UC Davis Zika Symposium: A Crucial Message

Biochemistry student Christian Wirawan introduces chemical ecologist Walter Leal, the first speaker. Wirawan was among the 18 student organizers. (Photo by Kathy Keatley Garvey)

The unique symposium, the work of chemical ecologist Walter Leal, professor in the UC Davis Department of Molecular and Cellular Biology and his 18 biochemistry students, drew an attentive crowd and scores of questions about the mosquito-borne virus, which is primarily transmitted by the yellow fever mosquito, Aedes aegypti.

In pregnant women, the Zika virus can cause fetal microcephaly and other severe brain anomalies, as well as a number of other medical issues. In adults, it can be sexually transmitted and can cause Guillain–Barré syndrome, a disorder of the immune system that damages the peripheral nervous system.

“I am certain that every person in attendance, either online or in Giedt Hall, whether specialist or not, knows more about Zika now then when the symposium started,” Leal said. “Mission accomplished! Those who did not attend and/or think that my statement is exaggerated or not accurate should go watch the recorded version of the symposium at https://video.ucdavis.edu/media/Zika+Virus+Public+Awareness+Symposium/0_n3aupf5c.”

“The highlight of the symposium, however, was the level of participation of the students," said Leal,  a fellow of the Entomological Society of America and co-chair of the International Congress of Entomology meeting, set Sept. 25-30 in Orlando, Fla. "Clearly, new teaching approaches lead to students' engagement. This was an experiment that worked.”

A native of Brazil, Leal is a noted mosquito researcher (his lab discovered the secret mode of DEET) who collaborates with colleagues in Brazil. He recently participated in the international Zika scientific conference there.

What prompted the symposium? Leal and the 18 students decided that a scientific symposium would generate increased public awareness about the growing threat. They brought in speakers from the Brazilian frontlines (through Skype) and a Colorado State University researcher who contracted the Zika virus in Senegal and transmitted it to his wife. He was the first to discover that the virus is transmitted sexually.

The 18 students excelled, drawing praise from attendees and participants alike. In an email to Leal, James Carey, distinguished professor of entomology, UC Davis Department of Entomology and Nematology, wrote: "All were poised, confident, well prepared and articulate. You should be given a lot of credit for this creative outcome of your teaching efforts."

Aedes aegypti, the yellow fever mosquito that transmits dengue, chikungunya and Zika viruses. (CDC Photo)

Symposium speakers included:
"The Zika Epidemic – An Overview"
Professor Walter S. Leal
UC Davis Department of Molecular and Cellular Biology

"Congenital Zika Syndrome"
Dr. Regina Coeli Ramos, University of Pernambuco, Brazil (remote)

"Zika Virus and Me"
Professor Brian Foy (remote)
Department of Microbiology, Immunology, and Pathology, Colorado State University

Zika Virus: Looking into Mosquitoes' Vectorial Capacity
Professor Constância F. J. Ayres
Department of Entomology, Fundação Oswaldo Cruz-Pernambuco, Brazil  (remote)

"Don't Let Mosquitoes Bug You with Zika – Repel Them"
Professor Walter S. Leal
UC Davis Department of Molecular and Cellular Biology

"DEET vs. Zika – I Would Go with the Former"
Dr. Emanual Maverakis
Department of Dermatology, UC Davis School of Medicine

"Keeping Mosquito at Bay, Not in Your Backyard"
Dr. Paula Macedo
Laboratory Director, Sacramento-Yolo Mosquito & Vector Control District

"Friends Don't Let Friends Get Zika"
Dr. Stuart H. Cohen
Chief of the Division of Infectious Diseases and director of Hospital Epidemiology and Infection Control, UC Davis Medical School.

Some key points from the symposium

• Most people who contract Zika do not exhibit any symptoms whatsoever
• Zika virus is sexually transmitted; if you contract Zika, you can transmit it to your sexual partner.
• The mosquito, Aedes aegypti, is already in California, including the Clovis area and Palo Alto area
• Nearly 600 cases of Zika have already been reported in the United States, mostly in New York, Florida and California. Each case involved a U.S. traveler from a Zika virus "hot spot"
• Zika can persist up to 62 days in human semen
• Laboratory tests show that the common mosquito, Culex, can vector the virus and field tests are underway. Culex transmits West Nile Virus, Japanese encephalitis, and equine encephalitis.
• The two mosquitoes have varying feeding and breeding patterns: Culex feeds at night; and Aedes aegypti in the day, while Culex lays its eggs in polluted water, and Aedes aegypti in clean/clear water
• Culex quinquefasciatus, the southern house mosquito, is a potential vector; it has similar vector competence, and is much more abundant

The Zika virus was first isolated in 1947, in a rhesus monkey in a forest near Entebbe, Uganda. Brazil reported a human  outbreak in early 2015. The virus is now spreading to other parts of South, Central and North America. The World Health Organization says the virus is likely to spread throughout most of the Americas by the end of the year.   It is advising that people returning from known Zika outbreak areas to follow safe sex practices or abstain from sex for at least eight weeks.