Typhoid fever antibiotic treatment

Typhoid fever caused by Salmonella typhi or S. paratyphi is an important and prevalent cause of continuous fever without localizing symptoms in the tropics. The diagnosis can be confirmed with a bloodculture. Response on therapy is often seen only after 3 days when the fever subsides. Chloramphenicol-resistant Salmonella typhi was first described in Vietnam in 1973. Its prevalence reached 95% in the 1970s and then decreased to 54% in the 1980s after cotrimoxazole became the treatment of choice. In the mid-1993, there was a dramatic increase in the number of strains of S. typhi, isolated in the hospital and from patients in the outbreaks, which are resistant to the three first-line antibiotics chloramphenicol, cotrimoxazol and ampicillin. This indicated that there was an urgent need for effective antibiotics for the treatment of typhoid fever. 

TMP-SMX is also used in the treatment of infection caused by ampicillin-resistant Shigella spp. and for antibiotic-resistant Salmonella spp.. The combination is also effective for covering the carrier state of Salmonella typhi, the agent of typhoid fever, and other Salmonella spp.. Successful treatment of traveler s diarrhea due to susceptible E. coli is another advantage of the use of this combination. The combination is not indicated in the therapy of enterohemorrhagic E. coli strains such as 0157 H7 because of the risk of developing hemolytic-uremic syndrome associated with the release of the cytotoxic enterotoxin by the drugs. 

The third-generation cephalosporins (e.g., ceftriaxone, ceflxime, cefotaxime, and cefoperazole) and azithromycin are also effective drugs for typhoid. Chloramphenicol, amoxicillin, and trimethoprim-sulfamethoxazole remain appropriate for the treatment of typhoid fever in areas of the world where the bacterium is still fully susceptible to these drugs and where the fluoroquinolones are not available or affordable. Although fluoroquinolones are not recommended in children, the pediatric use of ciprofloxacin in areas where multidrug-resistant S. typhi occurs is acceptable. In pregnant women, the p lactam antibiotics are safe, and there are some case reports to support fluoroquinolone use. 

Antibiotics indicated in the treatment of typhoid fever are ceftriaxone 1 g/kg M or IV b.i.d. and fluoroquinolones such as ciprofloxacin 500 mg PO b.i.d. or levofloxa-cin 500 mg or IV for 10-14 days. Fluroquinolones may be also administered in children. Chloramphenicol is still used but aplastic anemia is a consideration. Other antibiotics which are used depending on sensitivity are trimethoprin-sulfamethoxazole, amoxicillin, ampicillin, azithromycin and aztreonam. 

Ciprofloxacin is a fluoroquinolone antibiotic that interferes with microbial DNA synthesis. It is indicated in the treatment of infections of the lower respiratory tract, skin and skin structure, bones and joints, urinary tract gonorrhea, chancroid, and infectious diarrhea caused by susceptible strains of specific organisms typhoid fever uncomplicated cervical and urethral gonorrhea women with acute uncomplicated cystitis acute sinusitis nosocomial pneumonia chronic bacterial prostatitis complicated intra-abdominal infections reduction of incidence or progression of inhalational anthrax following exposure to aerosolized Bacillus anthracis. Cipro IV Used for empirical therapy for febrile neutropenic patients. 

Salmonella paratyphi is a bacterial enteric (intestinal) infection with an abrupt outbreak, which produces the following symptoms continued fever, headache, malaise, enlarged spleen, rose spots on the trunk of the body, and diarrhea. These symptoms are similar to those of typhoid fever, but the death rate is much lower. Mild and asymptomatic infections may also occur upon exposure. Outbreaks and locations are similar to those of the other salmonella bacteria. The infectious dose is 1000 organisms by ingestion. Transmission occurs by direct or indirect contact with feces or, in rare cases, urine of patients or carriers. It is spread by food, especially miUc and dairy products, shellfish, and in some isolated cases, water supplies. Incubation depends on the strength of the dose, but usually 1-3 weeks for enteric fever and 1-10 days for gastroenteritis. Antibiotic treatment with chloramphenicol, ampicillin, or TMP-SMX is usually effective. 

Chloramphenicol an antibiotic, M, 323, from Streptomyces venezuelae. There are 4 stereoisomers, of which only D(-)-threo-C. (Fig.) is an antibiotic. C. inhibits protein synthesis on 70S ribosomes of prokaryotes, and on the mitochondrial ribosomes of eukaryotic cells. Protein synthesis on SOS eukaryotic ribosomes is not affected. C. inhibits peptide bond formation and peptidyl transferase activity on the 50S ribo-somal subunit, by specifically binding to one of the SOS ribosomal proteins involved in these reactions. The protein in question is probably localized in the acceptor-donor region of the ribosome. C. is used as a broad-spectrum antibiotic in the treatment, e.g. of typhoid fever, paratyphus, spotted fever, infectious hepatitis, dysentery, phtheiia and viral influenza . Because it inhibits protein synthesis in mitochondrial ribosomes, C. is relatively toxic. It is now produced entirely synthetically. 

Chloramphenicol (Parke-Davis, 1949) was obtained from the soil bacterium Streptomyces venezuelae. Its use as a systemic treatment is restricted to very severe infections such as typhoid fever when careful clinical assessment indicates that no other antibiotic is effective. This is because it is known to have toxic effects on bone marrow. However, it is used topically for infections of the ear, skin and eye. Its mode of action is by the inhibition of bacterial protein synthesis. 

Chloramphenicol remains a major treatment of typhoid and paratyphoid fever in developing countries. However, with increasing resistance to ampicillin, trimethoprim-sulfamethoxazole and, to some extent, chloramphenicol, fluoroquinolones and some third-generation cephalosporins (e.g., ceftriaxone) have become the drugs of choice. Salmonella infections, such as osteomyelitis, meningitis and septicemia, have also been indications for chloramphenicol use. Nevertheless, antibiotic resistance patterns can be a problem. As noted previously, nonty-phoidal salmonella enteritis is not benefited by treatment with chloramphenicol or other antibiotics. 

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