Antibiotic-Resistant Gram-negative Bacteria Carriage in Healthcare Workers Working in an Intensive Care Unit / 감염과화학요법

Little is known about antibiotic-resistant Gram-negative bacteria (GNB) intestinal carriage among healthcare workers (HCWs) in Vietnam. All HCWs at a tertiary intensive care units were asked to undertake weekly rectal swabs. Among 40 participants, 65% (26/40) carried extended spectrum β-lactamases (ESBL)/AmpC β-lactamase-producing Escherichia coli. Two HCWs colonized with ESBL/AmpC β-lactamase-producing Klebsiella pneumoniae. One HCW colonized with Acinetobacter baumannii. No one carried Pseudomonas spp.. A quarter (10/40) of HCWs were identified as persistent and frequent carriers. There is an urgent need to screen antibiotic-resistant GNB among HCWs and improve HCWs' hand hygiene compliance to reduce the transmission of antibiotic-resistant GNB in the hospital.

Antibiotic-Resistant Gram-negative Bacteria Carriage in Healthcare Workers Working in an Intensive Care Unit / 감염과화학요법

Little is known about antibiotic-resistant Gram-negative bacteria (GNB) intestinal carriage among healthcare workers (HCWs) in Vietnam. All HCWs at a tertiary intensive care units were asked to undertake weekly rectal swabs. Among 40 participants, 65% (26/40) carried extended spectrum β-lactamases (ESBL)/AmpC β-lactamase-producing Escherichia coli. Two HCWs colonized with ESBL/AmpC β-lactamase-producing Klebsiella pneumoniae. One HCW colonized with Acinetobacter baumannii. No one carried Pseudomonas spp.. A quarter (10/40) of HCWs were identified as persistent and frequent carriers. There is an urgent need to screen antibiotic-resistant GNB among HCWs and improve HCWs' hand hygiene compliance to reduce the transmission of antibiotic-resistant GNB in the hospital.

Health Service Utilization Among People With Noncommunicable Diseases in Rural Vietnam.

CONTEXT: Chronic noncommunicable diseases (NCDs) have been shown to be major causes of morbidity and mortality in hospitals for the whole country. OBJECTIVE: This study aims to describe the situation of health service utilization among people with NCDs in a rural area and identify association between the situation of health service utilization among people with chronic diseases and their socioeconomic status. DESIGN: This was a cross-sectional study. SETTING: A rural district located in the North of Vietnam. PARTICIPANTS: People 15 years of age and older. Health service utilization was analyzed only among people who reported having NCD. MAIN OUTCOME MEASURES: Data were collected through a personal household interview conducted by 12 trained field workers. The dependent variable is health care service utilization among people with chronic NCDs. The explanatory variables include both household attributes such as household economic conditions, and so forth, and individual characteristics. RESULTS: Eighteen percent of the adults and 51% of the elderly respondents reported having at least 1 of the NCDs. The proportions of people with NCDs who used at least 1 outpatient service and used at least 1 inpatient health service during the last 12 months were 68.1% and 10.7%, respectively (the nonutilization rates of 31.9% and 89.3%, respectively). The statistically significant correlates of health care service utilization among people with NCDs were ethnicity (ethnic minority was significantly associated with a lower odds of health care service utilization) and health insurance (no health insurance was significantly associated with lower odds of health care service utilization). CONCLUSION: Given the evidence from this study, actions to improve access to health care services among people with NCDs are clearly needed. The capacity of primary health care system for the prevention and control of NCDs should be ranked a top priority.

Ventilator-associated respiratory infection in a resource-restricted setting: impact and etiology.

BACKGROUND: Ventilator-associated respiratory infection (VARI) is a significant problem in resource-restricted intensive care units (ICUs), but differences in casemix and etiology means VARI in resource-restricted ICUs may be different from that found in resource-rich units. Data from these settings are vital to plan preventative interventions and assess their cost-effectiveness, but few are available. METHODS: We conducted a prospective observational study in four Vietnamese ICUs to assess the incidence and impact of VARI. Patients ≥ 16 years old and expected to be mechanically ventilated > 48 h were enrolled in the study and followed daily for 28 days following ICU admission. RESULTS: Four hundred fifty eligible patients were enrolled over 24 months, and after exclusions, 374 patients' data were analyzed. A total of 92/374 cases of VARI (21.7/1000 ventilator days) were diagnosed; 37 (9.9%) of these met ventilator-associated pneumonia (VAP) criteria (8.7/1000 ventilator days). Patients with any VARI, VAP, or VARI without VAP experienced increased hospital and ICU stay, ICU cost, and antibiotic use (p < 0.01 for all). This was also true for all VARI (p < 0.01 for all) with/without tetanus. There was no increased risk of in-hospital death in patients with VARI compared to those without (VAP HR 1.58, 95% CI 0.75-3.33, p = 0.23; VARI without VAP HR 0.40, 95% CI 0.14-1.17, p = 0.09). In patients with positive endotracheal aspirate cultures, most VARI was caused by Gram-negative organisms; the most frequent were Acinetobacter baumannii (32/73, 43.8%) Klebsiella pneumoniae (26/73, 35.6%), and Pseudomonas aeruginosa (24/73, 32.9%). 40/68 (58.8%) patients with positive cultures for these had carbapenem-resistant isolates. Patients with carbapenem-resistant VARI had significantly greater ICU costs than patients with carbapenem-susceptible isolates (6053 USD (IQR 3806-7824) vs 3131 USD (IQR 2108-7551), p = 0.04) and after correction for adequacy of initial antibiotics and APACHE II score, showed a trend towards increased risk of in-hospital death (HR 2.82, 95% CI 0.75-6.75, p = 0.15). CONCLUSIONS: VARI in a resource-restricted setting has limited impact on mortality, but shows significant association with increased patient costs, length of stay, and antibiotic use, particularly when caused by carbapenem-resistant bacteria. Evidence-based interventions to reduce VARI in these settings are urgently needed.

Incidence of invasive salmonella disease in sub-Saharan Africa: a multicentre population-based surveillance study.

BACKGROUND: Available incidence data for invasive salmonella disease in sub-Saharan Africa are scarce. Standardised, multicountry data are required to better understand the nature and burden of disease in Africa. We aimed to measure the adjusted incidence estimates of typhoid fever and invasive non-typhoidal salmonella (iNTS) disease in sub-Saharan Africa, and the antimicrobial susceptibility profiles of the causative agents. METHODS: We established a systematic, standardised surveillance of blood culture-based febrile illness in 13 African sentinel sites with previous reports of typhoid fever: Burkina Faso (two sites), Ethiopia, Ghana, Guinea-Bissau, Kenya, Madagascar (two sites), Senegal, South Africa, Sudan, and Tanzania (two sites). We used census data and health-care records to define study catchment areas and populations. Eligible participants were either inpatients or outpatients who resided within the catchment area and presented with tympanic (≥38·0°C) or axillary temperature (≥37·5°C). Inpatients with a reported history of fever for 72 h or longer were excluded. We also implemented a health-care utilisation survey in a sample of households randomly selected from each study area to investigate health-seeking behaviour in cases of self-reported fever lasting less than 3 days. Typhoid fever and iNTS disease incidences were corrected for health-care-seeking behaviour and recruitment. FINDINGS: Between March 1, 2010, and Jan 31, 2014, 135 Salmonella enterica serotype Typhi (S Typhi) and 94 iNTS isolates were cultured from the blood of 13 431 febrile patients. Salmonella spp accounted for 33% or more of all bacterial pathogens at nine sites. The adjusted incidence rate (AIR) of S Typhi per 100 000 person-years of observation ranged from 0 (95% CI 0-0) in Sudan to 383 (274-535) at one site in Burkina Faso; the AIR of iNTS ranged from 0 in Sudan, Ethiopia, Madagascar (Isotry site), and South Africa to 237 (178-316) at the second site in Burkina Faso. The AIR of iNTS and typhoid fever in individuals younger than 15 years old was typically higher than in those aged 15 years or older. Multidrug-resistant S Typhi was isolated in Ghana, Kenya, and Tanzania (both sites combined), and multidrug-resistant iNTS was isolated in Burkina Faso (both sites combined), Ghana, Kenya, and Guinea-Bissau. INTERPRETATION: Typhoid fever and iNTS disease are major causes of invasive bacterial febrile illness in the sampled locations, most commonly affecting children in both low and high population density settings. The development of iNTS vaccines and the introduction of S Typhi conjugate vaccines should be considered for high-incidence settings, such as those identified in this study. FUNDING: Bill & Melinda Gates Foundation.

A Clinical and Epidemiological Investigation of the First Reported Human Infection With the Zoonotic Parasite Trypanosoma evansi in Southeast Asia.

BACKGROUND: Trypanosomais a genus of unicellular parasitic flagellate protozoa.Trypanosoma bruceispecies and Trypanosoma cruziare the major agents of human trypanosomiasis; other Trypanosomaspecies can cause human disease, but are rare. In March 2015, a 38-year-old woman presented to a healthcare facility in southern Vietnam with fever, headache, and arthralgia. Microscopic examination of blood revealed infection with Trypanosoma METHODS: Microscopic observation, polymerase chain reaction (PCR) amplification of blood samples, and serological testing were performed to identify the infecting species. The patient's blood was screened for the trypanocidal protein apolipoprotein L1 (APOL1), and a field investigation was performed to identify the zoonotic source. RESULTS: PCR amplification and serological testing identified the infecting species as Trypanosoma evansi.Despite relapsing 6 weeks after completing amphotericin B therapy, the patient made a complete recovery after 5 weeks of suramin. The patient was found to have 2 wild-type APOL1 alleles and a normal serum APOL1 concentration. After responsive animal sampling in the presumed location of exposure, cattle and/or buffalo were determined to be the most likely source of the infection, with 14 of 30 (47%) animal blood samples testing PCR positive forT. evansi. CONCLUSIONS: We report the first laboratory-confirmed case ofT. evansiin a previously healthy individual without APOL1 deficiency, potentially contracted via a wound while butchering raw beef, and successfully treated with suramin. A linked epidemiological investigation revealed widespread and previously unidentified burden ofT. evansiin local cattle, highlighting the need for surveillance of this infection in animals and the possibility of further human cases.

Identification of Salmonella enterica serovar Typhi genotypes by use of rapid multiplex ligation-dependent probe amplification.

Salmonella enterica serovar Typhi, the causative agent of typhoid fever, is highly clonal and genetically conserved, making isolate subtyping difficult. We describe a standardized multiplex ligation-dependent probe amplification (MLPA) genotyping scheme targeting 11 key phylogenetic markers of the S. Typhi genome. The MLPA method demonstrated 90% concordance with single nucleotide polymorphism (SNP) typing, the gold standard for S. Typhi genotyping, and had the ability to identify isolates of the H58 haplotype, which is associated with resistance to multiple antimicrobials. Additionally, the assay permitted the detection of fluoroquinolone resistance-associated mutations in the DNA gyrase-encoding gene gyrA and the topoisomerase gene parC with a sensitivity of 100%. The MLPA methodology is simple and reliable, providing phylogenetically and phenotypically relevant genotyping information. This MLPA scheme offers a more-sensitive and interpretable alternative to the nonphylogenetic subgrouping methodologies that are currently used in reference and research laboratories in areas where typhoid is endemic.

Suitable disk antimicrobial susceptibility breakpoints defining Salmonella enterica serovar Typhi isolates with reduced susceptibility to fluoroquinolones.

Infections with Salmonella enterica serovar Typhi isolates that have reduced susceptibility to ofloxacin (MIC ≥ 0.25 µg/ml) or ciprofloxacin (MIC ≥ 0.125 µg/ml) have been associated with a delayed response or clinical failure following treatment with these antimicrobials. These isolates are not detected as resistant using current disk susceptibility breakpoints. We examined 816 isolates of S. Typhi from seven Asian countries. Screening for nalidixic acid resistance (MIC ≥ 16 µg/ml) identified isolates with an ofloxacin MIC of ≥0.25 µg/ml with a sensitivity of 97.3% (253/260) and specificity of 99.3% (552/556). For isolates with a ciprofloxacin MIC of ≥0.125 µg/ml, the sensitivity was 92.9% (248/267) and specificity was 98.4% (540/549). A zone of inhibition of ≤28 mm around a 5-µg ofloxacin disc detected strains with an ofloxacin MIC of ≥0.25 µg/ml with a sensitivity of 94.6% (246/260) and specificity of 94.2% (524/556). A zone of inhibition of ≤30 mm detected isolates with a ciprofloxacin MIC of ≥0.125 µg/ml with a sensitivity of 94.0% (251/267) and specificity of 94.2% (517/549). An ofloxacin MIC of ≥0.25 µg/ml and a ciprofloxacin MIC of ≥0.125 µg/ml detected 74.5% (341/460) of isolates with an identified quinolone resistance-inducing mutation and 81.5% (331/406) of the most common mutant (carrying a serine-to-phenylalanine mutation at codon 83 in the gyrA gene). Screening for nalidixic acid resistance or ciprofloxacin and ofloxacin disk inhibition zone are suitable for detecting S. Typhi isolates with reduced fluoroquinolone susceptibility.

High prevalence of plasmid-mediated quinolone resistance determinants in commensal members of the Enterobacteriaceae in Ho Chi Minh City, Vietnam.

Antimicrobial-resistant pathogenic members of the Enterobacteriaceae are a well-defined global problem. We hypothesized that one of the main reservoirs of dissemination of antimicrobial resistance genes in Vietnam is non-pathogenic intestinal flora, and sought to isolate antimicrobial-resistant organisms from hospitalized patients and non-hospitalized healthy individuals in Ho Chi Minh City. The results identified substantial faecal carriage of gentamicin-, ceftazidime- and nalidixic acid-resistant members of the Enterobacteriaceae in both hospitalized patients and non-hospitalized healthy individuals. A high prevalence of quinolone resistance determinants was identified, particularly the qnrS gene, in both community- and hospital-associated strains. Furthermore, the results demonstrated that a combination of quinolone resistance determinants can confer resistance to nalidixic acid and ciprofloxacin, even in the apparent absence of additional chromosomal resistance mutations in wild-type strains and laboratory strains with transferred plasmids. These data suggest that intestinal commensal organisms are a significant reservoir for the dissemination of plasmid-mediated quinolone resistance in Ho Chi Minh City.

Antimicrobial drug resistance of Salmonella enterica serovar typhi in asia and molecular mechanism of reduced susceptibility to the fluoroquinolones.

This study describes the pattern and extent of drug resistance in 1,774 strains of Salmonella enterica serovar Typhi isolated across Asia between 1993 and 2005 and characterizes the molecular mechanisms underlying the reduced susceptibilities to fluoroquinolones of these strains. For 1,393 serovar Typhi strains collected in southern Vietnam, the proportion of multidrug resistance has remained high since 1993 (50% in 2004) and there was a dramatic increase in nalidixic acid resistance between 1993 (4%) and 2005 (97%). In a cross-sectional sample of 381 serovar Typhi strains from 8 Asian countries, Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, and central Vietnam, collected in 2002 to 2004, various rates of multidrug resistance (16 to 37%) and nalidixic acid resistance (5 to 51%) were found. The eight Asian countries involved in this study are home to approximately 80% of the world's typhoid fever cases. These results document the scale of drug resistance across Asia. The Ser83-->Phe substitution in GyrA was the predominant alteration in serovar Typhi strains from Vietnam (117/127 isolates; 92.1%). No mutations in gyrB, parC, or parE were detected in 55 of these strains. In vitro time-kill experiments showed a reduction in the efficacy of ofloxacin against strains harboring a single-amino-acid substitution at codon 83 or 87 of GyrA; this effect was more marked against a strain with a double substitution. The 8-methoxy fluoroquinolone gatifloxacin showed rapid killing of serovar Typhi harboring both the single- and double-amino-acid substitutions.