Common Insect-Borne Diseases in Pennsylvania
What to Know and When to Get Tested
Did you know some of the most dangerous health threats in Pennsylvania come from bug bites?
Tick bites, mosquito bites, and even cockroaches can spread infectious diseases, often without you knowing right away.
Learn the warning signs and when to get tested at HNL Lab Medicine.
Tick-Borne Diseases
Primary vectors: Blacklegged tick (Ixodes scapularis), American dog tick (Dermacentor variabilis), Lone star tick (Amblyomma americanum)
- Lyme Disease ¹
This bacterial infection causes fever, chills, headaches, tiredness, muscle and joint pain, and swollen lymph nodes. It can also cause a rash in 70-80% of people, which may look like a bull’s-eye. Most cases are in the late spring and summer. Any flu-like symptoms at this time of the year should be evaluated by your provider. - Anaplasmosis ²
Early signs and symptoms of anaplasmosis are usually mild or moderate and may include fever, chills, severe headache, muscle aches, nausea, vomiting, diarrhea, and loss of appetite. It is most common during April to September, but another peak can occur in October when adult deer ticks are feeding. - Babesiosis ³
This parasitic infection can cause fever, chills, sweats, headache, body aches, loss of appetite, nausea, fatigue, anemia, dark urine, or jaundice. Those most at risk of serious illness include people who do not have a spleen, people who have a weakened immune system, people with other serious health conditions, and the elderly. - Powassan Virus ⁴
Initial symptoms of Powassan virus can include fever, headache, vomiting, and weakness. It can be life-threatening if not treated quickly. Symptoms of severe disease include confusion, loss of coordination, difficulty speaking and seizures. Approximately 1 out of 10 cases with severe disease are fatal. Of those who survive severe disease, approximately half have long-term health problems such as recurring headaches, loss of muscle mass and strength, and memory problems. - Ehrlichiosis ⁵
The symptoms of this bacterial infection are generally nonspecific and can range from very mild to very severe illness. Symptoms may include fever, headache, muscle ache, fatigue, nausea, vomiting, diarrhea, confusion, and conjunctivitis. Rash occurs in up to 60 percent of children but is less common in adults. - Alpha-gal Syndrome (Red Meat Allergy) ⁶
Alpha-gal Syndrome (AGS) is linked to the bite of lone-star ticks and may be more likely with multiple tick bites. AGS triggers an allergic reaction after consuming red meat (beef, pork, or lamb) or dairy. Symptoms may begin several hours after eating red meat and include nausea, vomiting, heartburn, indigestion, diarrhea, hives, and anaphylaxis.
Mosquito-Borne Diseases 
Primary vectors: Culex, Aedes, and Culiseta mosquito species
- West Nile Virus (WNV) ⁷
Symptoms of this viral infection include fever, head and body aches, nausea, vomiting, swollen lymph glands, and a rash on the chest, stomach and back. About 1 in 150 patients will develop severe symptoms such as blindness, disorientation, coma, convulsions, headache, high fever, muscle weakness, neck stiffness, numbness, paralysis, stupor, and tremors. These symptoms may last for several weeks, and the neurological effects may be permanent. - Eastern Equine Encephalitis (EEE) ⁸
The symptoms of this rare viral infection show up three to ten days after someone is bitten by an infected mosquito. Symptoms may include high fever (103º to 106ºF), stiff neck, headache, and lack of energy. The disease gets worse quickly. Some patients may experience inflammation and brain swelling leading to a coma. EEE is fatal in 1 out of 3 cases. - Jamestown Canyon Virus (JCV) ⁹
Most cases of JCV are among adults. Initial symptoms include fever, fatigue, headache, cough, sore throat, or runny nose. About half of patients with JCV will require hospitalization, with symptoms such as stiff neck, confusion, loss of coordination, difficulty speaking, and seizures.
Other Household Insect Risks – Cockroaches
Cockroaches spread disease by contaminating food and surfaces. Cockroaches can carry bacteria, fungi, viruses, and parasites on their bodies. About 25% of the germs on their bodies can potentially cause food-borne illnesses (food poisoning), with symptoms such as diarrhea, stomach pain or cramps, nausea, vomiting, and fever 10.
Signs of severe food poisoning include bloody diarrhea, diarrhea that lasts more than 3 days, fever over 102°F, vomiting so often that you cannot keep liquids down, and signs of dehydration 11.
Cockroaches may also cause allergies and asthma, especially in children. Around 63% of homes in the United States contain cockroach allergens. In urban areas, that number rises to between 78% and 98% of homes 12.
Symptoms of a cockroach allergy can include coughing, skin rash, wheezing, ear infections, sinus infections, and nasal congestion. HNL Lab Tests Direct offers a cockroach allergy test to help you get to the bottom of any allergy-like symptoms.
Choose HNL Lab Medicine
Protect yourself and your family by using insect repellent, wearing long sleeves, and checking for bites after being outdoors.
If you feel sick or notice unusual symptoms, don’t wait! Visit your provider and complete any lab work at an HNL Lab Medicine Patient Service Center near you.
Short on time? Now you can order select tests through HNL Lab Tests Direct. For added convenience, try our HNL @Home service – one of our skilled phlebotomists will come to your home and complete your lab work for a small fee.
REFERENCES
¹ Pennsylvania Department of Health. (2025). Lyme disease. Commonwealth of Pennsylvania. https://www.pa.gov/agencies/health/diseases-conditions/infectious-disease/vectorborne-diseases/tick-diseases/lyme.html.
² Pennsylvania Department of Health. (2021, November 23). Anaplasmosis fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/Anaplasmosis.pdf.
³ Pennsylvania Department of Health. (2021, November 23). Babesiosis fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/Babesiosis.pdf.
⁴ Pennsylvania Department of Health. (2022, February 10). Powassan fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/vectorborne/Powassan%20Fact%20Sheet.pdf.
⁵ Pennsylvania Department of Health. (2021, November 23). Ehrlichiosis fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/Ehrlichiosis.pdf.
⁶ Pennsylvania Department of Health. (2023, September 15). Alpha gal fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/vectorborne/Alpha%20gal%20fact%20sheet.pdf.
⁷ Pennsylvania Department of Health. (2021, February 11). West Nile virus fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/vectorborne/West%20Nile%20Virus.pdf.
⁸ Pennsylvania Department of Health. (2022, February 10). Eastern equine encephalitis fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/vectorborne/Eastern%20Equine%20Encephalitis.pdf.
⁹ Pennsylvania Department of Health. (2023, July 13). Jamestown Canyon virus fact sheet. Commonwealth of Pennsylvania. https://www.pa.gov/content/dam/copapwp-pagov/en/health/documents/topics/documents/diseases-and-conditions/vectorborne/Jamestown%20Canyon%20Virus.pdf.
10 Donkor E. S. (2020). Cockroaches and Food-borne Pathogens. Environmental health insights, 14, 1178630220913365. https://doi.org/10.1177/1178630220913365.
11 Centers for Disease Control and Prevention. (2025, January 31). Symptoms of food poisoning. U.S. Department of Health and Human Services. https://www.cdc.gov/food-safety/signs-symptoms/index.html .
12 American College of Allergy, Asthma & Immunology. (2018, February 01). Cockroach allergy. https://acaai.org/allergies/allergic-conditions/cockroach-allergy/.