Acinetobacter bacteraemia in Thailand: evidence for infections outside the hospital setting.

SUMMARY: Acinetobacter is a well-recognized nosocomial pathogen. Previous reports of community-associated Acinetobacter infections have lacked clear case definitions and assessment of healthcare-associated (HCA) risk factors. We identified Acinetobacter bacteraemia cases from blood cultures obtained <3 days after hospitalization in rural Thailand and performed medical record reviews to assess HCA risk factors in the previous year and compare clinical and microbiological characteristics between cases with and without HCA risk factors. Of 72 Acinetobacter cases, 32 (44%) had no HCA risk factors. Compared to HCA infections, non-HCA infections were more often caused by Acinetobacter species other than calcoaceticus-baumannii complex species and by antibiotic-susceptible organisms. Despite similar symptoms, the case-fatality proportion was lower in non-HCA than HCA cases (9% vs. 45%, P < 0·01). Clinicians should be aware of Acinetobacter as a potential cause of community-associated infections in Thailand; prospective studies are needed to improve understanding of associated risk factors and disease burden.

Pneumococcal antigen testing of blood culture broth to enhance the detection of Streptococcus pneumoniae bacteremia.

The purpose of this investigation was to enhance the detection of pneumococcal bacteremia cases using the Binax NOW® immunochromatographic test (ICT) on blood culture broth as part of surveillance in two rural Thailand provinces. Blood cultures were collected as clinically indicated from hospitalized patients. ICT was performed on broth from culture bottles flagged as positive by BactT/ALERT® (alarm-positive) but which failed to grow organisms on subculture. During the period May 2005-June 2007, ICT was positive on 43 (24%) of 182 alarm-positive blood cultures with no growth on subculture. Compared to pneumococcal bacteremia cases confirmed by culture, cases detected only by ICT had a longer median time from culture collection to incubation and a longer median time from alarm positivity to subculture, and were more likely to be from patients pretreated with antibiotics. In a subsequent surveillance period (July 2007-December 2009), ICT continued to detect additional pneumococcal cases, but in a lower proportion of samples (7 of 221, 3.2%). Recently, as part of a separate study, ICT applied to uninoculated blood culture broth produced weak-positive results, mandating caution if testing broth from patient blood cultures. The antigen testing of blood culture broth appears to enhance the detection of pneumococcal bacteremia, but a controlled evaluation is needed.

Severe acute respiratory syndrome (SARS): knowledge, attitudes, practices and sources of information among physicians answering a SARS fever hotline service.

In June 2003, Taiwan introduced a severe acute respiratory syndrome (SARS) telephone hotline service to provide concerned callers with rapid access to information, advice and appropriate referral where necessary. This paper reports an evaluation of the knowledge, attitude, practices and sources of information relating to SARS among physicians who staffed the SARS fever hotline service. A retrospective survey was conducted using a self-administered postal questionnaire. Participants were physicians who staffed a SARS hotline during the SARS epidemic in Taipei, Taiwan from June 1 to 10, 2003. A response rate of 83% was obtained. All respondents knew the causative agent of SARS, and knowledge regarding SARS features and preventive practices was good. However, only 54% of respondents knew the incubation period of SARS. Hospital guidelines and news media were the major information sources. In responding to two case scenarios most physicians were likely to triage callers at high risk of SARS appropriately, but not callers at low risk. Less than half of all respondents answered both scenarios correctly. The results obtained suggest that knowledge of SARS was generally good although obtained from both medical and non-medical sources. Specific knowledge was however lacking in certain areas and this affected the ability to appropriately triage callers. Standardized education and assessment of prior knowledge of SARS could improve the ability of physicians to triage callers in future outbreaks.

Improved sensitivity of sputum smear microscopy after processing specimens with C18-carboxypropylbetaine to detect acid-fast bacilli: a study of United States-bound immigrants from Vietnam.

The goal of this study was to evaluate the effect of the specimen-processing method that uses the detergent C18-carboxypropylbetaine (CB-18) on the sensitivity of acid-fast bacillus (AFB) staining. Vietnamese immigrants with abnormal chest radiographs provided up to three sputum specimens, which were examined for acid-fast bacilli by use of direct auramine and Ziehl-Neelsen staining. The remaining sputum was split; half was cultured, and the other half was incubated with CB-18 for 24 h, centrifuged, and examined for AFB by both staining methods. CB-18 processing improved the sensitivity of AFB staining by 20 to 30% (only differences in auramine sensitivity were statistically significant) but reduced specificity by approximately 20% (P < 0.05). These findings have direct utility for overseas migrant tuberculosis screening programs, for which maximizing test sensitivity is a major objective.

Determining TB rates and TB case burden for refugees.

SETTING: DeKalb County, Georgia. OBJECTIVES: To calculate and compare tuberculosis (TB) rates in refugees to US-born, total foreign-born (refugee and other), and other foreign-born persons and to determine the contribution of refugees to the county TB case burden. METHODS: The study included: (1) collection of county TB case numbers and population figures from 1995 through 1999; (2) estimation of the refugee population; (3) comparison of TB rates; and (4) calculation of the refugee TB case burden. Sensitivity analysis was performed on refugee population estimates. RESULTS: From 1995 through 1999, estimating that refugees made up 10% of the foreign-born population, the average TB rate for refugees was 83.2 per 100,000, compared with 12.7 for US-born persons. From 1997 through 1999, refugees had a seven-fold greater risk of having TB than US-born persons and a two-fold greater risk than other foreign-born persons. Refugees represented respectively 7.6% and 19.3% of the county and foreign-born TB case burdens. For TB rates to be equal among all foreign-born persons, refugees would need to make up 15-25% of the foreign-born population. CONCLUSION: Despite overseas screening, refugees have high TB rates, and contribute substantially to the county TB case burden. Enhanced surveillance and targeted programs to address TB in refugees should be a public health priority.

Assessment of the protein quality of the smooth muscle myofibrillar and connective tissue proteins of chicken gizzard.

The objective of this study was to assess the protein quality of the myofibrillar and connective tissue proteins of chicken gizzard. Protein fractions were isolated from White Leghorn chicken gizzards and quantified by detailed amino acid analysis. This quantification involved repeated extractions of ground gizzards first with Triton X-100, then with low ionic strength imidazole-buffered saline (pH 7.1), followed by either 2% SDS or by 5 M guanidine hydrochloride. The total soluble intracellular protein fraction averaged 86.3% of the total protein and the insoluble extracellular connective tissue proteins comprised the remaining 13.7%. These fractions differed significantly in their essential amino acid (EAA) profiles, with the soluble intracellular fraction having the highest percentage EAA9 (48.6 to 49.0%) and the insoluble connective tissue fraction varying from 20.8 to 23%, compared to the FAO/WHO reference pattern value of 33.9% for a 2- to 5-yr-old child. Calculated protein efficiency ratios (PER) for intracellular proteins averaged 3.02 compared with a value of 1.65 for the extracellular matrix proteins. These results provide an accurate assessment of the protein quality of smooth muscle proteins of chicken gizzard and may prove valuable for industrial control of the amount of connective tissue added to formulations of meats and poultry products.

Bloodstream infections with vancomycin-resistant enterococci.

OBJECTIVES: To describe the population in whom bloodstream infections with vancomycin-resistant enterococci occur and the clinical and microbiologic features of infection. METHODS: From June 1, 1991, to January 31, 1994, 73 patients with bloodstream infections with vancomycin-resistant enterococci were identified by retrospective review of hospital charts and microbiology records. RESULTS: Fifty-two (73%) of 71 patients with evaluable data were hospitalized in an intensive care, unit, the adult oncology unit, or the acquired immunodeficiency syndrome unit. Before the development of the bloodstream infection with vancomycin-resistant enterococci, patients were hospitalized and received antibiotics for a median of 26 and 25.5 days, respectively. A hematologic malignancy, respiratory failure, or renal failure requiring dialysis was present in 59 patients (83%). Acute Physiology and Chronic Health Evaluation II scores of the patients ranged from 6 to 35 (median, 17). Forty-five (63%) of the patients died. Compared with 37 patients who had only a single positive blood culture, the 34 patients with 2 or more blood cultures positive for vancomycin-resistant enterococci more often were neutropenic or had acquired immunodeficiency syndrome (74% vs 35%; P = .002). CONCLUSIONS: Bloodstream infections with vancomycin-resistant enterococci predominantly affect severely ill patients who have received extensive antibiotic treatment during a prolonged hospitalization. Immunocompromised patients are more likely to have a persistent blood-stream infection with vancomycin-resistant enterococci.

Epidemiology and mortality risk of vancomycin-resistant enterococcal bloodstream infections.

Risk factors for vancomycin-resistant enterococcal (VRE) bloodstream infection (BSI) were studied at a tertiary-care hospital by comparing 46 patients with VRE-BSI with 46 randomly selected patients with vancomycin-susceptible enterococcal (VSE) BSI. Among patients with an enterococcal BSI, risk factors for mortality were determined. Independent risk factors for VRE-BSI were increasing APACHE II score (odds ratio [OR], 2.3/5-point increase; 95% confidence interval [CI], 1.4-3.9), receipt of vancomycin (OR, 11; 95% CI, 5.5-21), or diagnosis of hematologic malignancy (OR, 8.4; 95% CI, 3.9-18). After controlling for APACHE II score and gender, patients with VRE- versus VSE-BSI did not have a significantly elevated risk of mortality (OR, 3.3; 95% CI, 0.7-15). Five of 28 VRE blood isolates typed using pulsed-field gel electrophoresis had identical banding patterns. These data suggest that increasing severity of illness, underlying disease, and receipt of vancomycin are major risk factors for VRE-BSI.

Epidemic nosocomial pneumonia in the intensive care unit.

The changing and expanding spectrum of pathogens associated with nosocomial pneumonia (NP) will require modification in our approach to both endemic and epidemic NP in the ICU. Knowledge of specific pathogens, modes of transmission, and sources or reservoirs of epidemic NP is crucial to the recognition, control, and prevention of these infections in ICU patients. This article reviews the epidemiology of nosocomial NP outbreaks and outlines guidelines for investigating suspected epidemics of NP within the ICU. Preventive strategies including appropriate surveillance for recognizing epidemic clusters, adherence to barrier isolation precautions, proper disinfection and sterilization of respiratory care equipment, and judicious use of antimicrobial agents are also discussed.

Efficacy of control measures in preventing nosocomial transmission of multidrug-resistant tuberculosis to patients and health care workers.

OBJECTIVE: To assess the efficacy of control measures in decreasing nosocomial transmission of multidrug-resistant tuberculosis. DESIGN: Retrospective cohort study. SETTING: A teaching hospital in New York City. POPULATION: 40 patients hospitalized with multidrug-resistant tuberculosis (case-patients) and health care workers receiving tuberculin skin testing. INTERVENTIONS: Centers for Disease Control and Prevention (CDC) 1990 guidelines for preventing transmission of tuberculosis, including 1) prompt isolation and treatment of patients with tuberculosis; 2) rapid diagnostic techniques for processing Mycobacterium tuberculosis specimens; 3) negative-pressure isolation rooms; and 4) molded surgical masks for health care workers. MEASUREMENTS: Proportion of case-patients with nosocomially acquired tuberculosis and rate of tuberculin skin test conversion among health care workers before and after implementation of control measures. RESULTS: The proportion of patients with multidrug-resistant strains of M. tuberculosis decreased after the interventions (10 of 70 [14%] compared with 30 of 95 [32%] patients before the intervention; relative risk [RR], 0.5; 95% CI, 0.2 to 0.9). Before onset of multidrug-resistant tuberculosis, case-patients in the intervention period were as likely to be hospitalized on high-risk wards containing patients with tuberculosis (4 of 10 compared with 17 of 30 patients; RR, 0.7; P = 0.5) but were less likely to be exposed to another case-patient with tuberculosis (1 of 10 compared with 20 of 30 patients; RR, 0.2; P = 0.003). Tuberculin skin test conversion rates for health care workers assigned to wards housing patients with tuberculosis were lower in the intervention period than in the preintervention period (4 of 78 [5%] compared with 15 of 90 [17%] conversions; P = 0.02), decreasing to levels observed for workers assigned to other wards (4 of 78 [5%] compared with 9 of 228 [4%] conversions; P = 0.7). CONCLUSIONS: Implementing control measures reduced nosocomial transmission of multidrug-resistant strains to patients and health care workers.