The Imperial County Heath Officer, Dr. Stephen Munday, announced that a middle-aged resident of Imperial County passed away due to Rocky Mountain spotted fever (RMSF), a tickborne disease. The individual visited a local hospital in May after feeling ill with fever, nausea and vomiting but was unable to recover. Public health officials continue to investigate the death and it is unknown where the individual contracted the disease. This is the first case and death due to RMSF reported in Imperial County, according to a health department Facebook post Wednesday.
RMSF is a tick borne disease caused by the organism, Rickettsia rickettsii. Typically, the progress of the disease is a sudden onset of high fever, deep muscle pain, severe headache and chills. A rash usually appears on the extremities within 5 days then soon spreads to palms and soles and then rapidly to the trunk.
Fatalities can be seen in greater than 20% of untreated cases. Death is uncommon with prompt recognition and treatment. Still approximately 3-5% of cases seen in the U.S. are fatal. The absence or delayed appearance of the typical rash or the failure to recognize it, especially in dark-skinned people cause a delay in diagnosis and increased fatalities.
Early stages of RMSF can be confused with erlichiosis, meningococcal meningitis and enteroviral infection.
This infection is seen in the U.S. primarily April through September, mostly in the southeast and south central. In recent years, the most cases have been seen in Oklahoma and North Carolina. Few cases are actually seen in the Rocky Mountain region. Outside the U.S., cases have been reported in Argentina, Brazil, Canada, Columbia, Costa Rica, Mexico and Panama.
The organism is maintained in nature in ticks. It can be transmitted to dogs and other mammals, but most times these cases cause little illness. People usually get infected from an infected tick bite. The tick requires from several hours to 24 hours of attachment and feeding to become infectious to people. So prompt removal of the tick can prevent infection. It is not transmitted person to person.
RMSF can be diagnosed in the laboratory using serological techniques, PCR or culture; however because of the necessity of prompt treatment, diagnosis is based on symptoms. There is no vaccine available for RMSF. It can be treated with tetracyclines either orally or intravenously.
Prevention is through immediate removal of ticks, wearing clothes that cover skin and removing ticks from dogs. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page