Fatal Primary Amebic Meningoencephalitis due to Naegleria fowleri: The First Imported Case in Korea

Primary amebic meningoencephalitis (PAM) is a rare, but almost always fatal, central nervous system infection caused by Naegleria fowleri, which are thermophilic free-living amoeba. Here, we report the first case of PAM detected in South Korea, probably imported from Thailand. Despite antimicrobial treatment for N. fowleri infection with a combination of intravenous liposomal amphotericin B, fluconazole, azithromycin, and oral rifampin, the patient died 13 days after the onset of symptoms. Clinicians in South Korea treating severe meningoencephalitis, especially in individuals returning from tropical areas, are encouraged to include PAM in the differential diagnoses, given the accelerated global warming and increased overseas trips.

Real World Experience with Regdanvimab Treatment of Mild-toModerate Coronavirus Disease-19 in a COVID-19 Designated Hospital of Korea

Background@#Real-world clinical data concerning regdanvimab, a monoclonal antibody treatment for patients with mild-to-moderate coronavirus disease 2019 (COVID-19), are urgently needed. Here, we describe our experience with regdanvimab. @*Materials and Methods@#This retrospective cohort study enrolled high-risk adults with mild-to-moderate COVID-19 who were admitted to a dedicated COVID-19 hospital in Korea from March to September 2021. We used multiple logistic regression and propensity scorematching to compare the outcomes of patients who did or did not receive regdanvimab. The primary outcome was in-hospital progression to severe or critical status, or death. @*Results@#Of 586 patients eligible for regdanvimab, 256 patients who received regdanvimab and 251 untreated patients were included. The median age was 66 years and 47.5% were men. The most common underlying illnesses were hypertension (53.8%) and diabetes (36.9%). Patients were admitted to the hospital at a median of 2 days after symptom onset; regdanvimab was administered at a median of 3 days after symptom onset. Multivariate analysis indicated that regdanvimab significantly reduced the risk of disease progression during hospitalization [odds ratio (OR): 0.285; 95% confidence interval (CI): 0.144 - 0.564].In a 1:1 propensity score-matched cohort (172 patients in either group), regdanvimab also decreased the risk of progression (OR: 0.162; 95% CI: 0.068 - 0.386). @*Conclusion@#In high-risk patients with mild-to-moderate COVID-19, regdanvimab decreased the risk of progression to severe COVID-19.

Clinical Features of Adult COVID-19 Patients without Risk Factors before and after the Nationwide SARSCoV-2 B.1.617.2 (Delta)-variant Outbreak in Korea: Experience from Gyeongsangnam-do

Background@#Data on severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) delta variant virulence are insufficient. We retrospectively compared the clinical features of adult coronavirus disease 2019 (COVID-19) patients without risk factors for severe COVID-19 who entered residential treatment centers (RTCs) before and after the delta variant outbreak. @*Methods@#We collected medical information from two RTCs in South Korea. On the basis of nationwide delta variant surveillance, we divided the patients into two groups: 1) the delta-minor group (diagnosed from December 2020–June 2021, detection rate 90%). After propensity-score matching, the incidences of pneumonia, hospital transfer and need for supplemental oxygen were compared between the groups. In addition, risk factors for hospital transfer were analysed. @*Results@#A total of 1,915 patients were included. The incidence of pneumonia (14.6% vs.9.2%, P = 0.009), all-cause hospital transfer (10.4% vs. 6.3%, P = 0.020) and COVID-19-related hospital transfer (7.5% vs. 4.8%, P = 0.081) were higher in the delta-dominant group than those in the delta-minor group. In the multivariate analysis, the delta-dominant group was an independent risk factor for all-cause (adjusted odds ratio [aOR], 1.91; 95% confidence interval [CI], 1.16–3.13; P = 0.011) and COVID-19-related hospital transfer (aOR, 1.86; 95% CI, 1.04–3.32; P = 0.036). @*Conclusion@#Hospitalization rates were increased in the adult COVID-19 patients during the delta variant nationwide outbreak. Our results showed that the delta variant may be more virulent than previous lineages.

Lower Respiratory Tract Diseases Caused by Common Respiratory Viruses among Stem Cell Transplantation Recipients: A Single Center Experience in Korea

PURPOSE: To describe the incidence, clinical courses, and risk factors for mortality of lower respiratory tract diseases (LRDs) caused by common respiratory viruses (CRVs) in stem cell transplantation (SCT) recipients. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 1038 patients who received SCT between January 2007 and August 2011 at a single center in Korea. RESULTS: Seventy-one CRV-LRDs were identified in 67 (6.5%) patients. The human parainfluenza virus (HPIV) was the most common causative pathogen of CRV-LRDs at 100 days [cumulative incidence estimate, 23.5%; 95% confidence interval (CI), 3.3–43.7] and 1 year (cumulative incidence estimate, 69.2%; 95% CI, 45.9–92.5) following SCT. The 30-day overall mortality rates due to influenza-LRDs, respiratory syncytial virus-LRDs, HPIV-LRDs, and human rhinovirus-LRDs were 35.7, 25.8, 31.6, and 42.8%, respectively. Co-pathogens in respiratory specimens were detected in 23 (33.8%) patients. The overall mortality at day 30 after CRV-LRD diagnosis was 32.8% (22/67). High-dose steroid usage (p=0.025), a severe state of immunodeficiency (p=0.033), and lymphopenia (p=0.006) were significantly associated with death within 30 days following CRV-LRD diagnosis in a univariate analysis. Multivariate logistic regression analysis revealed that high-dose steroid usage [odds ratio (OR), 4.05; 95% CI, 1.12–14.61; p=0.033] and lymphopenia (OR, 6.57; 95% CI, 1.80–24.03; p=0.004) were independent risk factors for mortality within 30 days of CRV-LRDs. CONCLUSION: CRV-LRDs among SCT recipients showed substantially high morbidity and mortality rates. Therefore, the implement of an active diagnostic approaches for CRV infections is required for SCT recipients with respiratory symptoms, especially those receiving high-dose steroids or with lymphopenia.

Acute Myopericarditis caused by Human Metapneumovirus

Human metapneumovirus is known to be similar to respiratory syncytial virus. Because of an incomplete protective immune response to new genotypes, re-infection occurs frequently, especially in the elderly. However, the clinical manifestations of human metapneumovirus need to be further characterized in adults. A 73-year-old woman presented to the emergency room with acute dyspnea, chest discomfort and influenza-like illness. The patient was diagnosed with human metapneumovirus infection, complicated by pneumonia and myopericarditis. With supportive care including oxygen supplementation, the patient recovered completely without any serious sequelae. Human metapneumovirus infection may contribute to the development of cardiovascular manifestations, particularly in the elderly population.

Pulmonary Toxocariasis Mimicking Invasive Aspergillosis in a Patient with Ulcerative Colitis

A 45-year-old-male who had underlying ulcerative colitis and presented with fever and dry cough. Initially, the patient was considered to have invasive aspergillosis due to a positive galactomannan assay. He was treated with amphotericin B followed by voriconazole. Nevertheless, the patient deteriorated clinically and radiographically. The lung biopsy revealed eosinophilic pneumonia, and ELISA for Toxocara antigen was positive, leading to a diagnosis of pulmonary toxocariasis. After a 10-day treatment course with albendazole and adjunctive steroids, the patient recovered completely without any sequelae. Pulmonary toxocariasis may be considered in patients with subacute or chronic pneumonia unresponsive to antibiotic agents, particularly in cases with eosinophilia.

Etiology and Clinical Outcomes of Acute Respiratory Virus Infection in Hospitalized Adults

BACKGROUND: Etiologies and clinical profiles of acute respiratory viral infections need to be clarified to improve preventive and therapeutic strategies. MATERIALS AND METHODS: A retrospective observational study at a single, university-affiliated center was performed to evaluate the respiratory viral infection etiologies in children compared to that in adults and to document the clinical features of common viral infections for adults from July 2009 to April 2012. RESULTS: The common viruses detected from children (2,800 total patients) were human rhinovirus (hRV) (31.8%), adenovirus (AdV) (19.2%), respiratory syncytial virus (RSV) A (17.4%), RSV B (11.7%), and human metapneumovirus (hMPV) (9.8%). In comparison, influenza virus A (IFA) had the highest isolation rate (28.5%), followed by hRV (15.5%), influenza virus B (IFB) (15.0%), and hMPV (14.0%), in adults (763 total patients). Multiple viruses were detected in single specimens from 22.4% of children and 2.0% of adults. IFA/IFB, RSV A/B, and hMPV exhibited strong seasonal detection and similar circulating patterns in children and adults. Adult patients showed different clinical manifestations according to causative viruses; nasal congestion and rhinorrhea were more common in hRV and human coronavirus (hCoV) infection. Patients with RSV B, hRV, or AdV tended to be younger, and those infected with RSV A and hMPV were likely to be older. Those with RSV A infection tended to stay longer in hospital, enter the intensive care unit more frequently, and have a fatal outcome more often. The bacterial co-detection rate was 26.5%, and those cases were more likely to have lower respiratory tract involvement (P = 0.001), longer hospital stay (P = 0.001), and higher mortality (P = 0.001). CONCLUSIONS: The etiologic virus of an acute respiratory infection can be cautiously inferred based on a patient's age and clinical features and concurrent epidemic data. Large-scale prospective surveillance studies are required to provide more accurate information about respiratory viral infection etiology, which could favorably influence clinical outcomes.

Long-term immunogenicity of the influenza vaccine at reduced intradermal and full intramuscular doses among healthy young adults

PURPOSE: To prepare for vaccine shortages under an influenza pandemic, several antigen-sparing strategies have been investigated. This study was aimed to evaluate the immunogenicity of influenza vaccine at reduced intradermal and full intramuscular dose. MATERIALS AND METHODS: We compared the effect of one-fifth and one-half intradermal doses to the full intramuscular dose on immunogenicity in healthy young adults, using a commercial influenza vaccine. A hemagglutination inhibition assay was used to compare the immunogenicity of the vaccination methods. RESULTS: The one-fifth intradermal dose (3 microg hemagglutinin antigen, HA) was given to 30 participants, the one-half intradermal dose (7.5 microg HA) was given to 30, and the full intramuscular dose (15 microg HA) was given to 32. No significant differences among injection routes and dosages were seen for seroprotection rate, seroconversion rate, or geometric mean titer (GMT) fold-increase for A/H1N1, A/H3N2, and B at around 4 weeks from vaccination. Although GMT for influenza B was significantly lower at six months for the one-fifth intradermal vaccination compared to the full-dose intramuscular vaccination (32.8 vs. 63.2, p=0.048), all three groups met the Evaluation of Medicinal Products (EMA) immunogenicity criteria through 1 to 6 months. CONCLUSION: Intradermal administration of a one-fifth dose of influenza vaccine elicited antibody responses comparable to the intradermal one-half dose and a conventional intramuscular vaccination at 1 month post-vaccination. The immunogenicity of the one-fifth intradermal dose was sufficient to meet the requirement for the EMA criteria at six months after influenza vaccination.

Perceptions of Tetanus-diphteria-acellular pertussis (Tdap) Vaccination among Korean Women of Childbearing Age

BACKGROUND: The number of cases of pertussis reported has increased gradually in the last decade. Pertussis vaccination is the most effective strategy for the prevention of infection. Despite the fact that young infants are at the highest risk for pertussis, the rate of tetanus-diphtheria-acellular pertussis (Tdap) vaccination is presumed to be very low among women of childbearing age in Korea. The purpose of this study was to investigate the perceptions of women of childbearing age regarding Tdap vaccination in Korea. MATERIALS AND METHODS: Women of childbearing age, who visited the Department of Obstetrics and Gynecology at 3 University hospitals in the Seoul and Gyeonggi-do provinces of Korea, were surveyed. Individual questionnaires were administered from April to May 2012. Demographic data, Tdap vaccination history, general knowledge about pertussis, and information on factors associated with decision on vaccination were collected. RESULTS: Of the 500 reproductive-age women enrolled, only 4 (0.8%) had received the Tdap. The most common reason for non-vaccination was the lack of awareness of pertussis and information about the Tdap. Totally, 171 (34.2%) responded that they would receive a Tdap vaccination in the future. By multivariate analysis, general confidence in the effectiveness of the vaccine (odds ratio [OR] = 1.88, 95% confidence interval [CI] 1.17 to 3.01) was indicated as an important factor for deciding whether to receive the Tdap vaccine (P < 0.01). CONCLUSIONS: The coverage of Tdap vaccination of women of childbearing age, including pregnant women, is very low because of the lack of awareness of pertussis and the Tdap. Education of women of childbearing age about pertussis is very important to increase Tdap vaccination rates among these women, particularly during the perinatal period.

The Changing Patterns of Antibiotics Usage in Korea during 1981-2008

BACKGROUND: The actual trends in antibiotic use in Korea are difficult to determine because antibiotic usage, which is not covered by insurance or not consumed in all hospitals in Korea, cannot be calculated accurately. Therefore, this study estimated the antibiotic usage indirectly from the data available in the 'Annual Products of Medicine,' which is published by the Korean Pharmaceutical Manufacturers Association. MATERIALS AND METHODS: The data from 'Annual Products of Medicine in 2008' was analyzed. The cost and amounts of antibiotics produced were calculated and compared with previous data. RESULTS: In 2008, the total cost of antibiotics was $ 1.6 billion, and the total amount was 1,140 tons. Since 1993, there has been an upward trend in the total amount of antibiotics produced. In contrast, there has been a downward trend in the proportion of antibiotics among all pharmacological agents produced. In terms of the amount, the production of cephalosporins was highest since 2003, whereas the production of penicillins was highest before 2003. The production of third and fourth generation cephalosporins is increasing, whereas that of first generation cephalosporins is decreasing gradually. Regarding the class of penicillins, the production of beta-lactam/beta-lactamase inhibitor combinations was the highest after 2003, whereas the production of aminopenicillin was the highest before 2003. Compared to 2003, although the amount of quinolones produced in 2008 has decreased by 52.9%, the cost increased by 41.7%. This was attributed to an increase in the production of ciprofloxacin and levofloxacin instead of older quinolones. Since 1993, aminoglycoside, tetracycline, lincosamide and chloramphenicol have been decreasing in both amount and cost. The increase in carbapenems (241.9%), antifungals (128.4%) and antiviral agents (193.2%) in 2008 is remarkable compared to that in 2003. CONCLUSIONS: The production and cost of broader spectrum and more expensive antibiotics are increasing, and is believed to be responsible for the emergence of resistance. Therefore, restriction of these broader spectrum antibiotics, such as carbapenems, is recommended.

Clinical and Epidemiologic Characteristics of Mycoplasma pneumoniae Pneumonia in Adults During 2011 Epidemic

BACKGROUND: Recent data regarding the clinical epidemiologic characteristics of Mycoplasma pneumoniae pneumonia in Korean adults are insufficient. This study was conducted in order to compare epidemics in different ages and to identify the clinical characteristics in adults. MATERIAL AND METHODS: We investigated patients who visited Korea University Guro Hospital from January to December 2011 due to community acquired pneumonia and underwent mycoplasma antibody tests. M. pneumoniae pneumonia was diagnosed if mycoplasma antibody titer was > or =1:320 at any time, seroconversion or 4-fold rise was seen at convalescent phase. Patients under the age of 19 were classified as child and adolescent, otherwise adult. We investigated the number of monthly cases in all patients and reviewed the medical records of adult patients. RESULTS: A total of 249 young patients aged < or =18 years and 29 adults were diagnosed with M. pneumoniae pneumonia. Among young patients, 75.5% were concentrated in the 0-6 years age group and 58.6% of adults belonged to the 26-40 years age group. The number of young patients began to increase in July and continued to increase in December, while the number of adult patients began to increase in August and occurred continuously until December. The correlation coefficient of the epidemic trend between the two groups was 0.682 (P=0.015). Median age of adult patients was 33.3 years. Fever was observed in all patients and 25 patients (86.2%) complained of purulent sputum. The average white blood cell count was 7,066/mm3. The average values for aspartate aminotransferase, alanine aminotransferase, creatinine, and sodium were within the normal range. In chest X-ray study, ipsilateral lower patchy consolidation was found in 24 patients (82.8%). Twenty one adult patients (72.4%) were hospitalized. The mean duration of hospitalization was 7.3 days. Twenty three patients (79.3%) were initially treated with combinations of third generation cephalosporin and macrolide. Among them, five patients (17.2%) showed poor responses. Six cases (20.7%) were initially treated with quinolone, and treatment was maintained until the end without changing antibiotics. Development of cryptogenic organizing pneumonia occurred in one case and there was no occurrence of death. CONCLUSIONS: When M. pneumoniae pneumonia is epidemic among children and adolescents, it should also be suspected in adult patients with community-acquired pneumonia. Some patients showed poor responses to macrolide. Overall, it appears that additional studies are needed for evaluation of the effectiveness of macrolide in treatment of M. pneumoniae pneumonia in adults.

Risk Factors for Mortality in Patients with Carbapenem-Resistant Acinetobacter baumannii Bacteremia: Impact of Appropriate Antimicrobial Therapy

This study investigated predictors associated with 14-day mortality, and focused especially on the impact of appropriate antimicrobial treatment among patients with carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia. This retrospective study was performed at a tertiary care hospital in Korea from June 2007 to June 2010. Antibiotic therapy was considered appropriate if the antibiotics were administered via an appropriate route within 24 hr after the result of blood culture, had in vitro sensitivity to isolated strains, and of an adequate dosage according to the current guidelines. Ninety-five patients with A. baumannii bacteremia were included; of these, 53 (55.8%) were infected with CRAB. The overall infection-related 14-day mortality was higher in patients receiving inappropriate antimicrobial therapy than in patients receiving appropriate therapy (59.5% [22/37] vs 13.8% [8/58], P < 0.05). Multivariate analysis showed that septic shock (OR 10.5, 95% CI, 1.93-57.4; P = 0.006), carbapenem-resistance (OR 7.29, 95% CI 1.57-33.8; P = 0.01), pneumonia as a source of bacteremia (OR 5.29, 95% CI 1.07-26.1; P = 0.04), and inappropriate antimicrobial therapy (OR 8.05, 95% CI 1.65-39.2; P = 0.009) were independent risk factors for 14-day mortality. Early definite antimicrobial therapy had an influence on favorable outcomes in patients with A. baumannii bacteremia.

Hepatic and Small Bowel Mucormycosis after Chemotherapy in a Patient with Acute Myeloid Leukemia: A Case Report and Literature Review

We present a case of a 64-year-old woman with acute myeloid leukemia who developed a hepatic abscess during the neutropenic period after induction chemotherapy. To treat the abscess, meropenem and ciprofloxacin were administered to target Klebsiella pneumoniae and percutaneous drainage performed. As a result, the patient's fever and c-reactive protein (CRP) subsequently improved. After six weeks of antibiotic therapy, an abdominal computed tomography scan revealed remains of the liver abscess as well as an ileus in the small bowel. Molds from the Mucor genus were cultured from repeated liver abscess drainage and an abscess wall biopsy confirmed hepatic mucormycosis. Along with administration of amphotericin-B deoxycholate for four weeks, we performed lobectomy for hepatic mucormycosis and small bowel resection for a suspected small bowel mucormycosis. After these operations, the patient received liposomal amphotericin B for three weeks and was then maintained with oral posaconazole for more than four weeks. Our case report suggests that hepatic mucormycosis should be considered when a hepatic abscess exhibits a retarded response to antibacterial agents, especially for patients with risk factors. In addition, because an isolated hepatic mucormycosis is infrequent, a thorough search for the extent of the disease is necessary before surgical resection.

A Case of Alternaria Rhinosinusitis in a Patient with Myelodysplastic Syndrome during Neutropenic Period

The genus Alternaria contains several species of melanized hypomycetes that cause opportunistic human infections. The most frequent clinical manifestations of alternariosis are cutaneous and subcutaneous infections, followed by oculomycosis, invasive and non-invasive rhinosinusitis, and onychomycosis. So far, only 17 cases of rhinosinusitis caused by Alternaria species have been reported since 1977. Although several domestic cases of cutaneous alternariosis have been reported, there is no report of Alternaria rhinosinusitis in Korea. The majority of Alternaria rhinosinusitis involves immunocompromised patients. We report the first case of alternariosis in a patient with neutropenia and myelodysplastic syndrome that was treated with endoscopic debridement and a conventional antifungal agent.

Perception on influenza vaccination in Korean women of childbearing age

PURPOSE: Women who are pregnant, planning to become pregnant in the influenza season or caring for infant 6-59 months of age are identified as priority groups for influenza vaccination. Vaccination rate is presumed to be low in those women. The purpose of this study was to investigate perceptions of childbearing age women about influenza vaccination. MATERIALS AND METHODS: Childbearing age women visiting the department of Obstetrics and Gynecology in 3 University hospitals in Seoul and Gyeonggi-do province were surveyed. Individual interviews were performed to them with questionnaire for 2 months from April to May 2012. Demographic data, Immunization history, general understanding and factors associated with vaccination were asked. RESULTS: Three hundred fifty-five (71.0%) of total 500 reproductive age women had the experience of influenza vaccination. Among 343 women who has been pregnant at least once, 48 women (16.4%) had vaccination during pregnancy, and 46 of them got vaccination since 2009. One hundred ninety women of total 500 women responded that they would get vaccination if pregnant in the next influenza season (38.0%). In multivariate analysis, statistically significant factors associated with plans of influenza vaccination in pregnancy were as follows: experience of childbirth (odds ratio [OR], 1.97; 95% CI, 1.32 to 2.93), high level of education (OR, 1.96; 95% CI, 1.22 to 3.15), previous influenza vaccination (OR, 1.88; 95% CI, 1.17 to 3.01). CONCLUSION: Influenza vaccine coverage on childbearing age women including pregnant women is low because of misperception of vaccination during pregnancy. It is necessary for healthcare provider to correct misunderstanding and to recommend vaccination actively.

Liver Abscess by Aspergillus and Enterococcus faecium in a Patient with Acute Myeloid Leukemia: A Case Report and Literature Review

We report a case of liver abscess caused by Aspergillus and Enterococcus faecium in a patient with acute myeloid leukemia. As far as we know, this is the first case of hepatic aspergillosis in Korea. After remission induction chemotherapy, the female patient presented with abdominal pain and was found to have liver abscess. The patient was treated with antibiotics against E. faecium, which was isolated from the abscess drainage. However, the therapeutic response was unsatisfactory and a left lateral sectionectomy of the liver was conducted after 21 days of treatment. The liver tissue showed typical pathologic findings of aspergillosis and voriconazole was administered. Allogeneic hematopoietic stem cell transplantation was performed successfully after 4 months. The possibility of aspergillosis should be considered when an immunocompromised patient with hepatic abscess poorly responds to the use of broad spectrum antibiotics.

Efficacy of Vancomycin against Staphylococcus aureus according to Inoculum Size in a Neutropenic Mouse Infection Model

BACKGROUND: Staphylococcus aureus is one of the most important gram-positive pathogens in many clinical situations. Use of vancomycin against methicillin resistant S aureus (MRSA) has been anecdotally associated with treatment failure, which could be attributable to an inoculum effect (IE). Using a neutropenic mouse thigh infection model, we tried to evaluate the in vivo IE of vancomycin against S. aureus. MATERIALS AND METHODS: Twenty strains of S aureus were used. Minimum inhibitory concentrations (MICs) were determined by the Clinical and Laboratory Standards Institute guideline. Six-week-old specific-pathogen-free, female CD-1 mice weighing 23-27 grams were used. The neutropenic mice received inoculations of 5.02-5.74 log10 CFU/thigh in one thigh (low inoculum, LI), and 7.22-7.73 log10 CFU/thigh in the other thigh (high inoculum, HI) before therapy. The mice were treated with 6 hourly subcutaneous doses of vancomycin (3.125-100 mg/kg) for 24 h. Single-dose serum pharmacokinetics of vancomycin was determined. Dose-response data were analyzed by an Emax model using non-linear regression. Static doses and area under the curve (AUC)/MIC for bacteriostatic effect at each inoculum were calculated and compared. The ratio of static dose and AUC/MIC between HI and LI (IE index) provided the magnitude of IE for each organism. RESULTS: Five methicillin-susceptible S aureus (MSSA) strains and 15 MRSA strains were used. Vancomycin MICs of the 20 strains varied by 4-fold (0.5-2 mg/L). The AUC/MIC ratio was the major parameter determining the efficacy of vancomycin against S aureus . Mean (range) static dose on LI and HI was 20.7 (11.8-35.1) and 136.7 (32.1-314), respectively. The mean IE index of static dose between them was 7.39. Mean (range) of AUC/MIC on LI and HI was 27.0 (6.61-66.6) and 152.3 (46.2-344), respectively, which produced a mean IE index of AUC/MIC of 7.47. The IE indices of the MSSA strains were significantly higher than those of the MRSA strains (11.3 vs. 6.1 on static dose [P=0.018], 11.4 vs. 6.2 on AUC/MIC [P=0.034]). CONCLUSIONS: With a 100-fold inoculum increment of S aureus , at least a 7-fold dose of vancomycin would be required to show the same bacteriostatic effect. Thus, IE as well as MICs is an important parameter in selecting and adjusting a dose and dosage interval along with the resistance profile in the treatment of S. aureus infections. IE to vancomycin observed in the in vivo neutropenic mouse model was more evident for MSSA strains than for MRSA strains.

Two Cases of Pneumocystis Pneumonia after Liver Transplantation Presenting with Different Clinical Manifestations / 대한이식학회지

Pneumocystis carinii pneumonia (PCP), now known as Pneumocystis jirovecii, is a fungal pathogen that causes opportunistic disease, especially pneumonia, in immunocompromised patients. The patients can have a spectrum of illnesses ranging from asymptomatic to fulminant respiratory failure. Here we report two cases with pneumocystis pneumonia after liver transplantation who presented with different clinical features. One patient developed acute respiratory failure requiring mechanical ventilation and expired due to PCP and a superimposed bacterial infection. The other patient was asymptomatic and discovered by regular X-ray check-up. He was successfully treated with trimethoprim/sulfamethoxazole. As shown by our cases, PCP presents with broad clinical manifestations and leads to various clinical courses in liver transplant recipients. Thus, Pneumocystis jirovecii has to be considered a potential pathogen of pneumonia in liver transplant recipients regardless of severity, especially one who is not on prophylactic medications. We consider prophylaxis of PCP in liver transplant recipients in our center.

Co-infection with Giardia lamblia and Salmonella species after travel abroad / 대한내과학회지

As many Koreans now travel abroad, they are at increased risk for a variety of infectious diseases that are endemic to developing countries in the tropics and subtropics. We report two cases of co-infection with Giardia lamblia and Salmonella species not susceptible to nalidixic acid, after travel abroad.

Tako-Tsubo Cardiomyopathy by Transient Dynamic Left Midventricular Obstruction

A 48-year-old woman visited the emergency department with shock due to a urinary tract infection. The patient, who had a history of hypertension and diabetes mellitus, presented with precordial ST-segment elevation and Q waves, along with an increase of cardiac enzymes. An echocardiography showed moderately reduced systolic function, severe apical left ventricular ballooning, and a dynamic left ventricular outflow tract obstruction with a pressure gradient of 109 mmHg. Coronary angiography demonstrated normal coronary arteries. At the 1-month echocardiographic follow-up, the apical ballooning and left ventricular systolic function had recovered completely. There was no residual left ventricular intra-cavity gradient at rest, but it was induced in low-dose dobutamine stress-echocardiography. We demonstrated that dynamic left midventricular obstruction in the setting of either increased catecholamine stress or hypovolemia could develop Tako-tsubo cardiomyopathy.