Ingabe i- coronavirus yadalwa elebhu? Kuphendula usosayensi

Njengoba i-coronavirus yenoveli ebangela i-COVID-19 isakazeka emhlabeni jikelele, ngamacala manje angaphezu kwe-284.000 emhlabeni wonke (Mashi 20), i-disinformation isakazeka ngokushesha okukhulu.

Inganekwane ephikelelayo ukuthi leli gciwane, elibizwa ngeSARS-CoV-2, lenziwa ososayensi futhi laphunyuka elabhorethri eWuhan, eChina, lapho kwaqala khona lesi sifo.

Ukuhlaziywa okusha kwe-SARS-CoV-2 ekugcineni kungabeka umqondo wokugcina ekuphumuleni. Iqembu labacwaningi laqhathanisa ufuzo lwale noveli ye-coronavirus namanye ama-coronaviruses ayisikhombisa aziwa ukuthelela abantu: i-SARS, i-MERS ne-SARS-CoV-2, engadala izifo ezinkulu; kanye ne-HKU1, NL63, OC43, ne-229E, okudala ukudala izimpawu ezimnene kuphela, abacwaningi babhala ngoMashi 17 kumagazini i-Nature Medicine.

"Ukuhlaziya kwethu kukhombisa ngokusobala ukuthi abakwaSARS-CoV-2 akuyona indawo yokwakhiwa kwamalabhorethri noma yigciwane elenziwa ngokukhethekile," babhala kulo mbhalo wephephabhuku.

UKristian Andersen, onguprofesa ohlotshaniswa nezifo zokuzivikela komzimba kanye ne-microbiology eScripps Research, nozakwabo bahlola imodeli yofuzo yamaprotheni ama-spike aphuma ebusweni begciwane. I-coronavirus isebenzisa lawa ma-spikes ukubamba izindonga zamaseli ezingaphandle zomphathi wayo bese ingena kulawo maseli. Babheka ngqo ukulandelana kwezakhi zofuzo okubhekele izici ezimbili ezibalulekile zala maprotheni aphezulu: i-grabber, ebizwa ngokuthi isizinda se-receptor-binding, esinamathela ekubambeni amaseli; nendawo ebizwa ngokuthi yi-cleavage evumela ukuthi igciwane livuleke futhi lingene kulawo maseli.

Lokhu kuhlaziywa kukhombise ukuthi ingxenye "ebanjwe" yencopho ibisivele iguqukele ekukhombiseni i-receptor ngaphandle kwamaseli womuntu abizwa nge-ACE2, okubandakanyeka ekulawuleni umfutho wegazi. Isebenza kahle ekubopheni amaseli omuntu kangangokuba abacwaningi bathe amaprotheni ama-spike awumphumela wokukhethwa kwemvelo hhayi ubuchwepheshe bezakhi zofuzo.

Nakhu ukuthi kungani: I-SARS-CoV-2 ihlobene kakhulu negciwane elibanga isifo sokuphefumula esibucayi (i-SARS), esaliminyanisa umhlaba eminyakeni ethile engama-20 edlule. Ososayensi bafundile ukuthi i-SARS-CoV ihluke kanjani kwa-SARS-CoV-2 - ngezinguquko eziningana ezinhlamvwini eziyinhloko kukhodi yezofuzo. Kepha ekulingiseni kwamakhompiyutha, ukuguquka kwezinguquko ku-SARS-CoV-2 akubonakali kusebenza kahle kakhulu ekusizeni igciwane libophele kumaseli womuntu. Ukube ososayensi baliklama ngamabomu leli gciwane, bebengeke bakhethe ukuguquka kwezakhi zofuzo okusikiselwa yizinhlobo zamakhompyutha ukuthi bekungeke kusebenze. Kepha kuvela ukuthi imvelo ihlakaniphe ukwedlula ososayensi, kanti i-coronavirus yenoveli ithole indlela yokuguqula obekungcono - futhi ehluke ngokuphelele - kunoma yini ososayensi abebengayenza, ucwaningo lutholile.

Esinye isipikili emcabangweni "weqa kulabhorethri omubi"? Ukwakheka kwamangqamuzana onke kwaleli gciwane kwehlukile kuma-coronaviruses aziwayo futhi kunalokho kufana ncamashi namagciwane atholakala kumalulwane nakuma-pangolines abekade engafundwanga kangako futhi angakaze aziwe ukuthi angalimaza umuntu.

"Ukube kukhona umuntu obezama ukuklama i-coronavirus entsha njenge-pathogen, ngabe wayakha kusuka emgogodleni wegciwane elaziwa ukuthi lidala izifo," kusho isitatimende se-Scripps.

Livelaphi igciwane? Ithimba labacwaningi lisungule izimo ezimbili ezingaba khona ngemvelaphi yeSARS-CoV-2 ebantwini. Isimo esisodwa silandela izindaba zomsuka zamanye ama-coronaviruses akamuva adale umonakalo kubantu. Kuleso simo, sathola leli gciwane ngqo kuma-civet esilwane endabeni yabakwaSARS namakamela esimweni seMiddle East Respiratory Syndrome (MERS). Endabeni ka-SARS-CoV-2, abacwaningi basikisela ukuthi lesi silwane kwakuyilulwane, esadlulisela leli gciwane kwesinye isilwane esiphakathi (mhlawumbe i-pangolin, abanye ososayensi bathi) esihambisa leli gciwane ebantwini.

Kuleso simo esikhona, izici zofuzo ezenza ukuthi i-coronavirus entsha isebenze kahle ekutheleleni amaseli womuntu (amandla ayo we-pathogenic) ngabe abekhona ngaphambi kokudlulela kubantu.

Kwesinye isimo, lezi zici ze-pathogenic zivele ziguquke kuphela ngemuva kokuba igciwane selidlulile lisuka kumuntu ophethe isilwane laya kubantu. Amanye ama-coronaviruses aqhamuka kuma-pangolines "anohlaka lwe-hook" (leso sizinda sokubopha i-receptor) esifana naleso se-SARS-CoV-2. Ngale ndlela, i-pangolin idlulisele igciwane layo ngqo noma ngokungaqondile kumuntu ophethe. Ngakho-ke, uma selingaphakathi kwesikhungo esingumuntu, leli gciwane belingashintsha ukuze libe nesici salo esingabonakali: isiza sokuhlanza esivumela ukuthi singene kalula kumaseli omuntu. Lapho leli khono selithuthukisiwe, abacwaningi bathi i-coronavirus izokwazi ukusabalalisa phakathi kwabantu.

Yonke le mininingwane yobuchwepheshe ingasiza ososayensi ukubikezela ikusasa lalesi sifo. Uma igciwane lingene kumaseli womuntu ngendlela ye-pathogenic, lokhu kukhulisa amathuba okuqubuka okuzayo. Leli gciwane lalisazungeza phakathi kwezilwane futhi lingahle libuyele kubantu, lilungele ukudala ukubheduka. Kepha amathuba okuqubuka okuzayo esikhathini esizayo aphansi uma igciwane lizoqala lingene kubantu bese liguqula izakhiwo ze-pathogenic, kusho abacwaningi.