State health officials say a staggering number of ticks in a Pennsylvania city park carried a variant of the same rare and potentially deadly virus that killed a former US senator.
About 92% of adult tick samples taken during routine testing at the Lawrence Township Recreation Park in central Pennsylvania came back positive for Deer Tick Virusthe Pennsylvania Department of Environmental Protection said in a January 20 report.
The highest rate of Deer Tick virus infection previously recorded at a single location in the United States was 25%, officials said.
Deer Tick virus — also known as DTV — is a variant of the Powassan virus, which has contributed to the death of former North Carolina Senator Kay Hagan in 2019. The Powassan virus is transmitted to humans through tick bites female blacklegged ticks, LiveScience reported, and the transmission time is relatively short at 15 minutes.
Lyme disease, by comparison, can take more than 24 hours to be transmitted once a tick attaches to its host, the Pennsylvania DEP said.
According to the Centers for Disease Control and Prevention, Powassan virus disease was once considered a fairly rare occurrence in humans. But the data shows that there have been an increase in cases during the last years.
Routine testing yields ‘worrying’ numbers
Pennsylvania state environmental officials issued a warning to residents in January after receiving the alarming results from Lawrence Township Recreational Park in Clearfield, Pennsylvania.
DEP Secretary Patrick McDonnell called the infection rate “extremely high”.
“This finding is concerning, and we urge the public to exercise caution and take preventive measures to reduce the risk of tick bites and potential infection while DEP continues to address the situation,” said McDonnell in a statement.
The Department of Environmental Protection said it has an active tick monitoring program which began in 2018 and involves tracking the “habitats, life stages and peak activity levels” of ticks. ticks in every county in the state.
The ticks that were collected from Lawrence Township Recreation Park were part of those routine tests, officials said.
At least 25 ticks have been collected from the park, which includes a baseball diamond, soccer field, basketball court and playground. Officials said 23 of those ticks — or 92% — tested positive for DTV. Prior to testing in Clearfield, the highest infection rate found in a single location in Pennsylvania was 11%, according to the state Department of Environmental Protection. And in 2021, the statewide average was 0.6%.
What is the Powassan virus?
According to the CDC, most Powassan virus cases occur in the Northeast and Great Lakes regions.
Unlike some other viruses, it cannot be spread by coughing, sneezing or touching, the CDC said. The Powassan virus has, however, been spread in rare cases through blood transfusions.
Once infected, a person can develop a brain infection — also known as encephalitis — or an infection of the membranes around the brain and spinal cord — also known as meningitis, according to the CDC. Those infected have reported feeling sick between a week and a month after being bitten, but many show no symptoms.
Powassan virus symptoms include fever, headache, vomiting, and weakness. In severe cases, this may manifest as confusion, loss of coordination, difficulty speaking, or seizures.
According to the CDC, one in 10 people diagnosed with a serious illness such as encephalitis after contracting the virus will die. Half of those who survive face long-term health problems.
There is no drug to treat the Powassan virus, the CDC said.
Hagan, the North Carolina senator, was hospitalized in December 2016 with encephalitis.
She spent the better part of three years dealing with the fallout, McClatchy News previously reported. During one of his final public appearances on June 5, 2019, Hagan’s husband, Chip Hagan, said his speech and muscle movement were still limited.
Hagan died in his sleep on October 28, 2019. She was 66 years old.
An increase in tick-borne diseases
An October 2021 report from the CDC showed an increase in Lyme disease and other tick-borne illnesses in the United States in recent years.
There was a records 59,349 cases linked to tick-borne diseases in 2017 — up from 48,610 in 2016, the CDC said. Officials warned that the recorded cases “represent only a fraction of the total number of people with tick-borne diseases”.
Data specific to the Powassan virus follow a similar trajectory. Between 2011 and 2015, the CDC recorded only 44 cases in the United States, this figure rose to 134 between 2016 and 2020 with a record 39 cases in 2019.
The CDC said there could be several factors contributing to the increase in tick-borne diseases, including an expansion in the geographic range of ticks. According to the CDC, this is partly due to changes in land use patterns, such as reforestation and suburban development, as well as climate change.
The blacklegged tick, in particular, has seen considerable movement.
Alvaro Toledo, assistant professor of entomology at Rutgers University, told Medpage Today blacklegged tick has “moved north and west quite significantly over the past 20 years”, in part because populations of its main host – deer and mice – have also increased.
Warmer temperatures and shorter winters have also given ticks more time to find hosts, Medpage Today reported, citing Jean Tsao, an associate professor in Michigan State University’s Department of Fisheries and Wildlife.
“Once you have enough surviving ticks, you can also turn the pathogen cycle around,” she told the outlet.