Zika: ‘More Virulent and Dangerous’ Than Thought

Unusual new form of transmission is confirmed

There are still many unanswered questions in the case of a Utah man who contracted the Zika virus from his infected father. But what scientists now believe is that the otherwise healthy 38-year-old got it from touching his dad’s tears or sweat with his bare hands while helping nurses care for him in the hospital.

Research unveiled Wednesday by University of Utah doctors and reported in the New England Journal of Medicine found the unusual transmission method was likely caused by the older man’s extremely severe infection — 100,000 times the normal level of the virus.

Those who are not severely immunocompromised or chronically ill may still be at risk for fatal infection.

“That’s shocking and upsetting to read,” said Dr. David Gortler, a pharmacology expert, drug safety expert, and Food and Drug Administration policy expert at

“It’s not uncommon for other viruses to be spread by bodily fluids containing infectious components — other viruses like influenza and the common cold are transmitted by ‘droplet transmission,’ which means that they are airborne in particles of water when one exhales or sneezes,” Gortler told LifeZette. “This just goes to show that the Zika virus is probably more virulent and dangerous than we realize. The possibility exists that there are different strains of the Zika virus as well.”

What remains a mystery, however, is why the father’s levels were so high or why the son contracted the virus in a way not documented anywhere else.

The father, 73, had been receiving radiation and anti-androgen therapies for prostate cancer before his death in June. Researchers speculate his compromised immune system may have made it easier for the virus to replicate. He became ill after returning from a three-week trip to the southwest coast of Mexico — and died after only four days in the hospital, the report stated.

His son, a healthy 38-year-old who was not on the trip, became sick five days after visiting his father in the hospital. After recovering, he told doctors he had helped nurses care for his father, including wiping his eyes without gloves.

[lz_bulleted_list title=”Zika Virus in U.S.” source=”, as of 9.28.16″]U.S. States and D.C.,  3,625 confirmed|U.S. Territories, 22,069[/lz_bulleted_list]

None of the nurses or doctors who treated the older man became sick, nor did other family members; and there are no Zika-infected bugs so far found in Utah. Typically, Zika is spread through either mosquito bite or sexual activity with an infected person. (The 38-year-old did not have sexual contact with anyone who had traveled to a Zika-infected area.)

The cases, researchers state, illustrate some important points. First, “the spectrum of those at risk for Zika infection may be broader than previously recognized, and those who are not severely immunocompromised or chronically ill may nevertheless be at risk for fatal infection.”

Second, “the transmission of flaviviruses through intact skin or mucous membranes, although uncommon, has been shown in experimental animal models and in at least one human case. Whether contact with highly infectious body fluids from patients with severe [Zika virus] infection poses an increased risk of transmission is an important question that requires further research.”

It’s key for experts to understand how this older man’s case became so severe, Dr. Amesh Adalja, a board-certified infectious disease physician at the University of Pittsburgh, said. “His pre-existing antibodies to dengue may have served to amplify the Zika infection and there are several lines of converging evidence suggesting this could be a factor in severe Zika cases.”

Related: Zika Virus Can Live in Your Eyes

It also appears, added Adalja, that “based upon what occurred in Utah, those few individuals with extremely high levels of Zika in their blood and body fluids do have the capacity to transmit the virus in this manner.”

Even more upsetting, Gortler added, is this: “If this 73-year-old patient was bitten by another mosquito while here in the United States while he was infected, and that mosquito later laid eggs, those mosquito offspring have the potential to also be positive for the Zika virus.”

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While this opens up an entirely new set of concerns for the spread of Zika, the most important thing for the public to understand, said Adalja, is that deaths due to Zika are still very rare.

Still, “as diagnostic capacity increases, there will be many reports of emerging infectious diseases, including those that are mosquito-borne. In order to guard against these diseases, we must be very aggressive with mosquito control and use all tools at our hands,” said Adalja.

Congress approved a funding measure late Wednesday night to avoid a government shutdown at the end of the week. Included in that bill are desperately needed funds — $1.1 billion to further research, disease detection, effective mosquito-control measures, and outreach to combat the Zika virus.