Ching Fen Shen

Long-term Characteristics of Healthcare-associated Infections in a Neonatal Intensive Care Unit

BACKGROUND/PURPOSE Healthcare-associated infections in neonatal intensive care units (NICUs) are associated with a significant risk of morbidity and mortality. Knowledge regarding pathogens, primary sources of infection and antibiotic resistance in the NICU is essential for developing management strategies. This study aimed to analyze the long-term characteristics of healthcare-associated infections in a tertiary referral center in southern Taiwan. METHODS Infants < 30 days old, with positive blood, cerebrospinal fluid, urine or tissue fluid cultures during hospitalization in the NICU of National Cheng Kung University Hospital from July 1989 to June 2008 were included in the study. RESULTS In total, 1,417 organisms and episodes were identified during the study period. Gram-positive organisms, Gram-negative organisms and fungi constituted 923 (65.1%), 358 (25.3%) and 136 (9.6%) of the pathogens, respectively. Of the Gram-positive organisms, coagulase-negative staphylococci (51.5%), Staphylococcus aureus (34.8%) and Enterococcus spp. (6.1%) were the major pathogens; and 27% of Staphylococcus aureus isolates were oxacillin-resistant. For the Gram-negative organisms, Klebsiella pneumoniae (22%), Pseudomonas aeruginosa (21.8%), Escherichia coli (16.7%) and Enterobacter cloacae (16.7%) were dominant. Also, Candida albicans accounted for 50% of fungal infections. The most common source of infection was bloodstream infection (59.0%), and 5.6% of these were catheter-related. Skin and soft tissue infections were also frequent (26.3%). CONCLUSION Bloodstream and skin/soft tissue infections caused by commensal species play an important role in healthcare-associated infections in the NICU. New measures should be developed in response to the changing patterns in the NICU.

Childhood invasive pneumococcal disease caused by non-7-valent pneumococcal vaccine (PCV7) serotypes under partial immunization in Taiwan

BACKGROUND/PURPOSE Emerging non-7-valent pneumococcal conjugate vaccine (PCV7) serotypes have replaced PCV7 serotypes in childhood invasive pneumococcal disease (IPD). This study was designed to describe the IPD caused by non-PCV7 serotypes under partial PCV7 immunization in Taiwan. METHODS All children <18 years of age diagnosed with IPD at National Cheng Kung University Hospital from 1998 to 2010 were enrolled. Clinical and laboratory information was collected. Pneumococcal isolates were tested for antimicrobial susceptibility and interpreted using Clinical Laboratory Standard Institute guidelines (2008). Serotypes were determined using the capsular swelling method. RESULTS One hundred and five patients with IPD were identified, including 75 PCV7 and 30 non-PCV7 isolates. Pneumonia (63.3%) was the leading clinical manifestation of non-PCV7 IPDs and 78.9% of pneumonia cases were associated with necrotizing pneumonia or empyema. Children with non-PCV7 IPDs had longer febrile days, required longer intensive care unit stays, and had a higher C-reactive protein level than those with PCV7 IPDs (p < 0.05). Serotype 3 is the most common non-PCV7 serotype (46.7%) and possesses the highest potential for pulmonary complications (p < 0.05, odds ratio: 0.114; 95% confidence interval, 0.013 - 0.973). CONCLUSION The changing epidemiology of IPDs following the introduction of PCV7 has been noted. Expanded serotype coverage of the vaccine is warranted.

Echovirus 18 meningitis in southern Taiwan.

Eighty cases of echovirus 18 infection among young children during an outbreak in 2006 in Taiwan were enrolled. Twenty percent of the patients had a comorbid condition. Twenty-five cases (31%) were complicated by aseptic meningitis. The most frequent diagnoses in children without meningitis were pharyngitis/tonsillitis (35%) and vesicular viral exanthem (33%). The case-fatality rate among the children with meningitis was 4%. Echovirus 18 was isolated from the cerebrospinal fluid of 68% of the children.

The trend of macrolide resistance and emm types of group A streptococci from children at a medical center in southern Taiwan

BACKGROUND Group A streptococcus (GAS) is a common pathogen in children. Macrolide resistance in GAS has been described worldwide. The aims of this study are to analyze macrolide resistance of GAS isolates in southern Taiwan and to clarify the relationship of emm typing and macrolide resistance in the past decade. METHODS All GAS isolated from patients younger than 18 years at a single tertiary center in southern Taiwan were collected from 2000 to 2012. Antibiotics susceptibility to erythromycin, azithromycin, and clindamycin were determined by agar dilution method, and were interpreted by Clinical and Laboratory Standards Institute (CLSI) standards. emm typing was performed by polymerase chain reaction (PCR). RESULTS A total of 301 isolates were collected during the period of 13 years. Scarlet fever (38.5%) and acute pharyngitis (32.2%) were the most common diagnosis. Decreased resistance rate of erythromycin from 53.1% in 2000 to 0% in 2010 was found, but it increased rapidly to 65% in 2011. The resistance rate of azithromycin was the lowest (4.2%) in 2005, but was higher than 15% after 2006. The involvement of the erythromycin resistance genes were mefA (53.1%), ermB (35.9%), and ermTR (10.9%). The resistance of clindamycin also increased since 2011. emm12 was the most common serotype and accounted for 44.9% of all isolates. Compared with the non-emm12 group, resistance to erythromycin, azithromycin, and clindamycin were more frequently detected in the emm12 group. CONCLUSION Increased resistance of GAS to macrolide and clindamycin was found in recent years. emm12 was the main serotype for macrolide resistance.

Clinical and laboratory characteristics of human immunodeficiency virus-infected adolescents: Experience from a single medical center

BACKGROUND Recently, the proportion of adolescents diagnosed with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) has increased. The aim of this study is to evaluate the clinical and laboratory characteristics of HIV-infected adolescents in southern Taiwan. METHODS From June 1997 to December 2010, a total of 40 HIV-infected adolescents who sought medical care in a university hospital in southern Taiwan were enrolled in the study. They were classified into three HIV at-risk groups, men who have sex with men (MSM), heterosexuals, and intravenous drug users (IDUs). Clinical and laboratory data were obtained from medical records. RESULTS The median age of the 40 HIV-infected adolescents was 19 years. The HIV at-risk groups were MSM (22/40, 55%), heterosexuals (7/40, 17.5%), IDUs (5/40, 12.5%), and unknown (6/40, 15%). The initial median CD4 count and log plasma HIV viral load were 318 cells/mm(3) and 4.61, respectively. The seroprevalence of anti-HAV, anti-HBc, anti-HCV antibodies and HBsAg was 5.3%, 26.1%, 13% and 13%, respectively. Among 17 adolescents who had regular follow-ups more than twice, 7 (41.2%) had a concurrent sexually transmitted disease (STD). The most common STD was genital warts (41.2%) followed by syphilis (11.8%). Among 7 patients who received highly active antiretroviral agents (HAART) for more than 12 months, 5 (71.4%) had sustained virologic suppression. CONCLUSION MSM are the largest risk group in HIV-infected adolescents in southern Taiwan and are characterized by a high prevalence of anogenital warts and low seroprevalence of anti-HAV.

Childhood tuberculosis in southern Taiwan, with emphasis on central nervous system complications

BACKGROUND/PURPOSE Childhood tuberculosis (TB) continues to be a major public health problem in Taiwan. Taiwan remains a highly endemic area despite neonatal Bacillus Calmette-Guérin (BCG) vaccination and the availability of anti-TB therapy. The presentation is highly variable and it is often difficult to make an accurate diagnosis. This study was designed to evaluate the demographic, clinical, and laboratory findings and outcomes of TB in children with emphasis on central nervous system (CNS) complications. METHODS The medical records of 80 children diagnosed with TB at a medical center in southern Taiwan over the past 24 years (1988-2012) were reviewed. RESULTS Among them, 48.8% (39/80) had pulmonary TB, 27.5% (22/80) had isolated extrapulmonary TB, and 23.7% (19/80) had disseminated TB. Most infected cases were aged either < 4 years or > 12 years. TB contact history was found in 42.5% (34/80) cases. Fourteen (17.5%) of the cases had CNS involvement. The most common presentations were fever (85.7%), signs of increased intracranial pressure (71.4%), drowsiness (64.3%), and focal neurological signs (57.1%). The major radiological findings were tuberculoma (50%), basilar enhancement (41.6%), infarction (41.6%), hydrocephalus (16.6%), and transverse myelitis (16.6%). The case fatality of CNS TB was 14.3% and 21.4% had neurologic sequelae. CONCLUSION Findings suggest that positive exposure history and suspicious clinical presentations are important clues for further confirmatory laboratory and image studies in childhood TB. CNS TB usually presented as part of disseminated TB in children. Early diagnosis and treatment may lead to favorable outcomes in CNS TB.

Immunophenotype Expressions and Cytokine Profiles of Influenza A H1N1 Virus Infection in Pediatric Patients in 2009

Background. A novel swine-origin influenza A H1N1 virus (S-OIV) caused human infection and acute respiratory illness in 2009, resulting in an influenza pandemic. Objectives. This study characterized the immune responses of S-OIV infection in pediatric patients at risk of pulmonary complications. Methods. All enrolled pediatric patients were confirmed virologically for S-OIV infection in 2009-2010, prospectively. Changes in cellular immunophenotypes were analyzed using flow cytometry. Plasma cytokine levels associated with S-OIV infection by pulmonary and without pulmonary complications were measured using cytokine cytometric bead assay kits. Results. A total of 85 patients with a mean age of 10.3 years were recruited. The level of C-reactive protein (CRP) was high in patients exhibiting pulmonary complications. The percentage of cellular immunophenotypes did not change between patients with and without pulmonary complications. The absolute numbers of peripheral blood mononuclear cells (PBMC), CD3, CD8, and CD16CD56 decreased with acute S-OIV pulmonary complications. Acute influenza infection with pulmonary complications was associated with high plasma concentrations of IL-1β, IL-6, IL-12, and IFN-γ. Conclusion. Immunophenotype studies have reported variability in immune response to the severity of S-OIV infections. Acute phase cytokine profiles of the 2009 S-OIV infection might have contributed to the pathogenesis of the pulmonary complications.

Clinical perspectives of childhood tuberculosis in Taiwan

Tuberculosis (TB) is an important public health issue in Taiwan and worldwide. Taiwan has made major progress in combating TB in the past 40 years. However, childhood TB still constitutes a significant challenge in disease control. From January to mid December 2011, 369 new cases of pediatric TB were confirmed. The relatively low case number and variable clinical presentations made it difficult for early detection. Latent TB infections in children also pose further complexity in clinical management. Knowledge of the clinical features of active and latent TB infection is crucial for efficient TB control.

Clinical and epidemiological characteristics in hospitalized young children with acute gastroenteritis in southern Taiwan: According to major pathogens

BACKGROUND Acute gastroenteritis (AGE) can be caused by a wide array of pathogens, including bacteria, viruses, and parasites. A prospective study to investigate the epidemiology and clinical presentation in young children hospitalized with AGE was conducted in a medical center in southern Taiwan. METHODS Patients aged less than 5 years who was hospitalized due to AGE in National Cheng Kung University Hospital were enrolled from July 2014 to June 2016. The demographic information, clinical features and laboratory data were collected by chart reviews, and stool samples were sent to Centers of Disease Control, Taiwan (Taiwan CDC) for a panel of pathogen identification consisting of two viruses, nine bacteria, and five parasites. RESULTS Totally 441 patients were enrolled in this study. Salmonella spp. was the leading cause of disease (21.8%), followed by norovirus (17.0%), Clostridium difficile (9.5%), and rotavirus (9.3%). Norovirus identification rate was the highest among patients less than 6 months of age, while Salmonella was highest among patients between 2 and 3 years old. Patients with Salmonella infection frequently presented with fever, lethargy, bloody stool, and elevated serum level of C-reactive protein (CRP); norovirus and rotavirus infection frequently presented with vomiting. Salmonella gastroenteritis also resulted in longer hospitalization and more frequent antibiotics administration. C. difficile could be isolated from both gastroenteritis patients and control children. CONCLUSION Salmonella spp. was the most common pathogen of AGE in hospitalized children in southern Taiwan during 2014-2016, followed by norovirus and rotavirus. Further monitoring of epidemiology characteristics among cardinal pathogens of pediatric gastroenteritis is necessary.

Clinical features of community acquired adenovirus pneumonia during the 2011 community outbreak in Southern Taiwan: Role of host immune response

BackgroundHuman adenovirus 7 (HAdV-7) was responsible for a significant number of fatalities during the 2011 community outbreak in Taiwan. The mechanisms underlying the pathogenesis of severe adenovirus infections in non-immunocompromised individuals remain unclear. Adenovirus pneumonia was associated with pleural effusion in a number of patients from the 2011 outbreak suggesting that similar to bacterial pneumonia, patients diagnosed with adenovirus pneumonia who have pleural effusion are more severely and systemically infected, and may have a more protracted disease course. We hypothesized that the host immunological response determines the severity of adenoviral infection.MethodsThis retrospective case series study included patients diagnosed with severe lower respiratory tract infections at the National Cheng Kung University Hospital in southern Taiwan between December 2010 and October 2011. The main inclusion criteria were 1) presence of multifocal patchy infiltrates, lobar consolidation or reticular interstitial opacities in chest X-rays, and 2) presence of adenovirus isolated from respiratory specimens. All patients had adenovirus isolated from respiratory specimens, and were negative for other viruses. Pleural effusion was confirmed in all patients using chest echography. Clinical features and laboratory data were compared in patients with (n = 12) and without (n = 15) parapneumonic effusion.ResultsPresence of parapneumonic effusion was significantly associated with a longer febrile duration, more complicated clinical management, and a greater risk of extrapulmonary involvement, notably hepatitis. Patients without pleural effusion had significantly higher numbers of WBCs, platelets, and absolute segment cell counts (ASCs) compared to patients with pleural effusion (all p < 0.05). Patients without pleural effusion had significantly higher counts of CD4+, CD8+, and CD20+ T cells (all p < 0.05) compared to patients with pleural effusion.ConclusionOur data indicated that presence of parapneumonic effusion in adenoviral pneumonia was associated with longer febrile duration, more complicated clinical management, a greater risk of hepatitis, and suppression of host cellular immunity. Further prospective, large-scale studies are needed to validate our results.