{"id":884,"date":"2020-04-15T10:50:49","date_gmt":"2020-04-15T10:50:49","guid":{"rendered":"https:\/\/uni.hi.is\/apalsson\/?p=884"},"modified":"2020-04-15T10:50:49","modified_gmt":"2020-04-15T10:50:49","slug":"icelandic-eru-virkilega-til-haettuleg-afbrigdi-veirunnar-sem-veldur-covid-19","status":"publish","type":"post","link":"https:\/\/uni.hi.is\/apalsson\/IS\/2020\/04\/15\/icelandic-eru-virkilega-til-haettuleg-afbrigdi-veirunnar-sem-veldur-covid-19\/","title":{"rendered":"Eru virkilega til h\u00e6ttuleg afbrig\u00f0i veirunnar sem veldur COVID-19?"},"content":{"rendered":"

Arnar P\u00e1lsson. \u201eEru virkilega til h\u00e6ttuleg afbrig\u00f0i veirunnar sem veldur COVID-19?\u201c V\u00edsindavefurinn<\/i>, 15. apr\u00edl 2020. S\u00f3tt 15. apr\u00edl 2020. http:\/\/visindavefur.is\/svar.php?id=79179.<\/p>\n

Afbrig\u00f0i veira<\/a> eru skilgreind \u00fat fr\u00e1 mismun \u00ed erf\u00f0aefni<\/a> \u00feeirra.<\/span>[1]<\/a><\/sup> Veirur fj\u00f6lga s\u00e9r kynlaust og st\u00f6kkbreytingar<\/a> sem ver\u00f0a \u00ed erf\u00f0aefni \u00feeirra geta haft \u00e1hrif \u00e1 h\u00e6fni \u00feeirra \u00ed l\u00edfsbar\u00e1ttunni. \u00der\u00e1tt fyrir dramat\u00edskt nafn eru st\u00f6kkbreytingar a\u00f0eins fr\u00e1vik \u00ed erf\u00f0aefni sem geta haft j\u00e1kv\u00e6\u00f0, neikv\u00e6\u00f0 e\u00f0a engin \u00e1hrif \u00e1 h\u00e6fni l\u00edfvera.<\/span>[2]<\/a><\/sup> Neikv\u00e6\u00f0ar breytingar eru kalla\u00f0ar svo \u00fev\u00ed \u00fe\u00e6r draga \u00far h\u00e6fni l\u00edfvera til a\u00f0 fj\u00f6lga s\u00e9r e\u00f0a minnka l\u00edfsl\u00edkur. T\u00f6luver\u00f0ur hluti n\u00fdrra st\u00f6kkbreytinga eru neikv\u00e6\u00f0ar, en \u00fe\u00e6r eru yfirleitt sjaldg\u00e6far \u00ed stofnum, s\u00e9rstaklega \u00feeim sem fj\u00f6lga s\u00e9r kynlaust eins og \u00e1 vi\u00f0 um veirur. Mun sjaldg\u00e6fari eru j\u00e1kv\u00e6\u00f0ar breytingar, sem auka h\u00e6fni \u00e1 einhvern h\u00e1tt. Algengasta form erf\u00f0abreytileika eru hlutlausar breytingar, sem hafa engin \u00e1hrif \u00e1 h\u00e6fni l\u00edfvera. \u00d3l\u00edklegt er a\u00f0 st\u00f6kkbreytingar \u00ed erf\u00f0amengi veirunnar SARS-CoV-2<\/a> valdi illv\u00edgari sj\u00fakd\u00f3mi. Mest af breytileika sem finnst milli \u00f3l\u00edkra veira sem valda COVID-19 er \u00fev\u00ed hlutlaus. Afbrig\u00f0i veiranna sem valda COVID-19 eru talin vera jafngild af s\u00e9rfr\u00e6\u00f0ingum, \u00fea\u00f0 er a\u00f0 segja \u00feau valda \u00e1\u00feekkum sj\u00fakd\u00f3mi me\u00f0 svipa\u00f0ri d\u00e1nart\u00ed\u00f0ni. Erf\u00f0abreytileiki milli veiranna gerir okkur hins vegar kleift a\u00f0 rekja \u00e6ttir smitanna (mynd 1).<\/p>\n

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Mynd 1. St\u00f6kkbreytingar \u00e1 erf\u00f0aefni veiru sem berst milli einstaklinga m\u00e1 nota til a\u00f0 rekja smiti\u00f0. \u00c6ttartr\u00e9 veiranna endurspeglar smits\u00f6guna. Myndin s\u00fdnir einfalda\u00f0 tilfelli. S\u00fdndir eru litningar 5 ger\u00f0a af veiru sem eru \u00f3l\u00edkir vegna 7 st\u00f6kkbreytinga (lita\u00f0ar l\u00ednur). \u00deessir litningar mynda fimm \u00f3l\u00edkar setra\u00f0ir (e. haplotypes) sem einnig m\u00e1 kalla afbrig\u00f0i. Sumar st\u00f6kkbreytingar eru eldri (og finnast \u00ed tveimur e\u00f0a fleiri ger\u00f0um), en a\u00f0rar yngri og finnast bara \u00ed einni ger\u00f0.<\/p>\n<\/div>\n<\/div>\n

Engu a\u00f0 s\u00ed\u00f0ur hafa fj\u00f6lmi\u00f0lar upp \u00e1 s\u00ed\u00f0kasti\u00f0 fjalla\u00f0 um breytileikann \u00ed veirunni og slegi\u00f0 upp \u00e6silegum fyrirs\u00f6gnum. Snemma \u00ed mars birtist til a\u00f0 mynda fr\u00e9tt h\u00e9rlendis me\u00f0 fyrirs\u00f6gninni \u201eK\u00f3r\u00f3nuveiran hefur st\u00f6kkbreyst\u201c. Kjarninn \u00ed \u00feeim skrifum var a\u00f0 til v\u00e6ru mismunandi afbrig\u00f0i veirunnar og eitt afbrig\u00f0i v\u00e6ri h\u00e6ttulegra en hin. \u00d6nnur fr\u00e9tt birtist \u00ed USA TODAY<\/cite> \u00feann 31. mars undir fyrirs\u00f6gninni: \u201e8 strains of the coronavirus are circling the globe. Here's what clues they're giving scientists\u201c ( \u201e8 afbrig\u00f0i k\u00f3r\u00f3nuveirunnar eru \u00e1 ferli um j\u00f6r\u00f0ina. \u00deetta hafa v\u00edsindamenn l\u00e6rt af \u00feeim.\u201d) B\u00e1\u00f0ar fr\u00e9ttirnar byggja \u00e1 rangt\u00falkunum. Byrjum \u00e1 \u00feeirri fyrri sem var bygg\u00f0 \u00e1 meingalla\u00f0ri ranns\u00f3kn. Minnumst \u00feess a\u00f0 afbrig\u00f0i veirunnar eru flokku\u00f0 \u00fat fr\u00e1 erf\u00f0abreytileika, sem er a\u00f0allega hlutlaus. Vegna s\u00f6gu s\u00fdkinga ver\u00f0a sum afbrig\u00f0i algengari \u00e1 vissum landssv\u00e6\u00f0um en \u00f6nnur afbrig\u00f0i annars sta\u00f0ar. Greining l\u00edfuppl\u00fdsingafr\u00e6\u00f0ingsins Trevor Bedford og f\u00e9laga \u00e1 smitinu \u00ed Washington-fylki \u00ed Bandar\u00edkjunum er d\u00e6mi um \u00feetta. Flest smitin \u00ed fylkinu b\u00e1rust snemma fr\u00e1 Wuhan og voru flest af einni ger\u00f0 (afbrig\u00f0i) veirunnar.<\/p>\n

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Mynd 2. \u00c6ttartr\u00e9 k\u00f3r\u00f3nuveira sem valda COVID-19 \u00fat fr\u00e1 ra\u00f0greindum erf\u00f0amengjum veirunnar \u00e1 t\u00edmaskala faraldursins (x-\u00e1s). Rau\u00f0ir punktar eru 346 erf\u00f0amengi veira sem greindust \u00far einstaklingum \u00ed Washington-fylki \u00ed Bandar\u00edkjunum. H\u00f3pun rau\u00f0ra tilfella um mi\u00f0bik myndar s\u00fdnir smit sem barst fr\u00e1 K\u00edna um 15. jan\u00faar og fj\u00f6lda einstaklinga sem s\u00fdktust \u00ed kj\u00f6lfari\u00f0. \u00d6rvar tilgreina smit sem barst s\u00ed\u00f0ar til sv\u00e6\u00f0isins og olli smiti \u00ed sm\u00e6rri h\u00f3pum. Myndin s\u00fdnir a\u00f0 saga faraldursins veldur \u00fev\u00ed a\u00f0 viss afbrig\u00f0i ver\u00f0a algengari \u00e1 \u00e1kve\u00f0num landsv\u00e6\u00f0um en \u00f6nnur f\u00e1t\u00ed\u00f0ari.<\/p>\n<\/div>\n<\/div>\n

Sumir hafa haldi\u00f0 \u00fev\u00ed fram a\u00f0 afbrig\u00f0in s\u00e9u \u00e1 einhvern h\u00e1tt mismunandi. Fj\u00f6l\u00fe\u00e6ttar \u00e1st\u00e6\u00f0ur eru fyrir \u00fev\u00ed en mestu skiptir a\u00f0 mat \u00e1 d\u00e1nart\u00ed\u00f0ni vegna veirunnar getur veri\u00f0 mismunandi eftir sv\u00e6\u00f0um vegna margra \u00fe\u00e1tta. M\u00e1 \u00fear nefna mun \u00e1 greiningar\u00e1taki, \u00f3l\u00edk heilbrig\u00f0iskerfi, mun \u00e1 aldurssamsetningu landa e\u00f0a sv\u00e6\u00f0a og s\u00f6gulegra tilviljana. \u00cd fyrsta lagi er d\u00e1nart\u00ed\u00f0ni hlutfall \u00feeirra sem deyja vegna s\u00fdkingar og \u00feeirra sem eru greindir me\u00f0 sj\u00fakd\u00f3minn. Ef einungis \u00feeir sem deyja \u00far sj\u00fakd\u00f3mnum (e\u00f0a f\u00e1 alvarleg einkenni) eru pr\u00f3fa\u00f0ir og svo greindir virkar d\u00e1nart\u00ed\u00f0nin h\u00e1. En ef mj\u00f6g margir eru pr\u00f3fa\u00f0ir, l\u00edka f\u00f3lk me\u00f0 v\u00e6g einkenni e\u00f0a einkennalaust, \u00fe\u00e1 ver\u00f0ur d\u00e1nart\u00ed\u00f0ni metin l\u00e6gri. Fyrir veiruna sem veldur COVID-19 spanna gildin fr\u00e1 0,02 (2 af hverjum 1000 \u00ed Su\u00f0ur-K\u00f3reu) til 4 (4 af hverjum 100 \u00ed K\u00edna). Mynd 2. s\u00fdnir a\u00f0 saga faraldursins veldur \u00fev\u00ed a\u00f0 viss afbrig\u00f0i ver\u00f0a algengari \u00e1 \u00e1kve\u00f0num landsv\u00e6\u00f0um en \u00f6nnur f\u00e1t\u00ed\u00f0ari. \u00dea\u00f0 vir\u00f0ist \u00fev\u00ed vera samband \u00e1 milli afbrig\u00f0a veirunnar og d\u00e1nart\u00ed\u00f0ni en \u00fea\u00f0 er ekki raunverulegt. Fylgni milli \u00fe\u00e1tta er ekki s\u00f6nnun fyrir orsakasambandi. \u00cd annan sta\u00f0 eru sp\u00edtalar og heilbrig\u00f0iskerfi mismunandi eftir sv\u00e6\u00f0um og \u00fea\u00f0 hefur \u00e1hrif \u00e1 mat \u00e1 d\u00e1nart\u00ed\u00f0ni. \u00dea\u00f0 getur einnig b\u00fai\u00f0 til falska tengingu milli afbrig\u00f0a og alvarleika sj\u00fakd\u00f3msins. \u00cd \u00feri\u00f0ja lagi er aldurssamsetning mismunandi eftir l\u00f6ndum og landsv\u00e6\u00f0um. Yngra f\u00f3lk b\u00fdr e\u00f0a safnast saman \u00e1 vissum st\u00f6\u00f0um \u00e1 me\u00f0an eldri borgarar eru algengari \u00e1 \u00f6\u00f0rum sv\u00e6\u00f0um. Aldursdreifingin er \u00f3l\u00edk \u00e1 sk\u00ed\u00f0asv\u00e6\u00f0um \u00ed \u00d6lpunum og sm\u00e1\u00feorpum \u00e1 \u00cdtal\u00edu. \u00dear sem veiran leikur eldra f\u00f3lk verr en unga bjagar \u00fea\u00f0 mati\u00f0 \u00e1 d\u00e1nart\u00ed\u00f0ni. A\u00f0 s\u00ed\u00f0ustu getur \u00fea\u00f0 veri\u00f0 tilviljun h\u00e1\u00f0 hva\u00f0a h\u00f3pur innan \u00e1kve\u00f0ins sv\u00e6\u00f0is ver\u00f0ur \u00feungami\u00f0ja smitsins. Veiran fer ekki \u00ed manngreinar\u00e1lit en \u00f3lukkan getur valdi\u00f0 \u00fev\u00ed a\u00f0 smiti\u00f0 berst inn \u00e1 hj\u00fakrunarheimili \u00e1 einum sta\u00f0 en \u00ed p\u00f6nkhlj\u00f3msveitagengi \u00e1 \u00f6\u00f0rum sta\u00f0. Hin fr\u00e9ttin nota\u00f0i or\u00f0i\u00f0 afbrig\u00f0i eins og \u00fea\u00f0 er skili\u00f0 \u00ed almennu m\u00e1li sem er mun v\u00ed\u00f0t\u00e6kara en l\u00fdst var h\u00e9r a\u00f0 ofan. Afbrig\u00f0i veirunnar eru bara stofnar af sama mei\u00f0i og engin \u00e1st\u00e6\u00f0a til a\u00f0 halda a\u00f0 \u00feeir s\u00e9u \u00f3l\u00edkir e\u00f0a misalvarlegir. K\u00f3r\u00f3nuveirurnar fj\u00f3rar sem s\u00fdkja menn a\u00f0 sta\u00f0aldri \u00fer\u00f3ast vissulega en \u00e1 mun h\u00e6gari t\u00edmaskala en faraldurinn sem n\u00fa gengur yfir. Ef veiran sem veldur COVID-19 ver\u00f0ur enn \u00e1 sveimi eftir tv\u00f6 til \u00ferj\u00fa \u00e1r, \u00fe\u00e1 kann a\u00f0 vera a\u00f0 henni hafi gefist t\u00edmi til a\u00f0 a\u00f0lagast manninum betur. En sem fyrr er r\u00e9tt a\u00f0 skerpa \u00e1 \u00fev\u00ed a\u00f0 litlar l\u00edkur eru \u00e1 a\u00f0 h\u00fan st\u00f6kkbreytist \u00ed illv\u00edgara form. Samantekt:<\/strong><\/p>\n