This is the height of the season in an above-average year for WNV. We expect that 14 counties will report at least one human case during this week. Several counties have fallen back to having just average risk for this week, but average risk during the peak of the season still means substantial transmission, and the majority of counties are still at above-average risk. Mosquito infection rates seem to have stabilized and temperatures are average for this point in the year. However, humidity is still high and this is enhancing estimated risk.
Projected Cases for 2018
Temperatures have been average for these last few weeks and mosquito infection rates have returned to average on the eastern and western edges of the state. However, humidity remains above average, and we continue to expect that 2018 will be an above-average year overall for WNV in SD. We expect that there will be around 147 cases, down from 148 in last week's prediction. These estimates will change if we receive any surprising weather or mosquito data, but the stability in estimates of human risk means that a coherent picture is emerging from all the data we continue to receive.
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).