Uploaded May 2026 | Updated September 2026, 10 hours ago
The Johns Hopkins Bloomberg School of Public Health hosted a media briefing on May 5, 2026, about ticks and the growing threat of Lyme and other tickborne diseases.
Cases of Lyme disease have been on the rise in the U.S., according to the CDC, mainly in the Northeast, Upper Midwest, and parts of the West – though ticks’ habitats are expanding due to climate change.
Emergency department visits for tick bites were up more than 25% in April 2026 over the previous April, according to the CDC, an early indication that we might be facing a challenging year ahead.
State health departments reported more than 89,000 cases of Lyme disease in humans to the CDC in 2023, the most recent year numbers were published. Research suggests, however, that the actual number of cases is likely closer to half a million, which points to significant problems with underreporting, especially in endemic areas and in areas where tickborne diseases seem rare due to misdiagnoses.
If left untreated, Lyme disease can lead to serious complications affecting the heart, joints, and nervous system. Other tickborne illnesses are also of concern, including Powassan virus and Heartland virus. There is currently no vaccine against tickborne illnesses, though new Lyme disease vaccines are in development, and one created by Valneva with Pfizer has just completed a Phase 3 human clinical trial.
Topics discussed:
Why tickborne illnesses are increasing
The symptoms and outcomes of the illnesses
How people can protect themselves
The latest research
Current status of vaccine development
Insights from:
Nicole Baumgarth, DVM, PhD, a Bloomberg Distinguished Professor of Immunology and Infectious Diseases in the Department of Molecular Microbiology and Immunology and director of the Lyme and Tickborne Diseases Research and Education Institute at the Johns Hopkins Bloomberg School of Public Health.
Thomas Hart, PhD, an infectious disease microbiologist at the Lyme and Tickborne Diseases Research and Education Institute and assistant professor in the Department of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health.
0:00 Introduction
01:36 What is worrying about this tick season
05:25 Ticks are more prevalent this year
10:05 Post-treatment Lyme disease syndrome
12:00 Outlook for a vaccine
13:18 How El Nino might affect ticks
14:44 Other tickborne diseases
16:00 ER visits
16:26 How would climate change affect tick regions
17:26 How common are tickborne diseases in Africa
19:10 How brain is affected by tickborne diseases
20:04 Affect on farm workers
21:26 Treatment for the disease
23:04 Situation and diagnosis in the midwest
25:32 Why are misdiagnoses so common
26:54 Are there surprises this year
27:40 Doctor visits for tick bites
https://publichealth.jhu.edu
instagram.com/JohnsHopkinsSPH
facebook.com/JohnsHopkinsSPH
twitter.com/johnshopkinssph
The Johns Hopkins Bloomberg School of Public Health hosted a media briefing on May 5, 2026, about ticks and the growing threat of Lyme and other tickborne diseases.
Cases of Lyme disease have been on the rise in the U.S., according to the CDC, mainly in the Northeast, Upper Midwest, and parts of the West – though ticks’ habitats are expanding due to climate change.
Emergency department visits for tick bites were up more than 25% in April 2026 over the previous April, according to the CDC, an early indication that we might be facing a challenging year ahead.
State health departments reported more than 89,000 cases of Lyme disease in humans to the CDC in 2023, the most recent year numbers were published. Research suggests, however, that the actual number of cases is likely closer to half a million, which points to significant problems with underreporting, especially in endemic areas and in areas where tickborne diseases seem rare due to misdiagnoses.
If left untreated, Lyme disease can lead to serious complications affecting the heart, joints, and nervous system. Other tickborne illnesses are also of concern, including Powassan virus and Heartland virus. There is currently no vaccine against tickborne illnesses, though new Lyme disease vaccines are in development, and one created by Valneva with Pfizer has just completed a Phase 3 human clinical trial.
Topics discussed:
Why tickborne illnesses are increasing
The symptoms and outcomes of the illnesses
How people can protect themselves
The latest research
Current status of vaccine development
Insights from:
Nicole Baumgarth, DVM, PhD, a Bloomberg Distinguished Professor of Immunology and Infectious Diseases in the Department of Molecular Microbiology and Immunology and director of the Lyme and Tickborne Diseases Research and Education Institute at the Johns Hopkins Bloomberg School of Public Health.
Thomas Hart, PhD, an infectious disease microbiologist at the Lyme and Tickborne Diseases Research and Education Institute and assistant professor in the Department of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health.
0:00 Introduction
01:36 What is worrying about this tick season
05:25 Ticks are more prevalent this year
10:05 Post-treatment Lyme disease syndrome
12:00 Outlook for a vaccine
13:18 How El Nino might affect ticks
14:44 Other tickborne diseases
16:00 ER visits
16:26 How would climate change affect tick regions
17:26 How common are tickborne diseases in Africa
19:10 How brain is affected by tickborne diseases
20:04 Affect on farm workers
21:26 Treatment for the disease
23:04 Situation and diagnosis in the midwest
25:32 Why are misdiagnoses so common
26:54 Are there surprises this year
27:40 Doctor visits for tick bites
https://publichealth.jhu.edu
instagram.com/JohnsHopkinsSPH
facebook.com/JohnsHopkinsSPH
twitter.com/johnshopkinssph
