This article is more than 5 years old. Information may no longer be current.
Limited resources for Zika response slow progress in Puerto Rico
Click Here to Manage Email Alerts
After traveling to Puerto Rico to assess the ongoing Zika virus outbreak, CDC Director Thomas R. Frieden, MD, MPH, stressed that more funding and research are needed to reach the CDC’s goal of protecting as many pregnant women at risk for Zika virus infection as possible.
“Puerto Rico is on the front lines of the battle against Zika, and it is an uphill battle,” Frieden said during a teleconference. “I’m very concerned that before the year is out, there could be hundreds of thousands of infections in Puerto Rico, and thousands of infected pregnant women.”
Thomas R. Frieden
Puerto Rico has reported approximately 160 locally acquired Zika virus infections to date, and the number of infections is expected to dramatically increase, according to Frieden. To mitigate the outbreak, the CDC and its partners have employed more than 750 staff members who are dedicated to the Zika response, including nearly 100 people stationed in Puerto Rico. As part of the response, health officials accelerated efforts in Zika diagnostics and implemented interventions such as the distribution of Zika prevention kits, which include insect repellent, condoms, and information on how pregnant women can reduce their risk for infection. Additional efforts to provide screens and air conditioning to Puerto Rican communities, and contraceptives to women who do not want to become pregnant also are underway, Frieden said.
“Most of the pregnancies in Puerto Rico are unplanned, unintended, and there is an unmet need for contraception,” Frieden said. “We met with the providers and are working to address that need, emphasizing that whether or not to become pregnant is a decision for the woman to make in consultation with their partner, their family and their provider. But for those women who choose contraception, it should be readily available.”
CDC investigates mosquito control
While protecting pregnant women from acquiring Zika virus is the CDC’s first priority, the agency’s second goal is to increase mosquito control measures, which is difficult due to widespread resistance to pyrethroid insecticides, Frieden said. Health officials in Puerto Rico have launched studies to determine the extent and geographic variability of insecticide resistance. The results are expected to be released in 2 weeks.
“We are concerned about the degree of permethrin resistance we’re seeing,” Frieden said. “We’re sampling 19 different areas in Puerto Rico and testing nine different pyrethroid compounds. So far, we have seen at least one that looks promising, but we only tested four areas so far.”
In addition to insecticides, Frieden said the CDC is open to other technologies, including genetically modified mosquitoes. He warned, however, that several challenges with the technology may limit their impact. These include the short lifespan of the Aedes aegypti vector, which only travels about 200 yards in its lifetime.
“In the next few months, it would be difficult to see a large-scale impact of those new technologies in Puerto Rico, although we’re certainly very supportive of efforts to look into them and to explore that with communities and the government there,” he said. “While they’re promising technologies that we absolutely need to pursue, I think we also have to be realistic about what the impact during this mosquito season is likely to be.”
Additional funding warranted
As more evidence continues to strengthen the link of Zika virus infection with microcephaly and Guillain-Barré syndrome (GBS), as well as the risk for Zika transmission through sexual contact, Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said additional research funding is needed to answer “important” questions regarding Zika, including the differences between symptomatic and asymptomatic infection, the impact of infection during pregnancy on fetuses and the how long the virus is present in semen.
Anthony S. Fauci
“There are unanswered questions,” Fauci said during the teleconference. “As the weeks and months go by, we learn more and more and realize how much we don’t know. Unfortunately, the more we learn, the worse things seem to get.”
He added that recent findings published in the New England Journal of Medicine, which demonstrated that abnormalities were detected in 29% of fetuses of patients infected with Zika, were “disturbing”, and emphasized the need for natural history studies to assess the long-term outcomes of fetuses exposed to Zika virus infection.
“You may see things after infants are born involving … visual impairment, if not blindness, hearing abnormalities and developmental retardation,” Fauci said. “If 29% [of abnormalities are] clearly identifiable by an ultrasound, you can be almost certain that there’s going to be a definite additive percentage.”
Research funds also need to be allocated to vaccine development, according to Fauci. NIAID researchers continue to investigate inactivated Zika vaccines aimed at preventing infection in pregnant women and activated vaccines, which may eventually be used in women before they reach child-bearing age. A phase 1 trial evaluating the safety and immunogenicity of a vaccine candidate is slated for the end of the summer or early fall, with results expected to be released in early 2017, Fauci said.
Without funds for Zika vaccines, other areas of research at the CDC and NIAID are put on hold. For example, Fauci said that current research efforts for a universal influenza vaccine, an HIV vaccine and a respiratory syncytial virus vaccine at the NIAID may need to be decelerated in order to distribute funds to investigate the Zika vaccine.
“We have a limited amount of resources,” he said. “There’s a net sum there and you just can’t make it more than it is if you don’t have more resources, so something either has to slow down or stop.”
At the CDC, Frieden said research efforts including those for dengue and new tick-borne viruses discovered in the continental United States are at a standstill due to the intense Zika response.
“Much of the work that we do on drug resistance and other areas is having to take a backseat to Zika,” Frieden said. – by Stephanie Viguers