Diseases Rocky Mountain spotted fever

Ticks have a bad reputation for good reasons. Not only are they carriers of a number of diseases, the saliva of some can cause paralysis. North American natives were aware of tick paralysis, but the condition was officially noted as a disease of both animals and humans in 1912. The bites of at least 60 species of ticks can cause paralysis, which often does not appear until several days after the bite. The first indication is redness and swelling around the site of the bite. This is followed by neuromuscular weakness and difficulty in walking. If the tick is not removed, speech and breathing are affected, with eventual respiratory paralysis and death. Fortunately, removal of the tick results in a quick recovery of function. The exact mechanism of paralysis is not known but it appears to come from a substance that affects the neuromuscular junction. While not related to the venom of the tick saliva, the tick can also transmit diseases such as Lyme disease, Rocky Mountain spotted fever, Q fever, typhus, and others. Table 13.1 lists some venomous arachnids. 

Chapman AS, Bakken JS, Folk SM, et al. Diagnosis and management of tickborne rickettsial diseases Rocky Mountain spotted fever, ehrlichiosis, and anaplasmosis—United States A practical guide for physicians and other health-care and public health professionals. MMWR Recomm Rep. 2006 55 1-27. 

Suggested Alternatives for Differential Diagnosis Hepatitis, Legionnaires disease, myocarditis, pericarditis, cardiac tamponade, pneumonia, ehrlichiosis, relapsing fever, Rocky Mountain spotted fever, and tularemia. 

Suggested Alternatives for Differential Diagnosis Scarlet fever, cellulitis, cat scratch disease, gas gangrene, necrotizing fasciitis, tick-borne diseases such as Rocky Mountain spotted fever, pneumonia, septic shock, acute respiratory distress syndrome (ARDS), disseminated intravascular coagulation. 

Rickettsia A microorganism of the genus Rickettsia, made up of small rod-shaped coc-coids occurring in fleas, lice, ticks, and mites by which they are transmitted to man and other animals causing diseases such as typhus, scrub typhus, and Rocky Mountain Spotted Fever in humans. 

Another group of compounds, the tetracyclines, are made by fermentation procedures or by chemical modifications of the natural product. The hydrochloride salts are used most commonly for oral administration and are usually encapsulated because of their bitter taste. Controlled catalytic hydrogenolysis of chlortetracycline, a natural product, selectively removes the 7-chloro atom and produces tetracycline. Doxycycline and minocycline are other important antibacterials. Tetracycline can be prescribed for people allergic to penicillin. Doxycycline prevents traveler s diarrhea. Tetracyclines help many infections including Rocky Mountain spotted fever, Lyme disease, urinary tract infections, bronchitis, amoebic dysentery, and acne. 

Respiratory, skin, and soft-tissue infections UTIs pelvic inflammatory disease (PID) brucellosis trachoma Rocky Mountain spotted fever typhus Q fever lickettsia severe acne (Adoxa) smallpox psittacosis ornithosis granuloma inguinale lymphogranuloma venereum intestinal amebiasis (adjunctive treatment) prevention of rheumatic fever ... 

Inflammatory acne vulgaris, Lyme disease, mycoplasmal disease, Legionella infections. Rocky Mountain spotted fever, chlamydial infections in patients with gonorrhea PO... 

The differential diagnosis includes a number of viral and bacterial diseases, including influenza, meningo-coccemia. Rocky Mountain spotted fever, malaria, and others, as well as noninfectious causes such as idiopathic and thrombotic thrombocytopenic purpuras, hemolytic uremic syndrome, and DlC (disseminated intravascular coagulation). 

Although the clinical usefulness of tetracyclines is limited for most of the common microbial pathogens, they remain drugs of choice (or very effective alternative therapy) for a wide variety of infections caused by less common pathogens. These include brucellosis rickettsial infections such as Rocky Mountain spotted fever, typhus, and Q fever Mycoplasma pneumonia cholera plague Ureaplasma urethritis Chlamydia infections and Lyme disease. Oral doxycycline, 100 mg orally twice a day for 7 days, is a recommended treatment for chlamydial sexually transmitted disease. 

Ticks also live their adult lives among grasses and short shrubs. They are typically larger than mites, and it is the adult female that attaches itself to an animal host for a blood meal. Tick bites themselves can be painful and irritating. More importantly, ticks can carry a number of diseases that affect humans. The most common of these include Rocky Mountain spotted fever, Colorado tick fever, and the latest occurrence of tick-bome infections Lyme disease. 

Clinical usage Tetracylines are effective for sexually transmitted diseases caused by chlamydia and syphilis. They are also commonly used for the treatment of community-acquired pneumonia, Lyme disease, and Rocky Mountain spotted fever, and in combination with other agents for Helicobacter pylori. 

When given either parcnterally or in the diet to experimental animals, PABA protects (hem against otherwise fatal infections of epidemic or murine typhus. Rocky Mountain spotted fever, and tsutsugamushi disea.se. These diseases have been treated clinically with most encouraging results... 

Dumler JS, Walker DH. Diagnostic tests for Rocky Mountain spotted fever and other rickettsial diseases. Dermat Clin. 1994 12 25-36. 

Paddock GD, Greer PW, Ferebee TL, et al. Hidden mortality attributable to Rocky Mountain spotted fever immunohistochemical detection of fatal, serologically unconfirmed disease. J Infect Dis. 1999 179 1469-1476. 

Later many other diseases would be developed for use as weapons, including plague, Rocky Mountain spotted fever, Rift Valley fever, Q fever and various forms of encephalomyelitis. But in 1950 these four looked the most promising potential germ weapons. During the next two decades over seven hundred million dollars would be spent on the development of such weapons in the United States, and hundreds of millions more in research and testing projects in America, Britain and Canada. 

Tetracyclines are effective in the treatment of Rocky Mountain spotted fever, murine typhus, recrudescent epidemic typhus, scrub typhus, Q fever, lymphogranuloma venereum, psittacosis, tularemia, brucellosis, gonorrhea, certain urinary tract infections, granuloma inguinale, chancroid, syphilis, and disease due to Bacteroides and Clostridium. 

Tetracyclines usually are the preferred agents for the treatment of rickettsial diseases. In patients allergic to these drugs, in those with reduced renal function, in pregnant women, and in children <8 years of age who require prolonged or repeated courses of therapy, chloramphenicol may be the drug of choice. Rickettsial diseases, such as Rocky Mountain spotted fever, respond well to chloramphenicol. For adults, a dose of 50 mg/kg/day is recommended for all the rickettsial diseases. The daily dose of chloramphenicol for children with these diseases is 75 mg/kg, divided into equal portions and given every 6-8 hours. Therapy should be continued until the patient has improved and is afebrile for 24—48 hours. 

Lyme disease Tuberculous meningitis Fungal meningitis Rocky Mountain spotted fever Cat scratch disease... 

Chloramphenicol was the first broad-spectrum antibiotic to be used in medicine, but it came under a cloud when long-continued administration produced many cases of aplastic anaemia, which can be life endangering. Its use is now restricted to diseases where it is the most active known remedy, and which are likely to be cured quickly, within the safe period of the drug. Hence it is used to cure typhoid fever, bacterial meningitis, and anaerobic infections of the brain such as those caused by B.fragilis. It is the only common antibiotic to pass freely into the cerebrospinal fluid and to cross the blood—brain barrier. It also serves as a useful alternative to the tetracyclines in cholera and the rickettsial diseases such as typhus or Rocky Mountain spotted fever. 

Rocky mountain spotted fever Disease caused by Rickettsia rickettsia and transmitted by ticks. 

Another category of bacteria that plays a significant role in disease are the so-called rickettsial organisms, named after Harold T. Ricketts, who in 1907 first demonstrated the transmission of Rocky Mountain Spotted Fever (caused by a bacterium now named Rickettsia rickettsii) from a human to a guinea pig. Rocky Mountain Spotted Fever was determined by Picketts to be carried by... 

Antirickettsial. PABA is sometimes used in the treatment of certain rickettsial diseases—diseases in man and animals caused by microscopically small parasites of the genus Rickettsia, notably typhus and Rocky Mountain spotted fever. 

Rocky Mountain spotted fever—This rare disease is caused by rickettsia-parasite-infected wood or dog tick bites. If untreated with antibiotics, this disease can be fatal. 

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