Being a stowaway is risky, but people don’t often think of stowaways as posing a risk to the health of an entire nation – unless that stowaway happens to be a mosquito. Since 1986, Dr. Chester Moore, a Professor in the Department of Microbiology, Immunology and Pathology, has made it his business to track down these arthropod invaders and keep a database of incidents in an effort to ensure that new infectious diseases don’t become a threat to the United States.
“The introduction of a new variety of mosquito into any population of humans and animals can pose a significant health threat because they may introduce a new disease or strain of a disease,” said Dr. Moore, who is a faculty affiliate of the Arthropod-Borne and Infectious Disease Laboratory in the College of Veterinary Medicine and Biomedical Sciences. “As disease vectors, mosquitoes have the ability to significantly change the health or health threats to a community – much as we’ve seen with the rapid advancement of mosquito-transmitted West Nile virus across the United States.”
Dr. Moore began tracking the invasion of mosquitoes while working at the Centers for Disease Control, and brought the work with him when he joined Colorado State University in 2003. Dr. Moore is contacted when an official discovers and confirms a foreign mosquito in the United States. While most invaders don’t survive, some become established in a small area, then spreading if conditions are favorable.
The Aedes aegypti, which spreads yellow fever and dengue, or breakbone fever, was most likely the first stowaway to the Americas. It is native to Africa and scientists believe that it was brought to America through slave trade in the 1500s. It remains an important mosquito, in terms of human and animal health, and is a focus of Dr. Moore’s monitoring work. Dr. Moore also tracks ticks and other disease vectors moving into the country, as well as investigates how mosquitoes indigenous to regions within the United States are expanding their territory.
“Increased international commerce and travel will likely lead to more introductions,” Dr. Moore said. “We also are mindful of the fact that just because a species is not an important vector in its native environment does not mean it will not be a vector in a new environment.”
Locally, Dr. Moore has a significant role in tracking the presence of West Nile virus in the community. He runs the laboratory at CSU that tests all mosquitoes gathered in Larimer County for the virus. Thousands of mosquitoes are caught around the city and the two known to carry West Nile virus are sorted out and brought to Dr. Moore’s laboratory. Each week a newly captured batch is tested for the West Nile virus by lab technician Kamiey Price.
Dr. Moore and Price have encountered a lower number of WNV-positive mosquitoes this year, most likely due to cooler weather, and Dr. Moore anticipates seeing lower levels of transmission of the virus to people and animals. Next year could be a different story, depending upon the weather conditions.