Alarmed by the rapid spread of the Zika virus across the Americas, experts gathered at UC San Francisco to explore the many issues raised by the epidemic and to share information with other researchers and health care providers.
With scientists around the world scrambling for information about what was until recently an obscure virus, UCSF Global Health Sciences and UCSF Benioff Children’s Hospitals hosted the symposium, called “Preparedness for the Zika Virus: A Public Health Emergency,” on March 7 to help focus the research agenda. The symposium speakers addressed several topics around Zika, from how the virus may be crossing the placenta and infecting neural stem cells, to how the tragic emergence of apparently related birth defects could change attitudes toward contraception and abortion in Latin America.
“The impact of this is felt in areas around globe that are far less equipped than we are to handle such a devastating infection,” said UCSF Chancellor Sam Hawgood, MBBS, who is also chair of UCSF Health, in opening remarks. “In addition to thinking about our own local preparedness, it is imperative to think about what kind of contribution UCSF and the other institutions represented here can make to the larger global scale of this public health emergency.”
Recent Outbreaks and Birth Defects
The Zika virus is carried by the Aedes aegypti mosquito, which is found throughout much of Latin America and now also much of North America, and the recent outbreak has occurred across a vast swath of territory from Brazil to the Caribbean, including Puerto Rico. Affected countries are seeing an increase in birth defects like microcephaly and rare neurological conditions like Guillain-Barré syndrome, an autoimmune response that can result in severe temporary paralysis and also death.
While infection with Zika virus is usually mild and as many as 80 percent of cases may be asymptomatic, the sudden emergence of birth defects and neurological conditions have brought new urgency to the study of the disease.
“The Zika virus seems to be a pregnant woman’s worst nightmare,” said Kirsten Salmeen, MD, an assistant professor of Obstetrics, Gynecology and Reproductive Sciences. Infection might not be diagnosed until the third trimester, women cannot necessarily avoid it and they potentially do not know if they have been exposed to it. “Women across the world are terrified of this problem, and we really have no clinical care to ameliorate the effects of Zika virus in pregnancy.”
Further complicating the outcomes of a Zika virus infection during pregnancy, microcephaly may just be the tip of the iceberg of the spectrum of brain, eye and other malformations that the infection may be causing in fetuses, said Margaret Feeney, MD, chief of the Division of Pediatric Infectious Diseases and Global Health at UCSF Benioff Children's Hospital San Francisco. She noted that recent evidence has documented infections in women late in their pregnancies that resulted in many abnormalities, including fetal death, indicating that the fetus could be vulnerable to Zika infection throughout pregnancy.
Positive News About Battling Zika Virus
The UCSF Zika symposium’s transdiciplinary presentations yielded a mixture of good news and bad news, concluded UCSF Global Health Sciences Executive Director Jaime Sepúlveda, MD, MPH, DSc, who organized the symposium with Hawgood.
The good news is that researchers may be getting closer to understanding the basic biology of how Zika virus might cause microcephaly. Postdoctoral scholar Alex Pollen, PhD, presented findings that help to solidify the connection between Zika and microcephaly, as well as ocular defects. His group identified a receptor that may allow Zika to damage developing brain and eye tissue. It is the same receptor that the virus uses to cause a rash on the skin, one of the telltale signs of Zika infection.
Susan Fisher, PhD, professor of Obstetrics, Gynecology and Reproductive Sciences, presented data showing that this same receptor is also found on the placenta and in the uterus, and that there are many possible ways for the virus to get from the mother to her developing baby. “We think in a way this is a perfect storm where the placenta has the architecture, both physically and molecularly, to transmit this virus,” she said.
Charles Chiu, MD, PhD, associate professor of Laboratory Medicine, is planning to train microbiologists from Barbados, Brazil and elsewhere in how to use ultra-rapid metagenomic sequencing to diagnose emerging infections like Zika, using a USB-powered handheld device and a laptop computer. The new technology, developed by Oxford Nanopore, can detect any pathogen – even something that has never been seen before – by analyzing all the DNA in a sample – both from the host and the pathogen – in a matter of minutes with portable equipment that can easily be used in the field.
Zika and the Bay Area
Sepúlveda also pointed out that, despite the crisis elsewhere, Bay Area residents should not panic about Zika. While the Aedes mosquito has been found in California, including a few Bay Area counties, it does not yet, as far as anyone knows, carry the virus. And even if mosquitoes did get infected, the virus would be unlikely to spread here. Temperatures are too cool for the mosquito to thrive in the Bay Area, and modern amenities and a reliable public health system are strong barriers against the spread of the virus throughout California and the rest of the continental United States.
In the clinic, physicians can reassure pregnant women living in the Bay Area that they are at very low risk of contracting the disease.
Still, there already have been several imported cases of Zika virus in the Bay Area among people who had traveled to the affected region, and Sepúlveda warned there will be more: “We have 40 million Americans traveling to Zika-endemic countries, and that poses a risk for imported cases,” he said at a press conference.
Adrienne Green, MD, associate chief medical officer at UCSF Medical Center, said that, particularly after the extensive preparations undertaken during the Ebola epidemic, UC Health has a well-coordinated response to Zika and other emerging threats. “We have a great group of operational and clinical leaders who are able to respond quickly to whatever situation comes up in a way that ensures that our patients are safe and our community is safe.”
Difficult News About Fighting Zika Worldwide
But Zika is still is a little-studied pathogen that may be causing severe lifelong disabilities for a generation of babies born during the epidemic, and it continues to spread rapidly.
“Pandemics are the global health issue with the biggest mismatch between, on the one hand, the level of risk and the magnitude of the consequences, which is huge; and, on the other hand, the level of investment and the state of preparedness, which is somewhere on the scale of modest to pathetic right now,” said Richard Feachem, DSc, PhD, director of the Global Health Group at UCSF Global Health Sciences.
Sepúlveda said the whole point of the symposium was to create dialogue about the virus between researchers, academic institutions and health providers.
“In public health emergencies, it is a fine line between creating awareness and creating panic in the public,” said Sepúlveda. “We need to avoid the latter while being fully prepared.”
This article was originally written by by Mitzi Baker and published by UCSF.