Newsfeed display by CaRP Rocky Mountain spotted fever is a disease caused by the bacterium Rickettsia rickettsii, which is carried by ticks. People usually start having fevers and feeling nauseous about a week after being bitten by a tick, although some people do not remember having had a tick bite. A few days after the fever begins, people who have Rocky Mountain spotted fever often have a rash, usually on their arms or ankles. They also may have pain in their joints, stomach pain, and diarrhea. Sometimes people with this disease are very sick and have to go to the hospital.

Rocky Mountain spotted fever is the most severe and most frequently reported rickettsial illness in the United States. It also occurs in Mexico and in Central and South America. The disease is caused by Rickettsia rickettsii, a species of bacteria that is spread to humans by ixodid (hard) ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment it can be fatal.

Rocky Mountain spotted fever is a disease caused by the bacterium Rickettsia rickettsii, which is carried by ticks. People usually start having fevers and feeling nauseous about a week after being bitten by a tick, although some people do not remember having had a tick bite. A few days after the fever begins, people who have Rocky Mountain spotted fever often have a rash, usually on their arms or ankles. They also may have pain in their joints, stomach pain, and diarrhea. Sometimes people with this disease are very sick and have to go to the hospital.

People get this disease when they are bitten by a tick that is carrying the bacterium R. rickettsia. Because ticks on dogs can be infected with R. rickettsii, dogs and people can get Rocky Mountain spotted fever from the same ticks. These ticks can also bite other animals and pass Rocky Mountain spotted fever to them. When you remove ticks from any animal, the crushed tick or its parts can also pass this disease through any cuts or scrapes on your skin.

When returning from potentially tick-infested areas, check yourself and your children for ticks, especially in the hair. Additionally, ticks may be carried into the household on clothing and pets. Both should be examined carefully.

To prevent ticks from getting on your pets, consult your veterinarian.

Rocky Mountain spotted fever can be very difficult to diagnose in its early stages, even by experienced physicians who are familiar with the disease.

Patients infected with R. rickettsii generally visit a physician in the first week of their illness, following an incubation period of about 5-10 days after a tick bite. The early clinical presentation of Rocky Mountain spotted fever is nonspecific and may resemble a variety of other infectious and non-infectious diseases.

The classic triad of findings for this disease are fever, rash, and history of tick bite. However, this combination is not always detected when the patient initially presents for care.

Initial symptoms may include fever, nausea, and vomiting, severe headache, and muscle pain, lack of appetite.

The rash first appears 2-5 days after the onset of fever and is often not present or may be very subtle when the patient is initially seen by a physician. Younger patients usually develop the rash earlier than older patients. Most often it begins as small, flat, pink, non-itchy spots on the wrists, forearms, and ankles. These spots turn pale when pressure is applied and eventually become raised on the skin.

Later signs and symptoms include rash, abdominal pain, joint pain, and diarrhea

The characteristic red, spotted rash of Rocky Mountain spotted fever is usually not seen until the sixth day or later after onset of symptoms, and this type of rash occurs in only 35% to 60% of patients with Rocky Mountain spotted fever. The rash involves the palms or soles in as many as 50% to 80% of patients; however, this distribution may not occur until later in the course of the disease. As many as 10% to 15% of patients may never develop a rash.

Abnormal laboratory findings seen in patients with Rocky Mountain spotted fever may include thrombocytopenia, hyponatremia, or elevated liver enzyme levels.

Rocky Mountain spotted fever can be a very severe illness and patients often require hospitalization. Because R. rickettsii infects the cells lining blood vessels throughout the body, severe manifestations of this disease may involve the respiratory system, central nervous system, gastrointestinal system, or renal system. Host factors associated with severe or fatal Rocky Mountain spotted fever include advanced age, male sex, African-American race, chronic alcohol abuse, and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Deficiency of G6PD is a sex-linked genetic condition which occurs with highest frequencies in people of African, Middle Eastern, and Southeast Asian origin; it affects approximately 12% of the U.S. African-American male population; deficiency of this enzyme is associated with a high proportion of severe cases of Rocky Mountain spotted fever. This is a rare clinical course that is often fatal within 5 days of onset of illness.

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.

Rocky Mountain spotted fever is a seasonal disease and occurs throughout the United States during the months of April through September. Over half of the cases occur in the south-Atlantic region of the United States; Delaware, Maryland, Washington D.C., Virginia, West Virginia, North Carolina, South Carolina, Georgia, and Florida. The highest incidence rates have been found in North Carolina and Oklahoma. Although this disease was first discovered and recognized in the Rocky Mountain area, relatively few cases are reported from that area today.

Limiting exposure to ticks reduces the likelihood of infection with Rocky Mountain spotted fever. In persons exposed to tick-infested habitats, prompt careful inspection and removal of crawling or attached ticks is an important method of preventing disease. It may take extended attachment time before organisms are transmitted from the tick to the host.

Is unreasonable to assume that a person can completely eliminate activities that may result in tick exposure. Therefore, prevention measures should emphasize personal protection when exposed to natural areas where ticks are present:

1. Wear light-colored clothing which allows you to see ticks that are crawling on your clothing.
2. Tuck your pants legs into your socks so that ticks cannot crawl up the inside of your pants legs.
3. Apply repellents to discourage tick attachment. Repellents containing permethrin can be sprayed on boots and clothing, and will last for several days. Repellents containing DEET can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children. Application of large amounts of DEET on children has been associated with adverse reactions.
4. Conduct a body check upon return from potentially tick-infested areas by searching your entire body for ticks. Use a hand-held or full-length mirror to view all parts of your body. Remove any tick you find on your body.
5. Parents should check their children for ticks, especially in the hair, when returning from potentially tick-infested areas. Ticks may also be carried into the household on clothing and pets and only attach later, so both should be examined carefully to exclude ticks

Folklore remedies, such as the use of petroleum jelly or hot matches, do little to encourage a tick to detach from skin. In fact, they may make matters worse by irritating the tick and stimulating it to release additional saliva or regurgitate gut contents, increasing the chances of transmitting the pathogen. These methods of tick removal should be avoided.

Strategies to reduce vector tick densities through area-wide application of acaricides - chemicals that will kill ticks and mites and control of tick habitats e.g., leaf litter and brush have been effective in small-scale trials. New methods being developed include applying acaricides to animal hosts by using baited tubes, boxes, and feeding stations in areas where infected ticks are endemic. Biological control with fungi, parasitic nematodes, and parasitic wasps may play supportive roles in integrated tick control efforts. Community-based integrated tick management strategies may prove to be an effective public health response to reduce the incidence of tick-borne infections. However, limiting exposure to ticks is presently the most effective method of prevention of tick-transmitted diseases.