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Strengthening cassava virus diagnostic capacity in DR Congo

A training workshop on “Application Molecular Diagnostics for Cassava Virus Surveillance” took place 2 to 6 March, at IITA-Kalambo, Bukavu, Democratic Republic of Congo (DRC). This course is part of the USAID-funded project on “Actions to Control Cassava Brown Streak Disease in the Democratic Republic of Congo”. Twenty-three participants attended the workshop including six female participants from the DRC and the Congo Republic. Participants trained in the application of Recombinase Polymerase Amplification (RAP) for the detection of viruses responsible for cassava mosaic disease (CMD) and cassava brown streak disease (CBSD).

The Project Manager, Sikirou Mouritala said, “CMD, endemic to all regions in DRC, is controlled using the disease-resistant cassava cultivars, whereas CBSD–localized in eastern provinces–is controlled using virus-free propagation material.” He continued, “Work is in progress to develop CBSD resistant cultivars suitable for cultivation in DRC, while intensive efforts are focused on preventing the westward migration of CBSD. Another threat to cassava production, particularly in Western DRC, is dry root rot disease (DRRD), the cause of which is not yet clear. However, studies have shown that DRRD is not associated with any virus infection.”

“Reliable diagnostic tools are necessary for research and extension services for surveillance, production of virus-free planting material, and seed health testing,” said Lava Kumar, Head of Virology & Molecular Diagnostics, IITA-Ibadan, Nigeria, who was the key resource person for the training course. He mentioned that simple technologies usable with minimum equipment under laboratory and field conditions immensely benefit CBSD mitigation efforts in DRC.

Participants consisted of researchers and laboratory staff from different stations of the Environmental Institute for Agricultural Research (INERA) and IITA-Kalambo, as well as seed inspectors from the National Seed Service (SENASEM) and extension agents (SNV, ‘Service National de Vulgarization’). In addition, two participants from Congo-Brazzaville, the neighboring country, also benefited from this course. Participants were trained in:

• Recognition of cassava virus disease symptoms in the field
• Recognition of disease incidence and distribution within the field
• Early disease diagnostics for disease control
• Sampling and sample preservation for virus testing
• Conducting surveillance surveys
• Use of RPA and Loop-mediated Isothermal Amplification (LAMP) methods for cassava virus detection under laboratory and field conditions.

Participants visited INERA-Mulungu station in South Kivu, to demonstrate cassava breeding activities conducted at the station, and practice smartphone-based applications for disease reporting from the field and field virus detection using the RPA method.

“Diagnostics capacity will help the establishment of the CBSD control network with partners and the support of Dr Kumar are of vital importance for preventing CBSD spread in DRC,” said Mouritala.

Also speaking during the workshop, the DRC country representative, Zoumana Bamba said, “Development of national program capacity in tackling virus diseases is critical to improve cassava production and halt the expansion of CBSD spread towards Western DRC.” He thanked the continued support of USAID for improving cassava production in the country.

As a follow-up to the course, the USAID project will establish four cassava virus diagnostics laboratories in Mulungu, Mvuazi, Ngandadjika, and Yangambi INERA stations to support CBSD mitigation efforts. As part of this, each of the stations will receive the minimum equipment required for performing diagnostics tests.