You are here
‘Lab Strain’ Hinders Zika Detection in U.S.
In areas of the United States where the Zika virus poses a threat, public health departments are struggling to meet the need to test patients for the mosquito-borne virus––even for those the government has classified as “at risk,” according to a report from Kaiser Health News (KHN).
Doctors and health experts say last month’s approval of $1.1 billion in emergency funding by Congress—a spending package to fight the virus—could help, giving local laboratories the resources to determine whether people have been infected.
Specifically, Congress directed $394 million to the Centers for Disease Control and Prevention (CDC), the bulk of which will support state and local Zika response efforts, such as mosquito-control and emergency response teams; public education campaigns; efforts to improve diagnostic tests; and research to track how the virus affects children long-term. That includes money for expanding lab capacity—although it is unclear exactly how much of those resources will be used for lab improvements. The U.S. Department of Health and Human Services (HHS), which includes the CDC, has until the end of October to craft a spending plan.
But the additional federal funding will not be an immediate fix. Given how long processing and budgeting can take, public health labs aren’t expecting the cash infusion until early 2017, Peter Kyriacopoulos, senior director of public policy at the Association of Public Health Laboratories, told KHN.
While the congressional funding is a promising start, more investment is necessary, added Chris Gould, senior director for federal government relations at the Association of State and Territorial Health Officials. Local health departments have been shrinking over the past six years, according to Gould. Many don’t have staffs large enough to operate labs at the level needed, given the volume of samples coming in. They need to expand manpower, especially since testing for Zika isn’t their only responsibility, he said.
Kyriacopoulos estimates that labs would need approximately $39 million to adequately meet these challenges. And public health experts expect the virus to return next summer, he said, which could create a need for further funding down the road.
Meanwhile, the CDC has tried to alleviate some lab strain. Last month, it purchased $2.5 million worth of diagnostic supplies for states offering lab testing. And labs have been working on their own to try to expand capacity—especially those serving areas such as Florida, Texas, and California, where the warmer, mosquito-friendly climate heightens the risk that Zika could spread.
Still, local health departments offering Zika testing remain “understaffed and overwhelmed,” said Dr. Martha Rac, a maternal-fetal medicine specialist at Texas Children’s Pavilion for Women and Baylor College of Medicine in Houston.
The burden doesn’t fall evenly, she noted. In urban centers such as Houston, women who may have been infected are more likely to get a Zika test than are those from a poorer, rural town in south Texas. There, the public health clinics or lab systems may not be so well-resourced, so women have fewer options.
“We’re not there yet when it comes to turnaround and capacity,” said Dr. Umair Shah, executive director of the public health department in Texas’ Harris County, which encompasses Houston. The backlog, he said, makes it harder for women in particular to get the medical counseling they need in an appropriate timeframe.
Predicting future need is also tricky. States have been encouraging pregnant women to get tested for Zika, along with men who may have been exposed and are showing the virus’ flu-like symptoms. But that leaves out other groups, such as asymptomatic men who may have contracted Zika and could pass it on to female partners. If states start to push for that testing as well, it could exacerbate lab strain.
Moreover, it’s difficult to gauge whether demand will dip in the coming months. Technically, mosquito season peaks in the summer. But in high-risk states, such as Florida and Texas, the mosquitoes carrying Zika virus can persist into December and even January, Shah said.
Beyond lab capacity, HHS is also planning to invest some of its new Zika funding in developing better tests to detect the virus. Currently, labs use one test to detect the virus within two weeks of exposure, and another that will find it for up to three months. But the second test—which is more commonly used—is less precise and can, for instance, detect false positives if someone has been exposed to other, similar infections.
In addition, the federal government intends to use some of its funding to support trials for new, better diagnostics. That investment is crucial, Rac said, especially given the magnitude of the threat that Zika poses.
“There’s still a lot we need to figure out,” she said. “And who knows what’s going to happen? … This mosquito is pretty resilient to destruction. This is something we’re going to see for some time.”
Source: Kaiser Health News; October 7, 2016.