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Biomedical subjects

Cheng-Hsun Chiu

Publications and source records attributed to Cheng-Hsun Chiu.

At least 73 records · Page 4Linked to original sources

High rate of Simkania negevensis among Canadian inuit infants hospitalized with lower respiratory tract infections.

To determine the prevalence of Simkania negevensis in causing pulmonary infections in children, nasopharyngeal washes were obtained from 22 infants hospitalized with acute bronchiolitis in the Baffin Island, Canada. 14 (63.6%) were positive for S. negevensis. Mixed infections with other respiratory viruses were common. All patients recovered without specific antibiotic treatment. Even though a high prevalence of S. negevensis was found, this organism may potentially well be an opportunistic agent rather than a true pathogen.

Canada↗

Neonatal enterovirus infections: emphasis on risk factors of severe and fatal infections.

OBJECTIVES: Neonatal enterovirus infections have diverse manifestations, from asymptomatic to fatal. An understanding of the risk factors associated with severe cases might help to reduce enterovirus-related morbidity and mortality. METHODS: From July 1989 through June 1998, neonates with virus culture-confirmed nonpolio enterovirus infection at Chang Gung Children's Hospital were enrolled in the study and divided into three groups: nonspecific febrile illness; aseptic meningitis; and hepatic necrosis with coagulopathy (HNC). Demographic factors, clinical manifestations, laboratory data and outcome were analyzed to reveal factors associated with clinical severity and fatality. RESULTS: There were 146 cases including 43 neonates with nonspecific febrile illness, 61 with aseptic meningitis and 42 with HNC. By multiple logistic regression analysis, the most significant factors associated with HNC were prematurity, maternal history of illness, earlier age of onset (< or =7 days), higher white blood cell count (WBC > or =15 000/mm3) and lower hemoglobin (< or =10.7 g/dl). In 10 (24%) of 42 cases, HNC was fatal. In comparison with nonfatal cases of HNC, fatal cases had higher WBC, lower hemoglobin, higher bilirubin and higher incidence of concurrent myocarditis. Multivariate analysis showed the most significant factors associated with fatality from HNC to be total bilirubin >14.3 mg/dl (adjusted odds ratio, 29.1; 95% confidence interval, 2.5 to 355.5; P = 0.007) and concurrent myocarditis (adjusted odds ratio, 13.7; 95% confidence interval, 1.1 to 177.2; P = 0.04). Intravenous immunoglobulin did not correlate with clinical outcomes in cases with HNC. CONCLUSIONS: Prematurity, maternal history of illness, earlier age of onset, higher WBC and lower hemoglobin are significant factors associated with HNC; higher total bilirubin and concurrent myocarditis were most significantly associated with fatality from HNC.

Antiviral Agents↗

In vivo acquisition of ceftriaxone resistance in Salmonella enterica serotype anatum.

The emergence of resistance to antimicrobial agents within the salmonellas is a worldwide and severe problem. A case of treatment failure due to the emergence of resistance to ceftriaxone in Salmonella enterica serotype Anatum was studied. S. enterica serotype Anatum and Escherichia coli, both of which are susceptible to ceftriaxone, were initially isolated from a diabetic patient hospitalized for the treatment of wound and urinary tract infections. Resistant S. enterica serotype Anatum and E. coli strains were isolated concomitantly 2 weeks after the initiation of ceftriaxone therapy. The patient eventually died of a sepsis caused by the ceftriaxone-resistant salmonella. PCR, nucleotide sequence analysis, and DNA-DNA hybridization identified a bla(CTX-M-3) gene located on a 95.1-kb plasmid from the ceftriaxone-resistant isolates of S. enterica serotype Anatum and E. coli. The plasmid was proved to be conjugative. Molecular fingerprinting showed that the susceptible and resistant strains were genetically indistinguishable. The emergence of resistance to ceftriaxone in S. enterica serotype Anatum was due to the in vivo acquisition of a plasmid containing the bla(CTX-M-3) gene and was the cause for treatment failure in this patient.

Aged↗

Extended epidemic of nosocomial urinary tract infections caused by Serratia marcescens.

In recent years a significant increase in the incidence of Serratia marcescens infections was noted at the Chang Gung Memorial Hospital, Taoyuan, Taiwan. A review of laboratory (1991 to 2002) and infection control (1995 to 2002) records showed the possibility of an extended epidemic of nosocomial urinary tract infections (UTIs) caused by S. marcescens. Therefore, in 1998 and 1999, 87 isolates were collected from patients with such infections and examined and another 51 isolates were collected in 2001 and 2002. The patients were mostly elderly or the infections were associated with the use of several invasive devices. S. marcescens was usually the only pathogen found in urine cultures in our study. Neither prior infections nor disseminated infections with the organism were observed in these patients. Resistance to most antibiotics except imipenem was noted. Two genotyping methods, pulsed-field gel electrophoresis and infrequent-restriction-site PCR, were used to examine the isolates. A total of 12 genotypes were identified, and 2 predominant genotypes were found in 72 (82.8%) of the 87 isolates derived from all over the hospital. However, 63.9% of the isolates of the two genotypes were from neurology wards. A subsequent intervention by infection control personnel reduced the infection rate greatly. The number and proportion of the two predominant genotypes were significantly reduced among the 51 isolates collected in 2001 and 2002. Thus, a chronic and long-lasting epidemic of nosocomial UTIs caused by S. marcescens was identified and a successful intervention was carried out. Both a cautious review of laboratory and infection control data and an efficient genotyping system are necessary to identify such a cryptic epidemic and further contribute to the quality of patient care.

Adolescent↗

Dissemination of extended-spectrum beta-lactamase-producing Enterobacteriaceae in pediatric intensive care units.

To study the growing trend of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in pediatric intensive care units (PICUs), 88 nonrepetitive ESBL-producing isolates were prospectively collected and analyzed by molecular methods during a 16-month period. The emergence and dissemination of ESBL-producing Enterobacteriaceae in PICUs are the consequence of the clonal dissemination of a few epidemic strains along with the horizontal transmission of resistance gene-carrying plasmids among bacterial organisms.

Adolescent↗

Emergence of ceftriaxone-resistant Salmonella isolates and rapid spread of plasmid-encoded CMY-2-like cephalosporinase, Taiwan.

Of 384 Salmonella isolates collected from 1997 to 2000 in a university hospital in Taiwan, six ceftriaxone-resistant isolates of Salmonella enterica serovar Typhimurium were found in two patients in 2000. The resistance determinants were on conjugative plasmids that encoded a CMY-2-like cephalosporinase. During the study period, the proportion of CMY-2-like enzyme producers among Escherichia coli increased rapidly from 0.2% in early 1999 to >4.0% in late 2000. Klebsiella pneumoniae isolates producing a CMY-2-like beta-lactamase did not emerge until 2000. The presence of bla(CMY)-containing plasmids with an identical restriction pattern from Salmonella, E. coli, and K. pneumoniae isolates was found, which suggests interspecies spread and horizontal transfer of the resistance determinant. Various nosocomial and community-acquired infections were associated with the CMY-2-like enzyme producers. Our study suggests that the spread of plasmid-mediated CMY-2-like beta-lactamases is an emerging threat to hospitalized patients and the public in Taiwan.

Ceftriaxone↗

Severe adenovirus infection in children.

During the period from July 1, 1999 to September 30, 2000, 9 children with severe adenovirus infection were treated at Chang Gung Children's Hospital. The mean age was 22 months (range, 5-50 months). All of them had lower respiratory tract infections, which manifested as lobar or segmental pneumonia and pleural effusion. Eight (88.9%) of the 9 patients required intensive care and 4 of them required mechanical ventilation. Abnormal laboratory findings included leukocytosis, elevated C-reactive protein, anemia, and prolonged prothrombin time and partial thromboplastin time. Extrapulmonary complications included hepatitis (6 cases), encephalitis (3), conjunctivitis (3), periorbital ecchymosis (1), and coagulopathy (2). One patient died, resulting in a mortality rate of 12.5%. Follow-up at 3 months postdischarge, 5 patients (62.5% of survivors) had bronchiolitis obliterans and/or organizing pneumonia. Seven patients were infected by serotype 3 adenovirus, 1 patient by serotype 2, and another by serotype 11. In conclusion, the clinical, laboratory, and radiographic features of severe adenovirus infection may mimic bacterial infection. Rapid progression of the clinical course despite antibiotic therapy and the presence of unusual extrapulmonary symptoms are important clinical clues in the diagnosis of severe adenoviral infection.

Adenovirus Infections, Human↗

Safety and immunogenicity of a diphtheria, tetanus, and acellular pertussis-inactivated poliovirus vaccine/Haemophilus influenzae type B combination vaccine administered to Taiwanese infants at 2, 4, and 6 months of age.

BACKGROUND: Combined vaccines are urgently needed to ensure compliance with the increasing number of recommended vaccines for children. We evaluated the safety and antibody response to a diphtheria, tetanus, and acellular pertussis-inactivated poliovirus vaccine/Haemophilus influenzae type b (DTaP-IPV/Hib) combination vaccine administrated to infants at 2, 4, and 6 months of age. METHODS: Sixty healthy infants between 6 and 12 weeks of age were enrolled. One group of vaccines received the DTaP-IPV/Hib in a single injection, while another group concurrently received DTaP-IPV and Hib at separate injection sites. Solicited adverse events were monitored by parental observation and were recorded on a diary card. Levels of serum antibodies to DTaP and polyribosyl-ribitolphosphate-tetanus (PRP-T) antigens were collected before the first vaccine dose and 1 month after the third vaccine dose. RESULTS: The combined-injection group tended to have lower local reactions, and there was no increase in reactogenicity when compared with the separate-injection group. Seroconversion rates were 100% in both groups for all antigens, except for the anti-polio 2 antibody in the combined-injection group (96.4%). The combined-injection group had lower antibody levels of PRP (8.45 microg/ml) than did the separate-injection group (20.61 microg/ml). However, the percentage of vaccines achieving protective levels of antibody to PRP (> or = 0.15 microg/ml or > or = 1.0 microg/ml) was similar in both groups. CONCLUSIONS: DTaP-IPV/Hib may be safely and effectively administered to healthy infants, using a 2-, 4-, and 6-month vaccination schedule. This combined vaccine is cost-effective, more acceptable to parents and physicians, and minimizes distress to infants.

Antibodies, Bacterial↗

Acute hematogenous osteomyelitis and septic arthritis in children.

This retrospective study analyzed the clinical, bacteriological, and radiological features of pediatric patients with acute hematogenous osteomyelitis and septic arthritis. Eighty-four patients with septic arthritis and 39 with acute hematogenous osteomyelitis were enrolled. Their age ranged from 13 days to 17 years. In patients with septic arthritis, the hip joint was the most often infected site. The tibia was the most often involved site in acute hematogenous osteomyelitis. A bacteriological diagnosis was established in 78 (63%) patients. Overall, methicillin-susceptible Staphylococcus aureus (36 cases) was the most common causative organism identified, followed by methicillin-resistant S. aureus (10 cases). The median duration of antibiotic therapy was 33 days. Serum bactericidal titers were obtained for 19 (15%) of the 123 patients. The median duration of hospitalization and antibiotic treatment was not significantly different between patients with and without serum bactericidal titer testing. More patients without serum bactericidal titer testing had symptom relapse which required re-admission for further treatment. In conclusion, the incidence of methicillin-resistant S. aureus as a cause of bone and joint infections has been increasing. Serum bactericidal titer is valuable for the management of patients receiving sequential therapy for acute hematogenous osteomyelitis and septic arthritis.

Acute Disease↗

Antimicrobial susceptibility of common bacterial pathogens isolated from a new regional hospital in southern Taiwan.

BACKGROUND: Antimicrobial resistance has become a major health problem in Taiwan. While some trends in antimicrobial resistance are universal, others appear to be unique for specific regions. METHODS: To determine the distribution and antimicrobial drug resistance of bacterial pathogens in a new hospital in southern Taiwan, surveillance data on major bacterial pathogens isolated from Chang Gung Memorial Hospital at Chia-Yi from January 2002 through December 2002 were retrospectively analyzed. RESULTS: The most common gram-positive isolate was Staphylococcus aureus. Escherichia coli and Klebsiella pneumoniae were the two most common gram negative isolates. Pseudomonas aeruginosa ranked the first among gram-negative, glucose non-fermenting isolates, followed in the order of frequency by Acinetobacter baumannii. Oxacillin resistance rate of S. aureus was 58%, while vancomycin and teicoplanin remained effective against all of the isolates. The penicillin non-susceptibility rate of Streptococcus pneumoniae was 52%, and it is notable that the rate of resistance to erythromycin was 87%. Resistance to various antimicrobial agents for P. aeruginosa, Aeromonas hydrophila, and gram-negative enteric bacilli was very common in our study. Infections caused by multidrug-resistant A. baumannii was not uncommon in this hospital but fortunately, imipenem resistant A. baumannii was rarely encountered. Antimicrobial resistance was common in nontyphoid Salmonella, S. choleraesuis and serogroup B isolates in particular. CONCLUSION: The high rates of antimicrobial resistance among these major bacterial pathogens in this new hospital are impressive and alarming. Judicious use of antimicrobial agents can never be overemphasized. Continued surveillance of the changes of resistance patterns over time is necessary.

Drug Resistance, Bacterial↗

Lactoferrin inhibits enterovirus 71 infection of human embryonal rhabdomyosarcoma cells in vitro.

Enterovirus 71 (EV71), the newest member of Enterovirudae, is notable for its etiological role in epidemics of severe neurological diseases in children. It appears to be emerging as an important virulent neurotropic enterovirus in the upcoming era of poliomyelitis eradication, whereas no effective vaccine or antiviral agents are available at this moment. Human and bovine lactoferrins, iron-binding proteins belonging to the nonimmune defense system, were assayed in vitro to assess their inhibiting capacity on the cytopathic effect of EV71 on human embryonal rhabdomyosarcoma (RD) cells. Both bovine and human lactoferrins were found to be potent inhibitors of EV71 infection (mean IC(50), 10.5-24.5 microg/mL and 103.3-185.0 microg/mL, respectively). Lactoferrin probably exerts its effect at the level of viral adsorption, since the ongoing infection could not be further inhibited after the EV71 penetrated RD cells.

Antiviral Agents↗

Computed tomography-guided percutaneous drainage of intra-abdominal abscesses in neutropenic children.

The mortality associated with undrained intra-abdominal abscesses is high. Computed tomography-guided percutaneous drainage (CT-PD), a minimally invasive technique, allows a drainage catheter to be inserted into fluid collections throughout the body with minimal risk. We described two neutropenic patients with intra-abdominal abscesses treated with CT-PD after they failed to respond to antimicrobial therapy. With this modality, the surgery was successfully avoided or delayed. We are of an opinion that CT-PD is an efficient and simple urgent radiology procedure.

Abdominal Abscess↗

The 1998 enterovirus 71 outbreak in Taiwan: pathogenesis and management.

The most recently discovered enterovirus, enterovirus 71 (EV71), is neurotropic and may cause severe disease and sudden death in children. In 1998, a large outbreak of enterovirus infection occurred in Taiwan that resulted in 405 severe cases in children and 78 deaths. Of the 78 children who died, 71 (91%) were <5 years old. EV71 was the primary agent in fatal cases of infection. Most of these patients died within 1-2 days of admission to the hospital. We hypothesize that EV71 directly attacks the central nervous system and causes neurogenic pulmonary edema and cardiac decompensation through the mechanism of sympathetic hyperactivity and inflammatory responses. Early recognition of risk factors and intensive care are crucial to successful treatment of this fulminant infection. After poliovirus is eradicated, EV71 will become the most important enterovirus that affects children, and development of a vaccine may be the only effective measure against it.

Convalescence↗

The emergence in Taiwan of fluoroquinolone resistance in Salmonella enterica serotype choleraesuis.

BACKGROUND: Salmonella enterica serotype choleraesuis is a cause of serious systemic infections. Because fluoroquinolones are the drug of choice for the treatment of severe salmonella infections, the emergence and dissemination of fluoroquinolone-resistant S. enterica serotype choleraesuis have clinical consequences. METHODS: In Taiwan, a hospital-based surveillance system has been in place since 1987 to monitor the incidence of S. enterica serotype choleraesuis infections and the antimicrobial susceptibility of the isolates. We investigated the rapid emergence of fluoroquinolone resistance in this serotype in 2000 and 2001. Pigs in Taiwan were evaluated as a potential source of the resistant salmonella. RESULTS: A total of 501 clinical isolates of S. enterica serotype choleraesuis were recovered in our hospital from 1987 through 2000. The proportion of total salmonella isolates made up by S. enterica serotype choleraesuis decreased from an average of 8.4 percent before 1995 to 2.7 percent in 1996 through 1998. During 1999 and 2000, this proportion increased significantly, to an average of 5.0 percent. Ciprofloxacin resistance in S. enterica serotype choleraesuis has been observed since 2000. In the third quarter of 2001, 60 percent of isolates were resistant to ciprofloxacin. Molecular typing indicated that the primary source of S. enterica serotype choleraesuis isolates was herds of swine. All the resistant isolates from humans and swine had mutations that led to the substitution of phenylalanine for serine at position 83 and asparagine for aspartic acid at position 87 in the gene for DNA gyrase A. CONCLUSIONS: This investigation in Taiwan indicates that fluoroquinolone-resistant S. enterica serotype choleraesuis can spread from swine to humans. The use of fluoroquinolones in food animals should be prohibited.

Animals↗

Acute myeloid leukemia complicated with staghorn calculus.

An 11-year-old girl who presented with hyperleukocytosis accompanied by significant increases in serum uric acid and lactate dehydrogenase levels was discovered to be suffering from acute myeloid leukemia (AML). Subsequently a staghorn calculus was identified 22 months after the start of chemotherapy. The diagnosis of staghorn calculi was suggested by plain abdominal X-ray and ultrasonography. This paper describes the course of an adolescent patient with AML and focuses specifically upon her urological complications. To the best of our knowledge, this is the first reported pediatric case of AML complicated with staghorn calculi, which developed following repeated episodes of septicemia.

Child↗

Cutaneous lymphocytic vasculitis as the presenting feature of acute lymphoblastic leukemia.

The authors describe a patient with precursor B-cell acute lymphoblastic leukemia who presented with a 3-week history of indurated or ulcerative, purpuric lesions distributed mainly on her legs. A skin biopsy demonstrated a T-cell-mediated lymphocytic vasculitis. After the patient started chemotherapy, the skin lesions abated but she became febrile and a blood culture revealed cryptococci. The cryptococcal infection was successfully treated first with amphotericin B and later with fluconazole. The relationship between lymphocytic vasculitis and acute lymphoblastic leukemia may be an example of paraneoplastic association because both conditions seem to have appeared at about the same time, and both followed a parallel course. Lymphocytic vasculitis may also reflect a new manifestation of host-leukemia interaction.

Anti-Bacterial Agents↗

Molecular epidemiology of Salmonella enterica serovar Enteritidis isolated in Taiwan.

Incidence of Salmonella enterica serovar Enteritidis infection seems to be on the rise in Taiwan, and therefore, the characteristics of the isolate, including genotypes, were epidemiologically investigated. Of the 71 clinical strains isolated in 1997-1999, 61 (86%) remained susceptible to the eight antibiotics tested, while the remaining ten, eight of which were isolated in 1999, were resistant to one to three of the agents including three multiply resistant strains. The majority, 69 or 97% of the isolates, harbored a 60-kb spvC gene-carrying virulence plasmid and 12 of them harbored one or two additional various-sized plasmids. Strains with more than one plasmid were isolated mostly in 1999. Pulse-field gel electrophoresis (PFGE) revealed three major genotypes (Types A, B and C), in which type A was the predominant type. Of the 68 Type A, which contained 8 subtypes, 59 (83%) belonged to only two subtypes. Similar results were obtained with a PCR-based typing method, the infrequent-restriction-site (IRS) PCR. All four methods detected types that were rarely seen before and most of these were of recent isolates, indicating that these unusual types were new or strains of foreign origin. Though all four methods discriminated types well, PFGE and IRS-PCR showed higher sensitivity for classification. Between the two, the latter, though less discriminatory than PFGE, seems the method of choice, since it is simpler, less time-consuming and above all easy to perform.

DNA Fingerprinting↗

Characterization of a laboratory-derived, high-level ampicillin-resistant Salmonella enterica serovar Typhimurium strain that caused meningitis in an infant.

A Salmonella enterica serovar Typhimurium strain that harbored a plasmid carrying a TEM-1-type beta-lactamase gene was isolated from the blood and cerebrospinal fluid of an infant with meningitis. This 3.2-kb plasmid was further characterized to be a nonconjugative pGEM series cloning vector containing a foreign insert. The strain was likely laboratory derived and contaminated the environment before it caused the infection.

Ampicillin↗