Why a global surveillance system for crop diseases is urgently needed

Due to climate change and global trade, crop diseases, which annually kill off 20% of the five global staple crops that provide half the world’s communities with caloric intake, are able to thrive and spread. 

In a new report published in the journal Science, scientists argue that a Global Surveillance System (GSS) must be put in place to strengthen and connect biosecurity measures to prevent the spread and reemergence of crop diseases and therefore improve global food security.

“As part of efforts to satisfy global demand for food — which could mean increasing agricultural production by as much as 70 percent by 2050 — we need a GSS to reduce food lost to pests,” said lead author Mónica Carvajal, a researcher at the International Center for Tropical Agriculture (CIAT). “A lot of collaboration and discussion is needed to rapidly take action and avoid outbreaks that could negatively impact food security and trade.”

This GSS system would prioritize the six major food crops (maize, potato, cassava, rice, beans, and wheat) as well as other food and cash crops that are traded across borders.

Carvajal and her team used the Cassava Mosaic Disease (CMD) as an example of why a GSS must be instated. CMD was discovered in Cambodia in 2015, yet wasn’t properly reported until 2016. That gave CMD enough time to spread to Thailand and Vietnam by 2018, and is now estimated to be present in 10% of the land cultivated in this area, thus threatening millions of cassava smallholders, which generate $4 billion in export revenue.

“The question I asked was why does it take so long to respond to crop diseases in some cases?” said Carvajal. “What is the limitation to responding faster from the outset?”

If the proposed GSS was put into action, the network of “active surveillance” and “passive surveillance” personnel would be tightened. Labs at agricultural inspection stations, and customs and phytosanitary inspectors at borders and ports, make up the active surveillance personnel. And farmers, scientists and agronomists at universities and research centers, national agriculture organization extension workers, and agriculture industry specialists make up the passive surveillance group.

“For this infrastructure to be effective, connections between first detectors and downstream responders must be enhanced and actions coordinated,” the authors explain. “But diagnostic capacity, information sharing, and communications protocols are lacking or weakly established in some regions, especially in low-income countries.”

“Our reflection on many disease outbreaks is that whether in high-income countries or low-income countries, the passive surveillance infrastructure has the most in-field monitoring eyes but the least coordination from local to global,” they continue.

Furthermore, the GSS, which would consist of five separate formal global networks (a diagnostic laboratory network, a risk assessment network, a data management network, an operational management network, and a communications network), would use cutting-edge technology to better diagnose diseases, and it would also use social media to share information about specific findings.

“We encourage the annual G20 Agriculture Ministers Meeting, the World Bank Group, and FAO, among others, to join efforts toward enhancing cooperation for a multi-year action plan for the proposed GSS to more effectively reduce the impact of crop diseases and increase global food security,” the study authors conclude.

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By Olivia Harvey, Earth.com Staff Writer

Image Credit: Georgina Smith / International Center for Tropical Agriculture