As warmer weather raises the possibility of local Zika virus transmission in the continental United States, federal health officials are pushing state and local governments to devise plans aimed at protecting pregnant women from infection, to increase access to contraception, and to ensure better coordination by mosquito control districts.
On April 1, the U.S. Centers for Disease Prevention and Control hosted a day-long seminar on Zika attended by some 300 state and local public health professionals. Zika virus, which is increasingly linked to adverse fetal outcomes including microcephaly, is now spreading in Puerto Rico, the U.S. Virgin Islands, and American Samoa.
Though most of the U.S. response effort is currently concentrated in Puerto Rico, and no local transmission has yet been reported in the continental U.S., a CDC report issued concurrently with the conference highlighted the potential for Zika transmission within the U.S. The entire southern half of the continental U.S., and much of its east coast, is home to the Aedes aegypti mosquitoes that can carry Zika virus.
In the same report, CDC also stressed that pregnant women should avoid travel to areas where Zika is being rapidly transmitted, and avoid sexual contact or consistently use condoms with partners who “reside in or have traveled to areas with active Zika virus transmission.”
“The key here is to reduce the risk to pregnant women,” Dr. Tom Frieden, CDC director, said at a news conference during the meeting. “There is an urgent need for all of us to learn more and do more,” he noted, acknowledging that officials had concerns about securing sufficient federal funding, getting rapid screening tools commercially developed in the absence of such funding, and improving the capabilities of U.S. mosquito control districts in the states most likely to be affected.
As local clusters of dengue virus disease have occurred in Florida, Texas, and Hawaii, Dr. Frieden said these states need to be particularly responsive to the Zika threat. However, Zika transmission could follow a different pattern, he said.
While Dr. Frieden described some local mosquito control districts and their capabilities as robust, others are considerably less so. Many districts in vulnerable states are not contiguous, leading to potential gaps in vector control. Dr. Frieden noted that even where control is most intensive, such as in Puerto Rico, vector resistance to common pesticides is a problem.
Dr. Frieden also stressed the importance of widening local access to contraception. He clarified that the CDC was not advising couples to avoid or delay pregnancy, even in Puerto Rico. However, he said, “if a woman and her partner choose not to become pregnant [there should be] ready access to effective contraception,” particularly the long-term reversible methods likely to be most effective.
Amy Pope, deputy homeland security advisor in the Obama administration, underscored the concern about Zika-specific funding. In February, the administration requested some $1.9 billion from Congress to combat Zika, including by improving access to contraception, developing vaccines and diagnostics, and other efforts. This funding has yet to be approved, Ms. Pope noted, adding that some members of Congress proposed redirecting funding that had been earmarked to combat Ebola.
“Congress is asking the American people to choose which disease it wants the most protection from,” Ms. Pope said, and Dr. Frieden reminded the conference that the Ebola crisis was not over. A new case from Liberia was announced April 1, he noted, and an ongoing cluster of transmission is occurring in Guinea.