1. Utah Zika investigation, July 2016
Angela C. Dunn, MD MPH
CSTE All State Epi Call
26 September 2016

2. Patient A
In July 2016, public health was notified of a new Zika case. Upon interview, this case did not have any of the known risk factors for Zika. Namely, he hadn’t travelled to an area with ongoing Zika transmission nor had he had sexual contact with anyone who had travelled or was infected with Zika. However, he had cared for a family contact who had died from Zika at the end of June, the index patient.

3. Index Patient Male in his 70s Contracted Zika abroad
Returned on June 14
Symptoms started on June 17
Died June 25
Fever, joint pain, diarrhea, thrombocytopenia
Dengue Shock Syndrome
Positive Zika
Viral load 100,000 x higher than average
First Zika related death in the continental U.S.
Symptoms: abdominal pain, fevers, SOB, diarrhea, chest pain, musculoskeletal pain with bending and walking
Infectious diseases workup included negative blood cultures on June 19 and 22.
A blood specimen obtained on the day of his death was sent to a commercial laboratory for dengue virus testing. The sample was RT-PCR negative but was positive for dengue IgM and IgG antibodies at 2.04 and 7.95, respectively (positive greater than 1.64).
Subsequent testing for Zika virus, identified Zika viral RNA by RT-PCR testing with a low CT value (16 at the state laboratory and 20 at CDC).

4. Objectives
Assess the potential of nonsexual person-to-person transmission among family contacts and healthcare workers
Evaluate the potential of environmental transmission
An investigation was launched to determine how patient A contracted Zika. The 2 objectives of the investigation were…..
A CDC team of approximately 10 people came to Utah to assist with the investigation.

5. Methods Epidemiologic investigation Healthcare worker assessment
Assessment of vector-borne transmission
Vector surveillance
Community survey
In order to fulfill our objectives, we had 3 main parts to our investigation

6. Epidemiologic Investigation
Interviewed 19 family contacts and collected specimens for testing
Travel history, exposure to mosquitos, exposure to bodily fluids, contact with index case
We interviewed 19 family contacts all of whom visited the index case in the ICU, attended the viewing/funeral of index case, or lived with the index case.

7. Family Contacts
All were negative except for Patient A. Patient A did not have any unique exposures or medical history that would make him at grater risk than the others.

8. Healthcare Worker (HCW) Assessment
Objectives
Assessment
Identify Zika transmission among HCWs with direct patient care
Determine types of patient care associated with transmission
Seroprevalence survey with matched cohort
Reviewed infection control practices

9. Matched Cohort Exposed HCW Non-Exposed Controls
A healthcare personnel who had substantial contact with the index case or the index case’s bodily fluids
Healthcare personnel who did not have contact with the index case or the index case’s bodily fluids
Matched based on job title and similar work locations
Healthcare personnel included nurses, physicians, pharmacists, phlebotomists, radiology technicians, nursing assistants, laboratories, and environmental services staff
Controls were selected to provide a background rate of recent zika infection

10. HCW Identification and Classification
Reviewed index case’s medical records
Compiled list of potentially exposed
Employees and managers notified
Detailed questionnaire
Tested:
High risk contact
Pregnant
Attempting to become pregnant
Symptomatic
Hospital took the lead on this through their Work Wellness Center
Information that was collected included type of contact, type of care provided, exposure to blood or body fluids, and use of personal protective equipment (PPE) during care. We also collected relevant information on the employee's history, including recent travel, vaccinations, and pregnancy status.
reporting any two of the following symptoms fever, rash, arthralgia, or conjunctivitis.

11. HCW Assessment Results
132 potentially exposed
98 interviewed
20 not exposed
14 unable to reach
80 blood drawn
12 did not meet criteria
3 no shows
3 declined
All negative

12. HCW Assessment Results
113 controls
111 tested
2 unable to draw
All negative

13. Vector Surveillance
Mosquitoes trapped in 3 locations: 2 neighborhoods where index case visited and 1 neighborhood where Patient A lived
Mosquitoes collected using variety of trapping methods
698 specimens tested for Zika
Culex pipiens (50.7%)
Culex tarsalis (38.4%)
No invasive Aedes species detected

14. Community Survey Two neighborhoods where the index case spent time
Within a 200m radius of residences
Knocked on doors to survey residents on exposure to mosquitoes and draw blood samples
Urine was collected from recently symptomatic residents

15. Community Survey Results
235 households visited
87 (39%) had one resident complete a survey
209 individuals completed questionnaires
123/209 (59%) provided as sample
121 blood samples (negative)
8 urine samples (negative)

16. Conclusions
No other Zika cases identified as part of this investigation
No evidence of vector-borne spread
Unclear how Patient A was infected
Continue to recommend standard precautions to HCWs
Caregivers should be aware that Zika may be spread through bodily fluids

17. Questions?