Congratulations to Dr. Divya Shinde (now of Duke University) for successfully defending her dissertation, “Yellow Fever: Role of Heterologous Flavivirus Immunity on Urban Emergence”. Yellow fever virus (YFV), a mosquito-borne flavivirus that can cause severe and occasionally fatal disease characterized by hemorrhage and multi-organ failure with a characteristic jaundice from which the virus takes its name. YFV has distinct transmission cycles that vary by geographic region. In Africa, where YFV first evolved, there are sylvatic, intermediate, and urban cycles that can lead to large-scale outbreaks. In the Americas, the urban cycle was last reported in the mid-20th century, but the sylvatic cycle remains. Recently, this transmission cycle has led to large outbreaks in previously low-risk areas with spillover transmission resulting in thousands of cases and hundreds of deaths, but no apparent re-establishment of an urban (human-amplified) transmission cycle. Finally, despite numerous introductions and abundant vectors, Asia remains free of YFV. During her time in the WRCEVA, Dr. Shinde studied the impact of previous dengue virus or Zika virus infection on YFV disease outcomes and, critically, the ability of the host to transmit YFV to a mosquito (a necessary step in establishing a transmission cycle). She found that previous heterologous infection did not reliably protect against YFV-induced disease. It did, however, consistently decrease transmission to Aedes aegypti mosquitoes, demonstrating the potential for heterologous flavivirus infection to profoundly impact YFV transmission if they share a host species. Excellent work, Dr. Shinde!
Link: https://doi.org/10.3390/microorganisms10081578
Link: https://doi.org/10.1038/s41467-024-54146-9
Link: https://doi.org/10.3390/v16060836