E-United States, isifo sezinambuzane ezinqamule nezidakamizwa ezihlala njalo
Ekuqaleni kuka-2018, ukukhathazeka nge "zombie deer" ekusakazeni ukugula kubantu kugxila umphakathi. Nakuba kunokwenzeka, amathuba okuthola igciwane lesifo esingelapheki (CWD) -yinto efana nesifo sofuba sezinkomo-emva kokudla isidlo semfuyo siphansi kakhulu. Kuze kube manje, abantu abaningi bezinyamazane banesisindo esiphansi se-CWD. Ngaphezu kwalokho, akukaze kube khona icala eliqinisekisiwe lokugula lokugula okungapheli elidluliselwa kusuka enzalweni noma elk kubantu.
Ezinyamazane nase-elk, i-CWD iholela ekufeni okuphansi, okuhlukumeza okugcina kugubha isilwane ikhono layo lokudla nokuphuza. Kubantu, i-CWD ichitha ubuchopho kancane kancane. Kuyinto isifo sezinzwa esasakazwa yi-reindeer, elk, inyamazane ne-moose. Ngokuvamile, i-CWD ingahlukaniswa njengesifo "esincane" esithathelwanayo. Izifo ezithathelwanayo ezithathelwanayo zibangelwa amagciwane nama-prions; I-CWD ibangelwa ama-prions.
Izifo zokuchitha isifo esingapheli ziqondwa kangcono kumongo wezifo ze-prion. Ake siqale ngokubheka ngokwengeziwe isifo se-prion.
Iyini Izifo Zika Prion?
Ucwaningo lwamuva luye lwaveza amaphuzu amane mayelana nama-prions.
Okokuqala, ama-prions yiwo kuphela ama-pathogens awaziwayo angenayo i-nucleic acid. Ezinye izifo ezithathelwanayo ezifana nama-bacterium kanye nama-virus aqukethe i-DNA ne-RNA eqondisa ukukhiqizwa kwabo. Izinkinga ezihlukahlukene zamabhonasi ziphumela ezinhlobonhlobo zezifo.
Okwesibili, izimpendulo ziphumela ekuphazamiseni okuphazamisayo, izakhi zofuzo nezifo.
Azikho ezinye izifo ngenxa yesibalo esisodwa esibonakalayo kulolu hlelo olubanzi lwezethulo zemitholampilo.
Okwesibili, ama-prions ayenziwa amaprotheni ayenziwa ngokuzenzekelayo ebuchosheni. Ngokuvamile, iphrotheni ye-prion kucatshangwa ukuthi idlala indima ekuboniseni izinzwa. Le phrotheni evamile ebizwa nge-PrP C (prion protein cellular) inesakhiwo se-alpha-helical.
Ngezifo ze-prion, lesi sakhiwo se-alpha-helical sishintsha ephepheni elibizwa nge-beta-pleated sheet ebizwa nge-PrP SC (prion protein scrapie). Lezi-PrP SC ziqoqa zibe ama-filaments eziphazamisa ukusebenza kwe-nerve-cell futhi zibangele ukufa kweseli.
Ama-Prions asakazeka lapho ama-beta-pleated sheets (PrP SC ) asebenzisa ama-alpha-helical amafomu (PrP C ) ukuze abe ama-beta-pleated sheets. I-RNA yeselula ethize iqondisa lolu shintsho. Inothi, i-PrP SC ne-PrP C inomumo ofanayo we-amino-asidi kodwa ukufaniswa okuhlukile noma ubujamo. Ngokungafani, umehluko kulezi zivumelanisa ezimbili zingacatshangwa njengama-pleats noma amafolda endwangu.
Izifo Eziphambene Ne-Prion kubantu
Kubantu, izimpendulo zenza izifo ezithathelwanayo "eziphuza". Lezi zifo zinesikhathi eside sokukhushulwa futhi kuthatha isikhathi eside ukubonisa. Ukuqala kwabo kuhamba kancane, futhi inkambo yabo iyaqhubeka. Ngeshwa, ukufa akunakugwemeka.
Izifo ezikhulunywe nge-Prion kubantu zibizwa ngokuthi i-spongiform encephalopathies (TSE). Lezi zifo "ziyi-spongiform" ngoba zibangela ubuchopho ukuba bubukeke ngendlela ebonakalayo, obugcwele izimbobo ezithombeni zobuchopho.
Izinhlobo ezinhlanu ze-TSE zenzeka kubantu kubandakanya okulandelayo:
- I-Kuru
- I-Creutzfeldt-Jakob isifo (i-CJD)
- I-Variant Creutzfeldt-Jakob isifo (vCJD)
- Isifo se-Gerstmann-Sträussler-Scheinker (GSS)
- Ukushona komndeni okubulalayo
Isethulo semitholampilo ye-CJD sihlanganisa ukuwohloka komqondo, ukulahlekelwa komzimba, ukuphahlazeka, ukulahleka kokubukeka, nokukhubazeka okuthinta ohlangothini olulodwa lomzimba. Nakuba kufana ne-kuru, okuthinta izizwe ezize ku-New Guinea ngemuva kokungena kobuchopho bomuntu, i-kuru ayibangeli ukuwohloka komqondo. Ngaphezu kwalokho, i-CJD itholakala emhlabeni wonke futhi ingahlobene nemikhuba yokudla, umsebenzi, noma ukutholakala kwezilwane. Eqinisweni, izitshalo zikwazi ukuthuthukisa i-CJD. Ngokuvamile, i-CJD ithinta umuntu oyedwa kwabayisigidi futhi kwenzeka emazweni lapho izilwane zinesifo se-prion nakwamanye amazwe lapho izilwane zingenalo izifo ze-prion.
Izifo eziqeda ukuchitha isifo se-vCJD. Ifomu evamile kakhulu ye-vCJD yisifo se-spongiform encephalopathy noma isifo se-cow cow. Isizathu sokuthi kungani i-CWD ne-mad cow isifo esibizwa ngokuthi "i-CJD" iwukuthi lesi sifo sitholakala ezigulini ezincane kunalezo ezijwayelekile ngeCJD. Ngaphezu kwalokho, kunemiphumela ethile yokuthola izifo ezitholakala emtholampilo ehlukile eVCJD.
Ngo-1996, isifo sofuba sezinkomo sagxila ngemuva kokuvela kwamacala eGreat Britain. Abantu abagulayo kungenzeka ukuthi badla inyama yenkomo ehlanganiswe nobuchopho bezinkomo. Ukwengeza, abantu abanohlobo oluthile lwe-prion-prion amaprotheni abambisene ne-methionine-bathuthukisa ukugula. Ngokusobala, amaprotheni e-prion homozygous for methionine aphinda kalula afakwe kwifomu le-beta-pleated sheet (PrP SC ).
Izifo Eziqeda Isifo
Kuze kube manje, kubekho amacala awaziwayo okudluliselwa kwe-CWD kubantu. Kodwa-ke, kukhona ubufakazi obunjalo. Ngo-2002, isifo se-neurodegenerative sitholakale emadodeni amathathu adla inyama yenyamazane ngawo-1990. Omunye kulaba bantu uqinisekisiwe ukuthi uneCJD. (Khumbula ukuthi i-CJD "ihamba kancane" futhi ithatha isikhathi ukubonisa.)
Ngokusho kwe-CDC, kusukela ngo-January 2018, i-CWD e-deer, elk, ne-moose ekhululekile ibikwe okungenani ezingu-22 nezifundazwe ezimbili zaseCanada. E-United States, i-CWD ibonwe eMidwest, eNingizimu-mpumalanga, nakwezinye izingxenye ze-East Coast. Kungenzeka futhi ukuthi i-CWD ikhona ezindaweni zase-United States ezingekho izinhlelo zokuqapha eziqinile. Nakuba ngokuvamile etholakala e-United States naseCanada, i-CWD itholakale eNorway naseNingizimu Korea.
Ngokuthakazelisayo, i-CWD yaqala ukutholakala ekudleni okuthunjiwe ngasekupheleni kwawo-1960. Ngomnyaka ka-1981, kwatholakala endlawini yasendle. Nakuba ukusabalalisa kwe-CWD kubantu abaningi basendle kungokwehla, kwezinye izibalo, ukusabalala kwezifo kungadlulela amaphesenti ayishumi, kufinyelele kumaphesenti angama-25 okutheleleka okukhulunywa ngawo ezincwadini. Okuphawulayo, kubantu abathunjiwe, ukusabalalisa kwe-CWD kungaba ngaphezulu kakhulu. Ngokuqondile, cishe amaphesenti angama-80 wezinyamazane emhlambini owodwa wokuthunjwa wezinyamazane wayenesi-CWD.
Ucwaningo lwezilwane lubonisa ukuthi i-CWD ingadluliselwa ezimpilweni ezingezona zomuntu, njengezinkawu, ezidla inyama yenyamazane egcotshwe ngobuchopho noma emzimbeni womzimba.
Kuzinyamazane ne-elk, kungathatha isikhathi esingangonyaka ngaphambi kokuba izimpawu ze-CJD zibonakaliswe. Lezi zimpawu zihlanganisa ukulahlekelwa isisindo, ukungabi nalutho, nokukhubeka. Ayikho imithi noma imishanguzo ye-CWD. Ngaphezu kwalokho, ezinye izilwane zingafa nge-CWD ngaphandle kokuqala izimpawu.
Ngo-1997, i-WHO yancoma ukuthi zonke izinhlaka ezibangelwa izifo ze-prion-kuhlanganise inyamazane ne-CWD-zigcinwe ngaphandle kokudla ngenxa yokwesaba ukudluliselwa.
Ukuvimbela
Uma i-CWD izosabalaliswa kubantu, indlela engcono kakhulu yokuvimbela lokhu kudluliselwa kungukuthi ungadli inyamazane noma inyama ye-elk. Umkhuba wokudla inyamazane usakazeke e-United States. Ngo-2006-2007 uphenyo oluqhutshwa yi-CDC, amaphesenti angu-20 abaphendulile abika ukuzingela noma i-elk, kanti izingxenye ezimbili kwezintathu zibike ukuthi zidla inyamazane noma inyama e-elk.
Ngokusetshenziswa kwezinyamazane kanye ne-elk ezandakazekayo futhi akukho bufakazi obonakalayo bokudluliselwa okwamanje kodwa kubhaliwe, akunakwenzeka ukuthi eziningi zezilwane kanye ne-elk inyama aficionados zizoyeka ukusetshenziswa kwazo. Ngakho-ke, kunconywa ukuthi abazingeli bathathe izinyathelo zokuqapha lapho bezingela.
Amanye ama-ejensi asezilwane zasendle ase-state aqaphe ukusabalala kwe-CWD ezindaweni eziphilayo zasendle kanye ne-elk ngokusebenzisa izivivinyo. Kubalulekile ukuhlola amawebhusayithi wezwe kanye neziphathimandla zezilwane zasendle ukuze uthole isiqondiso futhi ugweme ukuzingela abantu lapho i-CWD ibonakala khona.
Okubalulekile, akuwona wonke amazwe aqaphele i-CWD endlawini yasendle kanye ne-elk. Ngaphezu kwalokho, ukuhlolwa okungalungile kwe-CWD akusho ukuthi inyamazane noma i-elk ayinaso isifo. Noma kunjalo, ithuba lokuthi inyamazane noma i-elk enovivinyo olungalungile ayinalo i-CWD ephezulu.
Nazi ezinye izeluleko zabazingeli mayelana ne-CWD:
- Ungabambi, udonsa noma udle inyamazane noma i-elk ebukeka igula noma yenza ngezindlela ezingajwayelekile
- Gwema ukubulala umgwaqo
- Ngenkathi ukugqoka insimu, gqoka i-latex noma iglavu yegravu, unciphise ukuphatha kwakho ubuchopho noma ezinye izitho, futhi ungasebenzisi izindlu zasekhaya noma izitsha zasekhishini
- Cabanga ukuthi unesidumbu noma u-elk ohlela ukuyidla uhlolwe i-CWD
- Uma unomdlalo owenziwe ngethengiselwano, cela ukuthi inyama yakho ilungiselelwe ngokwehlukana nakwezinye izinyamazane ne-elk
- Ungalokothi udle inyamazane noma i-elk evivinya ama-CWD
- Hlola neziphathimandla zasendle zasendle ukuze ufunde ukuthi ukuhlolwa kwezilwane noma i-elk ye-CWD kunconywa noma kuyadingeka
Ngokuphathelene nokudla kwezilwane kanye nokudla okunamafutha, uMnyango wezokuLawulwa kwezeMpilo weZilwane kanye nezitshalo weMnyango wezoLimo waseUnited States usebenza uhlelo lwe-CWD lwesiqinisekiso semfuyo. Lolu hlelo luzithandela, futhi abanikazi bezinkomo bayavuma ukuhambisa izifuyo zabo ukuhlola. Akubona bonke abanikazi bezinkomo abahweba ababambe iqhaza ohlelweni. Kungenzeka ukuthi umqondo omuhle wokudla inyamazane noma inyama e-elk kubaphakeli bezohwebo abahlanganyela kulolu hlelo.
Ama-Prions Ngezinhlobo ezithile Zomhlabathi
Ngo-2014, uKuznetsova kanye nosebenza nabo bathola ukuthi izinhlobo ezithile zenhlabathi eningizimu-ntshonalanga ye-Alberta naseningizimu yeSaskatchewan (izingxenye zaseCanada) zingabamba ama-prions aphethe i-CWD.
Ngokusho kwabacwaningi:
Ngokuvamile, inhlabathi ecebile yodaka ingabopha iminyango ngokucophelela futhi ikhulise ukutheleleka kwayo okufana ne-purem mineral mineral montmorillonite. Izingxenye ze-Organic zenhlabathi nazo zihlukene futhi azibonakali kahle, kodwa zingathinta ukuxhumana kwenhlabathi. Ezinye izinto ezibalulekile ezibangela ukufaka hlangana inhlabathi ipH, ukwakhiwa kwesisombululo somhlabathi kanye nenani lensimbi (metal oxides) .... Umhlabathi omkhulu endaweni yesigodi se-CWD e-Alberta naseSaskatchewan yi-Chernozems, ekhona endaweni engama-60% yendawo yonke; ngokuvamile zifana nokuthungwa, ubumba be-mineralogy kanye nokuqukethwe kwenhlabathi eziphilayo, futhi zingabonakaliswa njengomhlabathi we-clay loamy, i-montmorillonite (smectite) ene-6-10% yesikhumba esiphilayo.
Izilwane zidla inhlabathi ukuze zihlangabezane nezidingo zazo. Le nhlabathi iphinda isetshenziswe enhlabathini ngendlela yezindle noma izidumbu. Ngakho-ke, ama-prions angenziwa ngebhayisikili emhlabathini. Kubonakala sengathi amabhontshisi amathinta kahle ubumba.
Izwi elivela
Kuze kube manje, akuzange kube khona ukuthunyelwa okuqinisekisiwe kwesifo esingapheliyo kusuka ekudleni noma elk kubantu; Noma kunjalo, ochwepheshe bakhathazekile ngengozi. Izifo eziqeda ukuchitha isifo esifana nesifo sofuba sezinkomo, esiye sabhalwa ukuba sisakaze ezinkomeni kubantu.
Uma kudliwa inyamazane noma inyama elk, kungumqondo omuhle ukuthatha izinyathelo ezithile zokuqapha futhi uhlole isiqondiso ezivela eziphathamandla zasendle zasendle. Ngomdlalo ongasendle, ungalokothi udle inyama kusuka enyamazane noma i-elk ebonakala igula. Ngaphezu kwalokho, kuwumqondo omuhle ukuba unesilwane sasendle noma i-elk inyama ehlolwe i-CWD.
Uma uthenga inyamazane yezohwebo noma inyama ye-elk, qiniseka ukuthi le nyama iqinisekisiwe njengokungenayo i-CWD.
> Imithombo:
> Izifo Eziqeda Isifo. I-CDC.
> Kuznetsova A et al. Indima engenzeka yendawo yehlabathi ekusabalaleni kwe-CWD entshonalanga eCanada. Prion. 2014; 8 (1): 92-9.
> Umshicileli weSB, uMiller BL. Izifo ze-Prion. Ku: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. eds. Izimiso zikaHarrison ze-Internal Medicine, 19e eNew York, NY: McGraw-Hill; 2014.
> I-Virtual Slow & Prions. Ku: Levinson W. eds. Ukubukeza kwe-Microbiology Medical and Immunology, e-14e eNew York, NY: McGraw-Hill.