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

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.

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).

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.

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 . . . .

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.

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.

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

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

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.

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

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

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

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

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)

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

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