- Author: Kathy Keatley Garvey
The 11 scientists rank in the top 1 percent by citations, which represent how often their papers have been cited in other scientific papers.
Scott, who joined the UC Davis faculty in 1996, has published 288 papers to date. His total number of citations: more than 33,500. He is internationally known for his work on the ecology and epidemiology of dengue, a mosquito-borne viral infection transmitted mainly by Aedes aegypti.
“Although I retired from UC Davis in 2015, I have continued to carry out research just as I had previously,” Scott said. “In reality, I retired from UC Davis, but I did not retire from science.”
Scott focuses his research on epidemiology of mosquito-borne diseases, mosquito ecology, evolution of mosquito-pathogen interactions, and evaluation of novel products and strategies for disease control.
“I aim to generate the detailed, difficult to obtain data that are necessary for assessing current recommendations for disease prevention, rigorously testing fundamental assumptions in public health policy, and developing innovative, cost, and operationally effective strategic concepts for prevention of mosquito-borne disease.”
Scott has remained active on a variety of fronts. In 2015, he was in the early stages of two large grants (National Institutes of Health Program Project grant “Quantifying Heterogeneities in Dengue Virus Transmission Dynamics” and a sub-award from a Bill and Melinda Gates grant, “Spatial Repellent Products for Control of Vector-Borne Diseases”), which he continued to run and manage through the Department of Entomology and Nematology.
“So, I had plenty of support (more than $10 million) to continue my work,” he said. Both projects took place in Iquitos, Peru, and were jointly led with his long-term UC Davis collaborator, Amy C. Morrison, who is in the Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine.
The Gates grant was a clinical trial to determine whether and to what extent a chemical that repelled mosquitoes would reduce a person's risk of dengue or Zika virus infection. Scott served as the project leader for the Iquitos trial. “Earlier this year we determined that it had a big protective effect,” he related. “We are currently writing that manuscript.”
“Both of those grants ended earlier this year, but we still have a lot of work to do and will be busy for the next couple of years writing papers about those projects,” Scott said. He is currently working as a consultant in a follow-up study on spatial repellents for dengue prevention that will begin in Sri Lanka during 2021.
“Prior to and after retirement, I worked closely with the World Health Organization (WHO), where I served on numerous committees,” Scott related. He chaired the Vector Control Advisory Group, co-chaired the Global Vector Control Response, chaired the Emergency Response Consultation for Zika Virus, chaired the Technical Working Group for Dengue, served on the International Health Regulators Roster of Experts, and co-authored the updated version of WHO's dengue management and control guidelines. He recently applied for membership on the WHO Expert Advisory Group on Arboviruses.
“Working with WHO is important to me because at this stage of my career, being able to translate my science experience into improved quality of life, that is, improved public health policy, for other people, many of whom live in poverty, is the most meaningful thing I can do.”
Scott, who holds bachelor and master's degrees from Bowling Green (Ohio) State University, received his doctorate in ecology in 1981 from Pennsylvania State University and did postdoctoral research in epidemiology at Yale University School of Medicine's Arbovirus Research Unit, part of the Department of Epidemiology and Public Health. He served on the faculty of the Department of Entomology, University of Maryland, from 1983 to 1996 before joining the UC Davis entomology faculty as a professor of entomology and director of the Vector-Borne Disease Laboratory. He was acting director of the UC Davis Center for Vector-Borne Research from 1996 to 1999, and director of the UC Davis Arbovirus Research Unit (2001-2003). He was selected vice chair of the Department of Entomology in 2006, serving until 2008.
Highly honored by his peers, Scott won the coveted Harry Hoogstraal Medal from the American Society of Tropical Medicine and Hygiene in 2018. His other honors include fellow of three organizations: American Society of Tropical Medicine and Hygiene (2014), Entomological Society of America (2010), and the American Association for the Advancement of Science (2008). He was named a UC Davis distinguished professor in 2014. In 2015, he won the Charles W. Woodworth Award, the highest honor awarded by the Pacific Branch of the Entomological Society of America.
Other UC Davis scientists listed as Highly Cited Researchers include five others from the College of Agricultural and Environmental Sciences: Eduardo Blumwald and Jorge Dubcovsky, both from Plant Sciences; Alan Crozier, Nutrition; David A. Mills, Food Science and Technology; and Andrew Sih, Environmental Science and Policy.
- Author: Kathy Keatley Garvey
The event is free and open to the public and will be hosted by Jared Shaw of the UC Davis College of Letters and Science.
“It is actually going to be a very basic talk aimed at lay audiences and kids,” Attardo says. “I'll be talking about my background, how I became an entomologist and how I ended up working on tsetse flies. Then I am going to discuss the life history of tsetse flies, where they can be found, why they are of medical importance and how their reproductive biology differs so dramatically from other flies that people are familiar with. My plan is to go over their reproductive cycle, how they develop intrauterine larvae, the reproductive adaptations that allow them to perform this feat and then go over what we know about tsetse milk secretions and how they compare to mammalian milk in terms of nutritional content.”
“The aim is for it to be very informal, with very little scientific jargon and to be discussion-oriented so that there is lots of questions and answers. I am also bringing some items from the lab that can be passed around the audience for show and tell (homemade tsetse cages, the blood feeding system we use to feed the flies and some tsetse flies preserved in alcohol).
Attardo focuses his research on numerous aspects of the physiology of tsetse fly reproduction, with the goal to identify and understand key aspects of its reproductive biology. He joined the UC Davis Department of Entomology and Nematology in 2017 from the Yale University School of Public Health, New Haven, Conn., where he researched tsetse flies in the lab of Serap Aksoy.
Attardo considers the tsetse fly "one of the champions of the insect world."
"In addition to being vectors of a deadly disease, Trypanosomiasis, these flies have undergone amazing alterations to their physiology relative to other insects," he says. "Some examples of this are their ability feed exclusively on blood, their obligate relationship with a bacterial symbiont, the fact that they lactate and that they give birth to fully developed larval offspring."
Attardo is the co-author of Adenotrophic Viviparity in Tsetse Flies: Potential for Population Control and as an Insect Model for Lactation, published in January 2015 in the Annual Review of Entomology.
- Author: Kathy Keatley Garvey
Scott, internationally known for his work on the ecology and epidemiology of dengue, received the award "for his outstanding contributions to the study of mosquito ecology, evolution of mosquito-virus interactions, epidemiology of mosquito-borne disease and evaluation of novel products and strategies for mosquito control and disease prevention."
He focuses his work on contributing to improved public health in the United States and in the developing world, where resources are inadequate and help is desperately needed.
The coveted ASTMH award memorializes parasitologist-entomologist Harry Hoogstraal (1917-1986), a global authority on ticks and tick-borne diseases.
Scott, who joined the UC Davis faculty in 1996, received his bachelor and master's degrees from Bowling Green (Ohio) State University, and his doctorate in ecology in 1981 from Pennsylvania State University. He did postdoctoral research in epidemiology at Yale University School of Medicine's Arbovirus Research Unit, part of the Department of Epidemiology and Public Health.
Scott served on the faculty of the Department of Entomology, University of Maryland, from 1983 to 1996 before joining the UC Davis entomology faculty as a professor of entomology and director of the Vector-Borne Disease Laboratory. He was acting director of the UC Davis Center for Vector-Borne Research from 1996 to 1999, and directed the UC Davis Arbovirus Research Unit from 2001 to 2003. He served as vice chair of the Department of Entomology from 2006 to 2008.
In 2014, Scott was selected a “distinguished professor,” an honorary title bestowed by the provost “to recognize outstanding faculty in the professional series who have achieved the highest level of scholarship.”
Highly honored by his peers, Scott is a fellow of three organizations: American Society of Tropical Medicine and Hygiene (2014), Entomological Society of America (2010), and the American Association for the Advancement of Science (2008). In 2015, he won the Charles W. Woodworth Award, the highest honor awarded by the Pacific Branch of the Entomological Society of America.
Scott is the fifth medical entomologist from UC Davis to receive the Harry Hoogstraal Award since it was first presented in 1987. Other UC Davis recipients:
- 2012: William Reisen, director of the Center for Vectorborne Diseases (CVEC)
- 2007: Bruce Eldridge, former director of the statewide UC Mosquito Research Program and emeritus professor of entomology at UC Davis
- 2005: Robert Washino, emeritus professor and former chair of the UC Davis Department of Entomology
- 2004: John Edman, former director of CVEC and emeritus professor of entomology
- Author: Kathy Keatley Garvey
Male Aedes aegypti mosquitoes infected with a bacterium, Wolbachia pipientis, are being released in Clovis, Fresno County, where this mosquito was discovered in June 2013. Although this mosquito is now found in California, there has been no locally transmitted case of the Zika virus in the state.
The project, to determine dispersal and survival, began Monday, May 10.
“The daytime-biting mosquito, which feeds predominantly on humans, has spread to at least seven counties since its discovery in Clovis,” said Cornel, a mosquito researcher and faculty member with the UC Davis Department of Entomology and Nematology and the UC Kearney Agricultural Research and Extension Center, Parlier.
“The biting nuisance and potential of the mosquito Aedes aegypti to transmit Zika, Chikungunya and dengue viruses in California is cause for concern,” he said. “Efforts to curb its spread and reduce populations have not been very effective. Control efforts have included educating the public to remove standing water (source reduction) insecticide barrier sprays and bacterial larviciding.”
The collaborative effort involves Steve Mulligan, director of the Consolidated Mosquito Abatement District, based in Fresno County; Stephen Dobson of the University of Kentucky; MosquitoMate Inc, (mosquitomate.com); and UC Davis. The researchers will evaluate the population suppressive ability of the novel sterile insect technique, which is part of a comprehensive vector management approach.
Only Aedes aegypti is targeted. “When the Wolbachia-infected male mosquito mates with non-infected females, the result is “cytoplasmic incompatibility, which causes the female to lay infertile eggs that will not hatch,” Cornel explained.
“This approach requires the release of tens of thousands of Wolbachia-infected males into residential neighborhoods where this mosquito is a nuisance,” the medical entomologist said. “Releasing large numbers of males increases the chance that an introduced male will mate with the native females.”
Although residents will notice increased numbers of male mosquitoes, male mosquitoes do not bite and cannot transmit disease. Both U.S,federal and State regulatory agencies have approved the technique for evaluation of effectiveness.
“This sterile insect technique was evaluated in 2015 in Los Angeles to suppress another invasive mosquito, Aedes albopictus,” Cornel said, adding that the results from that trial look promising.
The Zika virus, now spreading throughout the Western hemisphere, was first identified in Uganda in 1947 in rhesus monkeys, according to the World Health Organization. It was subsequently identified in humans in 1952 in Uganda and the United Republic of Tanzania. Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.
Despite the mosquito's invasion into new areas of the United States, there are no reported cases of locally transmitted Zika virus in California or in the contiguous United States, according to the Centers for Disease Control and Prevention. The cases have all involved travelers returning home from countries plagued with disease outbreaks.
“We can't predict how far this mosquito will spread in California,” said Cornel, noting that its range has expanded “south of Fresno to San Diego. The farthest site north is Madera in the Central Valley, but it's also been found in the more coastal area of Menlo Park in San Mateo.”
It's troubling that the mosquito is becoming more and more resistant to pesticides, said Cornel, who collects, rears and researches mosquitoes from all over the world, including the United States, Mali, Cameroon, Comoros, Tanzania, South Africa and Brazil.
“We have found that Aedes aegypti have insecticide resistance genes which likely explains why the use of ultra-low volume and barrier spray applications for control have not worked as well as expected.”
- Author: Kathy Keatley Garvey
The lecture, to take place at 10:45 a.m. in the Alpha Gamma Rho (AGR) Hall, is sponsored by the College of Agricultural and Environmental Sciences and the Storer Life Sciences Endowment of UC Davis.
At Penn State, Thomas serves as the Huck Scholar in Ecological Entomology and directs the Ecology Institute, in addition to his duties as a professor of entomology in the Department of Entomology and Centre for Infectious Disease Dynamics.
He will be introduced by Professor Shirley Luckhart of the UC Davis Department of Medical Microbiology and Immunology, coordinator of the event.
Thomas researches many aspects of the ecology and evolution of insect pests and diseases in his drive to understand the consequences of global change and to improve the effectiveness and sustainability of pest and disease management. His work involves predicting and understanding the impact of invasive species, and researching biodiversity and ecosystem health, plus many aspects of biological control.
Last December Thomas and his research team at Penn State, in collaboration with partners in Europe and Africa, received a five-year, $10.2 million grant from the Bill and Melinda Gates Foundation to investigate a new method for preventing the transmission of malaria.
“The method involves limiting mosquito access to houses by blocking openings and installing ‘eave tubes' that contain a unique type of insecticide-laced mosquito netting developed by Dutch partner In2Care that kills the insects as they attempt to enter,” according to a Penn State news release.
Thomas was quoted as saying: “Nearly half of the world's population is at risk of contracting malaria, and according to the most recent World Health Organization report, an estimated 438,000 people died from the disease in 2015. The use of insecticides to control mosquitoes has saved millions of lives, but this tactic is increasingly challenged because mosquitoes quickly evolve resistance to the very limited number of insecticides currently used in public health. The eave tube approach presents a novel strategy to help combat this challenge by simultaneously making houses more mosquito proof and providing a novel way of delivering insecticides, which creates opportunities for using a wider range of insecticidal products."
"The small amount of insecticide used in the tubes means that it is cheap to treat an entire house," said Thomas. "Furthermore, retreatment is easy, as it requires simple replacement of small pieces of netting within the tubes."
Internationally recognized, Thomas is a recipient of the Commonwealth Scientific and Industrial Research Organization (CSIRO) Medal for Research Achievement, is a fellow of the American Association for the Advancement of Science, and an honorary professor at the University of Witwsatersand, South Africa. He also received Penn State's Alex and Jessie Black Award for Research Excellence.
