Case Series of Imported Enteric Fever at a Referral Center in Tokyo, Japan: Antibiotic Susceptibility and Risk Factors for Relapse.

Owing to the increase in Salmonella strains with decreased fluoroquinolone susceptibility in the endemic areas, we have been treating enteric fever with intravenous ceftriaxone empirically since 2007. In this study, we reevaluated our treatment protocol. This retrospective cohort study was conducted at a single institute in Tokyo, Japan, between January 2006 and December 2013. Enteric fever was defined as isolation of Salmonella Typhi or Salmonella Paratyphi A, B, and C from the blood and/or stool of patients with fever. Of the 35 patients with imported enteric fever, 28 (80%) had returned from south Asia. Ciprofloxacin-susceptible strains were detected in only 12% of the cases. The isolates showed excellent susceptibility to ampicillin (91%), chloramphenicol (94%), ceftriaxone (97%), and azithromycin (97%). One case of Salmonella Paratyphi B was excluded, and of the remaining 34 patients, 56% were treated with ceftriaxone alone, 26% with ceftriaxone then fluoroquinolone, and 9% with levofloxacin alone. The overall relapse rate was 6.1%; however, among those receiving ceftriaxone monotherapy, the relapse rate was 11% (N = 2). The relapse group was characterized by longer times to treatment initiation (P = 0.035) and defervescence (> 7 days) after treatment initiation (P = 0.022). In such cases, we recommend that ceftriaxone treatment be continued for > 4 days after defervescence or be changed to fluoroquinolone if the strains are found to be susceptible to prevent relapse. Furthermore, ampicillin and chloramphenicol, which are no longer prescribed, may be reconsidered as treatment options in Asia.

Trends in antibiotic susceptibility of enteric fever isolates in East London.

BACKGROUND: The study sought evidence for changes in the proportions of antibiotic resistant strains among isolates of Salmonella enterica serovar Typhi (S. typhi) and Salmonella enterica serovar Paratyphi (S. paratyphi) between 2005 and 2012. METHODS: Blood culture isolates of S. typhi and S. paratyphi from patients attending Newham and The Royal London Hospitals were included in the study. The organisms were cultured on selective media and identified by Maldi-ToF, API 20E and serology. Minimum inhibitory concentrations (MICs) of augmentin, chloramphenicol, co-trimoxazole, ceftriaxone, ciprofloxacin and azithromycin were determined by E tests for 194 isolates. RESULTS: Median MICs of ciprofloxacin and ceftriaxone were stable at 0.5 mg/L and 0.125 mg/L, respectively. Chloramphenicol, azithromycin, co-trimoxazole and augmentin median MICs were 4 mg/L, 8 mg/L, 0.064 mg/L and 0.5 mg/L, respectively. MIC90 values were lower than the resistant breakpoint for ceftriaxone, azithromycin and augmentin, but were >256 mg/L for chloramphenicol, 32 mg/L for co-trimoxazole and 1 mg/L for ciprofloxacin. CONCLUSIONS: Antibiotic resistance remained stable for enteric fever isolates between 2005 and 2012. The isolates remained susceptible to augmentin, ceftriaxone and azithromycin over this period, but the MIC90 was greater than the resistant breakpoint for chloramphenicol, cotrimoxazole and ciprofloxacin. The implications for clinical practice are that isolates of S. typhi and S. paratyphi from East London remain sensitive to ceftriaxone and azithromycin.

Laboratory-based surveillance of paratyphoid fever in the United States: travel and antimicrobial resistance.

BACKGROUND: The incidence of paratyphoid fever, including paratyphoid fever caused by antimicrobial-resistant strains, is increasing globally. However, the epidemiologic and laboratory characteristics of paratyphoid fever in the United States have never been studied. METHODS: We attempted to interview all patients who had been infected with laboratory-confirmed Salmonella serotypes Paratyphi A, Paratyphi B, or Paratyphi C in the United States with specimens collected from 1 April 2005 through 31 March 2006. At the Centers for Disease Control and Prevention (CDC), isolates underwent serotype confirmation, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis typing. RESULTS: Of 149 patients infected with Salmonella Paratyphi A, we obtained epidemiologic information for 89 (60%); 55 (62%) of 86 were hospitalized. Eighty-five patients (96%) reported having travel internationally, and 80 (90%) had traveled to South Asia. Of the 146 isolates received at the CDC, 127 (87%) were nalidixic acid resistant; nalidixic acid resistance was associated with travel to South Asia (odds ratio, 17.0; 95% confidence interval, 3.8-75.9). All nalidixic acid-resistant isolates showed decreased susceptibility to ciprofloxacin (minimum inhibitory concentration, > or = 0.12 microg/mL). Of 49 patients infected with Salmonella Paratyphi B, only 12 (24%) were confirmed to have Paratyphi B when tested at the CDC. Four (67%) of 6 patients were hospitalized, and 5 (83%) reported travel (4 to the Andean region of South America). One case of Salmonella Paratyphi C infection was reported in a traveler to West Africa with a urinary tract infection. CONCLUSIONS: Physicians should be aware of the increasing incidence of infection due to Salmonella Paratyphi A and treatment options given its widespread antimicrobial resistance. A paratyphoid fever vaccine is urgently needed. Continued surveillance for paratyphoid fever will help guide future prevention and treatment recommendations.

Ceftriaxone-resistant Salmonella septicemia and osteomyelitis in sickle cell disease adults.

The majority of data evaluating Salmonella infections in sickle cell anemia (SCD) comes from studies performed in children. We report a SCD adult who presented with ceftriaxone-resistant Salmonella bacteremia. After appropriate initial therapy, persistent back pain prompted evaluation by magnetic resonance imaging of the spine, which revealed osteomyelitis and a psoas abscess. The patient responded to percutaneous drainage and antibiotics. This report summarizes some of the findings of large SCD studies evaluating Salmonella bacteremia and osteomyelitis, focusing on adults. Our case exemplifies the need for antibiotic coverage for Salmonella species in adult SCD patients with septicemia. We argue that imaging studies looking for osteomyelitis should be done routinely in SCD patients with Salmonella bacteremia.

Acute disseminated histoplasmosis complicated with hypercalcaemia.

A case of acute progressive disseminated histoplasmosis complicated with hypercalcemia is reported and the literature is reviewed. This and the previously reported cases imply that physicians should have a higher index of suspicion for this infection and the probable underlying diseases resulting from impaired cellular-mediated immunity when encountering patients with hypercalcaemia.

Antimicrobial susceptibilities and beta-lactamase production of Hong Kong isolates of gastroenteric salmonellae and Salmonella typhi.

We examined the in-vitro antibiotic susceptibility of 760 gastroenteric salmonellae and 36 strains of Salmonella typhi isolated in Hong Kong between 1985 and 1988. S. typhi remained susceptible to all the antibiotics tested except for one isolate resistant to chloramphenicol, another to kanamycin and co-trimoxazole, and a third to nalidixic acid. In contrast, resistance and multiple resistance has increased significantly in gastroenteric salmonellae over the last ten years. Seventeen percent were resistant to ampicillin, 61% to tetracycline, 23% to chloramphenicol and 8% to gentamicin. Many ampicillin-resistant strains remained resistant to ampicillin even in the presence of sulbactam (69%) or clavulanic acid (25%). More than 50% of isolates were resistant to two or more antibiotics and one isolate was resistant to eleven. Ampicillin-resistance was usually due to the production of TEM-1 or OXA-1 beta-lactamases but a few isolates produced AER-1, PSE-1 or PSE-2. Genetic determinants for these enzymes were usually borne on plasmids ranging in size from 2 to 143.7 Md but half of the OXA-1 genes were chromosomally located.