Mosquito Survey Results Show Zika Threat Low in Missouri
After identifying 20 mosquito species a team of researchers determined the Aedes aegypti, the species linked to the Zika virus, are a low threat to Missourians.
Dr. David Claborn, Missouri State University associate professor of public health, spent four months this summer trapping and studying mosquitos. With a team of five, including two graduate students, they did not find the original vector of the virus.
A vector is an organism that spreads infections by transmitting bacteria or virus from one host to another.
Using two types of traps and funding from the Missouri Department of Health and Senior Services the team looked for which types of mosquitos were in what areas.
“The key part of this is to be able to identify these things through the species because some species are important in disease transmission and some species are not,” Claborn said.
Prior to the study, officials knew the Aedes albopictus (also known as the Asian tiger mosquito) – a secondary vector - was among the species found in Missouri. However, given the state’s climate, it’s not known how well this type of mosquito can transmit Zika here.
The project did find another invasive species; Aedes japonicas, or the Asian rock pool mosquito. This species carries Japanese Encephalitis and has been reported around St. Louis.
According to Claborn, it is unclear if this species would be able to carry the Zika virus.
“The question is would it be able to transmit Zika virus and we don’t know the answer to that yet,” Claborn said. “But it could play an important role if it in fact turns out to be an effective vector of the virus.”
The team spent the majority of its time surveying south of the Missouri River, an area suggested by the Centers for Disease Control and Prevention. The location was chosen based on historical evidence that the Aedes aegypti (also known as the Yellow Fever mosquito) had gathered there.
Claborn tells more about mosquito identification and trapping.
Claborn said yellow fever species have been confirmed in Missouri previously but may not be in the state anymore.
“We’ve trapped about 15,000 mosquitoes overall and have not found any specimens of the primary vector,” said Claborn in a news release. “This does not mean it does not occur in Missouri; however, if it does occur, the population is not large or easy to detect.”
The information resulting from this research project is passed on to DHSS who, in turn, shares it with the CDC.
The study may continue if the project receives additional funding. The next step would include pilot sanitation projects, insecticidal resistance studies, official training and public education.
“I don’t know what next summer will bring,” Claborn said. “I suspect that (Zika) will not make it into the mosquito population in some areas in the United States. I think Missouri is one of those transitional areas where it may or may not.”
For more information about what you need to know about Zika virus go to CDC.gov.