(Salt Lake City, UT) – Utah health officials today updated their progress on a months-long investigation into a unique case of Zika virus discovered in the state in July. The case was unique because the individual had no known risk factors for Zika virus, had not traveled to an area with Zika transmission and had no sexual contact with a person with Zika virus.
However, health officials were able to determine the person helped provide care to another patient who was infected with Zika virus. This other patient, who subsequently passed away, was infected with an unusually high amount of virus, approximately 100,000 times higher than an average infection.
The investigation was a collaborative effort of the Utah Department of Health (UDOH), Salt Lake County Health Department (SLCoHD), Davis County Health Department, University of Utah Health Care, U.S. Centers for Disease Control and Prevention (CDC), and local Mosquito Abatement Districts.
To date, as part of the investigation, public health officials have tested more than 200 people for Zika virus. These individuals included family contacts of both cases, health care workers who cared for the deceased patient, and members of the general public who lived near both of the cases. No additional cases of Zika virus have been identified as part of the investigation.
Local Mosquito Abatement Districts, working with the CDC, also trapped and tested mosquitoes around the homes of both cases. No mosquitoes from the two invasive species (Aedes aegypti or Aedes albopictus) known to carry Zika virus were found during the investigation.
“An important part of any public health investigation is working to identify additional cases of disease,” said Dr. Angela Dunn, deputy state epidemiologist for the UDOH. “Finding new cases can help lead us to answers during an investigation, and while we’re happy nobody else was infected, the lack of additional cases leaves many questions unanswered.”
The investigation has not been able to definitively identify how the case was infected. More than 2,900 cases of Zika have been identified in the continental United States and Hawaii and this is the only case that has an unknown mode of transmission.
“This investigation will remain active, and we will continue working to learn more about Zika virus and how it may be spread,” said Dr. Dagmar Vitek, medical director from the SLCoHD. “People should continue to take the appropriate steps to prevent Zika virus infection – especially pregnant women, and health care workers who are caring for severely ill patients with the disease.”
The Utah investigation was highlighted in this week’s MMWR report, a weekly publication issued by CDC that addresses public health information and recommendations. More tips on Zika prevention are available at http://health.utah.gov/epi/diseases/zika/.
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Utah Department of Health