North Dakota tick survey sees large uptick of samples. Here's what the health department found.
BISMARCK – Those creepy, crawly creatures are living up to their nasty reputation. In brief, the summary of a second season of a statewide survey of ticks confirms what most people fear – a high percentage of the bloodsucking, pincer pests are carriers of disgusting diseases that are easily transmitted to hosts.
The North Dakota Department of Health first ventured into tick surveillance in 2017 by collecting and testing a relatively small sample of ticks. The ticks in the sample were provided with the help of veterinarians and zoos in the state. The program was significantly expanded in 2018 with active participation from 37 veterinarians, four zoos, North Dakota Game and Fish, Department of Agriculture Wildlife Services and at least one individual.
“They all submitted ticks, which was a huge help,”said Laura Cronquist, NDDOH division of disease control. “We had more coverage throughout the state in 2018, which was real nice.”
Of the 13,640 ticks collected and sent to the state laboratory for disease testing, nearly half were contributed by a single interested individual – John Heiser of Grassy Butte. In all, ticks were submitted from 25 counties in the state.
“We had more participation last year, which was awesome,” said Cronquist. “More ticks were submitted. Our project is really unique for our area.”
The state’s most common tick is the American Dog tick. The dog tick and Rocky Mountain wood tick, which is also found within the state, are closely related. Both are known for their speciality, carrying the dreaded Rocky Mountain spotted fever virus.
Rocky Mountain spotted fever symptoms include stomach pain, nausea, vomiting, loss of appetite and muscle pain. Delayed treatment may lead to severe illness or death. Some Rocky Mountain spotted fever victims may suffer irreversible hearing loss, paralysis, mental disability and damage to blood vessels which could lead to amputation of extremities. Fourteen cases of Rocky Mountain spotted fever were reported in the state in 2017.
There’s another tick present in North Dakota with a well-deserved and ugly reputation too. A surprising number of them were collected in 2018.
“We ended up with more deer ticks from across the state,” noted Cronquist.
While the number of deer ticks submitted to the NDDOH was small in comparison to the number of other ticks, just 51, they were found in 22 of the 25 counties surveyed, including Ward County. Deer ticks are are known carriers of Lyme disease, 56 cases of which were reported in the state in 2017. In addition, deer ticks are believed to have transmitted 17 cases of anaplasmosis and one case of Powassan in 2017.
The symptoms of anaplasmosis are similar to Rocky Mountain spotted fever but can include chills, cough and confusion. Severe cases can lead to difficulty breathing, hemorrhage, kidney failure and disrupt various functions of the nervous system.
Fortunately, Powassan transmission from ticks remains quite rare in North Dakota. It is closely related to West Nile disease. A tick can transmit Powassan in as little as 15 minutes after biting a human. About 10 percent of Powassan cases result in death. According to the NDDOH report on the 2018 study, statistics show that approximately half of Powassan survivors have permanent neurologic conditions including headaches, muscle wasting and memory problems.
The Lone Star tick, whose range is primarily the southern and eastern United States, and has been linked to red meat allergies, is believed to be expanding its range. However, Lone Star ticks remain extremely rare in North Dakota.
“That’s correct,” said Cronquist. “Two years ago two were found. Last year just one and it’s unknown how they got here. They are not all that concerning yet.”
The state was divided into eight regions for the tick surveillance survey. Tick pools from each region, consisting of up to 20 ticks each, were tested for the presence of several diseases. Of the 176 pools made up of American Dog ticks and Rocky Mountain wood ticks, 106 tested positive for disease carrying pathogens. Half of the deer tick pools tested positive.
According to the NDDOH report, ticks can transfer some pathogens to their hosts in as little as 15 minutes. Some pathogens require that the tick to be attached from 24 to 48 hours. When a tick bites into flesh it inserts a feeding tube into the incision which enables the transmission of disease.
Complete results and information regarding the 2018 tick surveillance project can be found on the NDDOH website.