Zika virus was first isolated in 1947 in Uganda. It is transmitted primarily via Aedes mosquitoes and can cause microcephaly and other birth defects. There was an outbreak in Brazil in 2015-2016 which spread rapidly through the Americas. Pregnant women who travel to affected areas are advised to strictly follow steps to prevent mosquito bites. Testing involves RT-PCR of serum and urine within 2 weeks of symptoms, and IgM antibody testing if RT-PCR is negative. Interpretation of results must consider cross-reactivity with other flaviviruses.

1. Zika Virus
Sujata Ambardar MD. FACP
September 14, 2016

2. Zika Virus: Introduction
 In 1947 isolated in Zika forest of Uganda
 First major infectious disease linked to human birth
defects in last half century
 WHO declared a Public Health Emergency of International
concern
 Introduced to Brazil from Pacific islands spread rapidly to
America within span of 1 year
NEJM 374:16

3. Zika : Epidemiology
Flavivirus in family Flaviviridae
1953 First recognized in Nigeria ; mild febrile illness
Only 13 natural acquired cases during next 57 years
2007 Outbreak on several islands in State of Yap,
Micronesia: 5000 infections in 6700
2013/2014 Outbreak French Polynesia involved 32,000
2014/2015 Pacific islands, Easter Island, Cook Islands,
Samoa

4. In Africa, Zika virus circulates in a sylvatic
transmission cycle between nonhuman
primates and certain forest-dwelling
species of aedes mosquitoes. In this
setting, sporadic human infections may
occur. In suburban and urban settings, Zika
virus is transmitted in a human–mosquito–
human transmission cycle, mostly
involving A. aegypti mosquitoes.

6. Petersen LR et al. N Engl J Med 2016;374:1552-1563.
Areas in Which Zika Virus Infections in Humans Have Been
Noted in the Past Decade (as of March 2016).

7. Microcephaly Associated with Maternal Zika Virus
Infection

8. Zika Virus:Complications
 Increasing incidence of microcephaly, other neurologic findings
prompted evaluation
 Fetal abnormalities estimated at 29 % in ultrasounds done in Brazil
 Findings of Zika virus RNA in amniotic fluid of fetuses with
microcephaly
 Early fetal loss and death
 Ocular abnormalities
NEJM 374: 16

9. Expected and Observed Numbers of
Cases of the Guillain–Barré Syndrome

10. CDC Zika Case Counts in the US ( As of
Sept 7,2016)
 US States
 Locally acquired mosquito-borne cases reported: 43
 Travel-associated cases reported: 2,920
 Virginia 78 (3) ; all travel
 Florida 571 (20) ; travel
43 (100) mosquito -borne
 Laboratory acquired cases reported: 1
 Total: 2,964
 Sexually transmitted: 24
 Guillain-Barré syndrome: 7

11. Case Counts in the US
 US Territories
 Locally acquired cases reported: 15,809
 Travel-associated cases reported: 60
 Total: 15,869*
 Guillain-Barré syndrome: 31
 *Sexually transmitted cases are not reported for US
territories because with local transmission of Zika virus it
is not possible to determine whether infection occurred
due to mosquito-borne or sexual transmission.

12. Local transmission of Zika virus
 The Florida Department of Health has identified two areas
of Miami-Dade County where Zika is being spread by
mosquitoes. In addition to the previously identified area
in the Wynwood neighborhood, there is now mosquito-
borne spread of Zika virus in a section of Miami Beach

13. Zika: Screening Questions for every
pregnant woman to assess risk
 1) Have you traveled to a Zika-affected area within the
past 12 weeks?
 2) Have you had possible sexual exposure to Zika virus
within the last 12 weeks?
 3) Do you have ≥ 2 symptoms* of Zika and had mosquito
bite(s) in the 2 weeks before symptom onset?
Revised Algorithm on Inova Net 8/2016

14. *Symptoms of Zika
 Fever ( 65% )
 Rash ( 90%)
 Arthralgia (65%)
 Conjunctivitis ( 55%)
 Pregnancy complication (fetal loss, fetus or neonate
with congenital microcephaly, intracranial calcifications,
other structural brain or eye abnormality, or other
congenital central nervous system related abnormality)

15. Zika Testing: Pregnant patient
Test for Zika if patient has at least one risk factor listed
above
 1. Provider should contact the local health department to request Zika
testing.
 2. Upon approval, the local health department will FAX or e-mail the
following two forms to the requesting provider. These two forms must
accompany the sample(s) at all times and be filled out completely. The
laboratory will not accept samples unless these two forms are provided.
a. ZIKA VIRUS CASE REPORT FORM
b. DCLS MICRO/VIRO TEST REQUEST FORM

16. Zika Screening: Non-pregnant
Non‐pregnant individuals who did not travel to a
Zika‐affected area :
have ≥1 symptom of Zika and had possible sexual exposure to Zika virus*
have ≥3 symptoms of Zika not explained by another etiology and had
mosquito
bite(s) in the 2 weeks before symptom onset
Non‐pregnant individuals who traveled to a Zika‐affected
area:
have ≥2 symptoms of Zika during or
within 2 weeks of travel
A person diagnosed with Guillain‐Barré Syndrome not
known to be associated with another etiology

17. Zika Screening: Infants
Infants who:
 have ≥2 symptoms of Zika in the first 2 weeks of life not
explained by another etiology
 were born to mothers with laboratory evidence of
confirmed or possible Zika
 virus infection
 have fetal abnormalities consistent with congenital Zika
virus infection
 were diagnosed with microcephaly, intracranial
calcifications, brain or eye abnormality

18. Zika Testing
 rRT-PCR testing for Zika virus is available through some
commercial laboratories but VDH and Inova strongly
recommend that providers caring for pregnant women
pursue Zika virus laboratory testing through public health (at
no cost to the patient).
 Public health testing more timely combinations of rRT-PCR and
serological (IgM) testing with appropriate reflex testing
performed without need for additional orders or samples.
 Providers may contact their local health department with any
questions or to request Zika virus testing

19. Local Health Departments: Contact
Information
Health Department Electronic Approval Form Contact Number
 Alexandria https://www.alexandriava.gov/health/info/default.aspx?id=65006 571.259.8549

 Arlington https://health.arlingtonva.us/zika-resources-clinicians/ 703.228.5200,
 Fairfax http://go.usa.gov/cGuZ4 703.246.2433
 Loudoun https://www.loudoun.gov/index.aspx?NID=3843 703.771.5936
 Prince William - Manassas http://www.vdh.virginia.gov/lhd/PrinceWilliam/resources.htm 703.792.6301

 Prince William - Woodbridge http://www.vdh.virginia.gov/lhd/PrinceWilliam/resources.htm 703.792.7301

20. Zika Testing
Patients presenting at physician offices without blood draw capabilities
may be directed to an Inova Patient Service Location for blood collection
(see attached for a list of facilities).
 Locations available on Inovanet Zika page
 NOTE: Patients who present at an Inova Patient Service Location
WITHOUT the required 2 FORMS completed will not have
specimens collected and will be directed back to their provider. .

21. Zika Testing: Registration and Ordering
 Patient Presents at Facility for specimen collection.
 Patient will be registered in EPIC following normal registration
procedures. If possible, patient forms should be scanned into EPIC as
part of patient record.
 Staff will collect specimen using guidelines for acceptable specimens
below.
If being collected by NON-Laboratory Staff- Order in EPIC “ZIKA-Health
Department Lab Test (DCLS)” or LAB 12932
If being collected by Inova Laboratory Staff- Order in SOFT “ZIKA”,
collect and verify.
 **Laboratory staff should monitor pending for ZIKA test and verify
accordingly to complete test.
 Laboratory staff will package specimens and paperwork for transport
to the health department

22. Zika Testing : Background
 Zika virus is a single-stranded RNA virus in the genus Flavivirus and is closely related
to dengue, West Nile, Japanese encephalitis, and yellow fever viruses . Among
flaviviruses, Zika and dengue virus share similar symptoms of infection, transmission
cycles, and geographic distribution
 Zika virus antibody test results can be difficult to interpret because of cross-
reactivity with other flaviviruses, which can preclude identification of the specific
infecting virus, especially when the person previously was infected with or
vaccinated against a related flavivirus
Interim Guidance for Interpretation of Zika Virus Antibody Test Results. MMWR Morb Mortal
Wkly Rep 2016;65. DOI: http://dx.doi.org/10.15585/mmwr.mm6521e1

23. Zika Virus Infection and Immune
Response
 Most Zika virus infections are asymptomatic
 Viremia is expected to occur from several days before illness onset
until a week after illness onset
 Zika virus–specific IgM antibodies develop during the first week of
illness
 Data on duration of IgM antibody persistence following Zika virus
infection are limited
 IgM antibodies against West Nile virus, a closely related flavivirus,
have been detected in asymptomatic, infected blood donors for at
least 3 months after their viremic donation, and almost half of tested
patients with West Nile virus neuroinvasive disease had detectable
serum IgM antibodies >1 year after illness onset

24. Zika Virus Antibody Testing
 An enzyme-linked immunosorbent assay (ELISA) can be used to detect
anti-Zika virus IgM antibodies in serum or cerebrospinal fluid;
however, the Zika virus IgM ELISA can provide false-positive results
because of cross-reacting IgM antibodies against related flaviviruses or
nonspecific reactivity
 The plaque reduction neutralization test (PRNT) measures virus-
specific neutralizing antibody titers and should be performed against
various related flaviviruses to rule out false-positive ELISA results.

25. Zika Testing: Symptomatic patients
 For symptomatic women with exposure to Zika virus, rRT-PCR testing
of serum and urine is recommended up to 2 weeks after symptom
onset.
 Urine should always be collected with a patient-matched serum
specimen
 A positive rRT-PCR result on any sample confirms Zika virus infection
and no additional testing is indicated. A negative rRT-PCR result does
not exclude Zika virus infection and serum should be analyzed by IgM
antibody (serological) testing.

26. Zika Testing: Asymptomatic pregnant
patients with travel history
rRT-PCR testing is recommended on serum and urine within 2 weeks of
the date of last possible exposure.
rRT-PCR testing is also indicated for pregnant women who present for
care ≥ 2 weeks after exposure
In areas with active ZIKV transmission, asymptomatic pregnant women
should undergo IgM testing as part of routine obstetric care in the 1st and
2nd trimester.
Reflex rRT-PCR testing is included as a subsequent test for women who
are IgM positive

27. Interpretation of Zika Virus Testing
Results
 Serum IgM antibody testing for Zika and dengue virus infections
should be performed if rRT-PCR is negative.
 For serum specimens collected <7 days after onset of symptoms, the
combination of a negative rRT-PCR result and negative IgM antibody
testing suggests that there was no recent infection.
 A negative IgM antibody test, in the absence of rRT-PCR testing, might
reflect specimen collection before development of detectable
antibodies and does not rule out infection with the viruses for which
testing was performed

28. Zika : Pregnancy
 In addition to microcephaly, other problems have been detected
among fetuses and infants infected with Zika virus before birth, such
as eye defects, hearing loss, and impaired growth.
 Researchers are collecting data to better understand the extent Zika
virus impact on mothers and their children.
 Pregnant women with laboratory evidence of Zika virus infection
should be evaluated and managed for possible adverse pregnancy
outcomes and be reported to the U.S. Zika Pregnancy Registry or the
Puerto Rico Zika Active Pregnancy Surveillance System for clinical
follow-up

29. Prevention: Insect Repellents

30. Zika: Travel guidance in Pregnancy
 CDC recommends that pregnant women not travel to an area with
active Zika virus transmission.
 If a pregnant woman must travel to one of these areas, she should
talk to her healthcare provider.
 If she travels, she should be counseled to strictly follow steps to
avoid mosquito bites and prevent sexual transmission during the trip.

31. Zika:Transmission through Blood
Transfusions
 Zika virus currently poses a low risk to the blood supply in the
continental US
 Cases of Zika transmission through blood transfusion in Brazil. During
the previous French Polynesian Zika virus outbreak, 2.8% of blood
donors tested positive for Zika
 On August 26, 2016, the US Food and Drug Administration (FDA) issued
revised guidance to prevent the spread of Zika virus through the blood
supply. This new FDA guidance calls for blood collection centers in the
United States to screen all donated blood for Zika virus.

33. Additional resources:
 Centers for Disease Control and Prevention: http://www.cdc.gov/zika/
 About Zika: http://www.cdc.gov/zika/about/index.html
 Interim Guidance for Interpretation of Zika Virus Antibody Test Results (6/4/16):
http://www.cdc.gov/mmwr/volumes/65/wr/mm6521e1.htm
 CDC for Providers
 Interim Guidance for Healthcare Providers Caring for Pregnant Women with Possible Zika Virus
Exposure
 Clinical Guidance for Healthcare Providers Caring for Pregnant Women
 Clinical Guidance for Healthcare Providers Caring for Infants & Children
 MMWR, Interim Guidelines for Pregnant Women During a Zika Virus Outbreak — United States, 2016
 CDC Pregnancy Registry
 CDC Guidance for Travel and Testing of Pregnant Women and Women of Reproductive Age for Zika
Virus Infection Related to the Investigation for Local Mosquito-borne Zika Virus Transmission in
Miami-Dade and Broward Counties, Florida

34. Additional Resources:
 Division of Consolidated Laboratory Services (Virginia Department of General
Services)
 DCLS - Chikungunya, Dengue and Zika Virus Testing
 VDH Health Commissioner Zika Virus Update #4 (Aug. 1, 2016) Guide to
Interpreting Zika Virus Test Results Zika Virus Disease Information for
Clinicians Zika Checklist for Clinicians Chikungunya, Dengue and Zika Virus
Infections - Cheat Sheet for Healthcare Providers

35. THANK YOU