Urinary tract infections in the elderly.

Urinary infection is the most common infection in elderly populations. There is a high prevalence of asymptomatic bacteriuria, but this is benign and does not require treatment. A urine specimen for culture should be obtained before initiating antimicrobial therapy for symptomatic infection. Antimicrobial treatment regimens in the elderly are similar to other populations. Chronic indwelling catheters are associated with increased morbidity from urinary tract infection.

Variation in mortality rates among long-term care facilities for residents with lower respiratory tract infection.

OBJECTIVE: To identify variables contributing to interfacility differences in mortality among residents of long-term care facilities who have lower respiratory tract infection. DESIGN: Multicenter, prospective, 1-year observational study. SETTING: Twenty-one long-term care facilities in 4 geographic areas of Canada. PARTICIPANTS: Residents of long-term care facilities prescribed antimicrobials for treatment of lower respiratory tract infection. METHODS: Mortality rates were calculated for 3 definitions of lower respiratory tract infection: episodes with a clinical or radiographic diagnosis and treated with antimicrobials (definition 1); episodes with a physician diagnosis of pneumonia (definition 2); and episodes with chest radiography findings consistent with pneumonia (definition 3). Multilevel modeling was used to evaluate variables describing premorbid resident status, clinical presentation, management, and facility characteristics. Multivariable models were developed to identify independent predictors of mortality and determine whether facility-level variables remained independently associated with mortality rate after incorporation of individual-level variables. RESULTS: Facility mortality rates varied from 0% to 17.8% for definition 1, from 0% to 47.1% for definition 2, and from 0% to 37.5% for definition 3. There were significant differences in mortality rate depending on which definition was used; for definitions 1 and 2, there were significant differences in mortality rate across facilities. Poorer premorbid resident status and a more severe presentation remained independent predictors of mortality in the multivariable analysis. There were also significantly increased mortality rates for episodes in which a fluoroquinolone was prescribed for initial treatment. For definitions 1 and 3, facility-level variables remained independently associated with mortality rate in the final multivariable model. CONCLUSIONS: Rates of mortality due to lower respiratory tract infection varied among long-term care facilities and differed within a facility, depending on the definition applied. Variables describing premorbid resident status, severity of presentation, and management did not fully explain the variation in mortality rate. Some facility-level variables remained independent predictors of mortality.

Serological evidence of hepatitis E virus infection in an indigenous North American population.

BACKGROUND: Hepatitis E virus (HEV) infections are thought to be uncommon in North America. Recently, HEV transmission has been reported following the consumption of deer meat. Because deer are closely related to caribou and caribou meat is a staple of the Canadian Inuit and the American Eskimo diet, the present study explored the seroprevalence of HEV infection in an isolated Canadian Inuit community. METHODS: Stored sera were thawed and tested for immunoglobulin (Ig) G and IgM anti-HEV by ELISA, and tested for HEV-RNA by reverse transcriptase polymerase chain reaction. RESULTS: The study consisted of 393 sera (representing approximately 50% of the community's inhabitants). Eleven samples (3%) were IgG anti-HEV-positive. Their mean age was 29+/-8 years and three were male. Two of 11 (18%) were also IgM anti-HEV-positive. All IgG anti-HEV-positive individuals were HEV-RNA-negative. Liver biochemistry was normal in all. Seven of 11 (64%) were also positive for anti-hepatitis A virus, five (46%) were hepatitis B virus seropositive and none (0%) were positive for anti-hepatitis C virus. There were no associations between infections with HEV and other hepatropic viruses. Serological testing was negative for HEV infection in 25 caribou from an adjacent region. CONCLUSION: The results of the present study showed that serological evidence of HEV infection was present in 3% of the observed Canadian Inuit population; the presence of IgM anti-HEV suggested recent infection and HEV did not appear to coinfect with other common hepatotropic viruses. The source of HEV infection in the population remains unclear. These findings are interesting but preliminary. Additional data are required to determine whether HEV infections are responsible for otherwise unexplained acute hepatitis in the Canadian Inuit population and visitors returning from northern North American communities.

Microbiological outcomes in women with diabetes and untreated asymptomatic bacteriuria.

BACKGROUND: Asymptomatic bacteriuria is common in diabetic women. Treatment of asymptomatic bacteriuria is not beneficial, but the natural history of the microbiology of asymptomatic bacteriuria has not been well described. OBJECTIVE: To describe the microbiological outcomes of bacteriuria in diabetic women with untreated asymptomatic bacteriuria. METHODS: Study subjects were initially identified through ambulatory endocrinology clinics. They were enrolled if they had two positive urine cultures > or = 10(8) cfu/l with the same organism within 2 weeks and no symptoms referable to urinary tract infection. Women initially received a 2-week course of placebo with follow-up cultures obtained at the end of treatment and 4 weeks post-treatment. Subsequently, the prevalence of bacteriuria was determined with urine cultures obtained every 3 months to a maximum of 36 months. Outcomes at yearly intervals were designated as one of: persistent bacteriuria; spontaneous resolution; resolution with antibiotics for symptomatic urinary infection; or resolution with antibiotics given for other indications. Women with and without persistent or frequent bacteriuria were compared to identify variables associated with bacteriuria. RESULTS: The prevalence of bacteriuria in the study cohort declined to about 50% by 9 months, and subsequently remained stable throughout 3 years follow-up. Almost 20% of subjects remained bacteriuric with the original infecting organism throughout the period of observation. With evaluation at 12-month intervals, approximately one-quarter of subjects had each of the four potential outcomes of: resolution following antibiotic therapy for symptomatic urinary infection, following antibiotic therapy for other indications, spontaneous resolution without antibiotics, and persistent bacteriuria with the same organism. Women infected with gram-negative organisms were more likely to have persistent bacteriuria. Many women with resolution of initial bacteriuria, with or without antibiotics, became bacteriuric again during follow-up. CONCLUSIONS: Women with asymptomatic bacteriuria and diabetes tend to have persistent or recurrent asymptomatic bacteriuria. Bacteriuria is benign, and seldom permanently eradicable.

Complicated urinary tract infection in adults.

BACKGROUND: Complicated urinary tract infection occurs in individuals with functional or structural abnormalities of the genitourinary tract. OBJECTIVE: To review current knowledge relevant to complicated urinary tract infection, and to provide evidence-based recommendations for management. METHODS: The literature was reviewed through a PubMed search, and additional articles were identified by journal reference review. A draft guideline was prepared and critically reviewed by members of the Association of Medical Microbiology and Infectious Disease Canada Guidelines Committee, with modifications incorporated following the review. RESULTS: Many urological abnormalities may be associated with complicated urinary infection. There is a wide spectrum of potential infecting organisms, and isolated bacteria tend to be more resistant to antimicrobial therapy. Morbidity and infection outcomes in subjects with complicated urinary infection are principally determined by the underlying abnormality rather than the infection. Principles of management include uniform collection of a urine specimen for culture before antimicrobial therapy, characterization of the underlying genitourinary abnormality, and nontreatment of asymptomatic bacteriuria except before an invasive genitourinary procedure. The antimicrobial regimen is determined by clinical presentation, patient tolerance, renal function and known or anticipated infecting organisms. If the underlying abnormality contributing to the urinary infection cannot be corrected, then early post-treatment recurrence of infection is anticipated. CONCLUSIONS: The management of complicated urinary infection is individualized depending on patient variables and the infecting organism. Further clinical investigations are necessary to assist in determining optimal antimicrobial regimens.

Serological studies of West Nile virus in a liver transplant population.

BACKGROUND: Solid organ transplant populations are at increased risk for serious clinical manifestations of West Nile virus (WNV) infection. OBJECTIVE: To monitor liver transplant recipients during the 2003 WNV season in Manitoba and to identify incidence, clinical presentation and serology. METHODS: Serial blood specimens were obtained from adult patients followed at the liver transplant outpatient clinic between May 2003 and October 2003. Studies for WNV infection included immunoglobulin (Ig) G and IgM enzyme immunoassay (EIA), hemagglutination inhibition (HI), plaque reduction neutralization test and reverse transcriptase-polymerase chain reaction. RESULTS: None of the 79 patients had clinical presentations suggestive of WNV infection. On testing of the final serum specimen obtained, 14 patients (18%) had positive IgG anti-WNV by EIA and six patients (7%) had indeterminate IgG anti-WNV by EIA, although all were negative by IgM EIA. Four (20%) of the EIA-positive samples were reactive by HI, but all of these were negative by WNV plaque reduction neutralization test; this is consistent with the presence of non-West Nile flavivirus antibody in these sera. Blood specimens obtained throughout the season from EIA- and HI-positive individuals were uniformly negative for WNV-RNA by reverse transcriptasepolymerase chain reaction. Age, sex, hematology and biochemistry findings, hepatitis B or C virus status, immunosuppressive regimen (cyclosporin or tacrolimus) and pretransplant diagnosis of liver disease were similar for EIA-positive and EIA-negative patients. For the 10 patients with a positive IgG EIA maintained on cyclosporin, the cyclosporin level was 129.1+/-28.6 microg/L compared with 85.6+/-36.7 microg/L in 26 patients who were EIA-negative (P=0.002). CONCLUSIONS: False-positive IgG EIA serology for WNV was common in this cohort of liver transplant recipients, and was associated with elevated serum cyclosporin levels.

Three days of pivmecillinam or norfloxacin for treatment of acute uncomplicated urinary infection in women.

Pivmecillinam is a unique beta-lactam antimicrobial that has been used for the treatment of acute uncomplicated urinary infection for > 20 y. Since this agent was introduced, the quinolone antimicrobials have become widely used for the same indication. This study compared the efficacy of a 3-d regimen of pivmecillinam 400 mg b.i.d. with norfloxacin 400 mg b.i.d. Women aged between 18 and 65 y presenting with symptoms of acute cystitis of < 7 d duration were eligible for enrollment; 483 were randomized to receive pivmecillinam and 471 to receive norfloxacin. In each group, 30% of women had negative urine cultures prior to therapy. Bacteriologic cure at early post-therapy follow-up was achieved in 222/298 (75%) pivmecillinam patients and 276/302 (91%) norfloxacin patients [p < 0.001; 95% confidence interval (CI) 12.0-21.8]. Clinical cure/improvement at Day 4 following initiation of therapy was observed in 434/457 (95%) women who received pivmecillinam and 425/442 (96%) who received norfloxacin (p = 0.39; 95% CI 1.5-3.9). Early post-therapy (11 +/- 2 d) clinical cure was achieved in 360/437 women (82%) who received pivmecillinam and 381/433 (88%) who received norfloxacin (p = 0.019; 95% CI 0.9-10.3). In women aged < or = 50 y, early clinical cure rates were 294/351 (84%) for pivmecillinam and 299/340 (88%) for norfloxacin (p = 0.11; 95% CI 1.0-9.4). Adverse effects were similar for both regimens, and there was no evidence of the emergence of organisms of increasing resistance with therapy. Short-course therapy with norfloxacin was superior to that with pivmecillinam in terms of bacteriologic outcome, although differences in clinical outcome were less marked. In conclusion, short-course therapy with pivmecillinam is an effective empirical treatment for pre-menopausal women.