Most recent weekly forecast

Click here for the final West Nile Weekly in 2017

We have reached the end of the West Nile virus season in 2017. Although fewer than 1% of cases are transmitted during the week beginning October 2nd, the virus is still present in the environment and if birds, mosquitoes, and humans are all together in the same area, some late, unlucky cases may occur. However, this is very rare and any new cases appearing in the data were likely transmitted earlier and took some time to be diagnosed and reported. The season will officially end with the first killing frost, and this unpredictable event may occur at any time in October. See you all in 2018!

Most recent seasonal forecast

Click here for the West Nile Seasonal August 14th, 2017

Based on all data available Sept. 11th, we expect to see 53 cases in SD in 2017. This is essentially unchanged from last week's prediction of 52 cases. This low number is due primarily to low mosquito infection rates in the early season, a long stretch of dry weather, and cold weather in late July, early August.


NASASouth Dakota State UniversitySD Department of Health

South Dakota State University has partnered with the South Dakota Department of Health to implement a program of West Nile virus (WNV) research that will support public health decision makers at the state level and mosquito control programs at the local level. Major activities include mosquito surveillance and testing for WNV, monitoring environmental risk factors using data from earth observing satellites, and using this information to predict the risk of WNV to humans across the state. This work is supported in part by a grant from the NASA Applied Sciences Public Health and Air Quality Program (NNX15AF74G).