Tun farkon barkewar cutar, an ba mu tabbacin cewa bin abin rufe fuska na al'umma zai magance matsalolinmu kuma ya dakatar da yaduwar SARS-CoV-2. Amma duk da haka bayanan aikace-aikacen duniya na zahiri sun nuna a kai a kai sun gaza a matsayin ma'auni na rage kariyar mutum, kuma a maimakon gyara kwas kan jagorar rashin gaskiya da aka fitar, an gaya mana cewa rufe fuska wuya tare da ƙara takurawa, duk da ingantaccen na'urori marasa ragewa.
amma dalilin da ya sa sun kasa, kuma me yasa suka ci gaba da kasawa? A ƙasa, mun bincika ƙayyadaddun ƙayyadaddun abin da ya sa, koda kuwa ana ɗaukar cikakkiyar ƙarfin kamawa, N95s sun kasa rage yaduwar SARS-CoV-2.
Ya kamata mu fara da kallon kwayar cutar kwayar cuta da fitar da kwayoyin cuta a matsayin nau'i, bisa ga tsananin rashin lafiya, amsawar rigakafi na mutum, da ci gaba a cikin yanayin rashin lafiya. Wadannan duk an nuna suna da tasiri mai mahimmanci akan nauyin kwayar cutar kwayar cutar ta mutumin da ya kamu da SARS-CoV-2. Za mu tattauna alkaluman fitarwa da ƙimar kamuwa da cuta, da hanyoyin auna don mafi ƙarancin kashi.
Waɗannan su ne kowane mahimman abubuwan da za a yi la’akari da su a cikin raguwar ƙwayoyin cuta har ma da kansu, amma a haɗa su, za su iya nuna mana musamman ko hanyar da aka ba da ita za ta sami sakamakon da ake so a cikin kawar da haɗarin kamuwa da cuta. Alkaluman da aka fitar na fitar da iskar numfashi sun nuna nawa al'amarin da mutum ke fitar da shi, da kuma ko ana iya kamuwa da su tare da cututtukan numfashi ko a'a, amma alkaluman fitarwa sun bambanta sosai tsakanin matakai masu tsanani a farkon rashin lafiya, lokacin dawowa, da kuma lokacin da PCR-negative ga wani pathogen.
Ta hanyar kwatanta fitarwa tare da ma'auni-to- plaque forming unit (PFU), ana ba mu ƙimar adadin barbashi nawa da ke fitarwa suna iya haifar da kamuwa da cuta. Ana kiran kowane ɗayan waɗannan raka'a masu yaduwa a matsayin PFU. An ba da adadin PFU ɗin da ake buƙata don karɓar mai yuwuwar mai masaukin baki a matsayin adadi mafi ƙarancin kamuwa da cuta (MID), wanda shine ƙofa wanda da zarar ya hadu, fara kamuwa da cuta ya kasance ana tsammanin.
Ta hanyar duba ƙididdiga don rabo-zuwa-PFU da ƙididdige yuwuwar MID, ƙarshen samfurin shine yuwuwar adadin mutanen da za su iya kamuwa da cutar a cikin wani ɗan lokaci.
Tare da wannan kofa ta MID don yuwuwar kamuwa da cuta, sannan za mu iya amfani da cikakkiyar ƙarfin kamawa na na'urar da aka bayar don ganin ko mafi kyawun yanayin yana haifar da yuwuwar rage na'urar, ko hana madaidaicin MID gamuwa da haɗarin.
Anan, muna kallon fitarwa, ɓangarorin-PFU rabo, da MID don SARS-CoV-2, dangane da madaidaicin ikon kamawa na N95s, don nuna cewa ko da tare da cikakkiyar ƙimar kama (kuma a cikin wannan yanayin, na al'amarin da ya fi ƙanƙanta da na'urar da aka yarda ko an tsara shi don kamawa), kashi 5% ba a taɓa kamawa ba har yanzu yana da isasshen yiwuwar kamuwa da cuta.
Matsakaicin barbashi da halayen da suka dace na kwayoyin da aka fitar
Matakan rage cutar ya kamata su fara tare da mafi ƙarancin ƙwayar ƙwayar cuta, wanda na SARS-CoV-2 ya faɗi a 0.06-0.14 µm. Yayin da jami'an kiwon lafiyar jama'a ke turawa akai-akai, N95s ana ƙididdige su ne kawai kuma an amince da su don kama al'amarin da ya fi 0.3 µm. Fiye da kashi 90 cikin XNUMX na barbashi da aka fitar an nuna sun faɗi karkashin 0.3 m. Wannan girman nau'in kwayoyin halitta yana ci gaba da tsayi na tsawon lokaci - sa'o'i, har ma da kwanaki, dangane da farashin musayar iska a cikin sararin da aka ba. An nuna SARS-CoV-2 yana ci gaba da kasancewa bayan sa'o'i a matsayin iska mai iska a wajen mai masaukin baki, kuma na tsawon kwanaki akan saman.
"SARS-CoV-2 an lura da cutar iya aiki na 3hr. a cikin iska, tare da raguwar ƙwayar ƙwayar cuta daga 103.5 to 102.7 TCID50 kowace lita ta iska.”
Wannan binciken ya yi amfani da iskar da aka samar da dakin gwaje-gwaje da ke dauke da cutar SARS-CoV-2, kuma an lura da yuwuwar kwayar halitta da ke fitarwa a sama daban-daban kuma azaman iska na tsawon lokaci.
Lokacin yin la'akari da abubuwan da ke biyowa, mutum kuma yana mamakin idan abin rufe fuska da murfin numfashi yana taka rawa wajen haɓaka lokacin yuwuwar kwayar cutar hoto:
"Lokutan tsira na ƙwayoyin cuta na iska akan saman bambanta bisa ko saman ba maras tushe ba ne (misali, filastik, bakin karfe, gilashi) ko mara ƙarfi (misali, takardu da tufafi). Fuskokin da ba su da tushe sune manyan masu ba da gudummawa ga yada cututtuka tun lokacin da aka lura da lokacin rayuwa na ƙwayoyin cuta na iska akan su ya fi tsayi fiye da na wuraren da ba su da ƙarfi.”
Masks da na'urorin numfashi tabbas suna ƙidayar a matsayin filaye mai ƙura. Ana kuma gina na'urorin numfashi da yawa da robobi masu narke. Shin an yi nazarin iyawar ƙwayar cuta a kan membranes ɗin abin rufe fuska sosai?
Matsakaicin yuwuwar Aerosol yana da mahimmanci saboda suna nuna ƙarfin watsawa a cikin wuraren da ke kewaye ba tare da wani mai iya watsawa ba. tare da Mutum mai iya watsawa kuma yana fitarwa cikin sararin da aka bayar, fitarwa zai kasance akai-akai, kuma kwayar cutar kwayar cutar za ta kara yawan jikewar kwayar cutar a kowane lokaci.
Wani batun da ba a kula da shi ba har yanzu yana da mahimmanci tare da abin rufe fuska da na'urar numfashi shine hatimi - ƙananan wuraren rata suna sa waɗannan na'urorin ba su da tasiri ga mai sawa. Ba kasafai ba, idan har abada, akwai wanda ke sanye da waɗannan na'urorin daidai, ƙarƙashin ƙa'idodin sawa, don haka an sadu da mu da na'urorin da ba a rage su ba da ake sawa ba daidai ba.
Dangane da waɗannan alkalumman don dacewa da zubewa, ɗigon kashi 3.2% yayi daidai da rashin inganci 100%.
Waɗannan su ne duk abubuwan da dole ne a yi la'akari da su yayin magance abin da ya haifar da gazawar na'urar don rage haɗarin da aka bayar. Ta hanyar nazarin fitar da hayaki na gaba, Mafi qarancin Kashi mai cuta, Rukunin Samar da Plaque, da yadda suke da alaƙa, za mu iya ƙara fahimtar dalilin da yasa sarrafa injiniyoyi koyaushe shine daidaitaccen martani, ba yawan aiwatar da na'urorin kariya na numfashi ba.
Fitowar Numfashi daga Marasa lafiya "Masu Lafiya" - PCR-Tabbatacce da Sakamakon Gwaji mara Kyau:
A cikin bincike kan fitarwar iska a cikin lafiya tare da batutuwan gwaji na SARS-CoV-2 PCR, kashi 90% na abubuwan da aka fitar ta abubuwan gwajin PCR sun kasance ƙasa da 0.3 µm, kuma an gudanar da kididdigar al'amuran da aka fitar idan aka kwatanta mutanen da ke da nau'ikan cututtuka daban-daban tare da batutuwan PCR-marasa kyau.
"Matsakaici ya fitar Ƙididdigar barbashi ya haɓaka sosai a cikin marasa lafiya na SARS-CoV-2 PCR (1490.5/L [46.0-34,772.0/L]) idan aka kwatanta da kulawar lafiya (252.0/L [0.0-882.0/L]; p <0.0001.
Idan muka yi amfani da yawan fitar numfashi na lita 4.3-29 a cikin minti daya (daga EPA Exposure Factors Handbook), mafi girman fitowar PCR-tabbatacce kewayon barbashi 34,772 a kowace lita wanda aka ninka da lita 29 a minti daya ya kai 1,008,388 barbashi da ke fitarwa a minti daya.
Duk da yake ba na tabbatar da cewa duk waɗancan ɓoyayyun ƙwayoyin ƙwayoyin cuta ne na mutum ɗaya ba, ko ƙwayoyin cuta masu yuwuwa don wannan al'amari, duk da haka akwai babban bambanci sosai a cikin al'amarin da PCR-tabbatacce da mutane marasa kyau suka fitar (matsakaicin matsakaici na 1,490.5 vs 252). Za a gabatar da rabo don jujjuya barbashi zuwa PFU bayan an tattauna rawar PFUs.
Girman ɓangarorin da ƙimar fitarwa:
Binciken da aka yi a baya ya tattauna matakan da aka fitar da nau'ikan nau'ikan nau'ikan girman a cikin SARS-CoV-2 abubuwa masu kyau da mara kyau.
"Game da barbashi Rarraba girman, tashoshi masu girman samuwa (a duka, tashoshi masu girman 14 daga 0.15 zuwa 5.0 μm) an bincika su a cikin manyan nau'ikan girman guda uku: <0.3 μm, 0.3-0.5 μm, da> 0.5-5.0 μm. Ga ƙungiyoyin biyu, yawancin aerosols (> 90% a cikin ƙungiyar SARS-CoV-2 PCR-tabbatacce da> 78% a cikin rukunin marasa kyau) an samo su a cikin mafi ƙarancin kewayon (<0.3 μm). Musamman ga rukunin COVID-tabbatacce, karuwa a cikin jimlar aerosol ya mamaye karuwa a cikin barbashi ≤0.3 μm. ”
Mutane 64 daga cikin marasa lafiya 64.8 da aka kwantar da su a asibiti da aka yi samfurin, waɗanda ke cikin mafi munin lamuran da aka gabatar, suna da alhakin kusan kashi XNUMX% na adadin abubuwan da aka fitar, don haka yana da mahimmanci a wannan yanayin a duba. m kewayon fitarwa mai ra'ayin mazan jiya da yuwuwar kamuwa da cuta yayin gudanar da fitarwa da ƙaramin ƙididdiga na kashi mara lafiya. Musamman, takardar ta bayyana cewa:
"A cikin SARS-CoV-2 Ƙungiyar PCR-tabbatacce, 15.6% (n = 10/64) sun nuna ƙididdiga masu yawa kuma suna da alhakin 64.8% na duk abubuwan da aka fitar a cikin ƙungiyar. Bugu da ƙari, 15.6%, wanda yayi daidai da 3.5% na duk marasa lafiya (n = 10/288), shine ke da alhakin 51.2% na duk abubuwan da aka fitar.
Idan muka kwatanta waɗanda ke fama da tsananin rashin lafiya tare da ƙimar kamuwa da cuta, za mu iya ƙarin fahimta game da fitar da barbashi mai yuwuwa ta mutane masu iya yawo. Idan akai la'akari da ƙarancin fitarwa na duka abubuwan da aka fitar da su ta hanyar PCR-marasa kyau da kuma dawo da batutuwan gwaji na PCR, yana iya zama lafiya a yi hasashen cewa yana magana da ƙarancin yiwuwar watsa asymptomatic kasancewa babban abu a cikin yaduwar kwayar cutar.
Kasancewar kwafin RNA tare da yawa na virions masu yiwuwa
Ba duk kwafin RNA ko ƙwayoyin ƙwayoyin cuta ba ne ke da ikon samar da PFU wanda ke haifar da kwafin hoto. Yayin da aka samar da bayanai na nawa ne aka samar da cututtuka, wannan shine ba yawan fitar da hayaki. Waɗannan ƙididdiga ne akan jimillar samar da ƙwayoyin cuta yayin kamuwa da cuta.
"Rarraba da kimantawa don jujjuyawar ƙimar izinin hoto na hoto yana ba da kiyasin yawan samarwa na 3 × 109 ku 3 × 1012 virions, ko 3 × 105 ku 3 × 108 raka'a masu yaduwa a kan cikakken yanayin kamuwa da cuta."
Sauƙaƙe, wato jimilar samar da ƙwayoyin cuta biliyan 3 zuwa tiriliyan 3, ko kuma ƙwayoyin cuta miliyan 300,000 zuwa 300 da aka samar a tsawon lokacin rashin lafiya.
Virion fitarwa
Akwai hanyoyi daban-daban na kafa fitarwar virion, waɗanda ke ba da jeri daban-daban idan an kalli gefe-gefe. Wasu nazarce-nazarce sun nuna jimillar virions da ke fitowa, kamar haka:
"Wasu marasa lafiya suna da Kwayoyin cuta masu kamuwa da cuta waɗanda suka zarce matsakaicin titer na Wölfel et al ta fiye da umarni biyu na girma wanda hakan ya ƙara adadin virions a cikin ɗigon ruwa da aka fitar zuwa sama da 100,000 a cikin minti ɗaya na magana. ”
Sauran karatun suna ba da ƙidayar ɓangarorin gabaɗaya kuma sun dogara da amfani da abubuwan juyawa daga jimlar fitarwa zuwa virions mai yiwuwa. Abin da ke da mahimmanci a kafa shi ne cewa gabaɗayan ƙwayar ƙwayar cuta ba ta daidai da jimillar virions mai yiwuwa ba, ma'ana virions masu iya ƙirƙirar Rukunin Ƙirƙirar Plaque (PFU).
PFUs - Fahimtar ɓangarorin ƙwayoyin cuta da ake buƙata don ƙirƙirar Rukunin Samar da Plaque (PFU):
Duk da yake duk kwayar cutar kwayar cutar RNA da ƙwayoyin cuta ba su da ikon yin kwafi da ƙirƙirar PFUs, an fahimci cewa kowane PFU an ƙirƙira shi ta hanyar kwayar cutar kwayar cuta guda ɗaya. Abubuwan da ke biyowa suna tattauna tasirin PFU akan cututtukan hoto da farawa.
"An tsara gwajin ta yadda kowane plaque yana fitowa daga kamuwa da cuta ta hanyar ninka kwayar cutar kwayar cutar guda daya. Don haka, ana ɗaukar PFU/ml a matsayin ma'auni na adadin raka'a masu yaduwa a kowace millilita (IU / ml), tare da faɗakarwa cewa ba za a iya tabbatar da ƙimar ɗaya-da-ɗaya na plaques zuwa ƙwayoyin cuta ba a cikin aliquot.
"Ga yawancin ƙwayoyin cuta na dabba, kwayar cutar guda ɗaya ta isa ta fara kamuwa da cuta.”
"Halin layi na madaidaicin amsa kashi yana nuna cewa virion guda ɗaya yana iya fara kamuwa da cuta. Duk da haka, babban rabo-to-pfu na ƙwayoyin cuta da yawa ya nuna cewa ba duka virions ne suke cin nasara ba. Babban rabo-to-pfu wani lokaci ana haifar da shi ta kasancewar ɓangarorin da ba su da cuta tare da kwayoyin halitta waɗanda ke ɗauke da maye gurbi ko kuma waɗanda suka lalace yayin girma ko tsarkakewa.”
"Gabaɗaya ana ɗauka cewa plaque shine sakamakon kamuwa da kwayar cutar ta kwayar halitta ta kwayar halitta guda daya. Idan haka ne, duk kwayar cutar da aka samar daga kwayar cutar da ke cikin plaque ya kamata ta zama clone, a takaice dai ya zama kamanceceniya.
Don taƙaitawa, ƙwayoyin cuta guda ɗaya mai yuwuwa, ko virion, yana da ikon ƙirƙirar PFU ɗaya, wanda wannan kwayar cutar kwayar cutar ta kwafi. Wasu daga cikin al'amuran da aka ƙirƙira RNA ne kawai na hoto ko bidiyo mai zagaya yanar gizo da sauri wanda ba zai iya haifar da kamuwa da cuta da kansa ba, kuma wasu daga cikin al'amuran da aka ƙirƙira suna iya kwafi da kamuwa da cuta.
Abinda ke tsakanin jimlar fitarwa na barbashi da kuma halittar PFUs ake kira barbashi zuwa PFU rabo. Ga SARS-CoV-2, rabon barbashi da aka fitar zuwa PFU shine 1000 zuwa 1,000,000.
PFU da Karamin Nazarin Kashi na Cutar Cutar
Yawan numfashinmu ya bambanta dangane da shekaru da matakin aiki. Matsakaicin adadin numfashi na ɗan adam yana numfashi 16-20 a cikin minti daya. Don dalilan wannan tattaunawa, za a yi amfani da adadin numfashi na lita 4.3-29 a cikin minti daya (daga EPA Exposure Factors Handbook). Wannan bayanin yana ba da kewayon har zuwa lita 53 a minti daya. Za mu duba cikin fitarwa a matsayin virions a minti daya, kuma mafi ƙarancin kashi kamar PFUs da virions don watsawa, kamar yadda aka bincika duka biyu a cikin binciken da ake samu.
Mafi qarancin Kashi (MID) Bayanai daga Littattafan:
An yi amfani da nazarin kwatancen ƙwayoyin cuta na numfashi daban-daban da binciken dabbobi na SARS-CoV-2 don ba da gudummawa ga ƙididdigar MID da yawa, amma wannan takarda ta mai da hankali ne kawai kan karatun ɗan adam gwargwadon iko.
"Ko da yake MID SARS-CoV-2 a cikin mutane yana buƙatar ƙarin bincike, ana sa ran zai zama kusan kwayoyin cutar guda 100. Nazarin ɗan adam kawai game da coronavirus an ba da rahoton don HCoV-229E kuma MID ɗin sa shine 9 PFU. Bugu da ƙari, idan watsa aerosol shine mafi girman yanayin, to MID zai zama ƙasa. "
"A gaskiya, cututtuka na tushen aerosol na buƙatar ƙananan allurai, misali, ~ sau 100 kasa da cututtukan da ke tushen droplet."
"Mafi ƙarancin ƙwayar cuta na SARS-CoV-2 da ke haifar da COVID-19 a cikin ɗan adam a cikin ƙididdigar ɓangarorin ƙetarewa da nazarin jerin shari'o'i sun yi ƙasa; A cikin wani jerin binciken da ya bincika kashi 273 na marasa lafiya a cikin samfuran 15 daga 2 SARS-CoV-1.26-tabbatacce marasa lafiya, an gano mafi ƙarancin ƙwayar cuta shine 19 PFU in vitro a cikin COVID-1-RdRp/Hel assay.248 PFU."
"A cikin binciken jerin lokuta wanda aka kiyasta 97 yara 10 shekaru da ƙananan, 78 yara masu shekaru 11-17 shekaru, da kuma 130 manya, kashi marasa lafiya a cikin shekaru 11-17 yara sun kasance ƙasa da wasu kungiyoyi biyu (125 PFU). Yara suna da ƙananan ci gaban ƙwayoyin cuta, mafi girman ƙofofin zagayowar, da ƙananan ƙwayar cuta idan aka kwatanta da manya, don haka yara ba su ne manyan masu kamuwa da cuta ba. Yara masu shekaru ⩽ shekaru 10 sun fi zama asymptomatic fiye da sauran."
"Daya daga cikin mafi An tattauna sosai daya (sic) shine binciken da Basu et al., babban makasudinsa shine kimanta girman ɗigon ruwa waɗanda ke da yuwuwar haifar da kamuwa da cuta. Amma baya ga wannan binciken, sun kuma sami wasu abubuwan da suka shafi kwayar cutar kwayar cutar da ke haifar da kamuwa da cuta. Sun gano cewa adadin virions da ke sanyawa a nasopharynx na mutum kusa da tsawon sa'o'i 2.5 kusan (11/5) virions a minti daya × 60 min × 2.5 h = 330."
Nazarin kwatancen ciki har da sauran Coronaviruses sun nuna cewa PFUs na iya zama ƙasa kaɗan ga ƙwayoyin cuta na numfashi.
"Kiyasin kamuwa da cutar SARS-CoV-1 ya kasance kwatankwacin sauran coronaviruses ciki har da HCoV-229E, wakili mai haifar da sanyi mai laushi a cikin mutane. An ba da rahoton ID10 da ID50 na SARS-CoV-1 a matsayin 43 da 280 PFU (400 TCID50) a cikin gwajin gwaji.
"ID na mutum50 don yanayin coronavirus subtype 229E wanda ke haifar da sanyi na yau da kullun a cikin mutane an ba da rahoton 13 TCID50. "
Alkaluman da aka tattauna a cikin binciken da aka bayar akan SARS-CoV-2 sun kasance 1.26, 100, 125, 330, da 363 PFU don watsawa, suna sake magana game da yanayin cutarwa.
Fitowar virions mai yuwuwa tare da mafi ƙarancin ƙwayar cuta mai yuwuwar ƙofa
Ta amfani da waɗannan alkalumman da ake da su, za mu iya magance ikirari cewa N95s suna ba da ƙimar kariya mai ma'ana daga iska mai saurin kamuwa da cutar ta hanyar kallon gudummawar fitarwa, yuwuwar kamuwa da cutar ƙwayar cuta, kewayon PFU, sannan za mu iya auna waɗannan jeri a kan cikakken ƙarfin kamawa na N95s yana ɗaukar kashi 95% na kwayoyin halitta, tare da sauran kashi 5% da ba a kama ba. Bugu da ƙari, lura cewa N95s ba a tsara su ba kuma ba a yarda da su don kama <0.3 µm ba, kuma muna magana ne game da ƙwayar cuta wanda ke da mafi ƙarancin ƙwayar ƙwayar cuta na 0.06-0.14 µm.
Fitowar numfashi An nuna cewa daga mutum mai iya kamuwa da cuta ya kai sama da 100,000 virions a cikin minti daya, kodayake ba dukkanin cututtukan da ke fitowa ba za a iya ɗauka ba su da cutar. Ƙarin takaddun bincike sun yi iƙirarin fitar da abin da ya kai 750,000 virions/minti (amma bayanan da ke goyan bayan irin wannan iƙirarin ya rasa). Har ila yau, ya kamata a lura cewa ba shakka ba ma shaka dukkan abubuwan da mutum ya ƙare ba, amma kusancinmu da mutum mai iya canzawa, adadin fitar da su, tsawon lokacin da ke cikin sararin samaniya, da kuma iskar da ke cikin wannan sararin sararin samaniya, duk abubuwan da za su yi tasiri a kan yiwuwar watsawa wanda ba za a iya bayyana shi ta hanyar layi ko tsinkaya ba.
A cikin binciken Mun bincika a sama, mafi girman fitarwa PCR-tabbatacce kewayon shine barbashi 34,772 a kowace lita, tare da waɗanda ke fitar da mafi girman jeri na fitarwa wanda ya ƙunshi kashi 64% na jimillar abubuwan da aka fitar.
Na farko, za mu ƙirƙira fitowar sa'a guda na kowane ɗayan waɗannan jeri, sannan a yi amfani da rabon-da-PFU ga kowane kewayon 1,000 zuwa 1,000,000.
Kewayon fitarwa A
Sa'a guda na mutum a cikin sararin samaniya yana fitar da virions 100,000 a cikin minti daya zai zama fitarwa na virions miliyan 6 (minti 100,000 × 60). Tsawon sa'o'i 8 a cikin sararin samaniya ya yi daidai da virions miliyan 48 da aka fitar (minti 100,000 × 480). Tare da ɓangarorin-zuwa-PFU rabo na 1,000 zuwa 1,000,000, wannan yana ba mu 6,000 mai yiwuwa virions a cikin sa'a daya, 48,000 a cikin 8 hours.
Alkaluman PFU daga binciken da aka tattauna da aka bayar sune 1.26, 100, 125, 330, da 363 PFU da ake buƙata a matsayin ƙaramin ƙwayar cuta. Na raba kowane adadin virions mai yiwuwa ta kowane adadi na PFU don samun kowane yuwuwar MID da aka jera.
Kewayon fitarwa B
A cikin binciken tarin kwayoyin halitta na PCR, 34,772 barbashi a kowace lita shine mafi girman kewayon da aka tattara, tare da ~ 64% na jimlar abubuwan da aka fitar kuma an ƙidaya su daga tushe 10 waɗanda ke cikin waɗanda kamuwa da cuta ta SARS-CoV-2 suka fi shafa. Idan muka kalli barbashi 34,772 da aka ninka ta hanyar ƙarar hayaƙin lita 29 a cikin minti ɗaya, adadin abin da ake fitarwa ya kai 1,008,388 da ke fitarwa a cikin minti ɗaya.
Littafin Jagoran Bayyanar EPA ya lissafa kewayon kowane minti wanda ya kai lita 53 a cikin minti daya, don haka amfani da adadi na lita 29 a cikin minti daya ba shine mafi girman kewayon fitarwa ba. Za a yi amfani da kewayon fitarwa na lita 7 da 29 a cikin minti ɗaya saboda suna da kewayon fitarwa suna faɗowa cikin jeri zuwa matsakaicin matakan ayyuka.
A 29 lita a minti daya, ninka da 34,772 barbashi a kowace lita (1,008,388 barbashi), na 60-minti duration na fitarwa, samfurin ne 60,503,280 (1,008,388×60) barbashi a awa daya, da kuma 484,026,240 hours. minti).
Tare da rabo daga 1,000 zuwa PFU na 1,000,000 zuwa 60,503 don COVID, wannan yana ba mu 484,026 virions masu dacewa da ake fitarwa a cikin sa'a guda, da 8 masu iya aiki a cikin sa'o'i XNUMX.
Waɗannan ƙididdiga suna ba mu ƙarfin fitarwa na mutum mai iya canzawa dangane da ba kawai adadin ƙwayoyin ƙwayoyin cuta da ke fitarwa ba, amma yuwuwar isa ga matakin MID don cutar da adadin mutanen da aka bayar bisa ga abin da aka yi amfani da adadi na PFU.
Yayin da kewayon PFU da aka nuna don SARS-CoV-2 yana da faɗi sosai, yakamata mu yi tsammanin nau'in watsawa dangane da matsayin lafiyar mutum da amsawar rigakafi. Yayin da 1.26 PFU da alama yayi ƙasa sosai, PFU na SARS-Cov-1 an nuna ya yi ƙasa da 13 PFU don saduwa da MID kofa don fara kamuwa da cuta.
Ko da an yi amfani da ƙananan fitarwa na lita 7 a cikin minti daya, wannan yana ba da adadin 243,404 barbashi a minti daya (34,772 x 7)), 14,694,240 barbashi a kowace awa (234,404 x 60), da 116,833,920 (243,404 - particles per hour 480) Tare da ɓangarorin-zuwa-PFU rabo na 8 zuwa 1,000 da aka yi amfani da shi, lokacin sa'a 1,000,000 ɗaya shine fitarwa na 1 mai yiwuwa virions, da 14,604 a cikin sa'o'i 116,833.
Tare da waɗannan jeri na fitarwa na sedentary zuwa matsakaicin ƙarfi, sau da yawa ana saduwa da iyakar MID don duk ingantattun lambobi na PFU.
Me yasa N95s suka kasa / suna kasawa / zasu gaza
An tsara na'urorin numfashi masu kimar N95 kuma an amince dasu don kama kashi 95% na al'amuran da basu da tushe fiye da 0.3µm. SARS-CoV-2 yana da ƙaramin ƙaramin abu mai yuwuwa na 0.06-0.14 µm, da kyau a ƙarƙashin madaidaicin 0.3µm ko da an ɗaure shi da babban al'amari, don haka wannan hasashe ne na cikakkiyar ikon kamawa don kewayon ɓarna wanda waɗannan na'urorin ba a tsara su ko kuma an yarda da su don kamawa ba, kuma bayanan aikace-aikacen su ba su nuna su yin aiki a ko kusa da 95% ba.
Don manufar motsa jiki a cikin cikakken iyawar kamawa, za mu ba su zato na cikakken ƙimar kama kashi 95%. Idan muka yi amfani da kashi 5% na alkaluman MID da aka nuna don nunawa a cikin jeri na fitarwa A da B, zai nuna kamuwa da cutar virions mai yuwuwa da kashi 5% da ba a taɓa kamawa ba (misali, babu ɗigo) idan an cika hasashen kashi 95% na cikakken adadin kamawa.
Kewayon fitarwa A
Kewayon fitarwa B
29 lita a minti daya
7 lita a minti daya
Idan muka yi la'akari da cikakkiyar damar kamawa don N95s na nau'ikan nau'ikan nau'ikan kwayoyin halitta waɗanda ba a tsara waɗannan na'urori ko kuma an yarda da su don kamawa ba, kuma muna amfani da sauran kashi 5% waɗanda ba a taɓa kama su ba, yawancin jeri na fitarwa da PFU da ake buƙata don saduwa da ƙofar MID har yanzu suna ba da damar fallasa sau da yawa MID kofa don yuwuwar kamuwa da cuta na mutane da yawa a cikin sa'o'i 1 na fitowar kowane lokaci.
Summary
Mun zama lauje tare da ƙa'idodin ragewa yayin barkewar SARS-CoV-2 saboda wannan ƙwayar cuta ba ta da kisa ga yawancin mutane, tare da ƙimar tsira da aka nuna kusan kashi 99.8%. Wannan jujjuyawar zuwa takamaiman martanin haɗari yana da matuƙar haɗari idan aka yi amfani da shi ga ƙwayoyin cuta masu mutuwa da abubuwan fallasa.
Ta yin nazarin yanayin mafi kyawun yanayin, za mu iya yin hasashen ko ma'aunin da aka bayar zai yi tasiri mai tasiri akan haɗarin da aka gano. Don N95s dangane da fitarwa, rabo-zuwa-PFU rabo, da MID don SARS-CoV-2, mafi kyawun yanayin yanayin kamanni cikakke na al'amuran da waɗannan na'urorin ba a tsara su ba kuma ba a yarda da su don kama su ba yana nuna har yanzu ba su rage wannan haɗarin ba, kuma shawarwarin amfani da su yakamata a sake la'akari da su nan da nan.
Ƙarin albarkatun:
Ya tattauna matsakaicin nauyin ƙwayar cuta daga samfurori: https://www.nature.com/articles/s41586-020-2196-x.
Mafi ƙarancin Maganin Cutar
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7090536/ (a kan MID gabaɗaya, ba takamaiman SARS-CoV-2 ba).
Ƙamus
aerosol - barbashi da aka tarwatsa cikin iska ko gas, wanda aka ayyana a matsayin kasa da microns a girman.
asymptomatic (yaɗa) - Ma'anar ka'idar watsa kwayar cuta ga wasu yayin da ba a nuna alamun alamun cutar da aka ce ba.
yanayin yanayi - Adadin abubuwan da za a iya amfani da su wanda ya rage sama a cikin wani wuri da ke kewaye.
watsi - exhaled numfashi al'amarin.
tsarin tsarin laminar - barbashi ruwa suna bin santsin hanyoyi a cikin yadudduka.
mafi ƙarancin ƙwayar cuta - mafi ƙarancin adadin haɗari dole ne a fallasa shi don a yi tsammanin fara rashin lafiya.
N95 - na'ura mai tacewa wanda ba mai ɗaukar mai ba yana iya toshewa har zuwa 95% na kwayoyin halitta sama da 0.3µm.
farawa - farkon rashin lafiya da ake ɗauka da zarar an cika ƙaƙƙarfan ƙayyadaddun ƙwayar cuta.
fitarwa - fitar da fitar da hayaki a cikin wani yanayi da wani mai iya watsawa.
fitarwa a matsayin akai-akai - Mutumin da ke cikin sararin samaniya yana fitar da iskar iska mai ɗauke da ƙwayoyin cuta a cikin yanayin da aka bayar, yana mai da yanayin da aka ba shi fiye da ƙwayoyin cuta da kowane numfashi.
barbashi zuwa PFU rabo - Matsakaicin ƙididdiga na fitarwa na ƙwayoyin cuta wanda ke auna jimlar adadin barbashi da ke fitarwa akan ɓangarorin da ke iya kamuwa da cuta.
PCR-kowane- batun gwajin da aka bayar ba ya samun ingantaccen sakamakon gwaji lokacin da aka gwada shi tare da hanyar PCR don bazuwar cuta. PCR yana tsaye don amfani da dabarar amsa sarkar polymerase.
PCR-tabbatacce - batun gwajin da aka bayar yana samun ingantaccen gwaji lokacin da aka gwada shi ta amfani da dabarar amsawar sarkar polymerase don cutar da aka bayar.
cikakken iya kama - kama abubuwa masu haɗari a daidai gwargwadon ingancin da samfur ya bayar a matsayin mafi kyawun ƙimarsa mai yiwuwa.
Rukunin Ƙirƙirar Plaque (PFUs) - Halittar PFUs na buƙatar virion guda ɗaya wanda ke cutar da kwayar halitta, inda kwayar cutar ta fara. Ana buƙatar madaidaicin adadin da aka bayar na PFU don fara rashin lafiya, wanda aka sani da ƙaramin ƙwayar cuta.
Kwafin RNA - kwayoyin halitta da ake buƙata don yin kwafin sunadarai a cikin tantanin halitta. Kwafin RNA ba sa daidaita da virions masu iya yin kwafi.
TCID50- taƙaitaccen bayani ga al'adun nama masu kamuwa da cuta, wanda shine dilution na ƙwayar cuta da ake buƙata don cutar da kashi 50% na ƙwayoyin cuta a cikin gwajin al'ada.
kwayar cutar kwayar cuta - adadin ƙwayoyin ƙwayoyin cuta a cikin wani abu da aka bayar, fitarwa, ko cikin jikin mutum mai iya ɗauka.
viability viability - virions masu iya cutar da kwayar halitta da ƙirƙirar raka'o'in ƙirƙira plaque (PFUs).
virion ko viable virion- cikakken kwayar cutar kwayar cuta.
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Megan Mansell tsohon darektan ilimi na gundumomi ne kan haɗakar jama'a na musamman, yana hidima ga ɗaliban da ke da naƙasa sosai, marasa lafiya, marasa doka, autistic, da ƙalubalen ɗabi'a; Hakanan tana da asali a cikin aikace-aikacen PPE masu haɗari. Tana da gogewa a rubuce da kuma sa ido kan aiwatar da ƙa'idar don samun damar shiga sassan jama'a da ke da rauni a ƙarƙashin cikakken ADA/OSHA/IDEA. Ana iya samun ta a MeganKristenMansell@Gmail.com.
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