An update from federal officials today on Puerto Rico's Zika virus outbreak and the status of government's response, including vaccine development and the scaling up of mosquito control efforts, came with strong pleas for Congress to act on President Obama's $1.9 billion emergency funding request.
Officials also aired concerns about implications of recent studies on the association between Zika and serious complications.
The Obama administration announced on Feb 8 that it would seek $1.8 billion in emergency Zika funding and made a formal request for $1.9 billion on Feb 22. Congressional committees have held several hearings on the request and the government's response efforts, but so far there is no sign that the measure is moving forward.
Some members of Congress are insisting that unspent Ebola funds be used to cover the Zika request, but federal officials have said that some of that money is needed to satisfy Ebola response commitments and that leftover funds wouldn't be adequate to fully support the Zika epidemic response.
Mosquito challenges in Puerto Rico
CDC Director Tom Frieden, MD, MPH, just back from visiting Puerto Rico to assess its Zika virus response. He said at a media briefing today that the territory faces an uphill battle, with the rainy season just around the corner, an event that could bring an explosive increase in Zika cases, as well as dengue and chikungunya.
He added, however, that he's encouraged by the progress and actions that are under way there.
Over the past few months the CDC has warned that the US territory faces the prospect of hundreds of thousands of Zika virus cases. Frieden said 100 CDC responders are in Puerto Rico, and the agency has 750 staffers working on the Zika virus response.
One of the CDC's tasks in Puerto Rico, which Frieden observed firsthand, is defining which insecticides are most effective. A report from STAT News today, which cited CDC entomology experts, said Aedes mosquitoes in Puerto Rico and some parts of Mexico are resistant to permethrin. The CDC recommends clothing or apparel treated with the insecticide as a Zika prevention step for travelers.
Mosquito sampling is under way in 19 areas of Puerto Rico, and studies to gauge insecticide effectiveness will take another week or two to complete, Frieden said. So far it appears that resistance can vary, even within a small geographic area.
He said mosquito control will require a multipronged effort to protect pregnant women, adding that its not easy to implement even measures that on the surface seem straightforward, such as adding more screens to houses. Frieden said there's no magic bullet to battling the Aedes mosquitoes that carry the disease, though health officials may consider trying some of the new technologies.
The need for funding is critical for planning large-scale mosquito control efforts and responding to illness clusters, Frieden said. The CDC is scraping together all the money it can, which poses administrative challenges pulling together funding from different sources, he added. "We hope Congress will provide resources for a robust response."
Vaccine and diagnostic test developments
Tony Fauci, MD, director of the National Institute for Allergy and Infectious Diseases (NIAID), the arm of the government leading Zika vaccine development, echoed Frieden's pleas for emergency funding and said work on a vaccine will be hobbled without sustained resources.
Aside from the vaccine, much more research is needed about the virus itself and its clinical impact, Fauci said, noting that the latest research showing a strong connection to complications such as microcephaly in babies is raising more worrisome questions about the possibility of long-term effects of maternal Zika infection, even in babies who appear to have no problems at birth.
"The more we learn, the worse things seem to get," Fauci said, adding that a recent cohort study from Brazil, published last week in the New England Journal of Medicine, hints at a range of fetal development complications no matter what stage the mother was infected.
He said the DNA vaccine that NIAID scientists and their collaborators are working on fits the inactivated vaccine profile mentioned yesterday by a World Health Organization group of experts as a top priority for protecting childbearing-aged women, including pregnant ones. Fauci said, however, that it's important to develop other types of Zika vaccines, such as live-attenuated products that would be given to women before they hit childbearing age, similar to the immunization strategy for rubella—another virus that can cause birth defects.
NIAID scientists have the resources they need to launch a phase 1 study to test the safety of the DNA vaccine, but without emergency funding from Congress, researchers may not be able to prepare for a phase 2 study, Fauci said. He also said the funding gap could slow work on vaccine work currently under way for other diseases, such as HIV.
Tenuous support is also known to have a chilling effect on pharmaceutical companies looking to partner with the federal government on vaccine development, Fauci said. "Uncertainty about funding brands us as an unreliable partner," he said.
"We're not alarmist, but we need to step up to the plate," Fauci said of the need for emergency funds.
Regarding diagnostic tests, Frieden said CDC scientists are in the final stages of developing a new polymerase chain reaction (PCR) test that can distinguish between three common flaviviruses: dengue, chickungunya, and Zika. The test is a multiplex one and was mentioned yesterday by the WHO as a top Zika countermeasure priority.
So far the CDC has rolled out to labs in the United States and other countries 500,000 RT-PCR tests to assess for acute Zika infections, Frieden said.
Brazil's microcephaly totals grow
In related news, Brazil's health ministry said yesterday in its weekly update that it has received 249 more reports of suspected microcephaly but has ruled out 134 earlier ones, leaving the number under investigation at 4,231, according to a statement translated and posted by Avian Flu Diary, an infectious disease news blog.
Microcephaly, which manifests as babies born with smaller-than- normal heads and a constellation of other cerebral problems, is a strongly suspected complication of maternal infections.
The health ministry said since last week it has confirmed 104 more microcephaly cases, putting that total at 745. Over the span of Brazil's outbreak the country has reported 6,158 suspected cases and has ruled 1,182 of them.
See also:
Mar 10 STAT News story
Mar 9 Avian Flu Diary post
