In the latest scientific developments with Zika virus, researchers from the United Kingdom reported new findings on evidence of Zika virus in semen, which they said could help guide evolving advice about sexual transmission of the disease.
Microcephaly findings aired at hearing
Speaking before the appropriation committee's Subcommittee on Labor, Health and Human Services, Education, and Related Agencies, Tom Frieden, MD, MPH, director of the Centers for Disease Control and Prevention (CDC), and Tony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), told legislators that the link between microcephaly and Zika virus isn't yet definitive but became much stronger with yesterday's publication of two studies that found the Zika virus genome in fetal brain tissue.
One study examined Zika virus in tissue samples from Brazilian babies with microcephaly who died after birth and from early-pregnancy miscarried fetuses. The other study detailed Zika virus in the brain tissue of a microcephalic fetus in a Slovenian woman who was sickened by Zika virus while volunteering in Brazil.
"With each passing day the link gets stronger," Frieden said, adding that CDC scientists are in Brazil and Colombia doing the type of case-control and cohort studies that would provide the strongest evidence to confirm the link.
Fauci added that he was struck by new evidence suggesting a neurotropic effect.
Senators ask about priorities
Several senators asked federal officials about funding priorities. Frieden said the main concern is pregnant women and their babies, as well as the threat to Puerto Rico's population. He said the territory is at risk for an explosive spread of Zika virus, based on patterns seen with two other diseases—dengue and chikungunya—carried by the same Aedes aegypti mosquito that spreads Zika virus.
Frieden said about 34,000 births a year occur in Puerto Rico, and the immediate priorities for pregnant women are personal and household protection, followed by vector control, which is very challenging.
Sen Patty Murray, D-Wash., raised concerns about erosion over the past several years in public health funding for vectorborne illness surveillance, which she said has led some states and localities to discontinue the practice.
Frieden said the nation currently has a patchwork system. "Surveillance isn't done as well as we'd like," he said, adding that $828 million of the CDC's funds in the administration's Zika emergency funding request is earmarked for vector control. Fauci added that mosquito control is an action that can be taken done immediately while waiting for vaccine development and testing.
Senators also grilled federal officials about whether the $1.8 billion in funding is enough, about their assessment of a need for regular public health emergency funding, and about whether any money already allocated to the Ebola response can be shifted toward the Zika threat. Frieden said the Ebola funds are fully committed to the ongoing Ebola response and to other global health security work to help detect the next threat, such as Zika virus.
"Ebola isn't over," he said, adding that about 100 CDC staff are still on the ground in West Africa and about 10,000 tests were done for the virus in the countries in January.
When the committee adjourned today it said it would take the funding up again at a hearing on Feb 18.
Fauci and Frieden also testified in Washington yesterday before a joint subcommittee of the House foreign affairs committee.
A call for more consistent public health funding
Ahead of today's hearing, Trust for America's Health (TFAH), a health advocacy group based in Washington, DC, issued a statement urging policy makers to go beyond the $1.8 billion request, drawing attention to the need for consistent funding for the US public health infrastructure.
Richard Hamburg, TFAH's interim president and chief executive officer, said in the statement, "We simply can't jump from one supplemental funding vehicle to another as a substitute for true public health capacity. There is a lot more the country could be doing to be better prepared for the range of threats we face."
The group also recommended that Congress members work with public health officials on science-based risk communication messaging, support advanced countermeasure development, build up domestic public health capacity, enhance all-hazards preparedness, and strengthen global health infrastructure.
Tests indicate Zika lingers on in semen
Tests on a 68-year-old British man who got sick 1 week after returning from a trip to the Cook Islands in 2014 were positive for Zika virus, and follow-up tests on blood, urine, and semen found evidence of Zika virus in semen at 27 and 62 days after fever onset. Researchers from Public Health England (PHE) reported the findings today in a letter in Emerging Infectious Diseases.
The man's illness was identified after the PHE implemented active Zika virus in the wake of French Polynesia's outbreak. During the acute phase of the man's illness his viral load was low, and researchers weren't able to obtain sequence data.
Tests on the man's semen samples suggested higher viral loads than his original blood tests. Researchers said though they didn't culture infectious virus from the semen, tests hint at its prolonged presence, which could point to a lingering potential for sexual transmission.
See also:
Feb 11 Senate hearing page
Feb 11 TFAH statement
Feb 11 Emerg Infect Dis letter
Feb 10 CIDRAP News story "WHO addresses Zika fears as more microcephaly findings surface"
