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.

Single-dose compared with 3-day norfloxacin treatment of uncomplicated urinary tract infection in women. Canadian Infectious Diseases Society Clinical Trials Study Group.

UNLABELLED: BACKGROUND--This study was undertaken to determine whether therapy for acute uncomplicated urinary tract infection in women with single-dose therapy with norfloxacin was superior to 3 days of norfloxacin therapy in efficacy or adverse effects. METHODS--The study was a multicenter, prospective, randomized, double-blind trial. Women with acute, uncomplicated urinary tract infection were randomized to receive norfloxacin, 800 mg as a single dose or 400 mg twice daily for 3 days. Clinical and laboratory evaluations were obtained before therapy and at days 3 and 7 and 4 to 6 weeks after initiation of therapy. RESULTS--The 83 subjects for whom data could be evaluated who received 3-day therapy had significantly improved outcome compared with the 73 subjects for whom data could be evaluated who received single-dose therapy at 3 days and 7 days after initiation of therapy. At 4 to 6 weeks, 88% of subjects who received 3 days of therapy remained cured, compared with 78% who received single-dose therapy. Three-day and single-dose therapy were equivalent for Escherichia coli infection, but single-dose therapy was significantly less effective for other organisms, primarily because of failure of treatment of Staphylococcus saprophyticus infection. Women older than 40 years were significantly less likely to be cured with either treatment regimen and with single-dose therapy. Adverse effects were similar for both treatment regimens. CONCLUSIONS: -Three days of norfloxacin therapy is more effective than single-dose therapy for women with acute, uncomplicated urinary tract infection. The two regimens are equally effective for E coli infection, but single-dose therapy is ineffective for S saprophyticus.

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.

Prospective randomized comparison of therapy and no therapy for asymptomatic bacteriuria in institutionalized elderly women.

Fifty elderly (mean age, 83.4 +/- 8.8 years) institutionalized women with asymptomatic bacteriuria were randomly assigned either to receive therapy for treatment of all episodes of bacteriuria identified on monthly culture or to receive no therapy unless symptoms developed. Subjects were followed for one year. The therapy group had a mean monthly prevalence of bacteriuria 31 +/- 15 percent lower than those in the no-therapy group, but periods free of bacteriuria lasting six months or longer were documented for only five (24 percent) subjects. For residents receiving no therapy, 71 percent showed persistent infection with the same organism(s). Antimicrobial therapy was associated with an increased incidence of reinfection (1.67 versus 0.87 per patient-year) and adverse antimicrobial drug effects (0.51 versus 0.046 per patient-year) as well as isolation of increasingly resistant organisms in recurrent infection when compared with no therapy. No differences in genitourinary morbidity or mortality were observed between the groups. Thus, despite a lowered prevalence of bacteriuria, no short-term benefits were identified and some harmful effects were observed with treatment of asymptomatic bacteriuria. These data support current recommendations of no therapy for asymptomatic bacteriuria in this population.

Gross hematuria in residents of long-term-care facilities.

PURPOSE: To describe the epidemiology and characteristics of gross hematuria in elderly residents of nursing homes and to identify the associations of gross hematuria with urinary infection and the potential contribution of urinary infection to morbidity. PATIENTS AND METHODS: This was a prospective, descriptive study of episodes of gross hematuria identified by the nursing staffs at two long-term-care facilities over 2 years. Episodes were characterized with respect to patient variables, presence of bacteriuria, duration of hematuria, therapeutic interventions, and genitourinary investigations. Clinical and serologic criteria were used to identify invasive infection. RESULTS: The incidence of gross hematuria was 31/100,000 resident days. Bacteriuria was present in 58 (74%) of 78 episodes with evaluable cultures. Fifty-two (61%) episodes lasted more than 24 hours, 25 (29%) were temporally associated with fever, and antimicrobials were given for 53 (61%) episodes. Gross hematuria occurred more frequently in men than in women and was more frequently associated with fever in men. Twenty-four (28%) episodes occurred in subjects with indwelling catheters, 30 (34%) in subjects with known genitourinary abnormalities, 26 (30%) in subjects with no genitourinary investigations, and 4 (4.6%) in subjects with genitourinary investigations but no abnormalities identified. No adverse clinical outcomes were identified in patients in whom antimicrobial therapy was not initiated. The maximal estimated incidence of invasive urinary infection associated with hematuria was 5.8/100,000 resident days, and of bacterial hemorrhagic cystitis, 6.3/100,000 resident days. CONCLUSIONS: These data suggest that underlying genitourinary abnormalities are present in most elderly institutionalized subjects with gross hematuria when genitourinary investigations are performed. Although bacteriuria is usually present, urinary infection, by itself, is an infrequent cause of gross hematuria. Afebrile hematuria without irritative symptoms probably does not require antimicrobial therapy. A standard approach to this clinical problem in the institutionalized elderly should be developed to optimize patient management and appropriate use of antimicrobial therapy.

Febrile urinary infection in the institutionalized elderly.

PURPOSE: Bacteriuria is common among institutionalized elderly populations, but the contribution of urinary infection to febrile morbidity is unknown because of difficulties in clinical ascertainment. This study was undertaken to febrile morbidity using both clinical and serologic criteria. METHODS: Episodes of fever in residents of two long-term care institutions were identified prospectively for 2 years. Serum and urine specimens were obtained initially and at 4 weeks. The proportion of episodes attributable to urinary infection was determined by both standard clinical criteria proposed for use in these populations and serum antibody response to uropathogens. RESULTS: For 372 fewer episodes, 211 met clinical criteria for infection: 147 (40%) of the respiratory tract; 26 (7%) of the genitourinary tract; 25 (6%) of the gastrointestinal tract; and 13 (3%) of skin and soft tissue. Of the remaining 161 fever episodes, 2 (1%) were noninfectious and 159 (43%) were of unknown origin. The prevalence of bacteriuria for residents with nongenitourinary sources of fever varied from 32% to 75%. An antibody response meeting serologic criteria for urinary infection occurred in 26 (8.3%) of 314 episodes with paired sera obtained; 10 (43%) of 23 identified clinically as genitourinary infection, 14 (11%) of 132 unknown, 1 (4%) of 25 gastrointestinal, and 1 (0.8%) of 122 respiratory. The positive predictive value of bacteriuria for febrile urinary infection identified by clinical criteria was was 11% (95% confidence interval [CI] 4%, 18%) and identified by serologic criteria was 12% (95% CI 7%, 17%). CONCLUSIONS: Urinary infection contributes to less than 10% of episodes of clinically significant fever in this high-prevalence bacteriuric population. A restrictive clinical definition for genitourinary infection has poor sensitivity and specificity compared with serologic criteria for identification of fever of urinary source, and bacteriuria has a low predictive value for identifying febrile urinary infection.

A practical guide to the management of complicated urinary tract infection.

Complicated urinary tract infections are infections in the setting of structural or functional abnormalities of the genitourinary tract. They encompass a wide variety of clinical syndromes and anticipated outcomes. The infecting micro-organisms isolated are more varied and demonstrate a higher prevalence of antimicrobial resistance in complicated compared to uncomplicated urinary tract infections. The usual duration of therapy is 7 to 14 days, although comparative trials to define optimal treatment duration are lacking. Long term success of antimicrobial treatment is dependent upon whether or not the underlying genitourinary abnormality can be corrected. Treatment of complicated urinary tract infections will usually be successful and may be permanent if the underlying abnormality can be corrected. If the underlying abnormality cannot be corrected, failure rates of 50% at 4 to 6 weeks following therapy are expected. Antimicrobial agents are similar to those used to treat uncomplicated urinary tract infection. Certain agents, such as nitrofurantoin, should be avoided for individuals with renal failure. No specific agent or class of agents has consistently demonstrated greater therapeutic efficacy where the infecting organism is susceptible to the given agent.

Quinolones in the aged.

Pharmacokinetic studies of fluoroquinolone antibacterials generally demonstrate some quantitative alterations in elderly compared with younger populations. The most common observations are an increased maximal plasma drug concentration and area under the concentration-time curve, which are primarily attributable to the 10 to 15% decrease in lean body mass in the elderly. For quinolones excreted primarily by the renal route, there is a prolongation in elimination half-life correlated with the aging-associated decline in creatinine clearance. Quinolones with major routes of nonrenal clearance will not usually show a prolongation in half-life because of compensatory relative increases in nonrenal mechanisms. Alterations directly attributable to aging alone, however, are minor, and vary between different quinolones. They do not justify a consistent need for dosage alterations on the basis of age alone. Agents with primarily renal excretion, such as ofloxacin or levofloxacin, may require dosage adjustment in the very elderly or the frail elderly, if significant decreases in creatinine clearance are present. No age-related differences in adverse effects of fluoroquinolones have been reported. Studies in both community-dwelling and institutionalised elderly populations have consistently shown quinolones to be as effective as comparative parenteral or oral therapy. While elderly populations may be at greater risk of adverse effects because of comorbidities and concurrent therapies, an increased occurrence of adverse events in elderly populations receiving quinolone antimicrobials relative to younger populations has not been reported.

The varicella zoster virus: a pilot trial of a potential therapeutic agent in multiple sclerosis.

There are a number of similarities in the geographic, latitudinal, and epidemiological features of multiple sclerosis (MS) and varicella (V). In the experimental model of MS, repeated high antigen doses (myelin basic protein) have deleted both the clinical and pathological manifestations of the disease. Therefore, it seemed appropriate to explore the effects of varicella zoster vaccine on patients with MS. Fifty patients with chronic progressive MS were vaccinated with attenuated varicella virus vaccine and followed for one year. Fourteen patients improved, four became worse, and twenty-nine were unchanged. All patients were seropositive for varicella before vaccination and all had a rise in varicella antibodies after the vaccinations. There were no major untoward results from the vaccine. Four patients developed mild chicken-pox after vaccination. This was a short-term pilot trial without control subjects. Thus, the apparently favourable clinical and magnetic imaging changes must be assessed with caution, as must the lack of adverse effects.

Varicella zoster virus and multiple sclerosis in a Hutterite population.

There are similarities between multiple sclerosis and varicella. They are common in the same parts of the world and both are scarce in other areas. Immigration studies suggest the environmental cause of multiple sclerosis (MS) must be contracted prior to age 15 years and will usually remain dormant for years. At age 10 years varicella has occurred in greater than 95% of children living in the high-risk areas for both of these diseases. The varicella zoster virus (VZV) could be etiologically important in multiple sclerosis. The known host containment of the virus for decades with recrudescence and the variable cell-mediated immunity of the host, which can wax and wane without clinical manifestations, all lend themselves to the natural history of multiple sclerosis. A population-based study of the medical records of 5601 Hutterite Brethren was performed to determine the occurrence of multiple sclerosis, varicella, and herpes zoster. Compared to their matched non-Hutterite neighbors who acted as controls, these events were significantly less common among the Hutterites. Included in the study was an assessment of other common neurological diseases and "autoimmune" diseases among the Hutterites and the controls. There is evidence of a relationship between MS and VZV that may not be coincidental.

Risk factors for surgical wound infection among the elderly.

One hundred fifty-seven elderly patients with surgical wound infection were matched on wound classification and date of surgery to non-infected control patients. Factors examined for their association with wound infection included medical history, functional status, behaviour (e.g. smoking), factors predisposing to infection (e.g. results of CBC and urinalysis) and operative factors such as preparation, duration and type of operation. Conditional logistic regression analysis identified factors already known to be risk factors for wound infection at all ages (e.g. type and duration of operation), as well as factors unique to the elderly (e.g. age greater than 70 years and limited mobility).

Urinary tract infections in long-term-care facilities.

Urinary tract infection (UTI) is the most common bacterial infection occurring in residents of long-term-care facilities. It is a frequent reason for antimicrobial administration, but antimicrobial use for treating UTIs is often inappropriate. Achieving optimal management of UTI in this population is problematic because of the very high prevalence of bacteriuria, evidence that the treatment of asymptomatic bacteriuria is not beneficial, and the clinical and microbiological imprecision in diagnosing symptomatic UTI. This position paper has been developed, using available evidence, to assist facilities and healthcare professionals in managing this common problem.

The chronic indwelling catheter and urinary infection in long-term-care facility residents.

From 5% to 10% of residents of long-term-care facilities have urinary drainage managed with chronic indwelling catheters. These residents are always bacteriuric, usually with a complex microbiological flora of two to five organisms and a biofilm on the catheter that may contribute to obstruction. Residents with chronic indwelling catheters have increased morbidity from urinary infection compared to bacteriuric residents without chronic catheters. The most effective means to prevent infection is limitation of chronic indwelling catheter use. While appropriate catheter care and infection control precautions are recommended in managing these patients, the impact of these practices on the occurrence of urinary infection or prevention of symptomatic episodes has not been evaluated. Symptomatic infection can likely be prevented by attention to catheter care, including early recognition and replacement of obstructed catheters and prevention of catheter trauma. Appropriate use of prophylactic antimicrobial therapy prior to invasive genitourinary procedures is also necessary. Asymptomatic bacteriuria should not be treated. When symptomatic episodes occur, patients should be evaluated clinically and microbiologically and treated with appropriate antimicrobial therapy. Further technological advances in catheter material and urine drainage will be needed to have a substantial impact on the frequency of urinary infection with chronic catheter use.

Infection control in long-term-care facilities.

Although patients in long-term-care facilities are at increased risk of infection, little is known about how to practice infection control in this setting. This article reviews risk factors for infection, the components of an infection control program, and particular infections that are important in long-term-care facilities. In addition, special characteristics of long-term-care facilities that challenge the individuals charged with conducting effective infection control programs will be discussed.

Conjunctivitis in a long-term care facility.

OBJECTIVE: To determine the prevalence, incidence, and etiology of conjunctivitis in residents of a long-term care facility. DESIGN: Prospective surveillance of episodes of conjunctivitis during two 6-month periods. SETTING: Three-building, 319-bed, multipurpose, long-term care facility including units for personal care, chronic care, palliative care, rehabilitation, respiratory rehabilitation, and chronic ventilator patients. RESULTS: The incidence of conjunctivitis on different units varied from 0.6 to 3.5 per 1,000 patient-days. One building had a significantly higher rate of acute conjunctivitis and, within that facility, the most highly impaired patients had significantly more disease. Patients with chronic conjunctivitis generally were admitted with conjunctivitis; institutionally acquired conjunctivitis proceeding to chronic conjunctivitis seldom was observed except on the chronic ventilator unit. Residents with chronic conjunctivitis were significantly more likely to have a diagnosis of glaucoma, ectropion, or entropion. Potential bacterial pathogens were isolated from 3 (21%) of 14 and 24 (38%) of 69 acute episodes for which cultures were available in the two study periods. Staphylococcus aureus was the most frequent pathogen isolated. Empiric therapy was usually with topical sodium sulamyd or gentamicin, with substantial interphysician variability in prescribing patterns. Symptom duration did not differ for episodes which did or did not receive topical antimicrobials. CONCLUSION: Conjunctivitis is common in this facility and occurs with increased frequency in more highly impaired residents. Most episodes may not be due to bacterial infection. Further study of optimal management approaches to conjunctivitis is necessary.

Twelve-month surveillance of infections in institutionalized elderly men.

Surveillance of infectious episodes in institutionalized elderly men permanently resident on two wards of a veterans' hospital was undertaken for a 12-month period. One-hundred eleven episodes were identified in 50 residents (74 per cent). The most frequent infections included lower respiratory tract infections (incidence 59/100 patient-years), febrile episodes with no source (43.4), skin and soft tissue infections (36.5), and gastroenteritis (33). Only pneumonia was associated with significant mortality. A specific etiologic agent was seldom identified other than for skin and soft tissue infections. Antimicrobial therapy was prescribed for 87 per cent of all infections. Ward staff absenteeism was associated with peak occurrences of infections in residents. Resident characteristics that correlated with infection were incontinence of bladder and of bowel. Mental status or degree of mobility did not correlate. While infections occur frequently in this population, mortality is common only with pneumonia. Infections occur more frequently in residents who have greater functional impairment.

Nosocomial pneumonia in a Canadian tertiary care center: a prospective surveillance study.

OBJECTIVE: To determine the contribution of etiologic agents, including Legionella pneumophila and respiratory viruses to nosocomial pneumonia at a tertiary care center. DESIGN: Prospective surveillance of nosocomial pneumonia with standardized laboratory investigations. SETTING: A 1,100-bed tertiary care center. PATIENTS: All adult inpatients. RESULTS: One hundred and thirty-five Nosocomial pneumonias (5.7/1,000 discharges) were identified. Four (3.0%) were L pneumophila serogroup 1 infections (0.17/1,000 discharges). Legionellosis occurred in non-high-risk patients, and three cases would not have been identified without active surveillance. Viral seroconversion was identified in seven (19%) of 36 cases with specimens available (0.59/1,000 discharges): five influenza B, one influenza A, and one respiratory syncytial virus. IgM serology was positive in one case each for Mycoplasma pneumoniae and Chlamydia species. No geographical clustering was observed for viral infections, and these would not have been identified without active surveillance. Mortality for all nosocomial pneumonia was 25%. Patient factors significantly associated with a poorer outcome included older age, underlying disease, low serum albumin, renal insufficiency, lower platelet count, endotracheal intubation, respiratory failure, bacteremia, and use of antacids. CONCLUSIONS: This prospective surveillance suggested that L pneumophila and viral agents were uncommon causes of nosocomial pneumonia at our institution during this surveillance period.

Management of complicated urinary tract infection in older patients.

Urinary tract infection (UTI) in older persons is a common medical problem that is seen in both the ambulatory and institutional settings. It affects older women and men with a gender prevalence ratio of 2:1, respectively. UTI in older persons can be a complex problem in terms of the approach to diagnosis, treatment, and prevention. In this report the discussion will begin with the unique aspects of UTI in older persons, particularly as they relate to UTI in the younger, general population. The remaining discussion will then focus on three complicated clinical circumstances and conditions of UTI in the geriatric population: non-catheter recurrent UTI, asymptomatic bacteriuria, and catheter-related bacteriuria and UTI.

Nosocomial infections on a rehabilitation unit in an acute care hospital.

In a one-year retrospective review, 138 symptomatic infections were identified in 145 admissions to a rehabilitation unit. One hundred twenty-six (91%) infections were either urinary or skin and soft tissue infections. The daily incidence of infection increased with increasing numbers of infections for infected patients. Patient factors associated with infection included male sex, young age, spinal cord injury, admission for management of decubitus ulcers or urinary infection, history of urinary infection, urologic interventions or skin breakdown, and bladder and bowel incontinence. All patients with a history of chronic urinary infection or skin breakdown developed infection. In a logistic regression model, factors that were independently associated with risk of infection in the remaining patients included sex, incontinence, chronic neurologic disease, and prior urologic interventions. This review suggests rehabilitation patients are at high risk of acquiring nosocomial infection. The subgroup of patients with the highest risk of infection are identifiable by specific characteristics.

Antimicrobial use in long-term-care facilities.

There is intense antimicrobial use in long-term-care facilities (LTCF), and studies repeatedly document that much of this use is inappropriate. The current crisis in antimicrobial resistance, which encompasses the LTCF, heightens concerns of antimicrobial use. Attempts to improve antimicrobial use in the LTCF are complicated by characteristics of the patient population, limited availability of diagnostic tests, and virtual absence of relevant clinical trials. This article recommends approaches to management of common LTCF infections and proposes minimal standards for an antimicrobial review program. In developing these recommendations, the article acknowledges the unique aspects of provision of care in the LTCF.