A prospective observational study of community-acquired bacterial bloodstream infections in Metro Manila, the Philippines.

Community-acquired bacterial bloodstream infections are caused by diverse pathogens with changing antimicrobial-resistance patterns. In low-middle income countries in Southeast Asia, where dengue fever is endemic and a leading cause of fever, limited information is available about bacterial bloodstream infections due to challenges of implementing a blood culture service. This study describes bacterial bloodstream pathogens and antimicrobial-resistance patterns in Metro Manila, the Philippines. We aimed to identify the proportion of patients with a positive blood culture, the bacteria isolated and their antimicrobial resistance patterns, and the clinical characteristics of these patients, in this dengue endemic area. We conducted a prospective observational study in a single hospital enrolling febrile patients clinically suspected of having a community-acquired bacterial bloodstream infection between 1st July 2015 and 30th June 2019. Each patient had a blood culture and additional diagnostic tests according to their clinical presentation. We enrolled 1315 patients and a significant positive blood culture was found in 77 (5.9%) including Staphylococcus aureus (n = 20), Salmonella enterica Typhi (n = 18), Escherichia coli (n = 16), Streptococcus pneumoniae (n = 3) and Burkholderia pseudomallei (n = 2). Thirty-four patients had meningococcal disease diagnosed by culture (n = 8) or blood PCR (n = 26). Additional confirmed diagnoses included leptospirosis (n = 177), dengue virus infection (n = 159) and respiratory diphtheria (n = 50). There were 79 (6.0%, 95%CI 4.8%-7.4%) patients who died within 28 days of enrollment. Patients with a positive blood culture were significantly more likely to die than patients with negative culture (15.2% vs 4.4%, P<0.01). Among S. aureus isolates, 11/20 (55%) were methicillin-resistant (MRSA) and ST30: USA1100 was dominant sequence type (88.9%). Antimicrobial-susceptibility was well preserved in S. enterica Typhi. Among hospitalized patients with clinically suspected community-acquired bacterial bloodstream infection in Metro Manila, the Philippines, 5.9% had a blood culture confirmed infection of whom 15.6% died. S. aureus, including a significant number of MRSA (USA1100 clones), S. enterica Typhi, E.coli and Neisseria meningitidis were frequently identified pathogens.

Unique characteristics of new complete blood count parameters, the Immature Platelet Fraction and the Immature Platelet Fraction Count, in dengue patients.

The advanced platelet parameters Immature Platelet Fraction and Immature Platelet Fraction Count have been implemented in clinical practice as measures of thrombopoietic activity, mainly in hematologic disorders that cause thrombocytopenia. The purpose of this observational study was to examine thrombopoiesis as reflected by these 2 new CBC parameters in patients infected with dengue. The study was conducted in infectious disease referral hospital in Metro Manila, the Philippines. We enrolled hospitalized patients at admission who were diagnosed with acute dengue or community acquired bacterial infection (CABI). Immature Platelet Fraction (IPF) and Immature Platelet Fraction Count were evaluated at admission and during hospitalization. A total of 606 patients were enrolled from May 1, 2017 to June 1, 2018. The participants consisted of 152 patients with dengue infection, 180 confirmed CABI, and 274 suspected CABI patients. At admission, the percent IPF (IPF%) of the patients with dengue was significantly higher than that of the confirmed CABI patients (median 3.7% versus 1.9%; p <0.001). In a time course evaluation, there was no significant difference of IPF% between the patients with dengue infection and the confirmed CABI patients in the febrile phase (median 1.9% versus 2.4%; p = 0.488), however, the IPF% of the patients with dengue infection increased to be significantly higher than that of the confirmed CABI patients in the critical phase (median 5.2% versus 2.2%; p <0.001). Our study elucidated the unique characteristics and time-course trends of IPF percent and number (IPF#) in the patients with dengue infection. IPF% and IPF# are potentially valuable parameters in dengue and further investigation is required for the optimal use in clinical practice.

Outcomes associated with treatment change from tenofovir disoproxil fumarate to tenofovir alafenamide in HIV-1-infected patients: a real-world study in Japan.

OBJECTIVES: To investigate the impact of switching from tenofovir disoproxil fumarate (TDF)- to tenofovir alafenamide (TAF)-containing regimens on bone, kidney, serum lipids and body weight among Asian patients. METHODS: A prospective, multicentre, observational cohort study was conducted at three centres for HIV infection in Japan during 2017-2019. HIV-infected adults previously treated with TDF-containing regimens and scheduled to switch to TAF-containing regimens were included. Bone mineral density (BMD), renal markers, lipids and weight were measured consecutively from 12 months before to 12 months after the switch. RESULTS: Among 118 patients evaluated, the mean percentage change to spine BMD during 1 year of TAF treatment was higher than that during 1 year of TDF treatment (mean difference = 1.9%; 95% confidence interval (CI): 0.8-3.1). Urine protein and ß2 -microglobulin levels decreased significantly after the switch, while low-density lipoprotein cholesterol and triglycerides increased. During the TDF and TAF periods, the mean weight gains were 0.2 and 1.9 kg, respectively (mean difference = 1.6 kg; 95% CI: 0.9-2.3). Subgroup analysis revealed a significant difference between the mean body weight change associated with an integrase inhibitor (INSTI) (+2.8 kg) and that associated with a non-INSTI (+1.2 kg) third agent treatment only during the TAF period. CONCLUSIONS: Among predominantly Japanese HIV-infected patients, BMD and renal tubular markers improved, while lipid profiles worsened significantly after the switch. Weight gain during the TAF period was larger than that during the TDF period. Concurrent use of INSTI with TAF may act synergistically to gain body weight.

Ultrasensitive enzyme-linked immunosorbent assay for the detection of MPT64 secretory antigen to evaluate Mycobacterium tuberculosis viability in sputum.

OBJECTIVES: This study examined Mycobacterium tuberculosis (MTB)-secreted MPT64 as a surrogate of bacterial viability for the diagnosis of active pulmonary TB (PTB) and for follow-up treatment. METHODS: In this proof-of-concept prospective study, 50 PTB patients in the Tokyo metropolitan region, between 2017 and 2018, were consecutively included and 30 healthy individuals were also included. Each PTB patient submitted sputum on days 0, 14 and 28 for diagnosis and follow-up, and each healthy individual submitted one sputum sample. The following were performed: smear microscopy, Xpert MTB/RIF, MGIT and solid culture, and MPT64 detection on the sputum samples. Ultrasensitive ELISA (usELISA) was used to detect MPT64. The receiver operating characteristic analyses for diagnosis and follow-up revealed the optimal cut-off value of MPT64 absorbance for detecting culture positivity at multiple intervals. RESULTS: The sensitivity of MPT64 for diagnosing PTB was 88.0% (95% CI 75.7-95.5) and the specificity was 96.7% (95% CI 82.8-99.9). The specificity of MPT64 for predicting negative culture results on day 14 was 89.5% (95% CI 66.9-98.7). The sensitivity of MPT64 for predicting positive culture results on day 28 was 81.0% (95% CI 58.1-94.6). CONCLUSIONS: This study revealed that MPT64 is useful for diagnosing active PTB in patients and predicting treatment efficacy at follow-up.

A Case Series of Acute Kidney Injury During Anti-tuberculosis Treatment.

Objective The standard anti-tuberculosis (TB) regimen occasionally causes acute kidney injury (AKI). The major etiology is rifampicin-induced acute interstitial nephritis. However, the standard management of AKI induced by anti-TB drugs has yet to be established. Methods We retrospectively reviewed patients with TB who developed AKI after starting standard anti-TB treatment between 2006 and 2016 at a single TB center. The clinical characteristics and the management are described. Results Among 1,430 patients with active TB, 15 (1.01%) developed AKI. The mean age (standard deviation) was 61 years (18). The median (interquartile range) time to AKI development was 45 days (21-54 days). The median serum creatinine level before anti-TB treatment was 0.7 mg/dL (0.5-1.4 mg/dL), whereas the median peak serum creatinine level after AKI onset was 4.0 mg/dL (3.08-5.12 mg/dL). Five patients (33.3%) were pathologically confirmed as having acute interstitial nephritis (AIN), and 7 patients (46.7%) had a clinical diagnosis of the disease. All anti-TB drugs were stopped, and steroids were administered to 5 (100%) patients with pathologically confirmed AIN and 3 (42.8%) patients with clinically diagnosed AIN. The renal function was normalized in 12 patients (80.0%) after restarting anti-TB treatment without rifampicin (n=12) or isoniazid (n=1). Two patients died due to severe renal failure after restarting rifampicin. Conclusion Rifampicin is the leading cause of AKI. Levofloxacin may be an alternative to rifampicin thanks to its safety and potency. Restarting anti-TB treatment without rifampicin and short-term steroid administration may be a feasible management for AKI.

Risk factors for pneumonia in patients with schizophrenia.

AIM: Pneumonia is a major cause of death in patients with schizophrenia. Preventive strategies based on identifying the risk factors are needed to reduce pneumonia-related mortality. This study aimed to clarify the risk factors for pneumonia in patients with schizophrenia. METHODS: We retrospectively reviewed the clinical files of consecutive patients with schizophrenia admitted to Tokyo Metropolitan Matsuzawa Hospital during a four-year period from January 2014 to December 2017. We analyzed the clinical differences between patients with and without pneumonia. RESULTS: Of the 2209 patients enrolled, 101 (4.6%) received the diagnosis of pneumonia at the time of hospital admission while 2108 (95.4%) did not have pneumonia. Multivariable analysis to determine the risk factors related to pneumonia showed that the use of atypical antipsychotics had the highest odds ratio among the predictive factors (2.7; 95% confidence interval [CI] 1.0-17.7; P = 0.046), followed by a total chlorpromazine equivalent dose ≥600 mg (2.6; 95% CI 1.7-4.0; P < 0.001), body mass index <18.5 kg/m2 (2.3; 95% CI 1.6-3.6; P < 0.001), smoking history (2.0; 95% CI 1.3-3.1; P < 0.001), and age ≥50 years (1.7; 95% CI 1.2-2.6; P = 0.002). CONCLUSIONS: We found that advanced age, underweight, smoking habit, use of atypical antipsychotics, and large doses of antipsychotics were risk factors for pneumonia in patients with schizophrenia. Among these factors, it was unclear whether the use of antipsychotics was a direct cause of pneumonia due to is uncertain because our retrospective study design. However, our result might be a good basis of further study focused on reducing pneumonia-related fatalities in schizophrenic patients with pneumonia.

Risk Factors for Death from Psychiatric Hospital-acquired Pneumonia.

Objectives Pneumonia is a major cause of death among inpatients at psychiatric hospitals. Psychiatric hospital-acquired pneumonia (PHAP) is defined as pneumonia developed in inpatients at psychiatric hospitals. PHAP is a type of nursing and healthcare-associated pneumonia (NHCAP). The purpose of this study was to clarify the risk factors for mortality among PHAP patients. Methods We retrospectively reviewed the clinical files of patients transferred to Tokyo Metropolitan Matsuzawa Hospital from psychiatric hospitals for PHAP treatment during the 10-year period from September 2007 to August 2017. We analyzed the clinical differences between the survivors and non-survivors and assessed the usefulness of severity classifications (A-DROP, I-ROAD, and PSI) in predicting the prognosis of PHAP. Results This study included a total of 409 PHAP patients, 87 (21.3%) of whom expired and 322 (78.7%) of whom survived. The mortality rates, according to the A-DROP classifications, were 4.9% in the mild cases, 21.6% in the moderate cases, 40.7% in the severe cases, and 47.6% in the very severe cases. The mortality rates, according to the I-ROAD classifications, were 9.5% in group A, 34.7% in group B, and 36.2% in group C. The mortality rates, according to the PSI classifications, were 0% in class II and III, 23.1% in class IV, and 44.9% in class V. The mortality rate increased as the severity increased. We identified 3 factors (age ≥65 years, body mass index ≤18.5 kg/m2, and bilateral pneumonic infiltration) as significant predictors of mortality. We therefore added two factors (body mass index ≤18.5 kg/m2 and bilateral pneumonic infiltration) to the A-DROP classification and established a modified A-DROP classification with a range of 0 to 7. The area under the receiver operation characteristic curves for predicting mortality were 0.699 for the A-DROP classification and 0.807 for the modified A-DROP classification. Conclusion The mortality rate in PHAP patients tended to increase with increasing classifications of severity. The modified A-DROP classification may be useful for predicting the prognosis of PHAP patients.

TAFRO syndrome: current perspectives.

Multicentric Castleman's disease (MCD), a distinct subtype of Castleman's disease, is a rare, nonneoplastic, lymphoproliferative disorder. Patients with MCD present with systemic symptoms and multiple lymphadenopathy. Lymph node biopsy is necessary for the diagnosis of various histological MCD patterns including hyaline vascular, plasma cell, and mixed types. Human herpesvirus 8 (HHV8) infection was identified as an important etiology of MCD among immunocompromised patients such as those positive for human immunodeficiency virus. Although HHV8-negative MCD was reported in immunocompetent patients, the underlying etiology remains unknown. Several experts speculate that MCD in immunocompetent patients might be due to proinflammatory hypercytokinemia because of infection by a virus other than HHV8, inflammation, or neoplastic disease. In 2010, a distinct variant of HHV8-negative MCD reported in Japan was characterized by thrombocytopenia, anasarca, myelofibrosis, renal dysfunction, and organomegaly (TAFRO). Recent case reports and a systematic review suggest that TAFRO syndrome might have a unique pathogenesis among HHV8-negative MCD variants. This review introduces TAFRO syndrome as a subtype of HHV8-negative MCD and offers an overview of the current perspectives on this syndrome.

Evaluation of PyroMark Q24 pyrosequencing as a method for the identification of mycobacteria.

We evaluated PyroMark Q24 (QIAGEN) pyrosequencing as a method for the identification of mycobacteria, with potential application in clinical practice. Sequence data from the hypervariable region A of the 16S rRNA gene (43 and 35bp sequences) were obtained using PyroMark Q24, and a similarity search was performed automatically with PyroMark IdentiFire software. Of the 148 mycobacterial type strains tested, 138 (93.2%) were accurately identified to single or clade species level, including complex level. From the remaining 10 strains, 3 (Mycobacterium gilvum, Mycobacterium goodi, and Mycobacterium thermoresistible) showed poor sequencing quality of homopolymers. For 6 other strains (Mycobacterium cosmeticum, Mycobacterium flavescens, Mycobacterium pallens, Mycobacterium hodleri, Mycobacterium xenopi, and Mycobacterium crocinum), the sequences were unreadable from the middle, and Sanger sequencing indicated biallelic site. Finally, a 40bp sequence for Mycobacterium gordonae could not be obtained despite repeated attempts. PyroMark Q24 provided accurate identification of multiple mycobacterial strains isolated from common clinical settings, but additional gene sequencing is required to distinguish species identified as a group or complex.

Efficiency of the Lung Flute for sputum induction in patients with presumed pulmonary tuberculosis.

INTRODUCTION: High quality sputum helps increase the sensitivity of the diagnosis of pulmonary tuberculosis. OBJECTIVES: To evaluate the efficiency of the acoustic device (Lung Flute; LF) in sputum induction compared with the conventional method, hypertonic saline inhalation (HSI). METHODS: In this crossover study, patients with presumed pulmonary tuberculosis submitted 3 consecutive sputa: the first sputum without induction and the second and third ones using LF and HSI. We compared the efficiency of the 2 induction methods. RESULTS: Sixty-four participants were eligible. Thirty-five (54.6%) patients had negative smears on the first sputum without induction. Among those patients, 25.7% and 22.9% patients were smear-positive after using LF and HSI, respectively (P = .001). The positive conversion rate was not significantly different between the methods. The first samples without induction yielded 65.7% positive cultures, whereas 71.4% and 77.1% of the samples from LF and HSI were positive, respectively (P = .284). Similar results were observed in the nucleic acid amplification test [no induction (60.0%), LF (72.0%) and HSI (60.0%); P = .341]. In 29 smear-positive patients on the first sputum without induction, we observed no significant increase in smear grade, culture yield and nucleic acid amplification test positivity with either method. LF tended to induce fewer adverse events; desaturation (3.1% vs 11.1%; P = .082) and throat pain (1.5% vs 9.5%; P = .057). LF showed significantly fewer total adverse events (15.8% vs 34.9%; P = .023). CONCLUSIONS: Our study showed LF had similar sputum induction efficiency to HSI with relatively fewer complications.

Underweight and hypoalbuminemia as risk indicators for mortality among psychiatric patients with medical comorbidities.

AIM: Medical comorbidities are a major cause of death among patients with mental illness. The purpose of this study was to clarify the risk factors for mortality among psychiatric patients with medical comorbidities. METHODS: We retrospectively reviewed the clinical files of patients transferred to Tokyo Metropolitan Matsuzawa Hospital from a psychiatric hospital to treat medical comorbidities during the 3-year period from January 2014 to December 2016. We analyzed the clinical differences between the expired and alive patients. RESULTS: Of the 287 patients included, 29 (10.1%) had expired at the time of hospital discharge, while 258 (89.9%) were living. A multivariable analysis to determine the prognostic factors related to mortality from medical comorbidities showed that body mass index <18.5 had the highest odds ratio among the predictive factors (5.1; 95% confidence interval, 1.5-17.1; P < 0.05), followed by a serum albumin level < 3.0 mg/dL (3.0; 95% confidence interval, 1.1-8.1; P < 0.05). CONCLUSION: We found that underweight and hypoalbuminemia were risk factors for mortality among psychiatric patients with medical comorbidities. Physicians at psychiatric hospitals should consider transferring patients with medical comorbidities to a general medical hospital in the presence of underweight and/or hypoalbuminemia.

An anterior mediastinal lesion in TAFRO syndrome showing complete remission after glucocorticoid and tocilizumab therapy.

Thrombocytopenia (T), anasarca (A), myelofibrosis (F), renal dysfunction (R), and organomegaly (O) (TAFRO) syndrome is a variant of multicentric Castleman's disease. We describe here a 57-year-old man who presented with persistent fever, pleural effusion, and ascites. He was negative for human immunodeficiency virus and human herpes virus-8. A computed tomography scan showed an anterior mediastinal mass and small inguinal lymphadenopathy. Although a biopsy of the anterior mediastinum showed fatty tissue infiltrated with CD20 (+) and CD45RO (+) lymphocytes, a biopsy of the left inguinal lymph node revealed a hyaline vascular type of Castleman's disease. He subsequently developed severe thrombocytopenia and renal dysfunction. In addition, his bone marrow biopsy showed myelofibrosis. TAFRO syndrome was diagnosed based on the lymph node pathology and the characteristic manifestations of the syndrome. Tocilizumab and glucocorticoid therapy achieved complete remission and regression of the mediastinal mass. To our knowledge, this is the first report of TAFRO syndrome accompanied by an anterior mediastinal mass, which responded very well to therapy.

Evaluation of QuantiFERON-TB Gold Plus for Detection of Mycobacterium tuberculosis infection in Japan.

Performance of interferon-γ (IFN-γ) release assays still needs to be improved. The data on the performance of QuantiFERON-TB Gold Plus (QFT-Plus), a new-generation of QFT assay are limited. This study evaluated the diagnostic performance of QFT-Plus, and compared to that of QuantiFERON-TB Gold In-Tube (QFT-GIT). Blood samples were collected from 162 bacteriologically confirmed tuberculosis (TB) patients and 212 Mycobacterium tuberculosis-uninfected volunteers; these samples were then tested with QFT-GIT and QFT-Plus. The IFN-γ concentration of QFT-Plus was lower than that of QFT-GIT in TB patients (p < 0.001). Receiver operating characteristic curves were compared between QFT-GIT and QFT-Plus. Both assays showed area under the curve values over 0.99 without significant difference. Using the conventional cut-off (0.35 IU/mL) for QFT-GIT, QFT-Plus had a lower sensitivity of 91.1% compared to 96.2% (p = 0.008) at its optimum cut-off (0.168 IU/mL) with the same specificity. Moreover, IFN-γ values were significantly reduced with age in QFT-GIT (p = 0.035) but not in QFT-Plus. The diagnostic performance of QFT-Plus was as accurate as that of QFT-GIT despite a lack of TB7.7 antigen and despite the decrease in quantitative values. However, the cut-off value for QFT-Plus should be considered independently from that of QFT-GIT to obtain the best sensitivity without compromising specificity.

[A case of IgG4-positive inflammatory pseudotumor which rapidly resolved].

A 72-year-old man visited our hospital due to persistent cough, fever and weight loss. A chest X-ray film revealed a round tumor in the left lower lung field. A specimen obtained by transbronchial lung biopsy demonstrated histiocytic and lymphocytic infiltration in the alveolar space, with spindle myofibroblasts and plasmacytes in the interstitium, Those findings were consistent with inflammatory pseudotumor. Four weeks later, a chest X-ray film showed only scars of the primary lesion, and his symptoms resolved dramatically. He has had no recurrence of symptoms and pulmonary tumor since then. Although spontaneous remission is uncommon in inflammatory pseudotumor of the lung, there are several case reports about spontaneous remission of hepatic inflammatory pseudotumor and autoimmune pancreatitis, parts of IgG4-related sclerosing disease. Recently, inflammatory pseudotumor is thought to be IgG4-related sclerosing disease. We speculate that IgG4 may be associated with spontaneous remission of inflammatory pseudotumor of the lung, and we discuss this issue in relation to the pertinent literature.

[A cluster of paragonimiasis westermani infections in Thai immigrants].

We report a cluster of infections in four female Thai immigrants aged between 35 and 49 years who developed paragonimiasis westermani within 16 months of ingesting freshwater crabs purchased from a market in Japan. Their symptoms included cough, bloody sputum, chest pain, and dyspnea. Radiographic and CT findings comprised pleural effusion, pneumothorax, air-space consolidation, and nodular opacities. Paragonimus eggs were identified in the feces of one patient, and in the pleural effusion and the bronchoalveolar lavage fluid (BALF) of another. All diagnoses of paragonimiasis westermani were established by enzyme-linked immunosorbent assay (ELISA) of their serum. Paragonimiasis is a re-emerging disease in Japan. Moreover, since the number of immigrant patients is increasing, it is necessary to pay attention to infectious diseases resulting from their eating habits as well as imported diseases.

Activation of halophilic nucleoside diphosphate kinase by a non-ionic osmolyte, trimethylamine N-oxide.

The folding and activity of halophilic enzymes are believed to require the presence of salts at high concentrations. When the inactivated nucleoside diphosphate kinase (NDK) from extremely halophilic archaea was incubated with low salt media, no activity was regained over the course of 8 days. When it was incubated with approximately 2 M NaCl or 3 M KCl, however, it gradually regained activity. To our surprise, trimethylamine N-oxide (TMAO) also was able to induce activation at 4.0 M. The enzyme activity and secondary structure of refolded NDK in 4 M TMAO were comparable with those of the native NDK or the refolded NDK in 3.8 M NaCl. TMAO is not an electrolyte, meaning that the presence of concentrated salts is not an absolute requirement, and that charge shielding or ion binding is not a sole factor for the folding and activation of NDK. Although both NaCl and TMAO are effective in refolding NDK, the mechanism of their actions appears to be different: the effect of protein concentration and pH on refolding is qualitatively different between these two, and at pH 8.0 NDK could be refolded in the presence of 4 M TMAO only when low concentrations of NaCl are included.

Secondary and quaternary structural transition of the halophilic archaeon nucleoside diphosphate kinase under high- and low-salt conditions.

Most halophilic enzymes from extremely halophilic archaea are denatured immediately after transfer from high-salt to low-salt medium. However, nucleoside diphosphate kinase (HsNDK) from the extremely halophilic archaeon Halobacterium salinarum seems to be exceptional, since the enzyme exhibited catalytic activity even under the low-salt condition. Here we show the mechanism how HsNDK is active under both high- and low-salt conditions that the HsNDK hexamer in high-salt medium dissociates into a dimer in the low-salt medium without denaturation. The observed change of the subunit structure was accompanied by a large decrease of alpha-helical content and lowered thermal sensitivity, yet keeping the conformations. This novel hexamer to dimer conversion under high- and low-salt conditions, respectively, seems to be the mechanism by which HsNDK is avoided from the irreversible denaturation.