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