Which came first: high Zika viral load or a diminished immune system? This is a question that epidemiologists and medical experts from the Centers for Disease Control and Prevention are pondering in regards to the recent case of Zika identified in Salt Lake City, Utah that may have resulted in the individual's death.
Just last week a Utah resident was reported
to have died with a Zika infection in June. The CDC confirmed
that the male patient presented with a “unique situation”: an unusually elevated Zika blood viral load (100,000 times higher than any other sampled Zika patients). In what CDC experts called a “chicken or egg” investigation, it was noted that it is still unclear whether the elderly patient died from the Zika infection or from other underlying comorbidities. Thus, the CDC is conducting a “thorough review” to understand the clinical course of the deceased patient’s underlying comorbidities to uncover whether the high viral load contributed to the patient’s death, or if the patient’s comorbidities left him immunocompromised, which lead to the high viral load.
Now, a family member of the deceased patient has tested positive for the Zika virus. The individual experienced mild symptoms associated with a Zika infection, and a rapid recovery, as is the “typical clinical course” of the virus. At the moment there is no clear evidence as to how the patient became infected.
Although the primary mode of transmission of the Zika virus remains the bite of an infected female Aedes aegypti
mosquito, the virus has also been identified in contaminated saliva, blood, semen, and urine.
The CDC has dispatched an Emergency Response Team (CERT), including infection control, virology, mosquito control, disease investigation and health communications experts, to work in conjunction with the Utah Department of Health to help investigate this “unusual” case of Zika transmission. CERT will be conducting interviews with other family members of the deceased patient as well as healthcare workers who may have come in contact with him. In addition, although Utah does not harbor any of the Zika mosquito vectors (Ae. aegypti
and Aedes albopictus
), the team will be collecting local mosquitos for viral testing.
During a briefing, CDC experts confirmed that nothing can be truly ruled out in terms of modes of viral transmission. However, they believe that two scenarios are “extremely unlikely”: Zika is an airborne virus; other mosquito populations within this particular area have become Zika vectors. It was confirmed that, thus far, there has been no clinical evidence of Zika transmission through casual contact, sneezing, or coughing. Nonetheless, Michael Bell, MD, deputy director of the Division of Healthcare Quality Promotion, confirmed that the CDC is currently meticulously assessing the situation to see if any other mode of transmission is possible. Although the recently identified patient is a family member of the deceased, it is not impossible that this patient could have acquired a Zika infection through other means.
Throughout the briefing, CDC experts continuously stressed the importance of pregnant women and women who wish to become pregnant taking measures of precaution to avoid Zika infection, as the virus is confirmed to cause neurological complications to the fetus during pregnancy and at birth. Furthermore, correct and consistent use of condoms is advised to those who wish to avoid infection with Zika.
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