RT-PCR NGE TRUENAT?

SARS-CoV-2 (Covid-19 thlentu) hrileng vang hian mipui nawlpui bengah “scientific” thumal tam tak a ri nasa a, hrilhfiahna pawh mithiam engemaw zatin an ziak tawh a. Amaherawhchu, social media lamah thu dik tawk lo leh hriatthiam harsa deuhte a awm nual avangin, RT-PCR leh TrueNat chungchang tlem azawng, hriatthiam awlsam thei ang berin han ziak dawn ila.

Polymerase Chain Reaction

Polymerase Chain Reaction (PCR) kan tih hi hmanraw pawimawh tak, “medical research” leh “basic research” atana hman nasat em em a ni a. PCR khawl hnathawh ber chu, DNA awm sa tihpun (amplify) a ni. DNA awmsa tlemte aṭang pawhin reilote chhungin DNA tam tak a siam chhuak thei a ni. DNA awmsa entawnin, bawlhlo hrang hrang (chemicals) hmangin DNA dang a siam a, thil awmsa kan 'xerox' ang deuh a nih chu. 

DNA kan tih hi “deoxyribonucleic acid” tihna a ni a, thilnungte inthlah chhawnna atana 'information' pawimawh (genetic material) kengtu a ni. Heng DNA te hi kan taksa peng hrang hmun tin deuhthawa awm an ni a. DNA nei chi thilnungte chuan DNA aṭang hian RNA kan siam chhuak ṭhin a, chu chu 'Transcription' an ti. Virus ṭhenkhat hian DNA aiah an inthlah chhawnna atan RNA (ribonucleic acid) an nei thung a. Chung zingah chuan SARS-CoV-2 virus hi a tel a ni. Heng bakah hian kan hriat lar zualah HIV, Ebola, Polio leh Hepatitis 'C' virus-te pawh an tel. 

Heng virus-te hian thilnung dang an infect reng rengin, enzyme chi khat 'Reverse Transcriptase' hmang hian an RNA aṭangin DNA an siam chhuak leh ṭhin a. Transcription letling (opposite) chiah a nih avangin “Reverse Transcription” an ti thung a ni. 

PCR hi chi hrang engemaw zat a awm a. SARS-CoV-2 virus en nan hian chi hnih, Reverse Transcription-PCR leh Quantitative/ Real Time-PCR (qPCR) hman a ni. Heng pahnih hi inang thuak leh inzawm an nih avangin pakhat ang pawhin an sawi fo. RT-PCR kan tih mai hian a huam thei ve ve a ni. 

SARS-CoV-2 leh RT-PCR

A hmasa berah SARS-CoV-2 virus chhunga RNA kha lak chhuah phawt a ngaih avangin bawlhlo leh hmanraw hrang hrang hmangin virus tuamtu zawng zawng kha tihkeh (lysis) a ni a, he step hi fimkhur ngai leh hun mamawh rei tak a ni. 

RNA Extractor khawl neih erawh chuan awlsam takin a tih theih thung. 

He step hi a khawihtu tan pawh fimkhur ngai lai chu a ni a, Personal Protective Equipment (PPE) a inthuam chunga khawih tur a ni. Hemi bak hi chu PPE kher lo, laboratory thuam pangngai (Lab coat, gloves, masks, etc) nena khawih chhunzawm theih tawh a ni (Handbook for COVID-19 testing in Research Institutions, Issued by the Office of Principal Scientific Adviserto the Government of India, April 11, 2020). 

RT-PCR khawl chhungah hian SARS-CoV-2 virus RNA aṭangin “Reverse Transcription” kan tih hmangin DNA siam chhuah leh a ni phawt a, chu chu cDNA (complimentary DNA) tiin an vuah. He cDNA hi RT-PCR khawl hian a lo tipung (amplify) ta a ni. 

Sample-ah SARS-CoV-2 virus a awm lo a nih chuan SARS-CoV-2 cDNA pung tur a awm loh avangin RT-PCR khawl hian a hmu lo a, result 'negative' kan lo nei ta a ni. Sample-ah SARS-CoV-2 virus a awm a nih chuan cDNA insiamin, RT-PCR khawl hian a tipung a, result 'positive' kan lo nei ta ṭhin a ni. 

He cDNA tihpun a nih dawn hian 'primers' (nucleic acid tawite) hman a ngai ṭhin a, heng 'primers' te hi SARS-CoV-2 DNA mil thlap tura siam (design) a ni. SARS-CoV-2 test nan hian 'primers' chi hnih an hmang ṭhin a, chungte chu E-Gene (Envelope Gene) leh RdRp Gene (RNA-Dependant Reverse Transcriptase gene) te an ni. 

A hmasaah E-gene awm leh awm loh zawn phawt niin, a lo awm chuan 'confirmatory test' atan RdRp gene zawn leh a ni ṭhin (Gene kan han tih te hi DNA kan sawina ang deuh thoah ngaih theih a ni e). Virus aṭanga RNA lak chhuah hun tel lovin RT-PCR khawla sample en chhung hi darkar khat vel a ni. 

RT-PCR hian virus ni lovin virus RNA aṭanga siam cDNA zawk a tipung a, heng cDNA te hian hlauhawmna an nei lo tih hriat pawh a ṭha awm e. RT-PCR chungchang hi chu ziak dang a awm nual tawh avangin duh tawk phawt ang. 

TrueNat leh SARS-CoV-2

Tun hnaia kan hriat lar TrueNat khawl hi Molbio Diagnostics hnuaia Bigtec Laboratories, Bangalore-te'n Tuberculosis (TB) en nana an siam a ni a. ICMR (Indian Council of Medical Research) chuan May thla aṭang khan SARS-CoV-2 test nana hman theih a ni tih a puang a. A khawl hi ken awlsam, battery hmanga operate mai theih a ni a. A hnathawh danah hian PCR technology tho a hman avangin MicroPCR-te pawh an lo ti thin a ni. He TrueNatkhawl hi chip hmang a ni.

TrueNat-a sample en tur hi RT-PCR ang tho khan virus aṭangin RNA lakchhuah a ngai a. Chip te tak teah sample kha thlawr niin, chu chip chu TrueNat khawlah thun a ni a, tichuan khawl hian PCR kan tih ang khan a lo thawk ta a ni.

TrueNat hian chip pahnih a nei a, pakhat zawk chu “E Gene” enna a ni a, a dang leh hi “RdRp Gene” ennaniin, hemi hi “confirmatory chip” tiin an sawi thin bawk. TrueNat khawlin E gene hi a hmuh chuan confirmatory chip hian en leh a ngai ṭhin a ni. ICMR chuanTrueNat khawlin positive a hmuh hi RT-PCR khawla en leh kher a ngai lo tiin thuchhuah a siam a. TrueNat hmang hian a khawl azirin minute 45 aṭanga darkar khat chhungin sample a en zo thei a ni.

RT-PCR leh TrueNat

Tunlaia zawhna tam berte zinga mi chu “RT-PCR nge ṭha zawk TrueNat?” tih hi a ni a. Heng khawl pahnihte hi an hnathawh dan tlangpui a inang a, anmahni tawkah ṭhatna leh ṭhat lohna an nei ve ve.

TrueNat khawl hian khawl leh hmanraw dang leh thawktu (manpower)mamawh a nei tam lova, hman a awlsamin a hautak lo hle. Amaherawhchu, sample a en theih zat a tlem em em a. TrueNat model sang ber Quattro hian vawi khatah sample 4 chiah a test thei thung. Tin, TrueNat hian virus awm leh awm loh chauh a en thei a, a viral load (virus tam zawng) a en thei lo bawk a ni. Tin, he khawl hi khawl thar a nih avangin SARS-Cov-2 en nan hian a ṭhat tawk leh tawk loh zirchianna a tam lova. WHO-in Gaya District, Bihar-a TrueNat a zirchiannaah chuan he khawlin Covid-19 positive a hmuhte RT-PCR khawla en an nih lehin 70% lai chu Covid-19 vei lo an lo ni tih an hmuchhuak a ni (The Times of India, 25th June, 2020). TrueNat khawl hi a “chip” thlak mai hian natna dang (MTB, Dengue, H1N1, etc) en nan a hman ve leh zel theih bawk.

RT-PCR hian khawl leh hmanrua, hmunhma leh thiamthil bik nei hnathawktu (skilled manpower) mamawh a nei tam a, TrueNat ai chuan enkawl chu a hautak zawk. Chutihrual chuan zirbingna leh natna hmuhchhuahna atan chuan khawvel pumin “Gold Standard” tih khawpa an sawi a nih avangin tun dinhmunah chuan a tluk a awm lo va, khawl duhthusam chu a ni. RT-PCR-ah hian a khawl azirin a sample dah theihna khuar (wells) 96 aṭanga 384 vel a awm a. Tunah hian ICMR guidelines angin “pooled sampling” hman a nih avangin well khatah sample pakhat aia tam dah a ni ṭhin a. Tuna kan hman tam ber hi 96 wells a ni a. Darkar khat chhungin TrueNat khawlin sample 4 chauh a en theih laiin RT-PCR chuan sample 200 chuang a en thei a ni. Tin, RT-PCR hian viral cDNA awm leh awm loh mai bakah viral load a pek tel avangin a ṭangkaiin a hnathawh theih a tam zawk a ni.

TrueNat hi a tê fel thlap a, ama tawkah natna hrik kai leh kai lo (diagnosis) en nan hrim hrim chuan a ṭha viau, amaherawhchua thiltihtheihna hi natna hmuhchhuahah hian a tawp deuh tawp mai a, RT-PCR nena tehkhin chuan a tihtheih a tam lo zawk hle.

RT-PCR Hmanna Dang

RT-PCR hi Covid-19 chauh enna a ni lo va. Natna dang enna leh an enkawlna atana la ṭangkai zel tur a ni a. RT-PCR kan neih loh avang hian Mizoram pawnah sum tam tak sengin sample kan lo thawn tawh ṭhin a. Chung zingah chuan Hepatitis B leh C, EID-HIV (Nausen HIV)-te an tel a. Sample thawnna kawngah fuh lo palh a awm phei chuan thawn nawn fote a ngai ṭhin a. Hemi avang hian result mumal lo pawh a awm fo a ni.

Heng bakah hian natna dang Scrub typhus, Influenza Virus hrang hrang, H1N1, MTB leh a dangte hmuhchhuah nan pawh “gold standard” a ni a. Mizoramin kan buaipui em em cancer natna enkawlna ṭha chi “Targeted Therapy” atan pawha khawl pawimawh em em mai a ni a. HIV leh natna dang enkawlnaah pawh damdawi thawh ṭhat leh ṭhat loh enna thlenga hman theih a ni.

Natna dinhmun khirhkhan en hmanhmawhthlak, entirnan, Venous Thrombosis Risk Analysis, Prothrombin gene mutation kan tihte bakah inthlahchhawn natna hrang hrang (Genetic Diseases) Mizorama kan hmuh Thalassaemia, G6PD, etc. te pawh he RT-PCR hmang hian en theih vek a ni. Hmeichhe chhul cancer thlentu pakhat Human papillomavirus Virus (HPV)en nan te, cancer hrim hrimah pawh “Genetic Mutation” hrang hrang en nan a ṭangkai em em a. Taksa bung thlak (Organ Transplant) ti tawhte tana ṭangkai leh tih ngei ngei tur “Tacrolimus Genotyping” pawh he RT-PCR khawl hmanga tih tur hi a ni. Kan hmaah specialist leh super specialist thar rawn zirchhuak turte pawh kan nei nual a, hengho thiamna pawh hian he khawl hi a mamawh ngei ngei dawn a ni.

Tin, medical diagnosis bakah hian RT-PCR hi research khawl 

ṭangkai leh pawimawh em em mai a ni a. Mizorama kan research institution neih lian zual MZU, CAU, RIPANS leh PUC-ah te pawh an khawl hman ṭangkai em em a ni nghe nghe a. Mizo ṭhalai eng emaw zatin he khawl hmang hian an research an bei mek zel bawk a. Mizorama kan damdawi in leh zirna inte'n hma an sawn zel nan research a pawimawh hle, hetiang hmanraw ṭha hi a nihna ang taka kan hman ṭangkai phawt chuan Mizote hi research leh medical diagnosis-ah min tichangtlung sawt ngei ang.

Hri leng mithiamte (epide­miologist) chuan SARS-Cov-2 hian zual lam a pan dawn chauh niin an ngai a, India phei chuan a zualpui (peak) kan la thleng lovah an ngai hial a ni. Ram ṭhenkhat pawhin a thawh hnihna (2nd Wave) an hmachhawn chho leh mek bawk a. Kan ṭhenawm state 

ṭhenkhatah community transmission hial te pawh a thlen tawh avangin Mizoram pawh kan him chin tur hi a hriat loh va. Tin, kan hma huna hri dang la leng leh zel turah ngaih a ni bawk. Chuvangin, Mizoram pawh hian hetiang molecular diagnosic laboratory hi kan la mamawh belh zel dawn chauh niin a lang a, a tam thei ang ber kan neih a, a hmanrua khawih thiam tur mi kan in-train chhoh zel bawk a, kan inhmakhua lawk a pawimawh hle.