The Maine Center for Disease Control and Prevention (CDC) has issued an alert about an increase in anaplasmosis cases this year. Anaplasmosis is an emerging infectious disease in Maine. The vector-borne bacterial pathogen is transmitted via or deer ticks, which are also related to transmission of Lyme disease. Anaplasma phagocytophilum is the new name for the agent formerly called Ehrlichia equi.
The zoonotic risk is unknown at this time. Although horses and people appear to be infected with strains of the same agent, it is believed that human exposure occurs through tick bites and not by direct transmission from horses to people. So far, only human cases have been reported in Maine.
A deer tick
In horses, the severity of anaplasmosis symptoms varies with the age of the horse and duration of the illness and may be mild.
In horses, the severity of anaplasmosis symptoms varies with the age of the horse and duration of the illness and may be mild. Horses that are younger than a year old may have a fever only. Horses 1-3 years old may develop fever, depression, mild limb edema, and ataxia.
In humans, symptoms of anaplasmosis include headache, fever, chills, confusion, and abdominal pain. The CDC also illustrates certain difficulties in clinical diagnosis. Specifically, the generalized symptoms can be easily confused with other ailments, and lab-based antigen tests generally do not show up positive in the first 7-10 days of illness.
As a result, the best treatment may be prevention. When it comes to ticks, scanning after outdoor activity and proper removal with tweezers or a tick spoon can be effective. If symptoms begin, contact a physician immediately and a simple treatment regimen with Doxycycline, a broad-spectrum antibiotic, will most likely resolve the illness.
So far this year, 38 cases of anaplasmosis in humans have been reported in Maine, an increase from the 26 of 2011. However, a point of concern is the large influx of people into Maine, self-identified as Vacationland, during the summer months for outdoor activities that increase exposure to deer ticks.
Anaplasmosis fits into a larger picture of increasing tick-borne diseases in the United States. Since the mid-1990s anaplasmosis nationwide has exhibited a steadily increasing curve from near non-existence to a thousand incident cases annually. The cases tend to cluster in the summer months and disproportionately affect the elderly and immunocompromised.
If you are concerned about the effects of tick bites, you will want to read Tips for Removing Ticks