Distribution of non-bacterial pathogens in 1 788 children with community-acquired pneumonia / 中国当代儿科杂志

OBJECTIVES@#To investigate the distribution characteristics of non-bacterial pathogens in community-acquired pneumonia (CAP) in children.@*METHODS@#A total of 1 788 CAP children admitted to Shenyang Children's Hospital from December 2021 to November 2022 were selected. Multiple RT-PCR and capillary electrophoresis were used to detect 10 viral pathogens and 2 atypical pathogens, and serum antibodies of Chlamydial pneumoniae (Ch) and Mycoplasma pneumoniae (MP) were detected. The distribution characteristics of different pathogens were analyzed.@*RESULTS@#Among the 1 788 CAP children, 1 295 children were pathogen-positive, with a positive rate of 72.43% (1 295/1 788), including a viral pathogen positive rate of 59.68% (1 067/1 788) and an atypical pathogen positive rate of 22.04% (394/1 788). The positive rates from high to low were MP, respiratory syncytial virus (RSV), influenza B virus (IVB), human metapneumovirus (HMPV), human rhinovirus (HRV), human parainfluenza virus (HPIV), influenza A virus (IVA), bocavirus (BoV), human adenovirus (HADV), Ch, and human coronavirus (HCOV). RSV and MP were the main pathogens in spring; MP had the highest positive rate in summer, followed by IVA; HMPV had the highest positive rate in autumn; IVB and RSV were the main pathogens in winter. The positive rate of MP in girls was higher than that in boys (P<0.05), and there were no significant differences in other pathogens between genders (P>0.05). The positivity rates of certain pathogens differed among age groups (P<0.05): the positivity rate of MP was highest in the >6 year-old group; the positivity rates of RSV and Ch were highest in the <1 year-old group; the positivity rates of HPIV and IVB were highest in the 1 to <3 year-old group. RSV, MP, HRV, and HMPV were the main pathogens in children with severe pneumonia, while MP was the primary pathogen in children with lobar pneumonia, and MP, IVB, HMPV, RSV, and HRV were the top 5 pathogens in acute bronchopneumonia.@*CONCLUSIONS@#MP, RSV, IVB, HMPV, and HRV are the main pathogens of CAP in children, and there are certain differences in the positive rates of respiratory pathogens among children of different ages, genders, and seasons.

Plataforma laboratorial para monitorear el SARS-CoV-2 basada en la vigilancia de influenza y otros virus respiratorios en Perú / Laboratory platform for monitoring SARS-CoV-2 based on surveillance of influenza and other respiratory viruses in Peru

RESUMEN En el Perú, la pandemia de la COVID-19 ha evidenciado la utilidad de tener un sistema de vigilancia laboratorial estructurado y en funcionamiento desde hace 22 años, basado en la vigilancia de influenza; inicialmente en modalidad de unidades centinela, y después fortaleciéndose e innovándose, con recursos propios y con apoyo externo, para generar información de calidad. Se han implementado avances biotecnológicos para la confirmación diagnóstica e incrementado las capacidades de la red nacional de laboratorios, manteniendo la eficiencia, considerando las diversas y complejas realidades de los niveles regionales, y superando dificultades de comunicación y articulación entre instituciones. Resulta necesario consolidar este sistema, con trabajo colaborativo y coordinado entre sus componentes, impulsando su eficacia y oportunidad y promoviendo la vigilancia genómica de nuevos virus y variantes, como actualmente ocurre con el SARS-CoV-2.

ABSTRACT In Peru, the COVID-19 pandemic demonstrated the usefulness of having a structured laboratory surveillance system that has been operational for 22 years, based on influenza surveillance; initially in the form of sentinel units, and later strengthened and innovated, with its own resources and with external support, to provide quality information. Biotechnological advances have been implemented for diagnostic confirmation and the capacity of the national laboratory network has been expanded, maintaining efficiency, considering the diverse and complex realities of each region, and overcoming difficulties regarding communication and articulation between institutions. It is necessary to consolidate this system, with collaborative and coordinated work between its components, boosting its effectiveness and timeliness and promoting genomic surveillance of new viruses and variants, as is currently the case with SARS-CoV-2.

Expression of influenza B virus hemagglutinin and its immunogenicity determination / 生物工程学报

Influenza B virus is one of the causes for seasonal influenza, which can account for serious illness or even death in some cases. We tested the expression of extracellular domain of hemagglutinin (HA-ecto) of influenza B viruses in mammalian cells, and then determined the immunogenicity of HA-ecto in mice. The gene sequence encoding influenza B virus HA-ecto, foldon sequence, and HIS tag was optimized and inserted into pCAGGS vector. The opening reading frame (ORF) of neuraminidase was also cloned into pCAGGS. The pCAGGS-HA-ecto and pCAGGS-NA were co-transfected into 293T cells using linear polyethylenimine. Cell supernatant after transfection was collected after 96 h, and the secreted trimmeric HA-ecto protein was purified by nickel ion affinity chromatography and size exclusion chromatography. Subsequently, the mice were immunized with HA-ecto protein, and the corresponding antibody titers were detected by ELISA and hemagglutination inhibition (HAI) assays. The results showed that soluble trimeric HA-ecto protein could be obtained using mammalian cell expression system. Moreover, trimeric HA-ecto protein, in combination with the adjuvant, induced high levels of ELISA and HAI antibodies against homogenous and heterologous antigens in mice. Thus, the soluble HA-ecto protein expressed in mammalian cells could be used as a recombinant subunit vaccine candidate for influenza B virus.

Muerte súbita por miocarditis aguda asociada al virus influenza tipo B. Reporte de un caso / Sudden death due to acute myocarditis associated with influenza type B virus. Case report

Resumen La miocarditis es una inflamación del miocardio causada principalmente por infecciones virales, dentro de las cuales se encuentra el virus Influenza tipo B. Su presentación clínica varía desde individuos asintomáticos o con síntomas leves e inespecíficos a una miocarditis fulminante e incluso muerte súbita. La principal consecuencia a largo plazo es una miocardiopatía dilatada con insuficiencia cardiaca. Se presenta el caso de una femenina de 17 años, sin patologías crónicas conocidas, la cual presentó un cuadro viral de dos días de evolución y luego falleció de manera súbita; en la autopsia médico legal se documentó mediante estudios histopatológicos una miocarditis linfocítica aguda y por medio de la técnica de reacción en cadena de la polimerasa (PCR) de un frotis traqueal se evidenció la presencia del virus influenza tipo B. Se realizó una revisión de la literatura sobre miocarditis principalmente miocarditis viral causada por el virus Influenza B.

Abstract Myocarditis is an inflammatory disease of the heart muscle. Viral infections are the most frequent cause of myocarditis, incluided Influenza B virus. The clinical presentation of acute miocarditis is highly variable, ranging from subclinical disease to fulminant heart failure and sometimes with sudden death. The major long term consequence is dilated cardiomyopathy with chronic heart failure. We present a case of a 17 years old woman who presented with viral symptoms for two days and then died suddenly; in the medico-legal autopsy, an acute lymphocytic myocarditis was documented through histopathological studies and the presence of influenza type B virus was evidenced by means of the polymerase chain reaction (PCR) technique of a tracheal smear. A review of the literature on myocarditis, mainly viral miocarditis caused by the Influenza B virus, was made.

Infecção por Influenza B e doença de Kawasaki em adolescente durante a pandemia da COVID-19: relato de caso / Influenza B infection and Kawasaki disease in an adolescent during the COVID-19 pandemic: a case report

RESUMO Apresentação de um caso de infecção por Influenza B e doença de Kawasaki em adolescente ocorrido durante a pandemia da COVID-19. Adolescente asmática evoluiu com febre e síndrome gripal por 7 dias e deu entrada com quadro de insuficiência respiratória aguda, necessitando de intubação orotraqueal. Evoluiu também com instabilidade hemodinâmica respondedora ao uso de droga vasoativa. Foram introduzidas antibioticoterapia e medidas de suporte. Apresentou melhora hemodinâmica e respiratória progressiva, porém mantinha febre e alteração de provas inflamatórias. Durante internação, evoluiu com conjuntivite não purulenta bilateral, descamação de mão e pés, língua em framboesa e linfonodomegalia cervical, recebendo diagnóstico de doença de Kawasaki. Recebeu gamaglobulina e, por conta de quadro clínico refratário, foi administrado também corticoide, evoluindo afebril 24 horas após. Não apresentou alterações coronarianas. O único agente isolado foi Influenza B, mesmo realizando painel viral e investigação para COVID-19 com reação em cadeia da polimerase e sorologia. Durante internação, apresentou tromboembolismo pulmonar, e, em investigação de coagulopatias, foi diagnosticada com mutação em heterozigose de fator V de Leiden. Há uma potencial associação entre doença de Kawasaki e infecção por Influenza B ou outros vírus, como o coronavírus e, por isso, esses diagnósticos devem ser investigados nos pacientes pediátricos, incluindo adolescentes, com quadros febris prolongados.

ABSTRACT We report a case of Influenza B infection and Kawasaki disease in an adolescent, diagnosed during the COVID-19 pandemic. An asthmatic female adolescent presented with fever and flu-like symptoms for 7 days and was admitted with acute respiratory failure requiring mechanical ventilation. She progressed with hemodynamic instability responsive to vasoactive drugs. Antibiotic therapy and support measures were introduced, showing progressive hemodynamics and respiratory improvement, however with persistent fever and increased inflammatory markers. During the hospitalization, she developed bilateral non-purulent conjunctivitis, hand and feet desquamation, strawberry tongue, and cervical adenopathy, and was diagnosed with Kawasaki disease. She was prescribed intravenous immunoglobulin and, due to the refractory clinical conditions, corticosteroid therapy was added; 24 hours later, the patient was afebrile. No coronary changes were found. A full viral panel including COVID-19 C-reactive protein and serology could only isolate the Influenza B virus. During the hospitalization, she was diagnosed with pulmonary thromboembolism; coagulopathies were investigated, and she was diagnosed with heterozygous factor V Leiden mutation. There is a potential association between Kawasaki disease and infection with Influenza B or with other viruses such as coronavirus. Therefore, this association should be considered in pediatric patients, adolescents included, with prolonged febrile conditions.

Patrón electrocardiográfico Brugada tipo I asociado a un cuadro febril por Influenza B. A propósito de la pandemia de COVID-19. Caso clínico

We report a 44-year-old male who was admitted for Influenza B and fever, presenting a type I Brugada pattern on the electrocardiogram. He evolved without cardiovascular symptoms. The pharmacological test with intravenous Procainamide reproduced type I Brugada pattern and the programmed electrical stimulation was negative for ventricular arrhythmias. He was discharged without incidents. Clinical aspects of Brugada syndrome and the importance of fever are discussed in the current context of the COVID-19 pandemic.

Miositis aguda benigna epidémica por influenza B en pacientes pediátricos / Epidemic mild acute myosistis due to influenza B in pediatric patients

Introducción: La miositis aguda benigna infantil es una complicación transitoria de la gripe causada por los virus influenza A o B, observada en pacientes escolares. Objetivos: Contribuir a divulgar las características de la miositis aguda benigna infantil en el personal médico. Métodos: Investigación descriptiva transversal en 18 pacientes con edad inferior a 19 años atendidos con el diagnóstico de esta afección, en el Hospital Pediátrico Docente Cerro desde el primero de octubre hasta 31 de diciembre del 2019. Se tomó muestra de sangre para estudios hematológicos y enzimáticos, determinación de anticuerpos antidengue y exudado nasofaríngeo en busca de virus respiratorios. Se empleó el programa SSPS versión 19. Los resultados se expresaron en valores absolutos, porcentajes, y los del laboratorio clínico, en promedios y desviación estándar. Resultados: Predominó la edad de 5-14 años (88 por ciento), sexo masculino (72,2 por ciento) y residencia en los municipios Cerro y 10 de 0ctubre (55,5 y 22,2 por ciento), respectivamente. El tipo de marcha anormal más frecuente fue la Frankenstein, con un conteo leucocitario promedio de 7,01 × 109 ± 2,16; linfocitosis 53,3 por ciento y promedio de creatininfosfoquinasa 591 µl × L ± 435,74. Todos los pacientes se recuperaron. El virus influenza B se identificó en 77,7 por ciento de las muestras. Conclusiones: La miositis constituyó una complicación por los virus de la gripe en mayor proporción el tipo B, en pacientes varones escolares, que mostraron trastornos en la marcha, examen neurológico normal y creatininfosfoquinasa elevada. Todos los enfermos se recuperaron en los primeros tres días de iniciada la afección(AU)

Introduction: Children mild acute myositis is a transitory complication of the flu caused by the influenza A or B viruses which presents in school patients. Objectives: To contribute to spread the characteristics of children mild acute miositis in the medical staff. Methods: Descriptive cross-sectional research in 18 patients with ages under the 19 years that were attented with a diagnosis of the disease in "Cerro" Pediatric Teaching Hospital from October 1st to December 31st, 2019. There were taken blood samples to do enzymatic and hematologic studies, antidengue antibodies determination and nasopharinx exudates looking for respiratory viruses. SSPS version 19 program was used. The results were expressed in absolute values, percentages, averages and standard deviation. Results: There was predomiance of the ages from 5 to 14 years (88 percent), male sex (72.2 percent) and living in Cerro and 10 de octubre municipalities (55,5 percent and 22,2 percent, respectively). The most frquent type of abnormal walk was the Frankenstein with an average leukocytes count of 7.01 × 109 ± 2.16; lymphocytea of 53.3 percent; and an average of creatinine fosfoquinase 591 µl × L ± 435.74. All the patients recovered. The influenza B virus was identified in 77.7 percent of the samples. Conclusions: Myositis represented a complication by influenza viruses, mainly the type B, in school male patients who showed disorders in the walk, normal neurologic examination and high creatinine phosphokinase. All the patients recovered in the first 3 days after the onset of the disease(AU)

Influenza A and B in a cohort of outpatient children and adolescent with influenza like-illness during two consecutive influenza seasons

ABSTRACT Introduction Influenza is an important cause of morbimortality worldwide. Although people at the extremes of age have a greater risk of complications, influenza has been more frequently investigated in the elderly than in children, and inpatients than outpatients. Yearly vaccination with trivalent or quadrivalent vaccines is the main strategy to control influenza. Objectives Determine the clinical and molecular characteristics of influenza A and B infections in children and adolescents with influenza-like illness (ILI). Methods: A cohort of outpatient children and adolescents with ILI was followed for 20 months. Influenza was diagnosed with commercial multiplex PCR platforms. Results: 179 patients had 277 episodes of ILI, being 79 episodes of influenza A and 20 episodes of influenza B. Influenza A and B cases were mild and had similar presentation. Phylogenetic tree of influenza B viruses showed that 91.6% belonged to the B/Yamagata lineage, which is not included in trivalent vaccines. Conclusions: Influenza A and B are often detected in children and adolescents with ILI episodes, with similar and mild presentation in outpatients. The mismatch between the circulating influenza viruses and the trivalent vaccine offered in Brazil may have contributed to the high frequency of influenza A and B in this population.

Serologic evidence of seasonal influenza A and B in HIV patients on combined antiretroviral therapy in Lagos, Nigeria

Background: Influenza and HIV are endemic in Nigeria but there is no epidemiological data on the co-infection of influenza A and B among HIV patients.Objective: We investigated seasonal influenza A and B, and co-infection among HIV patients on combined antiretroviral therapy (cART) in Lagos, Nigeria.Methods: In a prospective cross-sectional study, clear sera collected from 174 HIV-positive patients between August and September 2018 were analysed for immunoglobulin M-specific antibodies to seasonal influenza A subtypes H1N1 and H3N2, and influenza B by enzyme immunoassay. Results: A total of 39.7% (69/174) of HIV patients were seropositive for influenza A or B viruses with 84.1% (58/69) being positive for influenza A, 13.04% (9/69) seropositive for both influenza A and B, and only 2.9% (2/69) positive for influenza B mono-infection. Median age was 44 (mean 45, mode 40, range 18­74) years. The 41­50 years age group had the highest seroprevalence (39.1%; 27/69). Seropositivity was highest among women (65.2%; 45/69). A total of 88.4% (61/69) of HIV patients seropositive for influenza A or B were on fixed dose cART, while 73.9% (51/69) were virologically suppressed. Furthermore, 27.5% (19/69) were immunocompromised, of which 21.1% (4/19) were severely immunosuppressed (cluster of differentiation 4 < 200 cells/mm>3).Conclusion: Influenza A and B was prevalent among HIV patients on cART, which may predispose them to life-threatening complications. We recommend strong advocacy on the need to reduce the risk of exposure to influenza and for the provision of an influenza vaccine in Nigeria

Miocarditis fulminante en adultos por el virus de la influenza B: reporte de dos casos y revisión de la literatura / Fulminant myocarditis due to the influenza B virus in adults: Report of two cases and literature review

Resumen La miocarditis es una enfermedad inflamatoria del miocardio. Las infecciones virales son la causa más común, aunque también puede deberse a reacciones de hipersensibilidad y de etiología autoinmunitaria, entre otras. El espectro clínico de la enfermedad es variado y comprende desde un curso asintomático, seguido de dolor torácico, arritmias y falla cardiaca aguda, hasta un cuadro fulminante. El término 'fulminante' se refiere al desarrollo de un shock cardiogénico con necesidad de soporte vasopresor e inotrópico o dispositivos de asistencia circulatoria, ya sea oxigenación por membrana extracorpórea o balón de contrapulsación intraaórtico. Cerca del 10 % de los casos de falla cardiaca por miocarditis corresponde a miocarditis fulminante. La miocarditis por influenza se considera una condición infrecuente; no obstante, su incidencia ha aumentado desde el 2009 a raíz de la pandemia de influenza por el virus AH1N1. Por su parte, la miocarditis por influenza de tipo B sigue siendo una condición infrecuente. Se describen aquí dos casos confirmados de miocarditis fulminante por el virus de la influenza B atendidos en un centro cardiovascular, que requirieron dispositivos de asistencia circulatoria mecánica.

Abstract Myocarditis is an inflammatory disease of the myocardium. Viral infections are the most common cause, although it can also be due to hypersensitivity reactions and autoimmune etiology, among other causes. The clinical spectrum of the disease is varied, from an asymptomatic course, followed by chest pain, arrhythmias, and acute heart failure, to a fulminant episode. The term fulminant refers to the development of cardiogenic shock with a need for vasopressor support and inotropic or assisted circulation devices either extracorporeal membrane oxygenation (ECMO) or intra-aortic counterpulsation balloon. About 10% of cases of heart failure due to myocarditis correspond to fulminant myocarditis. Influenza myocarditis has been considered an infrequent condition. However, its incidence has increased since 2009 as a result of the AH1N1 pandemic; otherwise, myocarditis due to the Influenza type B virus remains an infrequent entity. We describe the experience in a cardiovascular center of two confirmed cases of fulminant myocarditis due to influenza B that required circulatory assistance devices.

Encefalitis por virus influenza B en un paciente adulto: reporte de caso / Encephalitis caused by type B influenza virus in an adult: report of one case

Neurological manifestations associated with influenza virus infection include encephalitis, encephalopathy, acute necrotizing encephalitis, transverse myelitis, acute disseminated encephalomyelitis, mild encephalitis with reversible splenial syndrome (MERS), and Guillaín Barré syndrome. We report a 16-year-old female who was admitted at our emergency department with seizures, confusion, nystagmus and motor clumsiness five days after an upper a respiratory tract infection. Influenza type B virus infection was confirmed by chain polymerase reaction analysis. The initial electroencephalogram demonstrated a pattern of global slowness without epileptic discharges. One week later, it showed a progression to slow-wave focal bilateral discharges at both temporal and occipital lobes. The patient had a favorable evolution and was discharged 19 days after admission with phenytoin to prevent seizures.

Nucleoprotein vaccine induces cross-protective cytotoxic T lymphocytes against both lineages of influenza B virus

PURPOSE: The influenza B virus diverges into two antigenically distinct lineages: B/Yamagata and B/Victoria. Influenza B is the dominant circulating virus during some influenza seasons, and recent data demonstrated that influenza A and B infection similarly cause severe clinical symptoms in hospitalized patients. Nucleoprotein (NP) is a good target for a universal influenza vaccine. This study investigated whether NP epitope variation within two lineages affects the dominant cytotoxic T lymphocyte (CTL) responses induced by vaccination and the resultant protective immunity. MATERIALS AND METHODS: The NP of B/Yamagata/16/1988, the representative strain of the Yamagata lineage, includes a dominant CTL epitope, FSPIRITFL, while B/Shangdong/7/1997 from the Victoria lineage has one amino acid difference in this sequence, FSPIRVTFL. Two recombinant replication-deficient adenovirus (rAd)-vectored vaccines expressing either NP were prepared (rAd/B-NP(I) and rAd/B-NP(V), respectively) and administered to BALB/c mice intranasally. To examine the efficacy of vaccination, antibody responses, CTL responses, and morbidity/mortality after challenge were measured. RESULTS: Both vaccines induce similar antibody and CD8 T-cell responses cross-reacting to both epitopes, and also confer cross-protection against both lineages regardless of amino acid difference. CONCLUSION: The rAd-vectored vaccine expressing the NP could be developed as universal influenza B vaccine which provides broader protection.

Benign Acute Childhood Myositis Associated with Influenza B Virus / 대한신경근육질환학회지

Influenza B virus infections appear to be more common extra-respiratory tract symptoms, compared to influenza A virus infections. Benign acute childhood myositis (BACM) is a benign disease that is caused mainly by many viruses like influenza A or B virus infection. Usually BACM is fully cured with only supportive treatment without unnecessary investigation or invasive procedure. This report describes an eight-year-old boy with acute bilateral calf pain and walking difficulty who diagnosed with BACM after influenza B virus infection.

Protocolo del Sistema Nacional de Vigilancia Epidemiológica: Infecciones respiratorias agudas y meningitis bacterianas. No. 02 / Protocol of the National Epidemiological Surveillance System: Acute Respiratory Infections and Bacterial Meningitis. No. 02

Estos protocolos están dirigido a personal médico, paramédico y otros profesionales que realizan acciones gerenciales y operativas de vigilancia epidemiológica en los servicios de salud del país, y están divididos en varios tomos para dar a conocer y actualizar la identificación y medidas de control para diversos padecimientos a fin de continuar con el mejoramiento de las capacidades técnicas de los trabajadores de salud, que permita planificar la prestación de servicios con decisiones partiendo de un enfoque epidemiológico comprobado, para responder a los cambios de tendencias epidemiológicas y con ello contribuir al fortalecimiento de prácticas asertivas de la salud pública de nuestro país. Las infecciones respiratorias agudas (IRAS), son la principal causa de morbilidad en países en desarrollo, las cuales en su mayoría suelen ser desatendidas siendo una amenaza para la supervivencia de niños menores de 5 años. Se considera que la verdadera mortalidad es subestimada por la ocurrencia de muertes en el hogar, sin tener un diagnóstico médico. Se estimó que para el año 2010, hubo a nivel global 1,071 millones de defunciones por neumonía en menores de 5 años. Del total de muertes, un 90 % se considera que ocurrió en los países en desarrollo y de estos el 50% en África.

The influenza season 2016/17 in Bucharest, Romania - surveillance data and clinical characteristics of patients with influenza-like illness admitted to a tertiary infectious diseases hospital

ABSTRACT Background: Influenza continues to drive seasonal morbidity, particularly in settings with low vaccine coverage. Objectives: To describe the influenza cases and viral circulation among hospitalized patients. Methods: A prospective study based on active surveillance of inpatients with influenza-like illness from a tertiary hospital in Bucharest, Romania, in the season 2016/17. Results: A total of 446 patients were tested, with a balanced gender distribution. Overall, 192 (43%) patients tested positive for influenza, with the highest positivity rate in the age groups 3-13 years and >65 years. Peak activity occurred between weeks 1 and 16/2017, with biphasic distribution: A viruses were replaced by B viruses from week 9/2017; B viruses predominated (66.1%). Among the 133 (69.3%) subtyped samples, all influenza A were subtype H3 (n = 57) and all influenza B were B/Victoria (n = 76). Patients who tested positive for influenza presented fewer comorbidities (p = 0.012), except for the elderly, in whom influenza was more common in patients with comorbidities (p = 0.050). Disease evolution was generally favorable under antiviral treatment. The length of hospital stay was slightly longer in patients with influenza-like illness who tested patients negative for influenza (p = 0.031). Conclusions: Distinctive co-circulation of A/H3 and B/Victoria in Bucharest, Romania in the 2016/17 influenza season was found. While the A/H3 subtype was predominant throughout Europe that season, B/Victoria appears to have circulated specifically in Romania and the Eastern European region, predominantly affecting preschoolers and school children.

Swine-spread severe influenza-associated pneumonia: A case report and literature review / 中南大学学报(医学版)

We report and analyze the clinical data of the first case of severe pneumonia caused by influenza B virus from swine. The patient, a 62 year-old male domestic pig breeder, was admitted to hospital because of fever and muscle pain for 5 days, and anhelation for 3 days. One week before the onset of disease, the patient kept close contact with pigs. CT scan of the chest showed diffuse infiltration in both lungs. Influenza B virus antigen detection (colloidal gold method) was repeatedly positive. These all confirmed influenza B virus infection. Poor appetite, weight loss, cough, poor spirit of pigs, positive influenza B virus antigen test occurred in the pig, while the patient had no history of exposure to influenza B-infected patients. It was likely that influenza B virus was transmitted from domestic pigs to the patient by droplets or close contact. Influenza B virus epidemics always occur every five or six years a time, and patients and carriers are the main source of infection. After searching the Pubmed, Web of science, Elsevier, Wanfang, and CNKI databases, it was found that although there were many studies on influenza B virus infecting seals, ferret, domestic pigs, guinea pigs, and other animals, there was no case report for animal-to-human infection. It is the first case report of type B influenza virus transmission from domestic pigs to people in the world, which provides a new direction for the research and prevention of influenza B virus.

Clinical Features and Laboratory Findings in Children Diagnosed with Benign Acute Childhood Myositis (BACM) / 대한소아신경학회지

PURPOSE: This study was performed to review the relationship between the clinical features and laboratory findings of patients suspected of benign acute childhood myositis (BACM) in children and adolescents with bilateral calf pain and gait disturbances. METHODS: From January 1, 2010 to December 31, 2016, the clinical and laboratory findings of patients who visited Dongguk University Ilsan Hospital with the sudden onset fever and muscle pain were retrospectively examined. RESULTS: The total number of patients was 29 (21 males and 8 females), and their mean age was 5.5 years. The mean duration of fever was 4.2 days. The mean duration from the onset of fever to show the symptom was 3.2 days. The mean recovery period from myositis was 2.4 days. The mean duration of hospitalization was 2.2 days. Fever and bilateral calf pain were the most common symptoms; however, cough, rhinorrhea, sore throat, headache, and abdominal pain were also observed. The causative agent of BACM was influenza B infection in 23 (79.3%) of the cases. Creatinine phosphokinase (CPK), myoglobin, aspartate aminotransferase (AST), and alanine transaminase (ALT) values were higher in the shorter duration of fever and were statistically significant. The following values were noted: CPK (r=−0.472), myoglobin (r=−0.472), AST (r=−0.443), and ALT (r=−0.459). The longer the pain period, the lower the white blood cell (WBC) count (r=−0.655). CONCLUSION: BACM is mostly associated with the influenza B virus. Time to onset of symptoms after fever and WBC levels are related to muscle enzyme levels and duration of symptoms in BACM.

Outbreak of Influenza B related to Benign Acute Childhood Myositis / 대한소아신경학회지

PURPOSE: Benign acute childhood myositis (BACM) is a rare syndrome caused by a viral infection and is characterized by gait disturbance with calf pain in children. I investigated whether BACM is related to the incidences of seasonal influenza and of specific influenza subtypes in Korea. METHODS: Patients diagnosed with BACM between March, 2010 and December, 2014 were investigated retrospectively. The occurrence of BACM was compared with the incidence of influenza for each influenza season, as obtained from the Korea Centers for Disease Control and Prevention. RESULTS: All patients had previous infection preceding calf muscle pain or gait disturbance. Laboratory findings showed elevated levels of creatine kinase (median, 1243 U/L) and leukopenia ( < 4500/µL). Patients exhibited benign courses that resolved within a few days without any complications. The rate of influenza B was correlated with BACM occurrence (P=0.05) although this relationship was not statistically significant. Neither the rate of total influenza nor the rate of influenza subtype A was associated with BACM occurrence. CONCLUSION: The outbreak of influenza B was correlated with the occurrence of BACM. We should recognize the occurrence of this disease and avoid unnecessary evaluation to diagnose BACM when an outbreak of influenza B is expected.

Analysis of Clinical Manifestations and Laboratory Findings in Children with Influenza B-Associated Myositis: A Single Center Study / 가정의학회지

BACKGROUND: Influenza-associated myositis (IAM) is a rare and poorly recognized complication of influenza infection in children, and is characterized by acute onset of severe pain in the lower extremities and a refusal to ambulate walk. We sought to understand the association between IAM and influenza B infection and to investigate its clinical and laboratory characteristics in affected children. METHODS: Influenza B-associated myositis (IBAM) cases diagnosed in the pediatrics department of Wonkwang University Hospital from January 2010 and March 2016 were analyzed retrospectively. RESULTS: Medical records of affected children were examined, and clinical characteristics and laboratory findings were recorded. Of the 536 children diagnosed with influenza B infection, 47 children complained of bilateral calf pain with or without gait disturbance. All children exhibited elevated serum aspartate aminotransferase (AST) level. The median serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels, reportedly elevated in myositis, were 2,597 IU/L and 678 IU/L, respectively. While the immunofluorescence test results were negative for some patients, the polymerase chain reaction test results indicated influenza B infection in all 47 children. At the time of hospital discharge, the patients' symptoms had resolved, and their CK levels had improved. CONCLUSION: IBAM was generally benign and short, and although the blood AST, CK, and LDH levels were markedly high, the erythrocyte sedimentation rate and C-reactive protein levels were normal. Further, the duration of IBAM symptoms correlated with the duration of fever. The IBAM-associated clinical and laboratory findings are highly characteristic and may allow its rapid diagnosis during the influenza season.