Long-term health problems following acute Rocky Mountain spotted fever infection include partial paralysis of the lower extremities, gangrene requiring amputation of fingers, toes, or arms or legs, hearing loss, loss of bowel or bladder control, movement disorders, and language disorders. These complications are most frequent in persons recovering from severe, life-threatening disease, often following lengthy hospitalizations. Epidemiology
There are between 500 and 2500 cases of Rocky Mountain spotted fever reported in the United States per year, and in only about 20% can the tick be found.Host factors associated with severe or fatal Rocky Mountain spotted fever include advanced age, male sex, African or Caribbean background, long-term excessive alcohol use and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Deficiency of G6PD is a genetic condition affecting about 12 percent of the Afro-American male population. Deficiency in this enzyme is associated with a high proportion of severe cases of Rocky Mountain spotted fever. This is a rare clinical complication that is often fatal within five days of the onset of the disease. In the early 1940s, outbreaks were described in the Mexican states of Sinaloa, Sonora, Durango, and Coahuila driven by dogs and Rhipicephalus sanguineus sensu lato, the brown dog tick. Over the ensuing 100 years case fatality rates were 30%–80%. In 2015, there was an abrupt rise in Sonora cases with 80 fatal cases. From 2003 to 2016, cases increased to 1394 with 247 deaths.
Diagnosis
This disease can be diagnosed by a doctor with and without the use of lab testing. Lab tests are not always relied upon because treatment may be necessary before the results are returned.Abnormal laboratory findings seen in patients with Rocky Mountain spotted fever may include a low platelet count, low blood sodium concentration, or elevated liver enzyme levels. Serology testing and skin biopsy are considered to be the best methods of diagnosis. Although immunofluorescent antibody assays are considered some of the best serology tests available, most antibodies that fight against R. rickettsii are undetectable on serology tests during the first seven days after infection.Differential diagnosis includes dengue, leptospirosis, chikungunya, and Zika fever. Treatment
Appropriate antibiotic treatment should be started immediately when there is a suspicion of Rocky Mountain spotted fever. Treatment should not be delayed for laboratory confirmation of disease as early initiation of treatment of Rocky Mountain spotted fever is associated with lower mortality. Failure to respond to a tetracycline argues against a diagnosis of Rocky Mountain spotted fever. Severely ill people may require longer periods before their fever resolves, especially if they have experienced damage to multiple organ systems. Preventive therapy in healthy people who have had recent tick bites is not recommended and may only delay the onset of disease.Doxycycline (a tetracycline) is the drug of choice for patients with Rocky Mountain spotted fever. According to the CDC, "Doctors often avoid prescribing doxycycline to young children because of a warning that tooth staining may occur when used in children less than 8 years old.