas
• Evaluate a newborn whose mother had Zika virus infection
Hot Topics in ID: Zika Virus
www.cdc.gov/zika/
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Zika Virus • Discovery: 1947, Zika Forest, Uganda
• First human disease: Nigeria 1953
• Few cases recognized for next 50 years
• 2007 Micronesia: 5000 of 6700 infected
• 2013-14 French Polynesia: 32,000 cases
• Other islands then 2015 Brazil: > 1 mil
Zika virus• Flavivirus, African and Asian genotypes
• Mosquito transmitted: Aedes species
• Africa: monkeys and humans
• Suburban-urban: humans
• Vectors: A. aegypti, A. albopictus
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Areas With Risk of Zika
wwwnc.cdc.gov/travel/files/zika-areas-of-risk.pdf
Zika Transmission, Florida
www.cdc.gov/zika/intheus/florida-update.html
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Zika Transmission, Texas
www.cdc.gov/zika/intheus/texas-update.html
Areas With Risk of Zika• Tropical islands
• Central and South America, Sub-Saharan Africa, India, SE Asia
• Interactive map on CDC website:
www.cdc.gov/zika/intheus/texas-update.html
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Zika Cases in the US• 2015: not a reportable disease
US: 61 travelers Territories: 1 travel, 8 local
• 2016US: 4830 travelers Territories: 36,079
224 local48 other
• 2017 (as of May 10, 2017)US: 110 travel Territories: 493
www.cdc.gov/zika/reporting/2017-case-counts.html
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Zika Transmission• Aedes mosquito: aggressive, day
time biters, bite at night also
• Sexual transmission
• Pregnant woman to her fetus
• Blood transfusion
• Laboratory accidentwww.cdc.gov/zika/transmission/index.html
Range of A. aegypti in US
2016
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Zika Transmission
Aedes aegypti
• Adult life span 2-4 weeks, fly 400 meters
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Aedes aegypti• Best transmitter
• Feeds primarily on humans, live close
• Day and night biting, in and outdoors
• Almost imperceptible bites
• Multiple bites during feeding
• Zika, dengue, chikungunya, yellow fever
Sexual Transmission• Virus in semen for weeks
• Virus in vaginal secretions
• Frequency of transmission unknown
• Duration of risk unknown
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Mother to Fetus• Zika virus RNA detected in placenta,
amniotic fluid and fetal tissues
• Fetal loss, stillborn, brain abnormality
• Frequency and risk unknown
• Peripartum transmission reported
• Registry: ZikaPregnancy@cdc.gov www.cdc.gov/zika/hc-providers/registry.html
Other Routes• Blood transfusion
• Laboratory accidents
• Healthcare workers
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Clinical Illness• Only 1 in 5 have symptoms
• Fever, rash, joint pain, conjunctivitis
• Mild, self limited illness, lasts days
• Incubation: few days (range 3-12)
• Infection in a fetus: microcephaly
• Cases of Guillain-Barré syndrome
Neurologic Complications• Guillain-Barré syndrome: Polynesia
(38 cases) and Brazil
• Baseline GBS: 1-2/100,000 people
• Microcephaly increased incidence
• Baseline: 6/10,000 live births
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Fetal Infection• Virus is neurotropic and destroys brain
• Microcephaly, fetal brain disruption, ocular abnormalities
• In utero ultrasounds: calcification
• Zika confirmed in fetal brain tissue*
• Highest risk in 1st trimester*DOI:10.1056/NEJMoa1600651
Diagnosis• Detection of viral RNA by RT-PCR: viremia
lasts about a week, urine longer
• Specific IgM by MAC-ELISA: rises about a week after illness and lasts months
• Cross reacting antibodies: dengue +
• Plaque reduction neutralization test (PRNT)www.cdc.gov/mmwr/volumes/65/wr/mm6521e1.htm?s_cid=mm6521e1_e
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Treatment• Supportive care
• Note most will have no symptoms
• Monitor and test exposed pregnant women
• Register pregnant women
www.cdc.gov/zika/hc-providers/registry.html
Prevention – Travel• Avoid travel to areas with active Zika
transmission
• If you travel, avoid mosquito bites
• If you travel, avoid unprotected sex
wwwnc.cdc.gov/travel/page/zika-travel-information
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Prevention - Mosquitoes• Clothing: cover up
• Screens and air-conditioning; bed nets
• Repellents: DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol – follow directions!
• Permethrin-treated clothing and gearwww.cdc.gov/zika/prevention/index.html
Prevention - Sex• Recommendation for pregnant
women: abstain or use condoms consistently
• Recommendations for non-pregnant: abstain or use condoms consistently
• Testing of men of uncertain value…www.cdc.gov/zika/pregnancy/thinking-about-pregnancy.html
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Duration for Males
• Male traveler no symptoms: at least 6 months after departure
• Male resident: consider while active transmission persists
www.cdc.gov/zika/prevention/sexual-transmission-prevention.html
Duration for Females• Pregnant woman: throughout
pregnancy
• Non-pregnant: at least 8 weeks after symptoms or exposure
www.cdc.gov/zika/prevention/sexual-transmission-prevention.html
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Prevention - Other• Screen potential blood donors• Laboratory workers: routine safety
measures• Healthcare people: avoid needle sticks
Recommendations• Pregnant women forego travel to
areas with Zika virus transmission
• Exposed pregnant women should be tested
• If congenital infection is suspected, many tests are recommended
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Effects of Zika on Fetus• Microcephaly: fetal brain disruption
• Imaging: calcification, abnormal gyri, decreased brain volume, +
• Hypertonia, hypotonia, spasticity, irritability, seizures
• Eyes: chorioretinal atropy, optic disc hypoplasia, pallor and cupping
www.cdc.gov/mmwr/volumes/65/wr/mm6533e2.htm?s_cid=mm6533e2_w
Zika in PregnancyData as of April 25, 2017
• United States: 1793 pregnant women
• Outcomes: 1409 completed pregnancies
• 58 newborn with birth defects
• 8 fetal losses with defects
• US Territories: 3700 pregnant women
• Outcomes information not available
www.cdc.gov/zika/reporting/pregnancy-outcomes.html
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Pregnancy Outcomes• Any evidence of possible recent Zika:
51/972 (5%); microceph. 43, other 8• Confirmed Zika infection: 24/250 (10%);
microceph. 18, other 6• Zika infection in first trimester: 15/60
(15%); microceph. 8, other 1
• Postnatal studies: imaging in only 25%, Zika virus testing in 65%
Management of the BabyLaboratory testing recommended:
• Infants born to mother with evidence of Zika virus infection during pregnancy
• Infants with abnormal clinical or imaging findings and maternal epidemiologic link
rRT-PCR (serum, urine) and IgM for Zikawww.cdc.gov/mmwr/volumes/65/wr/mm6533e2.htm?s_cid=mm6533e2_w
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Baby of Zika + Mother • Zika virus testing: rRT-PCR, IgM within
2 days; if CSF obtained, test it as well• Comprehensive physical examination• Neurologic examination• Postnatal head ultrasound• Standard hearing screen• Report to Registry
www.cdc.gov/mmwr/volumes/65/wr/mm6533e2.htm?s_cid=mm6533e2_w
Interpretation of Tests• Positive infant serum or urine rRT-PCR
confirms congenital Zika virus infection
• +Zika IgM, -rRT-PCR indicates probable congenital Zika virus infection; PRNT
• -Zika IgM, -rRT-PCR means not infected
• Report Positives to Public Healthwww.cdc.gov/mmwr/volumes/65/wr/mm6533e2.htm?s_cid=mm6533e2_w
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Confirmed Congenital Zika• By 1 month: Comprehensive
ophthalmologic exam and hearing by Auditory brainstem response (ABR)
• Follow up depends on whether abnormalities are present
www.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
Baby With Abnormalities• CBC, metabolic panel (liver function)
• Coordinated evaluation by multiple specialists within first month of life
• Assess vision, hearing, feeding , growth, neurodevelopment and endocrine function in first year
www.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
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Baby With Abnormalities• Consultation: Neurology (imaging), ID
(r/o other), Ophthalmologist, Genetics, Endocrine (hypothalmus, pituitary)
• Others: orthopedics, rehab, pulmonary, lactation, nutritionist, GI, speech, OT
• Psychosocial support; coordinated care
• My opinion: palliative care essentialwww.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
Baby With Abnormalities• Multidisciplinary team and medical home
• Monthly visits X 6: growth, development, immunize, guidance, support
• Neurologic exam at ages 1 and 2 months
• Refer to developmental specialist and early intervention serviceswww.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
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Baby With Abnormalities• Repeat eye exam at 3 months• Repeat ABR testing at 4-6 months,
refer if abnormal• Repeat thyroid studies (TSH, T4) at 2
weeks and 3 months, refer if abnormal• Provide family and supportive services• Just launched Zika Care Connect
(http://www.zikacareconnect.org/)www.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
Baby Without Abnormalities• Medical home: growth, developmental
screen at each visit, anticipatory guide
• Standardized devel. screen at 9 mos
• Repeat hearing test, 4-6 mos
• Provide family and supportive services
www.cdc.gov/zika/hc-providers/infants-children/zika-evaluation.html
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Anticipatory Guidance• Encourage breastfeeding
• Watch for poor suck, swallowing difficulty, reflux, aspiration
• Sleep problems, excess irritability
• Monitor family for depression
• Social stigma, financial stresswww.cdc.gov/mmwr/volumes/65/wr/mm6533e2.htm?s_cid=mm6533e2_w
Zika Prevention• Avoid exposure: travel precautions
• Avoid mosquitoes
• Sexual transmission: abstinence or condoms
• Stay tuned for more information
• www.cdc.gov/zika/
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Mosquito Control• Public health: Integrated Vector
Management
• Community cleanup campaigns (tire removal, trash pickup, removal and cleaning of small and large containers).
• Insecticide resistance testing
• Larvicides in containers and bodies of water that cannot be removed or dumped.
www.cdc.gov/zika/public-health-partners/vector-control-us.html
The End
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