Vector-borne disease testing: Northeast
Combatting a growing concern
In the Northeastern U.S., earlier springs, later falls, and warmer temperatures overall have enabled several established and emerging tick and mosquito species to flourish. Their presence has brought new vector-borne illnesses to the region and exacerbated existing disease incidence. Knowing which illnesses to test for is integral for proper diagnosis and rapid initiation of therapy.
The main vectors for tick-borne illness in the Northeastern U.S are Ixodes scapularis, or the black-legged tick; Amblyomma americanum, or the lone star tick; and Dermacentor variabilis, or the American dog tick. According to the U.S. Centers for Disease Control and Prevention, tick vectors were responsible for upward of 77,000 cases of tick-borne diseases in the region in 2022.
Tick-borne illness
Lyme disease, anaplasmosis, and babesiosis are the most common illnesses in the Northeastern United States and are all transmitted by the black-legged tick. This tick also carries pathogens that cause rare diseases, such as the Powassan virus (caused by a flavivirus) and relapsing fever (caused by the Borrelia miyamotoi bacteria). Because these conditions have a similar initial presentation, they can be challenging for physicians to definitively identify based on symptoms alone. What’s more, one tick can carry multiple pathogens and can transmit more than one during a single blood meal. Importantly, babesiosis requires a different treatment regimen than Lyme disease or anaplasmosis, so diagnostic accuracy is essential.
Tick-borne disease testing
Mosquito-borne illness
The most common mosquito vectors in the Northeastern U.S. are Culex species, which carry the West Nile virus, and Culiseta species, which transmit the eastern equine encephalitis virus (EEEV). West Nile virus symptoms include headache, body aches, vomiting, diarrhea, fatigue, and skin rash, and can evolve into more serious neurological forms, including encephalitis or meningitis, if left untreated. In contrast, EEEV, although rare, is extremely serious and can cause fever, headache, vomiting, diarrhea, seizures, behavioral changes, and drowsiness. According to the U.S. Centers for Disease Control and Prevention, approximately 30% of people who develop EEEV encephalitis die.5 Understanding which infection is affecting a patient is paramount to disease management.
Mosquito-borne diseases testing
References
- Lyme disease surveillance data. Lyme disease. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/lyme/data-research/facts-stats/surveillance-data-1.html. Page updated 2/11/25. Page accessed 5/14/25.
- Epidemiology and statistics. Anaplasmosis. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/anaplasmosis/hcp/statistics/. Page updated 3/3/25. Page accessed 5/14/25.
- CDC Wonder. U.S. Centers for Disease Control and Prevention. NNDSS Annual Summary Data 2016-2022 Request
- Data and maps for West Nile. West Nile Virus. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/west-nile-virus/data-maps/index.html. Page updated 6/18/24. Page accessed 5/14/25.
- About Eastern Equine Encephalitis. Eastern Equine Encephalitis Virus. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/eastern-equine-encephalitis/about/index.html. Page updated 5/15/2024. Page accessed 5/14/2025.