Southeast Asia the Culprit in flu epidemics B Johnson

Vocabulary  annual ['ænju ə l]  relating to a period of one year 一年的  reservoir ['r ɛ z ɚ 'v ɑ r ]  a large amount of something that is available to be used （大量的）貯備，貯藏  strain [stren]  a particular type of plant or animal, or of a disease caused by bacteria, etc. （動、植物的）系，品系，品 種；（疾病的）類型

Vocabulary  culprit ['k ʌ lpr ɪ t]  a person or thing responsible for causing a problem 肇事 者；引起問題的事物  baton [b ə 't ɑ n]  a small light stick that one member of a team in a relay race passes to the next person to run （接力賽的）接力 棒  surveillance [s ɚ 'vel ə ns]  the act of carefully watching a person suspected of a crime or a place where a crime may be committed （對 犯罪嫌疑人或可能發生犯罪的地方的）監視

Background knowledge  Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals. The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness/fatigue and general discomfort. Sore throat, fever and coughs are the most frequent symptoms. In more serious cases, influenza causes pneumonia, which can be fatal, particularly for the young and the elderly. (from wikipedia) infectious diseaseRNA virusesOrthomyxoviridaechillsfever sore throatmuscle painsheadache coughingfatiguegeneral discomfortpneumonia

Paragraph 1~2  Influenza epidemics infect between 5 and 15 percent of the worlds population which cause between 250,000 and 500,000 deaths each year.  Q:Can anyone share the experience of infected by influenza epidemics?

Paragraph 3~6  Scientists believe that the unique climatic conditions in Asia especially in the tropics become the viral reservoir and culprits for new outbreaks of influenza.  Q:Try to explain why influenza always outbreak in tropical area?

Paragraph 7~8  Influenza usually causes epidemics during the winter in temperate zones and rainy season in the tropics because the vitamin D level and indoor activity.  Q:What is the relationship between the vitamin D level and indoor activity?

Supporting idea  Vitamin D receptor ligands have been shown to increase the activity of natural killer cells, and enhance the phagocytic activity of macrophages. Active vitamin D hormone also increases the production of cathelicidin(anti bacteria), an antimicrobial peptide that is produced in macrophages triggered by bacteria, viruses, and fungi.(from wikipedia) Vitamin D receptornatural killer cellsphagocytic macrophagescathelicidinantimicrobial peptidefungi

Paragraph 9~10  Some areas have rainy season and near the temperate zone, making the influenza thrive all year and thus always become the outbreak of influenza epidemics.  Q:Why East and SouthEast Asia always become the outbreak of influenza epidemics?

Paragraph 11~12  During the period of changing seasons, international travellers become the culprit of influenza epidemics.  Q:Explain why the same flu epidemics outbreak in north countries always six months later than in tropical countries?

Paragraph 13~15  Because the time duration of outbreak, scientists start to collect the sample all over the world especially the Influenza A virus subtype H3N2.  Q:Guess why scientists put emphasis on the subtype of H3N2.

Supporting idea  H3N2 is a subtype of the viral genus Influenzavirus A, which is an important cause of human influenza. Its name derives from the forms of the two kinds of proteins on the surface of its coat, hemagglutinin (H) and neuraminidase (N). By reassortment, H3N2 exchanges genes for internal proteins with other influenza subtypes. (from wikipedia)genus Influenzavirus Ahuman influenzaproteinshemagglutininneuraminidasereassortment

Paragraph 16~19  Many researches and studies found that the annual influenza from Asia seldom circuit back because the population has enough immunity.  Q:Why influenza epidemics still outbreak every year?

Supporting idea  Influenzaviruses(RNA virus) A, B and C are very similar in overall structure. Despite these varied shapes, the viral particles of all influenza viruses are similar in composition. These are made of a viral envelope containing two main types of glycoproteins, wrapped around a central core. (from wikipedia)viral envelopeglycoproteins

Paragraph 20~22  Every year, scientists will predict which strains of influenza have the possibility to outbreak and start the immunization programmers eight months later.  2A1B  Q:Anyone knows how the vaccine being produced?

Did H1N1 really a serious influenza? Name of pandemic DateDeaths Case fatality rate Subtype involved Pandemic Severity Index Asiatic (Russian) Flu 1889–18901 million0.15% possibly H3N8 NA 1918 flu pandemic (Spanish flu) 1918– to 100 million 2%H1N15 Asian Flu1957– to 1.5 million 0.13%H2N22 Hong Kong Flu 1968– to 1 million <0.1%H3N flu pandemic 2009–201018, %H1N1NA (from wikipedia)