Tickborne Disease Epidemiology Fairfax County Fairfax County, VA, May 30, 2015 Shawn Kiernan District Epidemiologist Fairfax County Health Department.

Tickborne Disease EpidemiologyFairfax County

Fairfax County, VA, May 30, 2015

Shawn Kiernan District Epidemiologist

Fairfax County Health Department

Outline

• Communicable Disease/Epidemiology Unit

• Tickborne Disease Epidemiology in Fairfax County

All Public Health is Local

• Nearly 3,000 local health departments in the U.S.– Governmental entities of towns, cities, counties,

and/or districts

7%

11%

82%

cities

towns ortownships

county or county-relatedjurisdictions

Public Health Core Functions

• Protect against environmental hazards • Prevent injuries • Promote and encourage healthy behaviors• Assure the quality and accessibility of health

services • Respond to disasters and assist communities

in recovery • Prevent epidemics and the spread of disease

CD/Epidemiology Unit

Objective: Identify and prevent the further spread of communicable diseases

Surveillance

Over 70 diseases on the Virginia Reportable Disease List– Physicians and directors of medical care facilities – Laboratories – Other facilities (e.g. nursing homes, day cares)– Includes bioterrorism agents, suspected outbreaks

of any disease, and diseases of public health concern

Vector-borne Transmission• Vector-borne transmission is the term commonly used to describe an illness caused by an

infectious disease that is transmitted to people by blood-sucking arthropods. • The arthropods (insects or arachnids) that most commonly serve as vectors include:

mosquitoes, fleas, lice, biting flies and bugs, mites, and ticks. • Vectors typically become infected by a disease agent while feeding on infected

vertebrates (e.g., birds, rodents, other larger animals, or humans), and then pass on the microbe to a susceptible person or other animal.

• In almost all cases, an infectious microbe must infect and multiply inside the arthropod before the arthropod is able to transmit the disease through its salivary glands. The most common vector-borne diseases in Virginia are carried by mosquitoes and ticks.

Lyme Disease

• 1975- Mysterious cases of rheumatoid arthritis in children living in Lyme, CT

• Symptoms increased during summer, and the children lived and played in wooded areas– Children often recalled having a skin rash prior to arthritis– Researchers suspected deer ticks to be vector

• (1982) Dr. Willy Burgdorfer, a zoologist and microbiologist, discovers the bacterium that causes Lyme disease, Borrelia burgdorferi

Dr. Burgdorfer / Source: NIAID/RML

Source: CDC

Reported Lyme disease cases, United States

Reported cases of tickborne disease, Fairfax County 2004-2013

Disease 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

5 year average (2008-2012)

Ehrlichiosis/Anaplasmosis 0 2 2 2 11 1 7 17 6 11 8.4

Lyme disease 1 10 102 208 191 260 256 146 149 260 200.4

Spotted fever rickettsiosis 7 8 11 5 9 6 11 20 26 23 14.4

Signs and symptoms of Lyme disease in humans

Treatment and Outcome

• Lyme disease is treated with antibiotics

• Recommended regimens range from 2-4 weeks, by pill or intravenously, depending on stage of illness

• Most patients treated with antibiotics recover completely

• A few patients, particularly those diagnosed with later stages of disease may have persistent symptoms

Questions