Ehrlichiosis

Ehrlichiosis is a reportable disease in Oklahoma.  It was first recognized as a disease in the United States in the late 1980’s, but did not become a reportable condition until 2000.  Ehrlichiosis is the general name used to describe several bacterial diseases that are spread to humans by the bite of an infected tick.  Both Erhlichia chaffeensis and E. ewingii are spread to humans by the bite of an infected lonestar tick in the southeastern or southcentral United States.

The persons most at risk for this disease include: males, people over 50 years of age, those with weakened immune systems, and people who reside near or spend time in wooded areas or areas with high grass.  The highest number of erhlichiosis cases are reported during warmer months when ticks are more active.  Precautions should be taken to avoid tick bites.

The symptoms of ehrlichiosis will generally include a sudden onset of fever, chills, headache, myalgia, and fatigue within five to ten days following a tick bite. The symptoms of ehrlichiosis are similar to Rocky Mountain Spotted fever; however, a rash occurs less often. Other common symptoms include nausea, vomiting, abdominal pain, and loss of appetite. The severity of disease ranges from asymptomatic infection to death. Half of the people with ehrlichiosis require hospitalization. In persons with severely weakened immune systems, ehrlichiosis can result in a fatal overwhelming infection.

Treatment for ehrlichiosis with antibiotics (usually doxycycline) is very effective at reducing the severity of the disease. It is important antibiotic treatment for ehrlichiosis is started without delay when suspected. Overall, an estimated 2%-3% of persons with ehrlichiosis will die due to the infection. Although ehrlichiosis can be severe, preventive antibiotic therapy in non-ill persons following a tick bite is not recommended.

Laboratory testing for ehrlichiosis includes blood samples taken in the early stages of the illness (acute) and follow-up (convalescent) specimens taken at least four weeks after the first specimen. Laboratory testing, though important, can take days to weeks for results to become available. If ehrlichiosis is suspected, it is important not to delay appropriate antibiotic therapy while waiting for laboratory confirmation. 

Ehrlichiosis Fact Sheets and Information:

Ehrlichiosis Fact Sheet (84kb)   
   Erliquiosis Hoja Informativa (41kb)
Tickborne Disease Prevention

Ehrlichiosis Surveillance Data and Statistics:

Ehrlichiosis 2010 Surveillance Summary (221kb)
Total Number of Confirmed and Probable Ehrlichiosis Cases by Month of Onset, Oklahoma 2006-2010 (14kb)

External Ehrlichiosis Resources:

Ehrlichiosis (CDC)
Tickborne Morbidity and Mortality Weekly Report Data (1000kb.pdf) (CDC)