Use of a molecular diagnostic test in AFB smear positive tuberculosis suspects greatly reduces time to detection of multidrug resistant tuberculosis

Background

The WHO has recommended the implementation of rapid diagnostic tests to detect and help combat M/XDR tuberculosis (TB). There are limited data on the performance and impact of these tests in field settings.

Methods

The performance of the commercially available Genotype MTBDRplus molecular assay was compared to conventional methods including AFB smear, culture and drug susceptibility testing (DST) using both an absolute concentration method on Löwenstein-Jensen media and broth-based method using the MGIT 960 system. Sputum specimens were obtained from TB suspects in the country of Georgia who received care through the National TB Program.

Results

Among 500 AFB smear-positive sputum specimens, 458 (91.6%) had both a positive sputum culture for Mycobacterium tuberculosis and a valid MTBDRplus assay result. The MTBDRplus assay detected isoniazid (INH) resistance directly from the sputum specimen in 159 (89.8%) of 177 specimens and MDR-TB in 109 (95.6%) of 114 specimens compared to conventional methods. There was high agreement between the MTBDRplus assay and conventional DST results in detecting MDR-TB (kappa = 0.95, p<0.01). The most prevalent INH resistance mutation was S315T (78%) in the katG codon and the most common rifampicin resistance mutation was S531L (68%) in the rpoB codon. Among 13 specimens from TB suspects with negative sputum cultures, 7 had a positive MTBDRplus assay (3 with MDR-TB). The time to detection of MDR-TB was significantly less using the MTBDRplus assay (4.2 days) compared to the use of standard phenotypic tests (67.3 days with solid media and 21.6 days with broth-based media).

Conclusions

Compared to conventional methods, the MTBDRplus assay had high accuracy and significantly reduced time to detection of MDR-TB in an area with high MDR-TB prevalence. The use of rapid molecular diagnostic tests for TB and drug resistance should increase the proportion of patients promptly placed on appropriate therapy.

Additional drug resistance in Mycobacterium tuberculosis isolates from resected cavities among patients with multidrug-resistant or extensively drug-resistant pulmonary tuberculosis

The pathogenesis of increasing drug resistance among patients with multidrug-resistant or extensively drug-resistant tuberculosis undergoing treatment is poorly understood. Increasing drug resistance found among Mycobacterium tuberculosis recovered from cavitary isolates compared with paired sputum isolates suggests pulmonary cavities may play a role in the development of worsening tuberculosis drug resistance.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) among patients admitted to adult intensive care units: the STAR*ICU trial

BACKGROUND

The multicenter, cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was performed in 18 U.S. adult intensive care units (ICUs). It evaluated the effectiveness of infection control strategies to reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission.

METHODS

Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis.

RESULTS

Of 5,512 ICU patient admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a nares sample culture result that was positive for MRSA. A total of 210 (34%) of 626 available isolates were selected for molecular typing by weighted random sampling. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USA100 clone, 26 (12%) were USA300, 12 (6%) were USA500, 8 (4%) were USA800, and 17 (8%) were other MRSA genotypes. In a multivariate analysis, patients who were colonized with a CA-MRSA genotype (USA300, USA400, or USA1000) were less likely to have been hospitalized during the previous 12 months (PR [prevalence ratio], 0.39 [95% confidence interval (CI), 0.21-0.73]) and were less likely to be older (PR, 0.97 [95% CI, 0.95-0.98] per year) compared with patients who were colonized with a healthcare-associated (HA)-MRSA genotype.

CONCLUSION

CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the United States. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community.

Diagnosis of latent tuberculosis infection among HIV discordant partners using interferon gamma release assays

BACKGROUND

There is limited data on the effect of HIV status and CD4 counts on performance of Interferon-g Release assays (IGRAs) for diagnosis of latent tuberculosis infection (LTBI).

METHODS

A cross sectional study was conducted to assess the prevalence of and risk factors for a positive diagnostic test for LTBI, using tuberculin skin test (TST) and IGRAs among HIV-discordant couples in Zambia.

RESULTS

A total of 596 subjects (298 couples) were enrolled. Median CD4 count among HIV positive persons was 388 cells/μl, (range 51-1330). HIV negative persons were more likely than their HIV positive partner, to have a positive diagnostic test for LTBI with TST (203 vs 128), QFT (171 vs 109) and TSPOT (156 vs. 109). On multivariate analysis, HIV negative status was an independent predictor for a positive QFT (OR = 2.22, 95% CI 1.42- 3.46) and TSPOT (OR = 1.79, 95% CI 1.16-2.77). Among HIV positive subjects a CD4 count ≥ 388 cells/μl was associated with a positive TST (OR = 1.76 95% CI 1.10-2.82) and QFT (OR = 1.71 95% CI 1.06-2.77) but not TSPOT (OR = 1.20 95% CI 0.74-1.94).

CONCLUSIONS

Persons with HIV had significantly fewer positive diagnostic tests for LTBI with TST, QFT and TSPOT. Persons with a CD4 count < 388 cells/μl were less likely to have a positive TST or QFT, but not less likely to have a positive TSPOT. TSPOT may perform better than TST or QFT in HIV positive individuals.

Vitamin D status and antimicrobial peptide cathelicidin (LL-37) concentrations in patients with active pulmonary tuberculosis

BACKGROUND

Vitamin D insufficiency is common in industrialized and developing nations. Recent studies have shown that vitamin D insufficiency is associated with a higher risk of active tuberculosis. Laboratory studies provided a mechanism for this link on the basis of findings that vitamin D metabolites regulate the expression of cathelicidin (LL-37), which is an endogenous antimicrobial peptide with activity against Mycobacterium tuberculosis. Little information is available on the clinical relation between vitamin D, LL-37 concentrations, and disease severity in patients with tuberculosis.

OBJECTIVE

The primary objective of the study was to evaluate the relation between vitamin D nutriture, serum LL-37 concentrations, and tuberculosis by using samples stored in the Tuberculosis Trials Consortium serum repository.

DESIGN

We measured 25-hydroxyvitamin D [25(OH)D] and LL-37 concentrations in 95 serum specimens from patients with culture-confirmed pulmonary tuberculosis and correlated these concentrations to clinical and demographic variables.

RESULTS

The prevalence of vitamin D insufficiency [serum 25(OH)D concentration lt 30 ng/mL] in patients with active tuberculosis was 86% (n = 95) with a mean baseline serum 25(OH)D concentration of 20.4 ng/mL. Factors associated with vitamin D insufficiency were black race and indoor lifestyle. The mean ( plusmn SD) baseline LL-37 concentration was 49.5 plusmn 23.8 ng/mL. Higher LL-37 concentrations correlated with acid fast bacilli sputum smear positivity and weight gt 10% below ideal body weight. Serum vitamin D status of the study subjects did not correlate with serum LL-37 concentrations.

CONCLUSION

More prospectively designed studies are needed to evaluate the clinical implications of vitamin D insufficiency in patients with tuberculosis and the utility of circulating LL-37 as a potential biomarker in patients with active tuberculosis disease. The parent trial was registered at clinicaltrials.gov as NCT00023335.

Impact of an antimicrobial utilization program on antimicrobial use at a large teaching hospital: a randomized controlled trial

BACKGROUND

Multidisciplinary antimicrobial utilization teams (AUTs) have been proposed as a mechanism for improving antimicrobial use, but data on their efficacy remain limited.

OBJECTIVE

To determine the impact of an AUT on antimicrobial use at a teaching hospital.

DESIGN

Randomized controlled intervention trial.

SETTING

A 953-bed, public, university-affiliated, urban teaching hospital.

PATIENTS

Patients who were given selected antimicrobial agents (piperacillin-tazobactam, levofloxacin, or vancomycin) by internal medicine ward teams.

INTERVENTION

Twelve internal medicine teams were randomly assigned monthly: 6 teams to an intervention group (academic detailing by the AUT) and 6 teams to a control group that was given indication-based guidelines for prescription of broad-spectrum antimicrobials (standard of care), during a 10-month study period.

MEASUREMENTS

Proportion of appropriate empirical, definitive (therapeutic), and end (overall) antimicrobial usage.

RESULTS

A total of 784 new prescriptions of piperacillin-tazobactam, levofloxacin, and vancomycin were reviewed. The proportion of antimicrobial prescriptions written by the intervention teams that was considered to be appropriate was significantly higher than the proportion of antimicrobial prescriptions written by the control teams that was considered to be appropriate: 82% versus 73% for empirical (risk ratio [RR], 1.14; 95% confidence interval [CI], 1.04-1.24), 82% versus 43% for definitive (RR, 1.89; 95% CI, 1.53-2.33), and 94% versus 70% for end antimicrobial usage (RR, 1.34; 95% CI, 1.25-1.43). In multivariate analysis, teams that received feedback from the AUT alone (adjusted RR, 1.37; 95% CI, 1.27-1.48) or from both the AUT and the infectious diseases consultation service (adjusted RR, 2.28; 95% CI, 1.64-3.19) were significantly more likely to prescribe end antimicrobial usage appropriately, compared with control teams.

CONCLUSIONS

A multidisciplinary AUT that provides feedback to prescribing physicians was an effective method in improving antimicrobial use. Trial registration. ClinicalTrials.gov identifier: NCT00552838.

Vitamin D for treatment and prevention of infectious diseases: a systematic review of randomized controlled trials

OBJECTIVE

To review the existing human controlled intervention studies of vitamin D as adjunctive therapy in settings of infection and provide recommendations for design and implementation of future studies in this field on the basis of the evidence reviewed.

METHODS

We conducted a systematic review of randomized controlled clinical trials that studied vitamin D for treatment or prevention of infectious diseases in humans. Studies from 1948 through 2009 were identified through search terms in PubMed and Ovid MEDLINE.

RESULTS

Thirteen published controlled trials were identified by our search criteria. Ten trials were placebo controlled, and 9 of the 10 were conducted in a rigorous double-blind design. The selected clinical trials demonstrated substantial heterogeneity in baseline patient demographics, sample size, and vitamin D intervention strategies. Serious adverse events attributable to vitamin D supplementation were rare across all studies. On the basis of studies reviewed to date, the strongest evidence supports further research into adjunctive vitamin D therapy for tuberculosis, influenza, and viral upper respiratory tract illnesses. In the selected studies, certain aspects of study design are highlighted to help guide future clinical research in the field.

CONCLUSION

More rigorously designed clinical trials are needed for further evaluation of the relationship between vitamin D status and the immune response to infection as well as for delineation of necessary changes in clinical practice and medical care of patients with vitamin D deficiency in infectious disease settings.

Outbreak of Pseudomonas aeruginosa infection associated with contamination of a flexible bronchoscope

BACKGROUND

A cluster of patients with respiratory cultures positive for Pseudomonas aeruginosa with a unique antibiogram was observed during June and July 2007 at a 1,000-bed urban teaching hospital in Atlanta, Georgia. These P. aeruginosa isolates were recovered from bronchoscopically obtained specimens.

METHODS

A cross-sectional study was performed to assess whether the cluster was associated with exposure to a particular bronchoscope (B1); cultures from specimens from the bronchoscopes and the environment were obtained, and the P. aeruginosa isolate type was determined using pulsed-field gel electrophoresis (PFGE). Records of patients exposed to B1 during the cluster period were reviewed.

RESULTS

Twelve patients with a culture positive for P. aeruginosa with the unique susceptibility pattern were identified in June-July 2007. No cases were documented from March 1 through May 31, 2007. Culture specimens obtained from B1 after high-level disinfection revealed P. aeruginosa, prompting removal of B1 from service on July 23, 2007. No cases occurred after that date. Eleven (55%) of 20 patients who were exposed to B1 during the cluster period had a culture positive for P. aeruginosa, compared with 1 (2%) of 53 patients who were exposed to other bronchoscopes (P < .001). PFGE patterns for P. aeruginosa isolates obtained from case patients and from B1 were identical. An engineering evaluation of B1 documented several internal damages. Two (10.5%) of 19 patients exposed to B1 during the cluster period may have developed P. aeruginosa infection following exposure to B1.

CONCLUSIONS

An outbreak or pseudo-outbreak of P. aeruginosa infection occurred in association with use of a damaged bronchoscope. Periodic engineering maintenance may be needed to prevent bronchoscope contamination that is resistant to high-level disinfection.

High mortality among patients with positive blood cultures at a children's hospital in Tbilisi, Georgia

BACKGROUND

The etiology and outcomes of blood-stream infections (BSI) among paediatric patients is not well described in resource-limited countries including Georgia.

METHODOLOGY

Patients with positive blood cultures at the largest paediatric hospital in the country of Georgia were identified by review of the medical and laboratory records of patients who had blood for cultures drawn between January 2004 and June 2006.

RESULTS

Of 1,693 blood cultures obtained during the study period, 338 (20%) were positive; of these, 299 were included in our analysis. The median age was 14 days from a range of 2 days to 14 years of which 178 (60%) were male; 53% of the patients with a positive culture were admitted to the Neonatal Intensive Care Unit (NICU). Gram-negative bacilli (GNB) represented 165 (55%) of 299 cultures. Further speciation of 135 (82%) of 165 Gram-negative rod (GNR) was not possible because of lack of laboratory capacity. Overall, mortality was 30% (90 of 299). Among the 90 children who died, 80 (89%) were neonates and 68 (76%) had BSI caused by Gram-negative organisms. In multivariate analysis, independent risk factors for in-hospital mortality included an age of less than 30 days (OR=4.00, 95% CI 1.89-8.46) and having a positive blood culture for a Gram-negative BSI (OR = 2.38, 95% CI 1.32-4.29).

CONCLUSIONS

A high mortality rate was seen among children, particularly neonates, with positive blood cultures at the largest paediatric hospital in Georgia. Because of limited laboratory capacity, microbiological identification of common organisms known to cause BSI in children was not possible and susceptibility testing was not performed. Improving the infrastructure of diagnostic microbiology laboratories in countries with limited resources is critical in order to improve patient care and clinical outcomes, and from a public health standpoint, to improve surveillance activities.

Alterations in vitamin D status and anti-microbial peptide levels in patients in the intensive care unit with sepsis

Background

Vitamin D insufficiency is common in hospitalized patients. Recent evidence suggests that vitamin D may enhance the innate immune response by induction of cathelicidin (LL-37), an endogenous antimicrobial peptide produced by macrophages and neutrophils. Thus, the relationship between vitamin D status and LL-37 production may be of importance for host immunity, but little data is available on this subject, especially in the setting of human sepsis syndrome and other critical illness.

Methods

Plasma concentrations of 25-hydroxyvitamin D (25(OH)D), vitamin D binding protein (DBP) and LL-37 in critically ill adult subjects admitted to intensive care units (ICUs) with sepsis and without sepsis were compared to healthy controls.

Results

Critically ill subjects had significantly lower plasma 25(OH)D concentrations compared to healthy controls. Mean plasma LL-37 levels were significantly lower in critically ill subjects compared to healthy controls. Vitamin D binding protein levels in plasma were significantly lower in critically ill subjects with sepsis compared to critically ill subjects without sepsis. There was a significant positive association between circulating 25(OH)D and LL-37 levels.

Conclusion

This study demonstrates an association between critical illness and lower 25(OH)D and DBP levels in critically ill patients as compared to healthy controls. It also establishes a positive association between vitamin D status and plasma LL-37, which suggests that systemic LL-37 levels may be regulated by vitamin D status. Optimal vitamin D status may be important for innate immunity especially in the setting of sepsis. Further invention studies to examine this association are warranted.

Poor concordance between interferon-gamma release assays and tuberculin skin tests in diagnosis of latent tuberculosis infection among HIV-infected individuals

Background

A new generation of diagnostic tests, the interferon-γ release assays (IGRAs), have been developed for the detection of latent tuberculosis infection (LTBI). Limited data are available on their use in HIV-infected persons.

Methods

A cross-sectional study was carried out at 2 HIV clinics in Atlanta to assess the utility of two IGRA tests (T-SPOT.TB [TSPOT] and QuantiFERON-TB Gold in Tube [QFT-3G]) compared to the tuberculin skin test (TST).

Results

336 HIV-infected persons were enrolled. Median CD4 count was 335 cells/μl and median HIV viral load was 400 copies/ml. Overall, 27 patients (8.0%) had at least 1 positive diagnostic test for LTBI: 7 (2.1%) had a positive TST; 9 (2.7%) a positive QFT-3G; and 14 (4.2%) a positive TSPOT. Agreement between the 3 diagnostic tests was poor: TST and TSPOT, [κ = 0.16, 95% CI (-0.06, 0.39)], TST and QFT-3G [κ = 0.23, 95% CI (-0.05, 0.51)], QFT-3G and TSPOT [κ = 0.06, 95% CI (-0.1, 0.2)]. An indeterminate test result occurred among 6 (1.8%) of QFT-3G and 47 (14%) of TSPOT tests. In multivariate analysis, patients with a CD4 ≤ 200 cells/μl were significantly more likely to have an indeterminate result [OR = 3.6, 95% CI (1.9, 6.8)].

Conclusion

We found a low prevalence of LTBI and poor concordance between all 3 diagnostic tests. Indeterminate test results were more likely at CD4 counts ≤ 200 cells/μl. Additional studies among HIV-infected populations with a high prevalence of TB are needed to further assess the utility of IGRAs in this patient population.

Prevalence and risk factors for multidrug-resistant tuberculosis in the Republic of Georgia: a population-based study

SETTING

Multidrug-resistant tuberculosis (MDR-TB, defined as resistance to at least isoniazid and rifampicin) has emerged as a serious global public health problem, especially in the former Soviet republics. The extent of the problem in Georgia has been incompletely defined.

OBJECTIVE

To determine the prevalence and risk factors for MDR-TB in Georgia.

DESIGN

A population-based study was carried out between July 2005 and May 2006.

RESULTS

Of 1314 patients with acid-fast bacilli smear- and culture-positive pulmonary tuberculosis (TB), 799 (60.8%) were newly diagnosed patients and 515 (39.2%) had been treated previously. Overall, 733 (56%) patients had resistance to at least one anti-tuberculosis drug and 195 (15%) had MDR-TB. Patients who had been treated previously for TB were significantly more likely to have MDR-TB than newly diagnosed patients (141/515 [27.4%] vs. 54/794 [6.8%], OR 5.27, 95%CI 3.75-7.41). In multivariate analysis, previous TB treatment (aOR 5.47, 95%CI 3.87-7.74) and female sex (aOR1.58, 95%CI 1.02-2.32) were independent risk factors for the presence of MDR-TB.

CONCLUSIONS

Drug-resistant TB, including MDR-TB, has emerged as a major public health problem in Georgia. Further TB control efforts need to be implemented to prevent the development of new cases of MDR-TB and to treat existing patients with MDR-TB.

Emergence of and risk factors for methicillin-resistant Staphylococcus aureus of community origin in intensive care nurseries

OBJECTIVE

The goal of this study was to define more clearly the impact of community-acquired methicillin-resistant Staphylococcus aureus clones (eg, USA300 and USA400) on colonization and infection in infants in intensive care nurseries and potential modes of transmission of community-acquired methicillin-resistant S aureus clones.

METHODS

Prospective surveillance for methicillin-resistant S aureus colonization and infection was performed among infants in the intensive care nurseries at Grady Memorial Hospital (Atlanta, GA) between 1993 and 2006. Beginning in September 2004, nares surveillance cultures were collected at admission. Methicillin-resistant S aureus isolates were genotyped by using pulsed-field gel electrophoresis and multiplex polymerase chain reaction assays for staphylococcal chromosomal cassette mec gene complex type and Panton-Valentine leukocidin genes. Prevalence of and risk factors for colonization with community-acquired versus health care-associated methicillin-resistant S aureus clones (eg, USA100) were assessed.

RESULTS

Between 1993 and 2006, 130 (3.5%) of 3707 infants were identified to be colonized with methicillin-resistant S aureus. Twelve (1.2%) of 996 admission nares cultures were positive for methicillin-resistant S aureus (since initiation of admission cultures in September 2004). Community-acquired methicillin-resistant S aureus clones were first recovered in 1998; the proportion of methicillin-resistant S aureus clones of community origin increased significantly between 1998 and 2004. Multivariate analysis identified vaginal delivery and maternal smoking, both among infants of mothers receiving systemic antibiotic treatment before delivery, as independent predictors for neonatal colonization with community-acquired methicillin-resistant S aureus. Systemic antibiotic therapy before delivery for nonsmoking mothers delivering through cesarean section and possibly endotracheal intubation were associated with the recovery of health care-associated methicillin-resistant S aureus clones.

CONCLUSIONS

Community-acquired methicillin-resistant S aureus clones have emerged as a major cause of methicillin-resistant S aureus colonization in high-risk newborns. Community-acquired methicillin-resistant S aureus recovery was associated with acquisition during birth, whereas health care-associated methicillin-resistant S aureus clones seemed to be transmitted nosocomially.

High prevalence of multidrug-resistant tuberculosis in Georgia

BACKGROUND

Tuberculosis (TB) has emerged as a serious public health problem in the country of Georgia. However, little or no data exist on rates and risk factors for drug-resistant TB, including multidrug-resistant (MDR)-TB, in Georgia.

OBJECTIVE

To assess the prevalence and risk factors for drug-resistant TB.

METHODS

A cross-sectional prospective survey of patients with suspected pulmonary TB was carried out at four sentinel sites (Tbilisi, Zugdidi, Kutaisi, and Batumi) in Georgia between January 1, 2001 and December 31, 2004.

RESULTS

Among 1422 patients with suspected pulmonary TB, 996 (70.0%) were culture positive; 931/996 (93.5%) had drug susceptibility testing performed. Overall, 64.0% of patients (48.3% of new and 85.3% of retreatment cases) had positive cultures for Mycobacterium tuberculosis resistant to >or=1 first-line antituberculosis drugs. The overall prevalence of MDR-TB was 28.1% (10.5% of newly diagnosed patients and 53.1% of retreatment cases). In multivariate analysis, risk factors for MDR-TB included: being a retreatment case (prevalence ratio (PR)=5.28, 95% CI 3.95-7.07), history of injection drug use (PR=1.59, 95% CI 1.21-2.09), and female gender (PR=1.36, 95% CI 1.12-1.65).

CONCLUSIONS

MDR-TB has emerged as a serious public health problem in Georgia and will greatly impact TB control strategies.

Prevalence and risk factors for latent tuberculosis infection among health care workers in Georgia

BACKGROUND

Tuberculosis (TB) is a major public health problem in Georgia, but few TB infection control measures have been implemented in health care facilities.

OBJECTIVE

To assess the prevalence and risk factors for latent TB infection (LTBI) among Georgian health care workers (HCWs) using two diagnostic tests, the tuberculin skin test (TST) and the QuantiFERON-TB Gold In Tube test (QFT-3G), an interferon-gamma release assay.

METHODS

A cross-sectional study was conducted between June and August 2006 among HCWs at the Georgian National TB Program.

RESULTS

Of 265 HCWs enrolled, 177 (67%) had a positive TST and 159 (60%) had a positive QFT-3G; 203 (77%) had a positive result for at least one of the tests and 50% tested positive for both tests. There was moderately good agreement between the tests (74%, kappa = 0.43, 95%CI 0.33-0.55). In multivariate analysis, employment for >5 years was associated with increased risk of a positive TST (OR 5.09, 95%CI 2.77-9.33) and QFT-3G (OR 2.26, 95%CI 1.27-4.01); age >30 years was associated with an increased risk of a positive QFT-3G (OR 2.91, 95%CI 1.32-6.43).

DISCUSSION

A high prevalence of LTBI was found among Georgian HCWs and longer duration of employment was associated with increased risk. These data highlight the need for effective TB infection control measures and provide important baseline information as TB infection control measures are implemented.

A population-based investigation of invasive vancomycin-resistant Enterococcus infection in metropolitan Atlanta, Georgia, and predictors of mortality

BACKGROUND

Vancomycin-resistant Enterococcus organisms (VRE) have emerged as common nosocomial pathogens, but few population-based data are available on the impact of invasive VRE infections.

METHODS

We assessed the incidence of invasive VRE infections and predictors of mortality among patients identified during prospective, population-based surveillance performed in the metropolitan statistical area (MSA) of Atlanta, Georgia.

RESULTS

From July 1997 through June 2000, a total of 192 patients who resided in the Atlanta MSA developed an invasive VRE infection, for a rate of 1.57 cases per 100,000 person-years. The incidence of invasive VRE disease significantly increased from 0.91 cases per 100,000 person-years during the first year of the study to 1.73 cases per 100,000 person-years during the third year of the study (P<.001). Rates of invasive VRE infection were significantly higher among African American patients than white patients (2.59 vs 0.70 cases per 100,000 person-years; P<.001). Blood was the most common sterile site from which VRE was recovered (161 [83%] of 193 isolates), followed by deep surgical sites (17 [9%]), peritoneal fluid (10 [5%]), pleural fluid (3 [2%]), and cerebrospinal fluid (1 [0.5%]). In multivariate analysis, a Charlson comorbidity index of 5 or greater, previous receipt of antibiotic therapy, having 2 or more sets of blood cultures positive for VRE, and receipt of central parenteral nutrition were independent predictors of mortality, whereas receipt of an antibiotic with in vitro activity against the VRE isolate was associated with a decreased risk of mortality. Molecular typing revealed 38 different pulsed-field gel electrophoresis patterns, but the 2 most common pulsed-field gel electrophoresis types were found at 3 Emory University-affiliated hospitals.

CONCLUSIONS

The incidence of invasive VRE infection significantly increased in the Atlanta MSA during the 3-year study period, with significant racial disparities detected. Receipt of an antimicrobial agent with in vitro activity against VRE was associated with a lower mortality rate. Molecular typing results demonstrated polyclonal emergence of VRE in Atlanta.

Extensively drug-resistant tuberculosis: are we learning from history or repeating it?

Tuberculosis (TB) is an enormous global public health problem. Cases of extensively drug-resistant TB (XDR-TB) are being reported in increasing numbers across the globe. A large outbreak of XDR-TB associated with rapid and nearly universal mortality has been reported among patients with human immunodeficiency virus infection or acquired immunodeficiency disease in South Africa who have been receiving standard TB therapy and antiretrovirals. Epidemiologic features of this outbreak make it highly suspicious for health care-associated transmission. We urge the Infectious Diseases Society of America and its members to increase involvement in ongoing international TB prevention and treatment efforts and to develop a registry of experts in infection control and laboratory and disease management. We urge advocacy for increased funding for domestic and global TB control programs, including expanded access to sputum culture and drug susceptibility testing, as well as funding for TB clinical trials and research capacity. We believe that substandard TB diagnostic tests are not acceptable for TB control in resource-poor countries. We urge the development of shorter, less toxic TB treatment and prevention regimens. Funding of TB control and research should be reassessed to prevent budget cuts at a time when the disease is killing as many as 2 million people a year.

Hematogenous Osteomyelitis Mimicking Osteosarcoma due to Community Associated Methicillin-Resistant Staphylococcus aureus

Community Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen with increasing clinical significance. Initially recognized as a cause of skin and soft tissue infections, it has soon been shown to cause life threatening illnesses. We describe two cases of osteomyelitis of the femur in young otherwise healthy adults. Initially a preliminary diagnosis of osteosarcoma was suggested by radiologic studies and both patients underwent an excisional biopsy. Following identification of the pathogen as CA-MRSA (Panton-Valentine leukocidin positive USA300 clone), both patients were successfully treated with prolonged courses of vancomycin.

Nosocomial tuberculosis in India

India is well positioned to address the problem of nosocomial tuberculosis transmission.

Most high-income countries implement tuberculosis (TB) infection control programs to reduce the risk for nosocomial transmission. However, such control programs are not routinely implemented in India, the country that accounts for the largest number of TB cases in the world. Despite the high prevalence of TB in India and the expected high probability of nosocomial transmission, little is known about nosocomial and occupational TB there. The few available studies suggest that nosocomial TB may be a problem. We review the available data on this topic, describe factors that may facilitate nosocomial transmission in Indian healthcare settings, and consider the feasibility and applicability of various recommended infection control interventions in these settings. Finally, we outline the critical information needed to effectively address the problem of nosocomial transmission of TB in India.

Risk factors for mortality among adult patients with newly diagnosed tuberculosis in Samara, Russia

SETTING

Five out-patient tuberculosis (TB) clinics and one in-patient TB hospital in Samara, Russia.

OBJECTIVE

To identify predictors of all-cause mortality among patients with newly diagnosed TB.

DESIGN

A retrospective case-control study of adult TB cases registered over a 5-year period from 1999 to 2003 using multivariate logistic regression modeling. Cases were defined as patients with TB who died within 12 months of diagnosis. Controls were patients with TB who survived at least 12 months.

RESULTS

The case fatality rate was 3.6%. A total of 92 cases and 368 controls were identified. Mean age was 43 years; 71% were male; 4% were human immunodeficiency virus (HIV) seropositive. The median survival time for cases was 39.5 days. In multivariate analysis, independent predictors of mortality included bilateral lung involvement (OR 3.65), cavitary lesions on chest radiograph (CXR) (OR 2.45), symptoms >4 weeks at the time of diagnosis (OR 2.62), anemia (OR 5.24), and injection drug use (IDU) (OR 4.45), controlling for age.

CONCLUSION

Advanced TB disease at the time of diagnosis (as demonstrated by having bilateral lung involvement, cavitary disease, symptoms >1 month, and anemia) and IDU were associated with increased TB mortality in Samara. Interventions targeted at improving earlier TB case diagnosis and treatment may help to reduce mortality among patients with tuberculosis in this region.