Chung-Chih Lai

Stenotrophomonas maltophilia bloodstream infection: Comparison between community-onset and hospital-acquired infections

BACKGROUND/PURPOSE Stenotrophomonas maltophilia has been recognized as an important nosocomial pathogen, but few reports have discussed S. maltophilia infection in the community settings. This study aimed to reveal characteristics of patients with community-onset S. maltophilia bloodstream infection (SMBSI), to specify the subgroup of healthcare-associated (HCA) infection in the community-onset group and to compare them with hospital-acquired (HA) SMBSI patients. MATERIALS AND METHODS Medical charts of adult patients with SMBSI presenting to a medical center in southern Taiwan from May 2008 to October 2011 were reviewed and analyzed retrospectively. RESULTS Among 153 patients, we observed a high percentage (38.6%) of SMBSI to be community onset. Among community-onset SMBSI, 45.8% were community-acquired (CA) and 54.2% were HCA. The crude mortality rates were 11.1%, 18.8%, and 60.6% in the CA, HCA, and HA groups, respectively. Structural/mechanical abnormalities were observed in 32.7% of all cases, and 60% of those were related to malignancy. Independent risk factors for mortality in community-onset SMBSI were liver cirrhosis, liver metastasis, and a high Pitt bacteremia score, whereas structural/mechanical abnormalities and a high Pitt bacteremia score related to increased mortality in HA SMBSI. CONCLUSION Community-onset S. maltophilia infection deserves attention. Patients with community-onset SMBSI have reduced disease severity and lower mortality rate when compared to HA SMBSI. Underlying structural/mechanical abnormalities, especially those caused by malignancies, are common in SMBSI cases and should be investigated when bacteremia occurs.

Trends of transmitted drug resistance of HIV-1 and its impact on treatment response to first-line antiretroviral therapy in Taiwan

OBJECTIVES To determine the impact of transmitted drug resistance (TDR) of HIV-1 on treatment outcome in areas where routine testing for drug resistance mutations may not be available before combination antiretroviral therapy (cART) is initiated. METHODS Genotypic resistance assays were performed on HIV isolates from archived blood samples obtained from 1349 antiretroviral-naive HIV-1-infected patients in Taiwan from 2000 to 2010. Resistance mutations were interpreted with the use of the HIVdb program of the Stanford University HIV Drug Resistance Database. The genotypic sensitivity score (GSS) of the regimens prescribed was calculated. A matched case-control study was conducted to assess the impact of TDR on treatment outcomes. RESULTS The overall prevalence of TDR to any antiretroviral agent was 8.0%, declining from 12.3% in 2003-06 to 5.1% in 2007-10. In the matched case-control study, 31 patients with high- or intermediate-level resistance, 16 with low-level resistance and 89 controls were enrolled. Compared with regimens with GSS >2.5, initiation of regimens with GSS ≤2.5 was associated with a higher treatment failure rate (39.3% versus 15.7%, P = 0.02) and shorter time to treatment failure (log-rank P < 0.001). In patients receiving regimens with GSS ≤2.5, protease inhibitor-based regimens were less likely to result in treatment failure, compared with non-nucleoside reverse-transcriptase inhibitor-based regimens (hazard ratio 0.26, 95% CI 0.06-1.12, P = 0.07). CONCLUSIONS In Taiwan the prevalence of TDR of HIV-1 strains declined and stabilized between 2007 and 2010. Receipt of antiretroviral regimens with GSS ≤2.5 was associated with poorer treatment responses than regimens with GSS >2.5.

Isolation and identification of Acanthamoeba species related to amoebic encephalitis and nonpathogenic free‐living amoeba species from the rice field

Aims:  Isolation and characterization of the clinically relevant amphizoic amoebas in vegetated farmlands, which may present a risk to farmers’ health.

Effects of Gender and Age on Development of Concurrent Extrapulmonary Tuberculosis in Patients with Pulmonary Tuberculosis: A Population Based Study

Most cases of adult-onset tuberculosis (TB) result from reactivation of a pre-existing Mycobacterium tuberculosis infection. Mycobacterium tuberculosis usually invades the respiratory tract and most patients develop intrapulmonary TB; however, some patients develop concurrent pulmonary and extra-pulmonary TB. The purpose of the present study was to identify the demographic and clinical factors associated with an increased risk of concurrent extra-pulmonary diseases in patients with pulmonary TB. We compared patients who had isolated pulmonary TB with patients who had concurrent pulmonary and extra-pulmonary TB. We initially analyzed one-million randomly selected subjects from the population-based Taiwan National Health Insurance database. Based on analysis of 5414 pulmonary TB patients in this database, women were more likely than men to have concurrent extra-pulmonary TB (OR: 1.30, p = 0.013). A separate analysis of the Kaohsiung Medical University Hospital database, which relied on sputum culture-proven pulmonary TB, indicated that women were more likely than men to have concurrent extra-pulmonary TB (OR: 1.62, p = 0.039). There was no significant gender difference in extra-pulmonary TB for patients younger than 45 years in either database. However, for patients 45 years and older, women were more likely than men to have concurrent extra-pulmonary TB (insurance database: 9.0% vs. 6.8%, p = 0.016, OR: 1.36; hospital database: 27.3% vs. 16.0%, p = 0.008, OR = 1.98). Our results indicate that among patients who have pulmonary TB, older females have an increased risk for concurrent extra-pulmonary TB.

Prevalence of and associated factors with chronic kidney disease in human immunodeficiency virus-infected patients in Taiwan.

BACKGROUND Chronic kidney disease (CKD) is an important issue for individuals who live with human immunodeficiency virus (HIV) following the use of highly active antiretroviral therapy; however, the prevalence rate of CKD varies between countries. METHODS The present study screened HIV-infected patients in a medical center and a regional teaching hospital in southern Taiwan from January 2008 to December 2012. CKD was defined as a urine microalbumin-to-creatinine ratio ≥30 mg/g, and/or a protein ≥1 + on urine dipstick examination, and/or an estimated glomerular filtration rate <60 mL/min/1.73 m(2) for 3 months. The prevalence rate and the analyzed associated factors of CKD were determined. RESULTS Among 1639 HIV-infected patients, only 512 had adequate data to be enrolled in the study. Thirty-six (7.03%) of these patients had CKD, and 476 did not. In a univariate analysis, CKD was associated with an older age, a higher peak HIV RNA load, diabetes mellitus (DM), hypertension, exposure to antiretroviral therapy, and cholesterol levels ≥240 mg/dL. Multivariate analysis revealed that DM, hypertension, and cholesterol ≥240 mg/dL were statistically significant factors. CONCLUSION In Taiwan, the prevalence of CKD in HIV-infected patients was low (7.03%). The classical risk factors for CKD, such as DM, hypertension, and hypercholesterolemia, were demonstrated to be associated with CKD in Taiwanese HIV-infected patients.

Transmitted drug resistance of HIV-1 strains among individuals attending voluntary counselling and testing in Taiwan

BACKGROUND Genotypic drug resistance testing for HIV-1 has been integrated into voluntary counselling and testing (VCT) programmes to investigate the trends of transmitted drug resistance (TDR), including integrase mutations, among individuals with recent or chronic HIV infections in Taiwan. METHODS Between 2006 and 2014, 745 of 21 886 subjects (3.4%) tested HIV positive in the VCT service. The BED assay was used to identify recent HIV infections. Genotypic resistance mutations were interpreted using the WHO 2009 list. Integrase resistance mutations were analysed using the Stanford HIV Drug Resistance Database. RESULTS Three-hundred-and-sixty (48.3%) patients were recently infected with HIV-1. Of 440 patients linked to HIV care with analysable reverse transcriptase and protease genes, 49 (11.1%) were infected with HIV-1 harbouring at least one resistance-associated mutation (RAM). The prevalence of TDR to NRTIs, NNRTIs and PIs was 4.1%, 6.4% and 2.3%, respectively. TDR prevalence did not change significantly during the study period. CD4 counts ≤500 cells/mm(3) and hepatitis B surface antigen positivity were independent factors associated with acquiring drug-resistant HIV. The prevalence of integrase mutations was 3.2%. Among the seven major integrase mutations (T66I, E92Q, G140S, Y143C/H/R, S147G, Q148H/K/R and N155H), only one strain harbouring the Q148R mutation was detected. We found no statistically significant difference between patients with chronic infection and those with recent infection in the prevalence of drug-resistant mutations to any of the four classes of antiretroviral agents. CONCLUSIONS The prevalence of TDR of HIV-1 strains to available antiretroviral agents is moderately high, but transmission of HIV-1 with drug-resistant mutations remains stable in Taiwan.

Effects of various antimicrobial stewardship programs on antimicrobial usage and resistance among common gram-negative bacilli causing health care-associated infections: A multicenter comparison.

BACKGROUND The effects of various antimicrobial stewardship programs (ASPs) on both antibiotic consumption and resistance among different hospitals within the same insurance system have rarely been investigated. METHODS This 6-year retrospective study included three medical centers with similar facilities and infection control measures in Taiwan. These hospitals used different types of ASPs: one had a hospital-wide preauthorization requirement by infectious diseases physicians for all broad-spectrum antibiotics, covering all intensive care units; the second used the same program, but excluded all intensive care units; and the third used postprescription review only. The nonsusceptibility of unduplicated isolates of gram-negative bacilli causing health care-associated infections and consumption of broad-spectrum antibiotics were analyzed. RESULTS Overall, the usage of broad-spectrum antibiotics of all classes escalated significantly over time in all three hospitals, but consumption was lowest under the hospital-wide preauthorization program. Under this ASP, despite a 2-fold increase in the total broad-spectrum antibiotic consumption during study period, some declining trends of resistance were found, including ciprofloxacin-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, and carbapenem-resistant P. aeruginosa. By contrast, the other two hospitals with preauthorization program excluding all intensive care units and postprescription review had similar high broad-spectrum antibiotic consumption, comparable growing trends of resistant strains in general, and the correlations of antibiotic consumption and resistance were basically positive. Carbapenem-resistant A. baumannii increased significantly over time in all three hospitals. CONCLUSION This interhospital comparison suggested that hospital-wide preauthorization program is the most effective to reduce key gram-negative bacilli resistance, with the exception of carbapenem-resistant A. baumannii.

A Mucormycosis Case in a Cirrhotic Patient Successfully Treated with Posaconazole and Review of Published Literature

Mucormycosis is an invasive fungal infection associated with a high mortality rate, especially in immunocompromised hosts. Mucormycosis rarely occurs in cirrhotic patients. Here, we report a case of mucormycosis with underlying liver cirrhosis and diabetes mellitus. The patient suffered from maxillary sinusitis and osteomyelitis, and the infection was successfully treated with antifungal agents, surgical debridement, and hyperbaric oxygen therapy. The antifungal treatments used were liposomal amphotericin B, itraconazole, and posaconazole. Although our patient had liver cirrhosis (Child-Pugh classification B), no hepatic decompensation was developed during the treatment course of posaconazole. This is the first report of the safe and effective use of posaconazole for the treatment of mucormycosis in a cirrhotic patient.

Risk factors for microbiologic failure among Taiwanese adults with Mycobacterium abscessus complex pulmonary disease.

BACKGROUND The Mycobacterium abscessus complex is a common cause of pulmonary nontuberculous mycobacteria infections in Taiwan. We examined the risk factors associated with treatment outcome in Taiwanese adults with pulmonary disease caused by the M. abscessus complex. METHODS We retrospectively reviewed the records of all patients from a southern Taiwan medical center from 2006 to 2012 who had respiratory specimens identified as M. abscessus complex and met the American Thoracic Society criteria for pulmonary disease. RESULTS Of the 106 included patients, females (58.5%) and nonsmokers (79.2%) predominated. The mean age of patients was 64.8 years. Sixty-three patients (59.4%) had pre-existing lung disease. Previous mycobacterial pulmonary disease (34.9%) was the most common underlying disorder. Chest radiography indicated that bronchiectasis was common (47.2%) and that cavitations were less common (14.2%). Fifty-six patients received antibiotic treatment. Clinicians were more likely to prescribe antibiotics if the initial sputum acid-fast staining was positive (p < 0.001). Treatment outcome was analyzed in 26 patients who were treated for more than 3 months; three of these patients (11.5%) had clinical failure and 18 (69.2%) experienced sputum conversion. Patients with cavitary lesions were more likely to experience microbiologic failure (p = 0.02). Nine patients had positive cultures after antibiotic treatment for > 1 year. Previous mycobacterial pulmonary disease (p = 0.011) and cavitary lesion (p = 0.034) are risk factors for persistence of M. abscessus complex. CONCLUSION With antimicrobial therapy, previous mycobacterial disease, and cavitary lesion are associated with microbiologic failure in Taiwanese adults with M. abscessus complex pulmonary disease.

Nemonoxacin (TG-873870) for treatment of community-acquired pneumonia

With a broad-spectrum of activity, fluoroquinolones have been widely and successfully used for decades for the treatment of and prophylaxis against various bacterial infections, including community-acquired pneumonia (CAP). However, the use of fluoroquinolones has been compromised by the emergence and spreading of bacterial resistance and the potential for adverse effects. Therefore, there is an unmet need for newer compounds that have a broader spectrum of activity to overcome existing bacterial resistance as well as the potential to minimize the risk of adverse effects. Nemonoxacin (TG-873870), a newly developed quinolone, has demonstrated broad-spectrum activity against Gram-positive, Gram-negative and atypical pathogens, including drug-resistant Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus. Results from Phases I and II studies of treatment of CAP are encouraging. This article reviews the updated data on nemonoxacin, including the bacterial susceptibility, the pharmacologic characteristics, and toxicities, and clinical trials using nemonoxacin for treatment of CAP.