Indiana University experts comment on risk posed by Zika virus

  • Feb. 2, 2016


BLOOMINGTON, Ind. -- The World Health Organization this week designated the Zika virus a public health emergency of international concern, paving the way for more funding and manpower to fight the mosquito-borne pathogen.

The virus, which was first identified more than 50 years ago, has alarmed health officials because of its possible association with microcephaly, a brain defect in newborns. The WHO estimates it will infect up to 4 million people this year.

Indiana University experts share the following perspectives.

Risk area could expand in the future

Robert C. Reiner Jr., an assistant professor in the IU School of Public Health-Bloomington, studies the spread of mosquito-borne illnesses, including Zika.

He said the mosquitoes that transmit the virus -- the yellow fever mosquito, or Aedes aegypti, and the tiger mosquito, or Aedes albopictus -- have recently expanded their range to include much of the southern United States. And while a Zika outbreak in the U.S. is unlikely at this time, the spread of the disease bears watching.

“It’s not a risk today,” he said, “but five years from now it could become a bigger risk if the mosquitoes continue to establish a larger range.”

Reiner said Zika has not been well-studied compared to better-known illnesses transmitted by the same species of mosquitoes, such as dengue and yellow fever. While researchers are working to develop vaccines, he said, the immediate way to limit Zika’s spread is to focus on mosquito populations.

“What is needed is more mosquito control and educating people on preventative methods such as removing items that can collect water and harbor mosquito larvae,” he said.

Reporters may reach Reiner by email at

Most infections produce no symptoms

John C. Christenson, professor of clinical pediatrics at the IU School of Medicine, said U.S. residents who travel to tropical regions of Latin America and the Pacific should be concerned about contracting the virus, but there is “no concern here in Indiana” at this time.

“About 80 percent of persons who are infected with Zika will have no symptoms,” said Christenson, who is also chief of clinical services at the Ryan White Center for Pediatric Infectious Disease and Global Health. “Most others will have an illness that resolves itself without treatment consisting of fever, joint pains, rash, conjunctivitis and malaise.”

Concern about the virus focuses on its association with microcephaly in newborns and, in rare cases, with Guillain-Barre syndrome, a neurological condition that causes muscle weakness. Christenson said researchers are conducting studies to clarify the link between the virus and microcephaly, but it’s likely to take several months to reach conclusions.

To speak with Christenson, contact Eric Schoch at 317-274-8205 or

Public health infrastructure could check spread of infection

Richard Hardy, a professor of biology in the College of Arts and Sciences at IU Bloomington who studies viral replication and virus-host interactions, said the range of one of the mosquitoes that transmit Zika, the tiger mosquito, extends from the Gulf Coast north to Illinois, Indiana and Ohio, and from the Eastern Seaboard west to Texas and the southern Plains states.

“This potentially places a huge proportion of the U.S. population at risk if the virus is introduced and begins to circulate,” he said. However, it’s important to note that the same mosquitoes can transmit other viral diseases that have not materialized in the U.S.

“Widespread dengue virus transmission has been feared for years and has not materialized,” Hardy said. “While isolated cases of Zika may occur in the U.S. in coming years, it is likely to be held in check due to the public health infrastructure and interventions available.”

To speak with Hardy, contact Kevin Fryling at 812-856-2988 or

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Robert C. Reiner Jr.

Robert C. Reiner Jr.

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John Christenson

John Christenson

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Richard Hardy

Richard Hardy

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Media Contacts

April Toler

Eric Schoch

Kevin Fryling