Ting-Yu Yen

The correlation between the presence of viremia and clinical severity in patients with enterovirus 71 infection: a multi-center cohort study

BackgroundEnterovirus 71 (EV71) is a great disease burden across the whole world, particularly in Southeast Asia. However, in recent decades, the pathogenesis of severe EV71 infection was not well understood. This study was aimed to investigate the correlation between the presence of viremia and the clinical severity of EV71 infection.MethodsWe organized a prospective cohort study and enrolled laboratory-confirmed EV71 cases in six tertiary care hospitals in Taiwan during the EV71 epidemic from 2011 to 2012. Blood samples were collected once in the acute stage, on the first day of admission. We used real-time RT-PCR to detect EV71 viremia. Demographical and clinical data were collected and the clinical severity was categorized into four grades. Data analysis was performed to identify the risk factors of viremia and the correlation between viremia and clinical severity of EV71 infection.ResultsOf the total 224 enrolled patients, 59 (26%) patients were confirmed to have viremia. Two-thirds (68%) of viremic cases were detected within the first three days of infection. Viremia occurred more frequently in children under the age of one year old (odds ratios [OR] 4.82, p < 0.001) but the association between the presence of viremia and complicated EV71 infection was not found (OR 1.02, p = 0.96). In the viremia group, patients had significantly more severe complications if viremia was detected after the third day of disease onset (26% vs. 5%, p = 0.03).ConclusionsViremia occurred more frequently in children under the age of one year and viremia detected beyond three days after the onset of disease correlated with more severe disease in EV71 patients.

Clinical features and phylogenetic analysis of Coxsackievirus A9 in Northern Taiwan in 2011.

BackgroundCoxsackievirus A9 (CA9) was one of the most prevalent serotype of enteroviral infections in Taiwan in 2011. After several patient series were reported in the 1960s and 1970s, few studies have focused on the clinical manifestations of CA9 infections. Our study explores and deepens the current understanding of CA9.MethodsWe analyzed the clinical presentations of 100 culture-proven CA9-infected patients in 2011 by reviewing their medical records and depicted the CA9 phylogenetic tree.ResultsOf the 100 patients with culture-proven CA9 infections, the mean (SD) age was 4.6 (3.4) years and the male to female ratio was 1.9. For clinical manifestations, 96 patients (96%) had fever and the mean (SD) duration of fever was 5.9 (3.4) days. Sixty one patients (61%) developed a skin rash, and the predominant pattern was a generalized non-itchy maculopapular rash without vesicular changes. While most patients showed injected throat, oral ulcers were found in only 19 cases (19%), among whom, 6 were diagnosed as herpangina. Complicated cases included: aseptic meningitis (n=8), bronchopneumonia (n=6), acute cerebellitis (n=1), and polio-like syndrome (n=1). Phylogenetic analysis for current CA9 strains is closest to the CA9 isolate 27-YN-2008 from the border area of mainland China and Myanmar.ConclusionsThe most common feature of CA9 during the 2011 epidemic in Taiwan is generalized febrile exanthema rather than herpangina or hand, foot, and mouth disease. Given that prolonged fever and some complications are possible, caution should be advised in assessing patients as well as in predicting the clinical course.

Immune response to 2009 pandemic H1N1 influenza virus A monovalent vaccine in children with cancer

This study investigated the immune response to 2009 pandemic H1N1 influenza monovalent vaccine in children with cancer receiving chemotherapy.

Emergence of oxacillin-resistant Staphylococcus lugdunensis carrying staphylococcal cassette chromosome mec type V in central Taiwan

BACKGROUND Staphylococcus lugdunensis has emerged as a key pathogen for clinical infection. It is sensitive to most antistaphylococcal agents, but it is increasingly resistant to β-lactam antibiotics. Oxacillin-resistant S. lugdunensis isolates carrying the mecA gene pose a major concern for therapy failure. METHODS To assess the epidemiology and presence of mecA in S. lugdunensis, we gauged the prevalence and antibiotic resistance of S. lugdunensis in clinical specimens by using multiplex polymerase chain reaction (PCR) and pulsed-field gel electrophoresis. RESULTS Thirty S. lugdunensis isolates were collected and examined between October 2009 and December 2010. The resistance to penicillin (87%) and oxacillin (20%) was noted. All oxacillin-resistant isolates (6/30) had type V or VT SCCmec. Most (67%, 4/6) isolates carried SCCmec type V. These organisms caused invasive infections such as peritonitis, osteomyelitis, and septic arthritis. Pulsed-field gel electrophoresis analyses showed most (83%, 5/6) isolates carrying mecA were pulsotype D with high similarity (93.8%). CONCLUSIONS The findings suggest oxacillin-resistant S. lugdunensis carrying SCCmec type V is emerging in central Taiwan.

Multidrug-resistant Acinetobacter baumannii infection among neonates in a neonatal intensive care unit at a medical center in central Taiwan

BACKGROUND Few studies have focused on multidrug-resistant Acinetobacter baumannii (MDRAB) infection in neonates. The aim of this study was to investigate risk factors for mortality in neonates with MDRAB infection. METHODS This retrospective case-series study was conducted at the Childrens Hospital of China Medical University, Taichung, Taiwan. All patients hospitalized between January 2010 and December 2013 in the neonatal intensive care unit (NICU) with MDRAB infections were reviewed. RESULTS A total of 67 isolates from 59 neonatal patients were positive for MDRAB. Of the 67 isolates, 38 were from blood (56.72%), 16 from sputum (23.88%), seven from pus (10.45%), three from ascites (4.48%), two from cerebrospinal fluid (2.99%), and one from pleural fluid (1.49%). There were five episodes of MDRAB clusters consisting of 28 cases during the study period. The mortality rate due to MDRAB sepsis was 20.34% (12/59). The statistically significant risk factors for mortality due to MDRAB infection were being infected with MDRAB within 7 days of admission to the NICU, use of umbilical vein catheters, absolute neutrophil count < 1500/mm(3), platelet count < 100,000/mm(3), and a delay in initiating adequate antibiotic treatment. CONCLUSION MDRAB infection is responsible for a high mortality rate among neonates in the NICU, especially in those who have neutropenia or thrombocytopenia. Infection control and appropriateness of the initial antimicrobial agent with colistin play an important role in reducing mortality.

Pyogenic liver abscess among children in a medical center in Central Taiwan

BACKGROUND Pediatric pyogenic liver abscess is uncommon. This study aimed to investigate the clinical characteristics, radiologic features, pathogens, duration of hospitalization, and management of pediatric pyogenic liver abscess. METHODS Pediatric patients with pyogenic liver abscess admitted to the China Medical University Hospital from 1995 to 2011 were reviewed. Their clinical characteristics, radiological features, laboratory data, clinical management, and outcomes were analyzed. Those with liver abscess due to the complication of oncologic disease were excluded. RESULTS Fifteen patients were diagnosed with pyogenic liver abscess. Their most common symptoms were fever and abdominal pain. Eight (53.0%) had leukocytosis (>15000/μL) and elevated C-reactive protein (CRP) level (>10 mg/dL). The main imaging presentation was a single abscess in right lobe of the liver (13/15, 86.7%). Blood culture were mainly negative (12/15, 80.0%). Pathogenic microorganisms cultured from pus revealed Klebsiella pneumoniae (6/15, 40.0%) and Streptococcus spp. (6/15, 40.0%) as the two most common pathogens. Percutaneous abscess drainage followed by adequate parenteral antibiotics were effective interventions. Hospitalization of at least 2 weeks was needed in most cases. There were no mortalities. CONCLUSION Pyogenic liver abscess should be considered in children presenting with fever, abdominal pain, and leukocytosis with a high CRP level. Most cases involve a single lesion on right lobe of the liver. K. pneumoniae and Streptococcus spp. are the two most common pathogens. Drainage with adequate antibiotics has significantly good response.

Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital

BackgroundTo probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a childrens hospital.MethodsFrom August 2009 to March 2010, serum samples were drawn from 150 HCWs in a childrens hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed.ResultsAmong the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion.ConclusionThe infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.

Immunogenicity and safety of a trivalent inactivated 2010–2011 influenza vaccine in Taiwan infants aged 6–12 months

This prospective study aimed to investigate the immune responses and safety of an influenza vaccine in vaccine-naïve infants aged 6-12 months, and was conducted from November 2010 to May 2011. Fifty-nine infants aged 6-12 months received two doses of trivalent inactivated influenza vaccine 4 weeks apart. Hemagglutination inhibition titers were measured 4 weeks after the two doses of study vaccine. Based on the assumption that a hemagglutination inhibition titer of 1:40 or greater against the antigen would be protective in adults, two doses of the study vaccine generated a protective immune response of 63.2% against influenza A(H1N1), 82.5% against influenza A(H3N2) and 38.6% against influenza B viruses in infants aged 6-12 months. The geometric mean fold rises against influenza type A and B viruses also met the European Medicines Agency criteria for flu vaccines. The solicited events within 7 days after vaccination were mild in intensity. No deaths or adverse events such as optic neuritis, cranial neuropathy, and brachial neuropathy or Guillain-Barre syndrome were reported. Two doses of inactivated influenza vaccine were well tolerated and induced a protective immune response against influenza in infants aged 6-12 months.

Possible infectious etiology among Kawasaki disease patients and their families

Kawasaki disease (KD), first described in 1967 by Tomisaku Kawasaki, is an acute febrile mucocutaneous lymph node syndrome with undetermined etiology. Based on the epidemiological features of KD, including temporal, seasonal, geographic, and family clustering, infectious etiology is supposed to be one of the possible predisposing factors. Tsai and colleagues reported a high prevalence of acute infectious illness among household members of KD patients during KD cases’ acute stage, and 92% of the families had clusters of infectious illness. This may prove that KD is strongly associated with infectious etiology. However, there are several issues that merit further discussion. Interestingly, there is a high prevalence of infectious illness among families of KD patients, but there is a relatively low positive rate (8.1%) of throat swabs for viral isolation. This may be attributable to several possible reasons. First, viral isolation is the gold standard to prove clinical viral infection, but not all viruses grow well in current culture systems. Second, there are various infectious symptoms observed in the families of KD patients, such as upper and lower respiratory tract infection, gastroenteritis, and conjunctivitis, but only throat swab is taken for viral isolation. Third, throat swab of symptomatic families is only performed once, at the time when KD patients are admitted to a hospital, when the virus may no longer be present or cannot be cultured. All these reasons may contribute to lower the positive viral isolation rate among symptomatic families of KD patients. To improve the detection rate of infectious etiology, collecting clinical specimens from multiple sites and at different periods, and including more sensitive and specific laboratory methods (e.g., serology or polymerase chain reaction) may provide more clinically relevant information. Moreover, in the current study, only symptomatic families are enrolled to

Subdural Hematoma Infected with Escherichia coli in a 5-Month-Old MaleInfant: Case Report

Hematogenous dissemination from a localized infection to a previous existing subdural hematoma is an extremely rare cause of subdural empyema which is termed infected subdural hematoma. We reported a 5-month-old male infant suffered from infected subdural hematoma by Escherichia coli (E. coli). In this patient, urinary tract infection was the most favorable origin from which seed the organism to subdural space hematogenously with evidence of pyuria and pyelonephritis. Subdural empyema was well treated after burr hole drainage with adequate antibiotic use. This infant is now doing well based on findings from regular outpatient followed-up without recurrence of infection and sequela. In conclusion, the applicable treatment strategy for infected subdural hematoma has not been determined due to its rarity. However, adequate drainage and duration of antibiotic use will be related to achieving a more satisfactory outcome when compared with subdural empyema associated with meningitis.