Trends In Bloodstream Infections Research Articles

The decline of typhoid and the rise of non-typhoid salmonellae and fungal infections in a changing HIV landscape: bloodstream infection trends over 15 years in southern Vietnam

The etiological spectrum of bloodstream infections is variable between industrialized and developing countries and even within a defined location over time. We investigated trends in bloodstream infections at an infectious disease hospital in Ho Chi Minh City, Vietnam, from 1994-2008. Amongst 66,111 blood cultures performed, a clinically relevant pathogen was isolated in 7645 episodes (positivity rate; 116/1000 cultures). Salmonella Typhi was the predominant pathogen until 2002; however, a considerable annual decline in the proportion of S. Typhi was observed (OR 0.6993, 95% CI [0.6885, 0.7103], p<0.0001). Conversely, there was a significant increase in the proportions of non-typhoidal Salmonella (NTS), Cryptococcus neoformans and Penicillium marneffei, concurrent with increasing HIV prevalence. These data document a substantial longitudinal shift in bloodstream infection etiology in southern Vietnam. We propose such changes are related to increasing economic prosperity and HIV prevalence, and this pattern marks a substantial change in the epidemiology of invasive salmonellosis in Southeast Asia.

Trends in nosocomial bloodstream infections following health care restructuring in Alberta between 1999 and 2005.

A previous study at the University of Alberta Hospital/Stollery Children's Hospital in Edmonton, Alberta, revealed an increase in hospital-acquired bloodstream infection (BSI) rates associated with an increase in patient acuity during a period of public health care delivery restructuring between 1993 and 1996. The present study assessed trends in BSIs since the end of the restructuring. Prospective surveillance for BSIs was performed using Centers for Disease Control and Prevention (USA) criteria for infection. BSI cases between January 1, 1999, and December 31, 2005, were reviewed. Available measures of patient volumes, acuity and BSI risk factors between 1999 and 2005 were also reviewed from hospital records. The University of Alberta Hospital/Stollery Children's Hospital (617 adult and 139 pediatric beds, respectively). All pediatric and adult patients admitted during the above-specified period with one or more episodes of BSIs. There was a significant overall decline in the BSI number and rate over the study period between 1999 and 2005. The downward trend was widespread, involving both adult and pediatric populations, as well as primary and secondary BSIs. During this period, the number of hospital-wide and intensive care unit admissions, intensive care unit central venous catheter-days, total parenteral nutrition days and number of solid-organ transplants were either unchanged or increased. Gram-positive bacterial causes of BSIs showed significant downward trends, but Gram-negative bacterial and fungal etiologies were unchanged. These data imply that, over time, hospitals can gradually adjust to changing patient care circumstances and, in this example, control infectious complications of health care delivery.

Secular trends in pediatric bloodstream infections over a 20-year period at a tertiary care hospital in Germany

Over the last 20 years, a number of medical innovations with impact on the incidence of bacterial and fungal bloodstream infections (BSIs) in children have been developed and implemented. Although appropriate empirical antimicrobial therapy is a prerequisite to the successful treatment of BSIs, to date, epidemiological data on long-term microbiological trends in BSIs of hospitalized children have not been available. Two cohorts of pediatric patients who were hospitalized in a single-center tertiary care hospital in Germany over a 20-year time span (period A from 1985 to 1995 vs. period B from 1997 to 2006) were retrospectively analyzed and compared with respect to the epidemiology and microbiology of BSIs. A total of 1,646 cases of monomicrobial BSIs were detected. The rate of positive blood culture results dropped from 4.5% in period A to 2.0% in period B. The proportion of gram-positive vs. gram-negative pathogens recovered from blood cultures remained stable. Among gram-positive pathogens, an increase in enterococci (3.3% vs. 8.2%) and in coagulase-negative staphylococci (CoNS) (22.9 vs. 28.2%) was observed. In contrast, BSIs caused by Staphylococcus aureus (16.4% vs. 11.7%), Streptococcus agalactiae (4.9% vs. 2.1%), Haemophilus influenzae (7.3% vs. 0.7%), and Neisseria meningitidis (1.9% vs. 0.5%) diminished. In analyzing subgroups, an increase of enterococcal and CoNS infections was noted among patients with immunosuppression and neonatal early-onset sepsis (EOS), while a decrease was found among late-onset sepsis (LOS) cases with S. viridans. Notably, aminopenicillin-resistant enterococci and aminopenicillin- and fluoroquinolone-resistant Enterobacteriaceae all increased over time, while the overall resistance pattern was still favorable. The overall mortality rate of BSIs decreased (5.2% vs. 2.6%). Over the 20-year study period, the spectrum of specific microorganisms among BSIs shifted, with opportunistic pathogens becoming predominant. Despite an increase in the proportion of antibiotic-resistant organisms, however, the mortality rate decreased.

Age- and Sex-Associated Trends in Bloodstream Infection

Despite increasing concerns about antimicrobial resistance and emerging pathogens among blood culture isolates, contemporary population-based data on the age- and sex-specific incidence of bloodstream infections (BSIs) are limited. Retrospective, population-based, cohort study of all residents of Olmsted County, Minnesota, with a BSI between January 1, 2003, and December 31, 2005. The medical record linkage system of the Rochester Epidemiology Project and microbiology records were used to identify incident cases. A total of 1051 unique patients with positive blood culture results were identified; 401 (38.2%) were classified as contaminated. Of 650 patients with cultures deemed clinically relevant, the mean +/- SD age was 63.1 +/- 23.1 years, and 52.5% were male. The most common organisms identified were Escherichia coli (in 163 patients with BSIs [25.1%]) and Staphylococcus aureus (in 108 patients with BSIs [16.6%]). Nosocomial BSIs were more common in males than females (23.8% vs 13.9%; P = .002). The age-adjusted incidence rate of BSI was 156 per 100 000 person-years for females and 237 per 100 000 person-years for males (P<.001), with an age- and sex-adjusted rate of 189 per 100 000 person-years. Rates of BSI due to gram-positive cocci were 64 per 100 000 person-years for females and 133 per 100 000 person-years for males (P<.001); gram-negative bacillus BSI rates (85/100 000 person-years for females and 79/100 000 person-years for males) were not significantly different between sexes (P = .79). The rate of S aureus BSI was 23 per 100 000 person-years for females and 46 per 100 000 person-years for males (P = .005). There are significant differences in the age and sex distribution of organisms among patients with BSIs. The incidence of BSI increases sharply with increasing age and is significantly higher in males, mainly because of nosocomial organisms, including S aureus.

Validation of a multicenter computer-based surveillance system for hospital-acquired bloodstream infections in neonatal intensive care departments

Automated systems can facilitate surveillance for health care–associated infections. The New York Antimicrobial Resistance Project (NYARP) electronically monitors trends in bloodstream infections from 6 medical centers in New York, NY. To validate NYARP's data, episodes of health care–associated bloodstream infections detected by this system were compared with those obtained by an infection control practitioner performing an unrelated study in 2 participating neonatal intensive care departments. The sensitivity (84%), specificity (99%), and positive (84%) and negative (99%) predictive values of NYARP were excellent when coagulase-negative staphylococcal bloodstream infections were removed.

Trends in bloodstream infections among human immunodeficiency virus-infected adults admitted to a hospital in Nairobi, Kenya, during the last decade.

Bloodstream infections are a frequent complication in human immunodeficiency virus (HIV)-infected adults in Africa and usually associated with a poor prognosis. We evaluated bloodstream infections across a decade in 3 prospective cross-sectional surveys of consecutive medical admissions to the Kenyatta National Hospital, Nairobi, Kenya. Participants received standard clinical care throughout. In 1988-1989, 29.5% (28 of 95) of HIV-positive patients had bloodstream infections, compared with 31.9% (46 of 144) in 1992 and 21.3% (43 of 197) in 1997. Bacteremia and mycobacteremia were significantly associated with HIV infection. Infections with Mycobacterium tuberculosis, non-typhi species of Salmonella (NTS), and Streptococcus pneumoniae predominated. Fungemia exclusively due to Cryptococcus neoformans was uncommon. Clinical features at presentation remained similar. Significant improvements in the survival rate were recorded among patients with NTS bacteremia (20%-83%; P<.01) and mycobacteremia (0%-73%; P<.01). Standard clinical management can improve outcomes in resource-poor settings.

Temporal trends in bloodstream infection in a neonatal Intensive Care Unit (NICU) at a University Hospital

Temporal trends in bloodstream infection in a neonatal Intensive Care Unit (NICU) at a University Hospital

Secular trends in bloodstream infection caused by antimicrobial-resistant bacteria in New Jersey hospitals, 1991 to 1995

Introduction: Antimicrobial resistance among bacteria is an increasing public health problem. In 1991, New Jersey was the first state to establish statewide, hospital-based surveillance for antimicrobial-resistant bacterial. Methods: Each month, all 96 nonfederal New Jersey hospital laboratories complete a form listing the species identity and drug susceptibility results for selected antimicrobial-resistant bacteria isolated from blood cultures from hospital inpatients. Penicillin-resistant Streptococcus pneumoniae and aminoglycoside-resistant gram-negative rods were studied from 1991 to 1995. Vancomycin-resistant enterococci and imipenem-resistant gram-negative rods were studied from 1992 through 1995. Results: From 1992 to 1995, the vancomycin-resistant enterococci bloodstream infection prevalence rate increased from 11 to 29 per 100,000 hospital admissions ( p < 0.001); the rate was higher at larger hospitals, urban and inner-city hospitals, and teaching hospitals. From 1991 to 1995, the penicillin-resistant S. pneumoniae bloodstream infection rate increased from 1.1 to 9.9 per 100,000 admissions ( p < 0.001). In contrast, bloodstream infection rates did not change significantly for imipenem-reistant (12.5 during 1992 and 14.1 during 1995, p = 0.4) or aminoglycoside-resistant (8.0 during 1991 and 6.8 during 1995, p = 0.4) gram-negative rods. Conclusion: We found that vancomycin-resistant enterococci and penicillin-resistant S. pneumoniae, but neither of two groups of antimicrobial-resistant gram-negative rods, are increasing rapidly in prevalence in New Jersey. Continued monitoring and interventions to slow these increases are needed.