Rickettsial infections

Tetracycline Demeclocy dine, minocycline, and tetracycline Syphilis, chlamydial infections and Lyme disease, mycoplasmal diseases and acne rickettsial infections... 

Suggested Alternatives for Differential Diagnosis Malaria, typhoid fever, shigellosis, meningococcemia, salmonella infection, other tick-borne diseases, rickettsial infections, leukemia, lupus, disseminated intravascular coagulation, hemolytic uremic syndrome, leptospirosis, thrombocytopenic purpura, and idiopathic or thrombotic thrombocytopenic purpura. 

Adults 50 mg/kg/day in divided doses every 6 hours for typhoid fever and rickettsial infections. Exceptional infections (ie, meningitis, brain abscess) caused by moderately resistant organisms may require dosage up to 100 mg/kg/day to achieve... 

Tetracyclines remain the agents of choice in rickettsial infections, and are also used in chlamydial, vibrio, mycoplasmal and spirochaetal infections, brucellosis and the management of chronic bronchitis and acne. They are used in combination with other agents in the treatment of malaria and amoe-biasis, and doxycycline is used for prophylaxis of malaria. 

Miscellaneous infections caused by susceptible strains of bacteria causing psittacosis, cholera, melioidosis, leptospirosis, brucellosis, bartonellosis, plague, tularemia, Campylobacter fetus infection, rickettsial infections including typhus and Q fever, relapsing fever due to Borrelia recurrentis and actinomycosis in penicillin allergic patients. 

Because of potential toxicity, bacterial resistance, and the availability of many other effective alternatives, chloramphenicol is rarely used. It may be considered for treatment of serious rickettsial infections such as typhus and Rocky Mountain spotted fever. It is an alternative to a B-lactam antibiotic for treatment of meningococcal meningitis occurring in patients who have major hypersensitivity reactions to penicillin or bacterial meningitis caused by penicillin-resistant strains of pneumococci. The dosage is 50-100 mg/kg/d in four divided doses. 

Chloramphenicol. Chloramphenicol (Chloromycetin) is a synthetically produced agent that exerts antibacterial effects similar to those of erythromycin that is, it binds to the 50S subunit of bacterial ribosomes and inhibits peptide bond formation. Chloramphenicol is a broad-spectrum antibiotic that is active against many gram-negative and gram-positive bacteria. This drug is administered systemically to treat serious infections such as typhoid fever, Haemophilus infections such as osteomyelitis, rickettsial infections such as Rocky Mountain spotted fever, and certain forms of meningitis. Chloramphenicol may also be administered topically to treat various skin, eye, and ear infections. 

Additional considerations include vaccinations of investigators against rabies or tuberculosis, especially when working with some mammals and their parasites. These preventative measures are needed to protect the researcher. Animal necropsy should include protective clothing and the containment of possible biohazards, in order to avoid contracting diseases such as psittacosis, erysipelas, rickettsial infections, and brucellosis.5 The... 

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. 

There have been rare reports of an association between sulfonamide antibiotics and increased severity of rickettsial infections. Sulfonamides do not increase the pathogenicity of Ehrlichia species, but a case of human monocytic ehrlichiosis compUcated by ARDS has previously been reported in a patient who had taken oral co-trimoxazole. It has been speculated that oral co-trimoxazole, given for acne, may have contributed to the unusual severity of Ehrlichia chaffeensis infection that progressed to respiratory faUure in a previously healthy 16-year-old boy (166). 

Salmonella typhi, S, pneumoniae. B. J rugilix, and N. meningitidis. Because of its penetration into the central nervous sy.stcm, chloramphenicol is a particularly important alternative therapy for meningitis. It is not recommended for the treatment of urinary tract infections bccau.se, i to 10% of the unconjugated form is excreted in the urine. Chloramphenicol is also used fur the treatment of rickettsial infections, such as Rocky Mountain spotted fever. 

Acute abdomen Leptospirosis Meningococcemia Other causes of renal failure Poststreptococcal nephritis Rickettsial infection... 

Recently IHC has been successfully used to identify Streptococcus pneumoniae in formalin-fixed organs with an overall sensitivity of 100% and a specificity of 71% when compared with cultures.Immunohistochemical assays are used to identify Clostridium sp., S. aureus, and S. pyogenes Haemophilus influenzae Chlamydia species i i Legionella pneumophila and L. dumoffiif Listeria monocytogenesf Salmonellaand rickettsial infections other than Rocky Mountain spotted fever such as boutonneuse fever, epidemic typhus, murine typhus,rickettsialpox, 489 African tick bite fever,i and scrub typhus. 

These drugs are useful in the therapy of Lyme disease and chlamydia infections. They are drugs of choice in rickettsial infections. 

Rickettsial Infections Tetracyclines may be life-saving in rickettsial infections, including Rocky Mountain spotted fever, recrudescent epidemic typhus, scrub typhus, rickettsialpox, and Q fever. Improvement often is evident within 24 hours. Doxycycline is the drug of choice for suspected or proven Rocky Mountain spotted fever in adults and children, including those <9 years of age, in whom the risk of staining of teeth is outweighed by the seriousness of the potentially fatal infection. 

Sulfonamides have minimal therapeutic actions in rickettsial infections. Chloramphenicol may be used for Rocky Mountain spotted fever in patients with established allergy or other contraindication to tetracyclines. The answer is (C). 

Antibiotic tetracycline prototype bacteriostatic inhibitor of protein synthesis (SOS). Broad spectnun, but many resistant organisms. Used for mycoplasmal, chlamydial, rickettsial infections, chronic bronchitis, acne, cholera a backup drug in syphilis. Tox GI upset and superinfections, antianaboUc actions. Fan-coni s syndrome, photosensitivity, dental enamel dysplasia. 

Typhoid fever and similar salmonellal infections are usually considered the prime indications for the use of chloramphenicol. It is also employed in acute infections due to Heamophilus influenzae, including meningitis attributed to ampicillin-resistant strains. It also find its enormous applications in topical infections of eye and skin. It has also been used to eradicate vibrios from patients with cholera. It is employed for rickettsial infections like typhus and Rocky Mountain spottedfever. 

Despite potentially serious limitations, chloramphenicol is an effective drug when used carefully. Its special value is in typhoid fever, Haemophilus infections (especially epiglottitis and meningitis, when given along with ampicillin), rickettsial infections, and in cases in which susceptible organisms have proven to be... 

Gray GC, Rodier GR, Matras-Maslin VC, et al. Serologic evidence of respiratory and rickettsial infections among Somali refugees. Am J Trop Med Hyg. 1995 52(4) 349-353. 

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