Researchers propose surveillance system for Zika virus and other infectious diseases (The Lancet)

Posted on by Catherine Zandonella
Test tube image courtesy of the NIH
Image courtesy of the National Institutes of Health

By Catherine Zandonella, Office of the Dean for Research

A group of prominent researchers from seven institutions including Princeton University are calling for the establishment of a worldwide program to collect and test blood and other human bodily fluids to aid in the study and prevention of emerging infectious diseases such as the mosquito-borne Zika fever, which is caused by the Zika virus and has spread throughout Latin America and the Caribbean since early 2015.

In an article published in The Lancet April 5, the authors call for the creation of a World Serology Bank that would include storage repositories located around the world that use a common set of best practices to collect and evaluate blood and other bodily fluids from people infected by various pathogens. The resulting data would help scientists better understand the susceptibility of humans to emerging diseases such as Zika fever. The information could be shared widely among scientists who track disease.

The authors include Princeton’s C. Jessica Metcalf, an assistant professor of Ecology and Evolutionary Biology and Public Affairs in the Woodrow Wilson School for Public and International Affairs, and Bryan Grenfell, the Kathryn Briger and Sarah Fenton Professor of Ecology and Evolutionary Biology and Public Affairs. In the interview below, Metcalf explains more about the World Serology Bank proposal.

Why is it important to create a World Serology Bank?

Serology is the study of bodily fluids including serum, the part of the blood that contains antibodies, with the aim of detecting the body’s immune response to pathogens. Serology provides us with the clearest window we have onto the landscape of susceptibility to pathogens across human populations, and the consequent risk of outbreaks. A World Serology Bank would shed light on the global risk of infectious disease outbreaks, and would be of tremendous public health benefit.

Why do you feel it is important to address this issue now?

With the emergence of pathogens like Zika virus, it becomes ever more important to understand what enhances or limits the global spread of these pathogens, and what the consequences of such spread may be across our pathogen communities. A World Serology Bank would provide a powerful mechanism toward such a global perspective.

What are the challenges involved in creating the Bank?

Challenges range from developing systems for collecting fluids, which can be done on a regular schedule or during specific disease events, to methods for sera storage and sera testing. Other challenges include defining who will administer the World Serology Bank, and what global data-sharing agreements will be put in place. Finally, we will need to develop new methods to translate what we learn from the evaluation of sera, such as patterns of susceptibility to specific pathogens, or protection from those pathogens. These methods will be driven by the underlying biology, and are likely to require an array of analytical innovations.

Read more

The article, “Use of serological surveys to generate key insights into the changing global landscape of infectious disease,” by C. Jessica E Metcalf, Jeremy Farrar, Felicity T. Cutts, Nicole E. Basta, Andrea L. Graham, Justin Lessler, Neil M. Ferguson, Donald S. Burke and Bryan T. Grenfell was published online in the journal The Lancet on April 5, 2016. http://dx.doi.org/10.1016/S0140-6736(16)30164-7.

 

Do biofuel policies seek to cut emissions by cutting food? (Science)

Posted on by Catherine Zandonella

By Catherine Zandonella, Office of the Dean for Research

2015_03_27_cornfieldA study published today in the journal Science found that government biofuel policies rely on reductions in food consumption to generate greenhouse gas savings.

Shrinking the amount of food that people and livestock eat decreases the amount of carbon dioxide that they breathe out or excrete as waste. The reduction in food available for consumption, rather than any inherent fuel efficiency, drives the decline in carbon dioxide emissions in government models, the researchers found.

“Without reduced food consumption, each of the models would estimate that biofuels generate more emissions than gasoline,” said Timothy Searchinger, first author on the paper and a research scholar at Princeton University’s Woodrow Wilson School of Public and International Affairs and the Program in Science, Technology, and Environmental Policy.

Searchinger’s co-authors were Robert Edwards and Declan Mulligan of the Joint Research Center at the European Commission; Ralph Heimlich of the consulting practice Agricultural Conservation Economics; and Richard Plevin of the University of California-Davis.

The study looked at three models used by U.S. and European agencies, and found that all three estimate that some of the crops diverted from food to biofuels are not replaced by planting crops elsewhere. About 20 percent to 50 percent of the net calories diverted to make ethanol are not replaced through the planting of additional crops, the study found.

The result is that less food is available, and, according to the study, these missing calories are not simply extras enjoyed in resource-rich countries. Instead, when less food is available, prices go up. “The impacts on food consumption result not from a tailored tax on excess consumption but from broad global price increases that will disproportionately affect some of the world’s poor,” Searchinger said.

The emissions reductions from switching from gasoline to ethanol have been debated for several years. Automobiles that run on ethanol emit less carbon dioxide, but this is offset by the fact that making ethanol from corn or wheat requires energy that is usually derived from traditional greenhouse gas-emitting sources, such as natural gas.

Both the models used by the U.S. Environmental Protection Agency and the California Air Resources Board indicate that ethanol made from corn and wheat generates modestly fewer emissions than gasoline. The fact that these lowered emissions come from reductions in food production is buried in the methodology and not explicitly stated, the study found.

The European Commission’s model found an even greater reduction in emissions. It includes reductions in both quantity and overall food quality due to the replacement of oils and vegetables by corn and wheat, which are of lesser nutritional value. “Without these reductions in food quantity and quality, the [European] model would estimate that wheat ethanol generates 46% higher emissions than gasoline and corn ethanol 68% higher emissions,” Searching said.

The paper recommends that modelers try to show their results more transparently so that policymakers can decide if they wish to seek greenhouse gas reductions from food reductions. “The key lesson is the trade-offs implicit in the models,” Searchinger said.

The research was supported by The David and Lucile Packard Foundation.

Read the abstract.

T. Searchinger, R. Edwards, D. Mulligan, R. Heimlich, and R. Plevin. Do biofuel policies seek to cut emissions by cutting food? Science 27 March 2015: 1420-1422. DOI: 10.1126/science.1261221.