General considerations in the management of typhoid fever and dysentery

Fleroxacin vs Ciprofloxacin in the Management of Typhoid Fever: A Randomised, Open, Comparative Study in Nigerian Patients

OBJECTIVE

The antibacterial efficacy of fleroxacin was compared with that of ciprofloxacin in 72 adult Nigerian patients with typhoid fever.

PATIENTS AND METHODS

On inclusion into the study, patients were randomised to treatment with either fleroxacin 400mg once daily for 7 days or ciprofloxacin 500mg twice daily for 14 days. Clinical evaluations were performed on days 0, 1, 2, 3, 5 and 7 or 14, and 2 weeks after treatment. Bacteriology was performed on days 0, 3, 7 or 14, and 21 or 28. Laboratory tolerability parameters were monitored for all patients as well as incidence of adverse events.

RESULTS

Bacteriological response on day 3 was 93.5 and 64.0% for fleroxacin and ciprofloxacin, respectively. At term and follow-up there was bacteriological cure in 97.0% of patients with fleroxacin and 100% with ciprofloxacin. The clinical cure was 100% for both groups at term. The incidence of adverse events was 5.4% with fleroxacin and 2.8% with ciprofloxacin.

CONCLUSION

The results demonstrated that while the clinical response rate with both drugs was comparable, fleroxacin exhibited a faster bacteriological clearance rate. We therefore concluded that 7 days' therapy with fleroxacin 400mg once daily was as effective as 14 days' therapy with ciprofloxacin 500mg given twice daily in the management of typhoid fever in Nigerian patients. It was also observed that the quinolones possessed greater potential and benefits as first-line therapy for the management of typhoid fever in this environment. The tolerability profile was good for both treatment regimens.

Problem pathogens: extra-intestinal complications of Salmonella enterica serotype Typhi infection

Typhoid fever, caused by Salmonella enterica seroptype Typhi (S typhi), has an estimated worldwide prevalence of 12-33 million cases. The pathogenesis of this disease depends on the ingested inoculum size of S typhi, the virulence of the strain, the host's immune response and previous exposure, and local protective factors. Numerous extra-intestinal complications can occur with S typhi infection, including the involvement of the central nervous system (3-35%), cardiovascular system (1-5%), pulmonary system (1-86%), bone and joints (< or =1%), hepatobiliary system (1-26%), genitourinary system (<1%), and others. Due to an increase in multidrug-resistant S typhi, fluoroquinolones and third-generation cephalosporins have been increasingly used for typhoid fever and its complications. We describe the epidemiology, clinical manifestations, pathogenesis, and treatment of extra-intestinal S typhi infections.

Treatment of enteric fever with pefloxacin for 7 days versus 5 days: a randomized clinical trial

In this prospective study of enteric fever, 22 patients received 400 mg of pefloxacin twice daily for 5 days (group A) and 24 received 400 mg of pefloxacin twice daily for 7 days (group B). Causative microorganisms were Salmonella typhi (8 in group A, 11 in group B) and Salmonella paratyphi B (14 in group A, 13 in group B). The clinical cure and bacterial eradication rates were 96% (21 of 22) in group A and 100% in group B. In conclusion, 5-day oral administration of pefloxacin was as effective as 7-day treatment of enteric fever caused by Salmonella spp.

Typhoid fever associated with adult respiratory distress syndrome

Adult respiratory distress syndrome (ARDS) is rarely reported in association with typhoid fever despite the fact that sepsis is a common manifestation and endotoxemia has been described in this multisystem condition. We describe the course of a patient with ARDS and typhoid fever. With conventional treatment of the lung injury and with specific antimicrobial therapy, the patient survived. Recent consensus definitions of sepsis and ARDS simplified reporting of this case. Clinicians caring for individuals from or recent visitors to developing countries should be aware of the association of typhoid fever, sepsis, and ARDS.

Resistance to the nitroheterocyclic drugs

The nitroheterocyclic drugs have been available since the early 1960's for the treatment of anaerobic protozoa. The application of these drugs has widened since then and they are presently used to treat anaerobic pathogenic bacteria and protozoa. The activity of the nitroheterocyclic drugs depends on the all-important nitro group attached to the imidazole or furan ring. Although the nitro radicals, generated by reduction of the parent drugs, are similar for both families of nitroheterocyclics, the nitroimidazoles and the nitrofurans, the electron potential of each is different and thus the mechanism of action depends on different pathways. The nitroimidazoles depend on reduction by ferredoxin or flavodoxin. The nitrofurans require nitroreductase activity, but the natural substrate of these enzymes has not been identified. Increased use of nitroheterocyclic drugs, in response to drug resistance to other commonly used antibiotics, has in turn resulted in drug resistance to a number of nitroheterocyclic drugs. Bacteroides strains and other bacteria, including Helicobacter, have developed resistance. Among the protozoa, Trichomonas has developed resistance to metronidazole via a number of mechanisms, especially a decrease in drug reduction, as a result of alterations in the electron transport pathways. Resistance to both types of nitroheterocyclic drugs has been reported in Giardia. Although resistance to these drugs is not widespread, their increased use world-wide as a prophylaxis and in chemotherapy will inevitably result in increased resistance in organisms commonly found in asymptomatic infections, including Trichomonas, Giardia and Entamoeba. However, the variety of substitutions which can be attached to the ring structures has led to a great variety of drugs being synthesised, some of which are many-fold more active than the commonly prescribed nitroheterocyclics. With careful administration of currently available drugs and continued interest in synthesising more active compounds, we can optimistically expect to have useful nitroheterocyclic drugs available for some time.

Multi-drug resistant typhoid fever in hospitalised children. Clinical, bacteriological and epidemiological profiles

A total of 592 children with clinical diagnosis of typhoid fever admitted to the Dr B. C. Roy Memorial Hospital for Children, Calcutta, India during the period between February 1990 and January 1992, were screened for Salmonella typhi by blood culture. S. typhi was isolated from 221 (37.3%) cases. The majority of the strains (92.3%) showed multi-drug resistant (MDR). They were resistant to chloramphenicol, ampicillin, tetracycline and trimethoprim-sulphamethoxazole. However, all the strains were uniformly (100%) susceptible to gentamicin, amikacin, furazolidone, norfloxacin and ciprofloxacin. Minimum inhibitory concentration of the antimicrobial agents against the resistant strains of S. typhi ranged between 200 and > 1600 micrograms/ml. Phage type 0 was most frequently encountered. The rate of isolation of S. typhi was more or less the same in all the pediatric age groups. The majority of the cases came from lower socio-economic classes with poor personal hygiene. Fever was the main presenting feature in all the cases. Other associated features of the MDR typhoid fever cases, who were uncomplicated during admission, were headache (36.0%), chill and rigor (23.2%), diarrhea (37.2%), anorexia (26.2%), vomiting (23.8%), cough (18.0%) and abdominal pain (19.8%). Hepatosplenomegaly was present in 42.4% cases. However, complications were less frequently encountered among the MDR typhoid fever cases who were uncomplicated during admission and treated as in-patients. Fourteen bacteriologically-confirmed MDR typhoid fever cases had jaundice and another 18 cases had an abnormal state of consciousness during admission. Four (2.0%) bacteriologically-confirmed MDR typhoid fever patients died during the period of observation.

Randomized clinical trial of furazolidone for typhoid fever in children

The efficacy of furazolidone and chloramphenicol was compared in a randomized trial involving 133 children with bacteriologically confirmed typhoid fever. Sixty-five children were randomized to receive furazolidone, 7.5 mg/kg/day, and 68 children to receive chloramphenicol, 75 mg/kg/day. Both drugs were administered orally. The clinical characteristics of the two treatment groups were comparable on admission. All the strains of Salmonella typhi isolated from the furazolidone group were susceptible to furazolidone. However, of the 68 strains of S. typhi isolated from the chloramphenicol group, 10 were susceptible and 58 were resistant to chloramphenicol. Clinical and bacteriologic cure was observed in 56 (86.2%) children treated with furazolidone and in 35 (51.5%) children given chloramphenicol who were infected with S. typhi strains, irrespective of susceptibility pattern (P = 0.00003). Cure was achieved in 86.2% of furazolidone recipients and 90.0% of chloramphenicol recipients who were infected with strains of S. typhi susceptible to both drugs (P = 0.6). The difference in cure rate was statistically significant (P = 0.000003) when the two treatment groups infected with furazolidone-susceptible but chloramphenicol-resistant strains of S. typhi were compared. There was no relapse or carriers in either of the groups. Furazolidone appears to be a satisfactory alternative to chloramphenicol in the treatment of typhoid fever caused by chloramphenicol-resistant strains of S. typhi.