1. The Spread of Lyme Disease
Amelia Wurzburg and Anna Driscoll

2. Outline Overview of Lyme disease Life cycle of the tick
Transmission of the disease
History of Lyme disease
Environmental factors
Controlling the spread of Lyme disease

3. What IS Lyme disease? Caused by bacteria Borrelia burgdorferi
Transmitted to humans via the Blacklegged tick
Potentially life threatening if left untreated.
Can result in chronic health problems
An increasing human problem, specifically in the Northeast

4. Symptoms
Early stages
Fever, headache, fatigue, chills, swollen lymph nodes
Similar to symptoms of many other common illnesses.
Rash (Erythma Migrans)

5. Symptoms Erythma Migrans Symptom UNIQUE to Lyme disease
Appears at the site of the tick bite
Bull’s eye rash (clear center)
Increases over time (up to 12 inches)
Warm but not painful
Over time, can develop multiple
25 % of people infected never get them

6. Symptoms Later stages Can occur months or years after tick bite
Loss of muscle tone in face, nervous system problems, severe headaches and neck stiffness due to meningitis, heart palpitations, dizziness, severe fatigue, joint pain and swelling (esp large joints)
10-20% of untreated Lyme disease patients have chronic arthritis
5% of untreated Lyme disease patients develop neurological symptoms such as problems with short-term memory and concentration.

7. Treatment
The sooner the disease is detected the simpler and more effective the treatment.
Treated with antibiotics
More specific antibiotics needed if neurological or cardiac symptoms occur.
Untreated Lyme disease may require 2 rounds of antibiotic treatment
Some symptoms persist even after antibiotic treatment

8. Life Cycle of the Blacklegged Tick
3 feeding stages
Larvae- Hatch free of Lyme disease, but contract Lyme during first feeding
Nymphal- Most active stage. Feed on small mammals and humans.
Adult- Feed and breed on large mammals esp. deer

9. Transmission
Small mammals (white footed mouse) harbor the Lyme bacteria, but do not become afflicted by it
Deer do not transmit Lyme but do transport ticks and allow for breeding
Blacklegged ticks are only transmitters to humans
Process begins as soon as host’s blood enters ticks body

10. Transmission
Takes hours of tick feeding for host to become infected.
Untreated Lyme can be transmitted from mother to fetus during pregnancy
No other means of transmission have been discovered.
However, Lyme bacteria is known to survive in stored blood.

11. History of Lyme Disease
Identified in 1970s in Old Lyme Connecticut
First case documented 1988 in New Jersey
Believed to be present in the Northeastern US for 10,000 years
Lyme disease has increased dramatically in Vermont in the last few years

12. Lyme Disease In Vermont

13. Environmental Factors
Global warming
Spread of disease carrying vectors
Warmer winters = less winter kill
Warmer summers = longer breeding and transmission season

14. Environmental Factors
Decreased Biodiversity
Higher biodiversity = lower rate of infectious disease
Humans have wiped out predators of animals that are important in the transmission of Lyme
Killing off of possible barrier hosts (Western fence lizard)
Dominance of White-tailed deer and White-footed mouse increase prevalence of Lyme

15. Suburbanization Humans living in close proximity to animals
More ecotonal zones providing prime habitat for ticks
Habitat fragmentation

16. Controlling Lyme Disease
Personal Prevention
Avoid tick habitats especially during May, June, and July
Insect repellants
Long clothing
Checking for ticks often
Keep lawn sunny and dry - bad tick habitat

17. Controlling Lyme Disease
Large scale prevention
Minimizing deer herds (controversial)
Reducing global warming
Reducing habitat fragmentation and suburbanization
Increasing biodiversity
These are complex problems with complex solutions