Watch Public Health Entomologist Dr. Liz Dykstra at Work

As a public health entomologist, I focus on insects like mosquitoes, bed bugs, and hornets. I also work with other arthropods, like ticks and spiders, that can hurt people by either making them sick or injuring them by biting, stinging, or causing allergic reactions.

My job involves field and lab work ,data analysis, and communicating information through writing and speaking. That means I do a lot of public speaking!

After the mosquitoes are collected, they need to be identified. Because only some species transmit disease, identification is how I sort out the vectors. Non- vector species are used to study population dynamics at a particular site. Mosquitoes are either killed or anesthetized by freezing or using dry ice. Vector species are then tested for pathogens like West Nile virus.

I grew up on farms in the Midwest and was very active in 4H, showing my horses, cattle, and goats at the county fair.

After graduating from college with a Bachelor’s in Biology, I took a break from school and served in the Peace Corps for four years in Senegal, West Africa. While I was in Senegal, I had the opportunity to work as a research assistant on a project studying a tick-borne disease. That experience hooked me on vector borne disease ecology and epidemiology. And after hearing a state health department entomologist talk about her experience conducting a plague investigation, I knew I wanted to work in public health.

Finding vectors requires a variety of techniques! Mosquitoes spend part of their life cycle in water, and tires are a favorite habitat! Here I am conducting surveillance for mosquito larvae.

19,000 mosquitoes make up this pile- all from one trap.

Adult mosquitoes fly, so I use a trap baited with dry ice to create a plume of carbon dioxide. Carbon dioxide is what we breathe out that attracts mosquitoes to us. The trap has a motorized fan that sucks mosquitoes into a catch bag.

Looking for ticks is completely different from mosquito surveillance. Here I’m using a white flannel cloth to drag over vegetation. Ticks can’t fly or jump; they grab onto their host when it brushes against their perch and climb aboard. The drag cloth takes advantage of that behavior. I periodically stop to check and put any ticks I find into collection bottles.

Following my Peace Corps tour, I returned to school and completed my Master’s in Epidemiology and Ph.D. in Entomology – a total of 11 years of college! I then became a commissioned officer and entomologist in the U.S. Navy.

My 6½ years on active duty gave me a broad foundation of vector surveillance and control methods. It was great training for a career as a public health entomologist. It also provided me opportunities to work and travel in Italy, Honduras, Argentina, Japan, Ghana, Yemen, and Egypt. I love to travel, so getting to spend time in those countries was fantastic! I now work for a state health department.

At first, talking to large groups of people was really hard. But I kept working at it, and now I’m very comfortable speaking in front of people. I think that vector-borne diseases are so interesting because each disease is maintained in nature by an arthropod vector, a vertebrate host, and a pathogen. In order to understand vector-borne disease dynamics, you need to learn about the biology of all three and how they interact with each other in nature. There’s always something new to learn!

Tick surveillance also includes searching for them on potential hosts. Sometimes that means taking advantage of a situation to check hosts that I normally would not be able to. Here I’m inspecting a freshly killed deer for ticks during hunting season.

When a person gets sick from a vector-borne disease, sometimes we conduct an environmental investigation in the area where the person was bitten by a vector. Here I’m looking through material collected from a rodent burrow for nest-dwelling ticks that transmit tick-borne relapsing fever (TBRF). I’m wearing personal protective equipment to protect me from any potentially contaminated dust [it might contain hantavirus, a virus carried by the deer mice whose burrows the material came from]. We were looking for evidence of the TBRF bacteria in the tick and mice populations near where the person lived. All of the ticks that we found tested negative for the TBRF pathogen.

Fun Facts

What’s a vector? Arthropods that transmit pathogens (bacteria and viruses) that cause disease in people and animals.

Ticks are not insects! They are more closely related to spiders. However, insects, ticks, and spiders are all arthropods.

Only female mosquitoes bite. They need the protein in blood for their eggs to develop. Males only feed on nectar.

Did you know that vector-borne diseases have caused some of the greatest disease outbreaks in history? Plague, aka the Black Death, is transmitted by rat fleas and killed a third of Europe’s population during the 14^th century! Malaria, which is transmitted by mosquitoes, is a deadly disease that still affects approximately half of the world’s population. Lyme disease and West Nile virus are vector-borne diseases that threaten our health here in the United States.

Analyzing surveillance data and giving talks about our findings is an important part of my job. I spend a lot of time on my computer!

Best part of my job

Helping people learn more about medically important insects and other arthropods, as well as getting to spend time in the field looking for ticks and mosquitoes.

Word of Advice If you want to work as a public health entomologist, take math and science classes and develop your writing and speaking skills. Shadow an entomologist on the job who studies vectors, works in pest control, or works at a mosquito control district. Entomologists work in a wide variety of settings - if something sounds interesting, check it out!