Genetic Diversity and Molecular Epidemiology of Circulating Respiratory Syncytial Virus in Central Taiwan, 2008-2017.

In this study, we investigated the molecular evolution and phylodynamics of respiratory syncytial virus (RSV) over 10 consecutive seasons (2008-2017) and the genetic variability of the RSV genotypes ON1 and BA in central Taiwan. The ectodomain region of the G gene was sequenced for genotyping. The nucleotide and deduced amino acid sequences of the second hypervariable region of the G protein in RSV ON1 and BA were analyzed. A total of 132 RSV-A and 81 RSV-B isolates were obtained. Phylogenetic analysis revealed that the NA1, ON1, and BA9 genotypes were responsible for the RSV epidemics in central Taiwan in the study period. For RSV-A, the NA1 genotype predominated during the 2008-2011 seasons. The ON1 genotype was first detected in 2011 and replaced NA1 after 2012. For RSV-B, the BA9 and BA10 genotypes cocirculated from 2008 to 2010, but the BA9 genotype has predominated since 2012. Amino acid sequence alignments revealed the continuous evolution of the G gene in the ectodomain region. The predicted N-glycosylation sites were relatively conserved in the ON1 (site 237 and 318) and BA9 (site 296 and 310) genotype strains. Our results contribute to the understanding and prediction of the temporal evolution of RSV at the local level.

Respiratory presentation of patients infected with enterovirus D68 in Taiwan.

BACKGROUND: Enterovirus-D68 (EV-D68) has been endemic in Taiwan for some years with a small number of positive cases. Detailed information about respiratory presentation is lacking. This study characterized the clinical course in children admitted to the medical center and regional hospital in Taichung during 2015. METHODS: Retrospective chart review of patients with confirmed EV-D68 infection admitted to the medical center and regional hospital in Taichung with respiratory symptoms in the second half of 2015. Past medical history, clinical presentation, management, and course in hospital were collected and analyzed. Simple demographic data and clinical symptoms were also collected from patients confirmed with EV-D68 infection who visited clinics in Taichung. RESULTS: Six children were included. Two patients had a prior history of asthma or recurrent dyspnea, and one had other preexisting medical comorbidities. One child was admitted to the pediatric intensive care unit. All the patients were cured. Cough, rhinorrhea, tachypnea and fever were the most common clinical symptoms among inpatients, while influenza-like illness (ILI) was prevalent in outpatients. CONCLUSION: EV-D68 infection resulted in respiratory presentations of asthma-like illness in the hospitalized pediatric population. Patients with a prior history of asthma or recurrent dyspnea appear to be more severely affected.

Co-morbidity of Kawasaki disease.

Despite more than four decades of investigation, the etiology of Kawasaki disease remains obscure, and none of the proposed etiologic theories for the disease have achieved independent confirmation. Clinical and epidemiologic features support an infectious cause, but the etiology remains unclear. The authors present a case of Kawasaki disease associated with Epstein-Barr virus and Mycoplasma pneumoniae infection in a 3.5-y-old boy. He received two doses of intravenous immunoglobulin due to prolonged course of Kawasaki disease but later had complicated autoimmune haemolytic anaemia. His prolonged fever subsided after azithromycin administration. Epstein-Barr virus infection was confirmed by molecular microbiological pathology of cervical lymph node and serological tests. The serological tests for Mycoplasma pneumoniae also revealed a positive result. Thus, it is concluded that Mycoplasma pneumoniae and Epstein-Barr virus infections may occur simultaneously in a child with Kawasaki disease. In addition, autoimmune hemolytic anaemia may be noted in Kawasaki disease patients after high-dose IVIG administration. To the authors' knowledge, this is the first report of Kawasaki disease with Epstein-Barr virus and Mycoplasma pneumoniae in the English-language literature.

Outbreak of influenza A and B among military recruits: evidence from viral culture and polymerase chain reaction.

BACKGROUND AND PURPOSE: Influenza is an important cause of acute respiratory illness among military recruits, and pneumonia is the most frequent complication. This study was performed to categorize the clinical manifestations of influenza infections among military recruits. METHODS: In this retrospective chart review, epidemiologic investigation of patients who met the definitions of acute respiratory illness, influenza-like illness, and pneumonia was conducted. Surveillance of influenza by viral culture and polymerase chain reaction was performed weekly from a random selection of 4 patients with influenza-like illness of less than 3 days duration. RESULTS: 2074 and 2046 men recruited to the Substitute Service Training Center in Taiwan, from November 30 to December 31, 2006 (outbreak 1), and January 11 to February 12, 2007 (outbreak 2), respectively were enrolled. During outbreak 2, 1182 men (57.7%) were identified to have acute respiratory illness, including 607 (29.6%) with influenza-like illness and 19 (0.9%) with pneumonia. During outbreaks 1 and 2, sixty two nasal and throat swabs were obtained, 15 of which were influenza A and 6 were influenza B. All the influenza A isolates were A/Wisconsin/67(H3N2) viruses. Haemophilus influenzae was isolated from 9 of 19 patients with pneumonia (47.3%); 8 from sputum specimens and 1 from a blood specimen. H. influenzae was the primary identifiable bacterium. CONCLUSIONS: The 2 outbreaks consisted of concurrent infection of influenza A and B, with subsequent pneumonia. These results have implications for outbreak management and treatment of influenza among military recruits. Surveillance of influenza-like illness enables early detection of an outbreak and better understanding of the epidemiology of influenza in this setting.

Expression of VP1 protein in the milk of transgenic mice: a potential oral vaccine protects against enterovirus 71 infection.

Enterovirus 71 (EV71) is the most common etiological agent detected in cases of hand-foot-and-mouth disease (HFMD) resulting in incidences of neurological complications and fatality in recent years. The clinical data have already shown the significant increase in recent EV71 epidemic activity throughout the Asia-Pacific region. Due to the lack of an effective antiviral agent, primary prevention of the disease, including the development of an effective vaccine, has been the top priority in terms of control strategies. In this study, we first generated a transgenic animal system to produce the EV71 VP1 capsid protein under the control of alpha-lactalbumin promoter and alpha-casein leader sequences. A high level of recombinant VP1 protein (2.51 mg/ml) was expressed and secreted into the milk of transgenic mice. Mouse pups that received VP1-transgenic milk orally demonstrated relatively better health conditions after challenge with the respective virus as compared with the non-transgenic milk fed group; moreover, the mice fed with the VP1-milk had body weights similar to those of the PBS placebo control groups. According to the serum-neutralization assay and serum antibody detection, the littermates suckling VP1-milk generated antibodies specific to EV71. Our data suggest that EV71 VP1-containing milk is suitable for development as a potential oral vaccine.

Recombinant porcine lactoferrin expressed in the milk of transgenic mice protects neonatal mice from a lethal challenge with enterovirus type 71.

The human Enterovirus genus of the piconavirus family causes most of the febrile illnesses that affect children during the summer season in Taiwan. Enterovirus type 71 (EV71) plays a key role in patients with hand-foot-and-mouth disease (HFMD) combined with severe paralysis or encephalitis. It is important to find a method for preventing infection with EV71 since there is no antiviral agent or vaccine for humans. In this study, we developed a transgenic mouse model for demonstrating the protective effects of recombinant lactoferrin (LF) against EV71 infection. Transgenic mice carrying alpha-lactalbumin-porcine lactoferrin (alphaLA-pLF) and BALB/c wild-type mice were subjected to EV71 inoculation. First, we analyzed the expression efficiencies of recombinant pLF (rpLF) in hemizygous and homozygous transgenic mice. Following EV71 inoculation on the 4th day of life, pups ingesting transgenic milk showed the significantly higher survival rate and heavier body weight compared to wild-type mice. RT-PCR analysis for EV71 viral RNA showed that the recombinant pLF had a blocking effect on EV71 infection. Our data suggest that oral intake of pLF-enriched milk exhibited the ability to prevent infection with EV71. The study also provides an animal model for validating the protective effects of pLF.

Rapid diagnosis of Mycoplasma pneumoniae infection in children by polymerase chain reaction.

BACKGROUND AND PURPOSE: Endemic atypical pneumonia was noted in central Taiwan during 2005. The serological response to Mycoplasma pneumoniae infection was usually poor in its early course; convalescent serum was needed in most cases, which was sometimes difficult to obtain in children. Empiric antimicrobial therapy was usually initiated before serological testing. A rapid test would be useful to define the etiology and initiate appropriate management. We studied the usefulness of polymerase chain reaction (PCR) analysis for diagnosis in this setting. METHODS: This 1-year prospective study conducted during 2005 in central Taiwan enrolled 307 hospitalized children (aged 3 months to 16 years) with respiratory tract infections, some complicated with systemic manifestations, such as encephalitis and skin rash. Fifty one patients were excluded due to unavailability of data or lack of consent. PCR analysis of samples using a primer set for the P1 gene of M. pneumoniae was compared to serological testing, including particle agglutinin test and enzyme-linked immunosorbent assay. RESULTS: 263 throat swabs from 256 patients were available for PCR tests, and serological tests were performed in 140 children (55%) with clinical suspicion of atypical pneumonia. Eighty two children (32%) were positive by the PCR method and 76 (30%) were serologically positive. Seventy one patients (87%) with duration of disease onset of 2 to 7 days had positive PCR results. The mean age of patients with M. pneumoniae infection was 5.2 years, with 27% of patients <2 years old and 73% of patients >2 years of age. The diagnoses were as follows: pneumonia (n = 44); pneumonia complicated with pleural effusion (n = 12); bronchitis and bronchopneumonia (n = 18); asthmatic bronchitis (n = 2); croup syndrome (n = 1); pharyngitis (n = 3); and herpangina (n = 2). Coinfection with bacteria or virus was found in 21% of patients with M. pneumoniae infection. CONCLUSIONS: The PCR method could provide earlier diagnosis of M. pneumoniae infection and was useful to identify variable clinical features of infection, especially in younger children.

Increased circulating CD31+/CD42- microparticles are associated with impaired systemic artery elasticity in healthy subjects.

BACKGROUND: Impaired artery elasticity has been found in various pathological conditions related to endothelial dysfunction. Recently, CD31+/CD42- microparticles (MPs) emerged as a marker of endothelial injury. Whether CD31+/CD42- MPs, generated under physiological conditions, are correlated with artery properties has not been reported. METHODS: We evaluated brachia-ankle pulse-wave velocity (baPWV) (n = 76) and C1 large-artery and C2 small-artery elasticity indices (n = 56), using noninvasive devices for pulse-wave analysis in a group of healthy persons. The number of circulating CD31+/CD427- MPs (n = 76) was measured by flow cytometric analysis. RESULTS: Circulating CD31+/CD42- MPs were positively correlated with values of baPWV (r = 0.371, P = .008) and with C1 large-artery and C2 small-artery elasticity indices (r = -0.294, P = .037; and r = -0.310, P = .027, respectively). Multivariate analysis identified CD31+/CD42- MPs as potent contributors to the development of impaired systemic artery elasticity. CONCLUSIONS: The level of circulating CD31+/CD42- MPs, an important biomarker of dysfunctional endothelium and vascular injury, is closely associated with impaired systemic artery elasticity in healthy subjects. The present study suggests that CD31+/CD42- MPs may be a novel surrogate marker for the clinical evaluation of vascular damage.