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