Severe Human Case of Zoonotic Infection with Swine-Origin Influenza A Virus, Denmark, 2021.

During routine surveillance at the National Influenza Center, Denmark, we detected a zoonotic swine influenza A virus in a patient who became severely ill. We describe the clinical picture and the genetic characterization of this variant virus, which is distinct from another variant found previously in Denmark.

Possible bidirectional human-swine and subsequent human-human transmission of influenza virus A(H1N1)/2009 in Japan.

In 2019, sows at a swine farm in Japan showed influenza-like illness (ILI) shortly after contact with an employee that exhibited ILI. Subsequently, a veterinarian became sick shortly after examining the sows and was diagnosed with influenza A virus (IAV) infection. Then, her family also contracted the infection. Subsequently, Pandemic A(H1N1)2009 viruses were isolated from all samples obtained from the sows, veterinarian and her family. Whole-genome analysis of the isolates confirmed that the viruses belonged to the same lineage (6B.1A) and the genome sequences obtained from all of the isolates were almost identical to each other. Furthermore, an epidemiological survey revealed no contact between veterinarians or their families and influenza patients prior to the onset of illness. These results strongly indicated a case of bidirectional infection between humans and sows. At the same time, we found a few unique mutations in the IAV genomes corresponding to the host species. The mutations that occurred in the virus after it was transferred from the farm worker to the sows were not observed in the humans infected from the sows, probably as a result of the mutations reverting to the original nucleotides. These results demonstrate that the bidirectional transmission of IAV is a potential risk for the next pandemic outbreak due to the emergence of new mutant strains.

Conocimientos sobre enfermedades tipo influenza en estudiantes de Medicina de la Universidad de Guayaquil, Ecuador / Knowledge about influenza-like illnesses in medical students at Guayaquil University, Ecuador

RESUMEN Fundamento: las enfermedades tipo influenza son de fácil contagio y sus vías de transmisión difíciles de controlar si no son tratadas adecuadamente. Objetivo: determinar los conocimientos que poseen los estudiantes de pregrado y posgrado de la Facultad de Ciencias Médicas de la Universidad de Guayaquil sobre las enfermedades tipo influenza. Métodos: se realizó un estudio descriptivo transversal durante el mes de febrero de 2018. Se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción, y empíricos: la encuesta en forma de cuestionario para indagar sobre el conocimiento de los estudiantes sobre la influenza. Resultados: la totalidad de ellos refirió poseer conocimientos sobre el tema. El 96,32 % de los de pregrado identificaron como más frecuentes la transmisión de tipo viral y el contagio por contacto con persona enferma; mientras en posgrado el 100 % expresó conocimientos al respecto; la complicación habitual más señalada fue la automedicación referida por el 72 % en pregrado y en el posgrado por el 57 %. En relación con las medidas preventivas, manifestaron conocerlas el 87 % y 89 % en el pregrado y posgrado respectivamente. Conclusiones: se comprobó que el grado de conocimientos sobre las enfermedades tipo influenza en cuanto a transmisión, etiología, acciones de protección y medidas preventivas en estos estudiantes de la Facultad de Ciencias Médicas de la Universidad de Guayaquil es aceptable, pero aún persisten algunas carencias identificadas en el estudio realizado.

ABSTRACT Background: influenza is an easily transmitted disease and its way of transmission is difficult to control if it is not properly treated. Objective: to determine the knowledge undergraduate and graduate students have on influenza-like disease at Guayaquil University Medical Sciences Faculty. Methods: a cross-sectional descriptive study was carried out at Guayaquil University Medical Sciences Faculty, during the month of February 2018. Theoretical methods were used: analysis-synthesis and induction-deduction, and empirical methods: the survey in the form of a questionnaire to inquire about students' knowledge on influenza. Results: all the students reported having knowledge on influenza. 96,32 % of the undergraduates identified the transmission of viral type by contact with the sick person as more frequent; in postgraduate studies 100 % expressed knowledge in this regard; the most common complication was self-medication referred by 72 % of undergraduate students in 72 % and in postgraduate students by 57 %. In relation to preventive measures, 87 % and 89 % expressed knowledge in undergraduate and postgraduate respectively. Conclusions: it was found that the degree of knowledge on the influenza-like disease in terms of transmission, etiology, protective actions and preventive measures in these students at Guayaquil University Medical Sciences Faculty is acceptable. There are still some shortcomings identified in the study carried out.

Antibody Determinants of Influenza Immunity.

Understanding antigenic variation in influenza virus strains and how the human immune system recognizes strains are central challenges for vaccinologists. Antibodies directed to the 2 major viral surface membrane proteins, hemagglutinin (HA) and neuraminidase (NA), mediate protection against reinfection following natural infection or vaccination, but HA and NA protein sequences in field strains are highly variable. The central questions are how to achieve protective antibody responses in a higher proportion of individuals and how to induce responses with more breadth and durability. Studies using isolation of human monoclonal antibodies followed by structural and functional characterization revealed conserved antigenic sites recognized by broadly cross-reactive antibodies. The antigenic landscape on HA and NA proteins is coming into focus to inform studies of the correlates and mechanisms of immunity. Understanding the antibody determinants of influenza immunity points the way toward development and testing of next-generation vaccines with potential to confer broadly protective immunity.

Analysis of haemagglutinin gene of the first influenza A-H1N1 viral strain isolated in Guangdong Province during an influenza A pandemic in 2009 / 中华传染病杂志

Objective To detect and analyze the haemagglutinin (HA) gene of the first influenza A-H1N1 viral strain isolated in Guangdong Province during an influenza A pandemic in 2009.Methods A-H1N1 virus strain was isolated from the throat swab of the first patient diagnosed with A-H1N1 virus infection in Guangdong Province in 2009. Viral nucleonic acid was extracted from supernatant of cell culture and amplified using reverse transcriptase-polymerase chain reaction (RT-PCR) with HA gene-specific primers. The product was cloned, sequenced, and the homology was analyzed. Results A 1710 bp HA gene of the first influenza A-H1N1 viral strain in Guangdong Province in 2009 was acquired, which was named as A/GuangzhouSB/01/2009 (H1N1) HA with GenBank access No. GQ268003. The homology of the studied HA gene and the 277 influenza A (H1N1) isolates reported in the epidemic areas was 99.0%-99.8%, and as high as 99.8% when compared with the isolates reported in the United States where the patient had traveled. When the studied HA gene was compared with 25 isolates of Chinese seasonal A-H1N1 virus, the homology was 72.3%-85.6%. Conclusions The homology of the first isolated A-H1N1 viral strain in Guangdong Province in 2009 and epidemic influenza A-H1N1 virus is high, while it is low compared with Chinese seasonal A-H1N1 virus.