Factors influencing interactions between ticks and wild birds

1. Factors influencing interactions between ticks and wild birds Amy A. Diaz Faculty Sponsor: Dr. Howard Ginsberg

2. Objective • Investigate the factors influencing the associations between ticks and wild birds • Increase awareness of those most at risk for Lyme disease infection • Decrease the number of human infections • Especially in the young and elderly

3. Research • Analyze bird characteristics and possible effects on tick recruitment, attachment, and drop-off time. • Infection status • Body weight • Body temperature • Foraging habits

4. Reported cases of Lyme disease by year United States, 1992-2007

6. Lyme disease • Causative agent • Spirochete bacteria: Borrelia burgdorferi (USA) • Vector • Ixodes scapularis tick (Eastern United States) • Reservoirs • Rodents • Birds • NOT Deer

7. Symptoms • Often asymptomatic • Summer-time “flu-like” symptoms • Fever, fatigue, joint and muscle pain • Erythema migrans (EM) rash • If left untreated • Neurologic, cardiac, rheumatoid complications

8. Transmission • Tick acquires infection from infected and infective reservoir, while taking a blood meal. • During subsequent feedings, susceptible hosts may be infected if tick is attached for greater than 24 hours.

9. Reservoirs • Competent reservoirs • White-footed mice • Deer mice • Backyard bird species • American Robin • Song Sparrow

10. Analysis • Bird banding data available from Fire Island, New York and literature • Statistical analyses • Chi2 Test • Fisher’s Exact test • Regression Analysis

11. Tick Recruitment • No correlation between larval recruitment and the following: • Nymphal recruitment • Bird weight • Body temperature • Foraging habits • Migration versus local habitats

12. Attachment & Feeding • No correlation between tick attachment and successful feeding and the following: • Bird weight • Body temperature

13. Attachment • No variation between species • Except for Northern Cardinal

15. Tick Drop-off Time • No effect of body weight and temperature on drop-off time

16. Drop-off • Ticks remained attached longer to and dropped off later from birds infected with B. burgdorferi • 1997 & 1998 • Ixodes scapularis & Amblyoma ticks • Gray Catbirds & Song Sparrows

18. Drop-off • Additionally, the greatest change in drop-off time between infected and uninfected birds tended to be seen in birds with significant weight loss. • Indicator of stress • Species susceptibility to stress • Further study warranted

20. Conclusions • No correlations between the following: • Larval Recruitment • Nymphal Recruitment • Bird Weight • Body Temperature • Foraging Habits • Attachment & Successful Feeding • Bird Species • Bird Weight • Body Temperature

21. Conclusions • No correlations between the following: • Drop-off Time • Bird Weight • Body Temperature • Evidence for relationship between infection status and tick drop-off time • However, no implications for Lyme disease transmission

22. Implications • Birds are significant players in the transmission cycle of Lyme disease. • Factors affecting the attraction of ticks to birds, as well as successful feeding and length of time attached, are key to understanding the importance of wild birds as reservoirs of disease. • Infection status • Stress

23. Implications • Lyme disease is preventable • Realize importance of common wild birds as reservoirs for disease • Hosts to infected vectors • Competence to infect feeding vectors • Disease amplification • Precautions to protect family

24. Acknowledgments Maxon G. Balmforth Shaibal Mitra P.A. Buckley Howard S. Ginsberg

25. Questions