Risk of recurrent nontyphoid Salmonella bacteremia in HIV-infected patients in the era of highly active antiretroviral therapy and an increasing trend of fluoroquinolone resistance.
BACKGROUND
Risk of recurrent nontyphoid Salmonella (NTS) bacteremia and trends of antimicrobial resistance of NTS remain unknown in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART).


METHODS
Ninety-three patients who received a diagnosis of NTS bacteremia from June 1994 through June 2006 were prospectively followed up. Incidence of recurrent NTS bacteremia was compared between the pre-HAART era (June 1994-March 1997) and the HAART era (April 1997-June 2006). Prevalence of antimicrobial resistance was compared among the NTS isolates obtained in the pre-HAART era, the early HAART era (April 1997-June 2002), and the late HAART era (July 2002-June 2006).


RESULTS
Compared with patients enrolled in the pre-HAART era, patients who received HAART had an incidence of recurrent NTS bacteremia that was significantly reduced by 96%; the incidence of recurrent NTS bacteremia was 2.56 cases per 100 person-years in the HAART era, compared with 70.56 cases per 100 person-years in the pre-HAART era (rate ratio, 0.036; 95% confidence interval, 0.012-0.114; P<.001). In the HAART era, the incidence of recurrent NTS bacteremia did not increase among patients receiving fluoroquinolone prophylaxis for <or=30 days (1.69 cases per 100 person-years), compared with among patients receiving fluoroquinolones for >30 days (3.95 cases per 100 person-years), with a rate ratio of 0.43 (95% confidence interval, 0.07-2.58). Although resistance to ampicillin, cotrimoxazole, and chloramphenicol decreased, the proportion of NTS isolates resistant to fluoroquinolones increased from 0% in the pre-HAART era to 6.2% in the early HAART era and 34.2% in the late HAART era (P=.002).


CONCLUSIONS
The risk of recurrent NTS bacteremia decreased significantly in the HAART era, although NTS isolates obtained from HIV-infected patients were increasingly resistant to fluoroquinolones.
Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. hcc0401@ntu.edu.tw
Chien-Ching
CC
Hung
Min-Nan
MN
Hung
Po-Ren
PR
Hsueh
Sui-Yuan
SY
Chang
Mao-Yuan
MY
Chen
Szu-Min
SM
Hsieh
Wang-Huei
WH
Sheng
Hsin-Yun
HY
Sun
Yu-Tsung
YT
Huang
Yi-Chun
YC
Lo
Chin-Fu
CF
Hsiao
Shan-Chwen
SC
Chang
D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D016470:Bacteremia / Q000150:complications* / Q000453:epidemiology*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology*; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012008:Recurrence; D012480:Salmonella Infections / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D013624:Taiwan / Q000453:epidemiology
D044966:Anti-Retroviral Agents; D024841:Fluoroquinolones