Highlights
- RT-PCR test has a high specificity rate; gives less false positives
- Only nasopharyngeal swabs are collected for Rapid Antigen Test
- RAT has moderate sensitivity, can give false negative results for COVID-19
New Delhi: Testing for Coronavirus has been ramped up in India from 2.07 lakh tests on June 24 to over 4.08 lakh tests per day on July 28 and 6.19 lakh samples tested on August 4. Rapid Antigen Tests (RAT) has helped in a substantial increase in testing in the country and especially in the national capital Delhi. In a media briefing on August 4, ICMR Director General Dr Balram Bhargava informed that 25-30 per cent of the tests conducted are RAT. However, it’s a known fact that RAT can give a high number of false negatives. Recently, Delhi High Court pulled UP the AAP government for choosing Rapid Antigen Testing (RAT), as the primary test of COVID-19 infection over RT-PCR (Reverse transcription-polymerase chain reaction) which is considered as the gold standard for testing.
NDTV spoke to experts to understand the two main kinds of tests for COVID-19 diagnosis – RT-PCR and RAT and their reliability.
According to Dr Navin Dang, founder of Dr Dang’s lab in Delhi, all the tests available in the market for testing of COVID-19 have their own pros and cons but RT-PCR remains the gold standard for testing. Explaining the process of RT-PCR test, Dr Dang said,
This is performed by taking swabs from nasal and oral tracts which are then put in viral transport medium and brought to the lab. It is processed under bio safety level 2 plus facilities; we do RNA (Ribonucleic acid) extraction to detect the presence of the virus.
RT-PCR test has a specificity rate (ability to identify those without the disease) of nearly 100 per cent whereas the sensitivity rate (ability to identify those with the disease) of about 67 per cent. This means, RT-PCR test will not give false positives but there are 30-35 per cent chances of getting false negatives. Explaining the reason behind the low sensitivity rate and why is RT-PCR test still considered the gold standard for testing, Dr Dang said,
There are three main reasons, one, the technology itself which we cannot consider as a limitation. Secondly, if the samples are not taken properly then the result can be a false negative. This is the reason we take both nasal and oral swabs. Ideally, samples should be collected by experts who are trained to go to the nasopharyngeal or oropharyngeal cavity. Thirdly, people are now seeing it as a preventive test which means they are getting the test done even in the absence of symptoms. The average incubation period of SARS-CoV-2 is 5.6 days so an individual will test positive only after six days of contracting the virus. Undergoing a COVID-19 test at the initial stage when the viral load is very low can give negative results. Also, there is no other test that has got better sensitivity.
Also Read: Coronavirus Explainer: 20 COVID-19 Related Terms And What These Mean
At the initial stage of the Coronavirus pandemic, RT-PCR test was priced at Rs. 4,500 but now the cost has been brought down to Rs. 2,500. It is still expensive and takes a day to give results.
Talking about the time consuming process, Dr Harsh Mahajan, Founder of Mahajan Imaging and Chairman of CARINGdx, said,
In RT-PCR you can put 96 samples at a time so one has to wait for the samples to reach the laboratory and then process them. Less than 96 samples can be processed but it will increase the cost of testing.
As far as Rapid Antigen Test (RAT) is concerned, it is gaining grounds and has led to a spike in the number of tests being conducted, as it is quick and cheap. Only nasopharyngeal swabs are collected by trained healthcare workers. RAT detects the presence of viral proteins (antigens – attributes of the virus) in a sample from the respiratory tract of a person. However, it is capable of giving more false negatives. Explaining the same, Dr Mahajan said,
RAT has moderate sensitivity (around 50 per cent) and high specificity which means if you test 100 COVID-19 patients, it will give positive results for only 50 of them.
According to the ICMR protocol, if RAT gives negative result and an individual has symptoms of ILI (influenza like illness), then he/she should undergo RT-PCR test.
Also, RAT is a point of care test which means it can be performed only in hospital settings rather than standalone testing labs. Elaborating on this, Dr Dang said,
Sanctity of the test that is from the time sample is taken and is processed, is about 1 hour so it cannot be done at any collection centre. It is not possible to collect, label, transport and process the sample within one hour, even if it is collected within three to four kms from the lab.
If RAT does not provide standardised testing and results, why is India conducting RAT? Answering the question, Dr Dang said,
RAT has its own advantages in the way it can be done on a mass level. The numbers of tests that are being performed are in thousands now. The tests are being performed even in community centres, Gurdwara and other places. But too much of reliability on rapid antigen tests which shows a lot of false negatives is a questionable thing and I think the government may have to reconsider it. Right now, the number of people asking for a test is high and the number of RT-PCR tests labs are being able to provide is not that great.
Explaining how a government should increase testing with RAT and at the same time ensure it doesn’t miss COVID-19 positive patients, global health expert Anant Bhan suggests a balance between RAT and RT-PCR test. He added,
If antigen tests are being used it needs to be backed by RT-PCR test and only then we can say that yes there has been a decrease in coronavirus cases in that particular area. If the numbers of both the tests are not matching then it is a serious issue and it may reflect a bad picture.
Mr Bhan recommends all states to ramp up testing by not only increasing the number of rapid antigen tests, but also backing it by RT-PCR tests.
Also Read: Coronavirus Crisis: Community Transmission Taking Place In India, Here’s What Experts Have To Say
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.
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State & District Details
State | Cases | Active | Recovered | Deaths |
---|---|---|---|---|
DistrictCases Mumbai45,478 Thane13,660 Pune9,920 Mumbai Suburban5,363 Aurangabad1,974 Nashik1,575 Raigad1,462 Palghar1,421 Solapur1,291 Jalgaon1,039 Akola757 Nagpur692 Kolhapur646 Satara629 Ratnagiri350 Amravati291 Dhule228 Hingoli208 Jalna201 Ahmednagar190 Nanded176 Yavatmal150 Sangli145 Latur139 Osmanabad125 Sindhudurg114 Buldhana88 Parbhani78 gondia69 Beed54 Nandurbar42 Gadchiroli42 Bhandara41 Chandrapur32 Washim13 Wardha11 | 19,97,992 3,015 | 47,982 1,633 | 18,99,428 4,589 | 50,582 59 |
DistrictCases Udupi1,176 Kalaburagi669 Yadgir538 Bengaluru Urban529 Raichur369 Mandya346 Belagavi337 Bidar219 Hassan205 Davangere204 Vijayapura201 Dakshina Kannada179 Chikkaballapura149 Mysuru107 Bagalkote103 Uttara Kannada95 Shivamogga67 Dharwad61 Ballari60 Gadag45 Bengaluru Rural40 Tumakuru36 Kolar29 Haveri24 Chikkamagaluru19 Chitradurga14 Koppal5 Kodagu4 Ramanagara3 Chamarajanagara0 | 9,33,578 501 | 7,716 168 | 9,13,677 665 | 12,185 4 |
DistrictCases Kurnool795 Krishna557 Guntur511 Anantapur428 East Godavari356 Chittoor319 Sri Potti Sriramulu Nell*296 Y.S.R.205 West Godavari199 Srikakulam183 Prakasam104 Visakhapatnam103 Vizianagaram23 | 8,86,418 173 | 1,637 23 | 8,77,639 196 | 7,142 |
DistrictCases Kannur357 Kasaragod333 Palakkad224 Malappuram119 Kollam118 Thrissur106 Thiruvananthapuram104 Pathanamthitta98 Kozhikode90 Alappuzha76 Kottayam73 Ernakulam60 Idukki40 Wayanad36 | 8,64,195 6,815 | 69,914 567 | 7,90,757 7,364 | 3,524 18 |
DistrictCases Chennai23,324 Chengalpattu1,314 Thiruvallur774 Villupuram509 Kanchipuram503 Tiruvannamalai496 Cuddalore477 Ariyalur444 Tirunelveli433 Tuticorin333 Kallakurichi324 Madurai322 Salem258 Coimbatore188 Virudhunagar185 Dindigul175 Perambalur133 Ranipet133 Thanjavur130 Theni129 Tiruchirappalli119 Ramanathapuram119 Tiruppur116 Kanniyakumari110 Tenkasi103 Nagapattinam99 Karur88 Namakkal83 Erode75 Vellore71 Thiruvarur67 Pudukkottai53 Sivaganga46 Tirupathur45 Krishnagiri43 The Nilgiris17 Dharmapuri15 | 8,32,415 549 | 5,314 173 | 8,14,811 713 | 12,290 9 |
DistrictCases North West5,463 Central4,817 West4,768 New Delhi3,405 North3,059 East2,472 South East2,446 South West2,391 South2,329 North East1,914 Shahdara1,580 | 6,33,049 228 | 2,147 187 | 6,20,128 405 | 10,774 10 |
DistrictCases Gautam Buddha Nagar1,119 Agra933 Ghaziabad794 Meerut504 Lucknow386 Saharanpur298 Kanpur Nagar286 Moradabad252 Varanasi243 Hapur225 Aligarh215 Basti214 Amethi206 Rampur203 Jaunpur194 Firozabad190 Barabanki168 Gorakhpur166 Bulandshahr166 Siddharth Nagar159 Ghazipur159 Bijnor157 Deoria143 Azamgarh138 Sant Kabeer Nagar132 Mathura129 Ayodhya120 Muzaffarnagar117 Sambhal116 Sultanpur97 Ambedkar Nagar92 Maharajganj85 Amroha80 Rae Bareli78 Bahraich73 Kheri72 Kannauj69 Baghpat68 Kushi Nagar67 Bhadohi60 Ballia60 Gonda59 Etah52 Hardoi49 Balrampur49 Mau48 Mainpuri46 Etawah46 Hathras43 Unnao42 Jalaun41 Jhansi41 Shamli40 Chandauli38 Auraiya37 Farrukhabad36 Sitapur32 Prayagraj30 Banda27 Shahjahanpur25 Shravasti23 Budaun23 Mirzapur22 Bareilly17 Kasganj16 Pratapgarh15 Pilibhit15 Sonbhadra10 Kaushambi6 Kanpur Dehat4 Chitrakoot4 Lalitpur3 Hamirpur3 Mahoba3 Fatehpur3 | 5,97,628 390 | 7,873 299 | 5,81,164 682 | 8,591 7 |
DistrictCases Kolkata2,777 Howrah1,435 24 Paraganas North1,031 Hooghly604 24 Paraganas South281 Maldah235 Dinajpur Uttar216 Coochbehar210 Birbhum206 Medinipur West159 Medinipur East153 Nadia139 Purba Bardhaman130 Murshidabad125 Bankura116 Darjeeling97 Jalpaiguri88 Paschim Bardhaman70 Purulia66 Dinajpur Dakshin50 Alipurduar39 Kalimpong18 Jhargram9 | 5,66,482 409 | 6,675 106 | 5,49,727 509 | 10,080 6 |
DistrictCases Ganjam581 Jajapur322 Khordha238 Baleshwar190 Kendrapara164 Cuttack155 Bhadrak137 Balangir129 Puri103 Sundargarh102 Jagatsinghapur91 Nayagarh86 Mayurbhanj73 Nuapada69 Gajapati61 Dhenkanal36 Boudh34 Kendujhar34 Deogarh33 Kalahandi33 Sonepur29 Kandhamal28 Anugul26 Malkangiri20 Bargarh16 Koraput16 Sambalpur16 Jharsuguda8 Nabarangpur2 Rayagada2 | 3,33,723 157 | 1,500 113 | 3,30,321 270 | 1,902 |
DistrictCases Jaipur2,177 Jodhpur1,748 Udaipur724 Bharatpur563 Kota503 Nagaur500 Ajmer379 Dungarpur374 Pali352 Jhalawar329 Bhilwara250 Sikar231 Chittorgarh188 Tonk171 Jalore164 Rajsamand140 Sirohi130 Bikaner112 Banswara91 Alwar90 Churu81 Jhunjhunu64 Dausa61 Dholpur60 Baran59 Jaisalmer53 Barmer34 Hanumangarh31 SawaiMadhopur26 Karauli17 Pratapgarh14 Ganganagar8 Bundi5 | 3,15,816 213 | 4,077 227 | 3,08,985 438 | 2,754 2 |
DistrictCases Bilaspur100 Korba100 Mungeli87 Baloda Bazar85 Jashpur77 Janjgir-Champa56 Mahasamund54 Rajnandgaon52 Kabirdham52 Raigarh47 Raipur46 Balod41 Korea39 Durg31 Bemetara21 Kanker19 Balrampur17 Surguja14 Gariyaband10 Surajpur9 Dhamtari6 Bijapur2 Bastar2 Dantewada0 Kondagaon0 Narayanpur0 Sukma0 | 2,94,949 594 | 5,798 134 | 2,85,566 718 | 3,585 10 |
DistrictCases Hyderabad2,475 Ranga Reddy183 Suryapet87 Jagitial77 Nizamabad76 MedchalMalkajgiri75 Mancherial43 YadadriBhuvanagiri40 Jogulamba Gadwal40 Vikarabad40 Nalgonda33 Warangal Urban32 Mahabubnagar30 Sangareddy26 Khammam26 Adilabad22 Nirmal21 Karimnagar17 RajannaSircilla16 Medak11 Kamareddy11 Mahabubabad10 Jayashankar Bhupalapally9 Nagarkurnool8 Kumuram Bheem Asifabad8 Jangoan8 Siddipet7 Peddapalli5 Bhadradri Kothagudem5 Warangal Rural4 Mulugu3 Narayanpet3 Wanaparthy1 | 2,92,621 226 | 3,920 1 | 2,87,117 224 | 1,584 1 |
DistrictCases Gurugram2,950 Faridabad867 Sonipat404 Rohtak145 Palwal120 Jhajjar114 Karnal104 Hisar98 Ambala93 Panipat78 Nuh68 Bhiwani60 Rewari56 Kurukshetra55 Sirsa50 Kaithal48 Mahendragarh47 CharkiDadri43 Panchkula39 Fatehabad38 Jind38 Yamunanagar19 | 2,66,686 105 | 1,734 103 | 2,61,955 204 | 2,997 4 |
DistrictCases Patna279 Bhagalpur266 Rohtas256 Khagaria253 Begusarai243 Madhubani199 Munger188 Jehanabad178 Katihar175 Darbhanga143 Samastipur139 Siwan139 PurbiChamparan138 Purnia135 Banka134 Buxar134 Nalanda123 Gopalganj123 Nawada122 Sheikhpura118 Gaya115 Kaimur (bhabua)105 Bhojpur103 Saran101 Muzaffarpur96 Saharsa88 Supaul87 Vaishali87 Madhepura82 Kishanganj75 Aurangabad75 Sitamarhi73 Lakhisarai72 Araria68 Pashchim Champaran57 Arwal52 Jamui47 Sheohar20 | 2,58,176 185 | 3,143 98 | 2,53,569 280 | 1,464 3 |
DistrictCases Ahmadabad17,125 Surat2,311 Vadodara1,555 Gandhinagar410 Mahesana159 Banas Kantha147 Bhavnagar146 Rajkot135 Arvalli134 Mahisagar125 Anand107 PanchMahals107 Patan105 SabarKantha101 Kachchh99 Kheda98 Jamnagar63 Bharuch56 Botad55 Surendranagar55 Valsad47 GirSomnath45 Dohad43 Chhotaudepur37 Naysari35 Junagadh31 Narmada25 DevbhumiDwarka22 Amreli16 Porbandar11 Tapi6 Dang5 Morbi4 | 2,57,342 490 | 5,748 219 | 2,47,223 707 | 4,371 2 |
DistrictCases Indore3,839 Bhopal1,880 Ujjain799 Burhanpur351 Neemuch319 Jabalpur276 East Nimar266 Sagar228 Gwalior211 Khargone196 Dewas140 Dhar132 Mandsaur112 Morena109 Bhind87 Raisen71 Barwani60 Ratlam51 Rewa39 Shajapur39 Hoshangabad37 Vidisha37 Chhatarpur35 Betul35 Rajgarh31 Dindori29 Sheopur26 Damoh26 Satna24 Anuppur22 Panna20 Tikamgarh18 Sidhi17 Narsinghpur17 Chhindwara16 Agar Malwa15 Mandla15 Shivpuri15 Jhabua14 Shandol14 Singrauli13 Ashoknagar13 Datia12 Sehore12 Umaria10 Balaghat9 Guna8 Harda4 Alirajpur3 Katni3 Seoni2 Niwari0 | 2,52,466 280 | 5,008 724 | 2,43,688 997 | 3,770 7 |
DistrictCases Kamrup Metro276 Golaghat203 Nagaon143 Hojai89 Dima Hasao86 Karimganj85 Tinsukia84 Cachar80 Dibrugarh61 Hailakandi57 Lakhimpur57 Marigaon50 Dhemaji47 Kamrup42 Kokrajhar37 Dhubri30 Charaideo29 Barpeta28 Udalguri28 Sonitpur27 Jorhat24 Nalbari23 Darrang20 Sivasagar20 Goalpara19 Biswanath16 Baksa14 KarbiAnglong13 Bongaigaon12 Chirang6 West KarbiAnglong5 South SalmaraMancachar4 Majuli2 | 2,16,919 32 | 2,663 65 | 2,13,179 95 | 1,077 2 |
DistrictCases Amritsar485 Jalandhar297 Ludhiana293 Tarn Taran163 Gurdaspur154 Hoshiarpur140 S.A.S Nagar137 Patiala132 Sangrur107 Shahid Bhagat Singh Nagar (Nawanshahr)99 Pathankot86 Rupnagar (Ropar)74 Faridkot74 Sri Muktsar Sahib71 Moga65 Bathinda60 Fatehgarh Sahib57 Fazilka53 Firozepur50 Kapurthala44 Mansa31 Barnala25 | 1,71,136 199 | 2,405 7 | 1,63,211 202 | 5,520 4 |
DistrictCases Anantnag395 Srinagar300 Kulgam295 Baramulla271 Shopian255 Kupwara231 Bandipora175 Udhampur155 Ramban151 Jammu138 Budgam110 Pulwama108 Kathua53 Rajouri39 Ganderbal37 Poonch35 Doda27 Reasi26 Samba25 Kishtwar10 Mirpur0 Muzaffarabad0 | 1,23,647 109 | 1,099 4 | 1,20,625 113 | 1,923 |
DistrictCases East Singhbum170 Ranchi148 Hazaribagh110 Garhwa80 Ramgarh75 Koderma58 Simdega48 Dhanbad32 Gumla28 Palamu27 West Singhbhum21 SaraikelaKharsawan20 Giridih19 Bokaro16 Latehar14 Khunti10 Lohardaga8 Deoghar5 Dumka5 Pakur4 Jamtara2 Godda2 Chatra1 Sahebganj0 | 1,18,012 125 | 1,102 45 | 1,15,853 170 | 1,057 |
DistrictCases Dehradun370 Nainital323 Tehri Garhwal110 Haridwar94 Udam Singh Nagar83 Almora71 Champawat45 Pithoragarh43 Chamoli36 PauriGarhwal36 Bageshwar31 Rudraprayag30 Uttar Kashi24 | 95,192 153 | 2,005 13 | 91,565 137 | 1,622 3 |
DistrictCases Hamirpur117 Kangra105 Una41 Solan32 Chamba29 Bilaspur21 Mandi21 Sirmaur11 Shimla10 Kullu4 Kinnaur2 Lahaul And Spiti0 | 57,082 63 | 575 9 | 55,540 72 | 967 |
DistrictCases South Goa69 North Goa57 | 52,657 87 | 865 3 | 51,036 84 | 756 |
DistrictCases Pondicherry111 Mahe4 Karaikal2 Yanam0 | 38,737 31 | 296 1 | 37,798 32 | 643 |
DistrictCases Dhalai196 Sepahijala174 Gomati74 South Tripura53 Unakoti49 West Tripura45 Khowai24 North Tripura14 | 33,339 3 | 37 1 | 32,911 4 | 391 |
DistrictCases Churachandpur32 Kangpokpi26 Imphal West21 Thoubal18 Imphal East10 Tengnoupal9 Bishnupur7 Senapati6 Chandel5 Kamjong5 Ukhrul4 Jiribam3 Pherzawl3 Kakching2 Tamenglong2 Noney1 | 28,919 19 | 244 9 | 28,308 10 | 367 |
DistrictCases Chandigarh313 | 20,623 28 | 171 14 | 20,122 42 | 330 |
DistrictCases Changlang31 Papum Pare8 Lohit3 Namsai2 West Siang1 East Siang1 Upper Siang1 Tawang1 PakkeKessang1 West Kameng0 Upper Subansiri0 Tirap0 Siang0 Shi Yomi0 Anjaw0 Lower Subansiri0 Lower Dibang Valley0 Longding0 Leparada0 KurungKumey0 KraDaadi0 Kamle0 East Kameng0 Dibang Valley0 Lower Siang0 | 16,815 | 46 6 | 16,713 6 | 56 |
DistrictCases East Khasi Hills22 West Garo Hills5 South West Garo Hills4 North Garo Hills1 West Jaintia Hills1 West Khasi Hills1 East Garo Hills0 East Jaintia Hills0 Ribhoi0 South Garo Hills0 South West Khasi Hills0 | 13,717 7 | 133 0 | 13,440 7 | 144 |
DistrictCases Dimapur20 Mon8 Kohima7 Kiphire3 Tuensang3 Peren2 Phek1 Longleng0 Mokokchung0 Wokha0 Zunheboto0 | 12,067 1 | 106 6 | 11,873 7 | 88 |
DistrictCases Kargil77 LehLadakh43 | 9,668 6 | 76 3 | 9,463 9 | 129 |
DistrictCases East District3 South District3 North District0 West District0 | 6,057 5 | 160 4 | 5,766 1 | 131 |
DistrictCases South Andamans33 Nicobars1 North And Middle Andaman1 | 4,991 2 | 29 1 | 4,900 3 | 62 |
DistrictCases Kolasib11 Aizawl10 Mamit8 Lawngtlai2 Lunglei2 Saitual1 Champhai0 Hnahthial0 Khawzawl0 Saiha0 Serchhip0 | 4,346 12 | 69 2 | 4,268 10 | 9 |
DistrictCases Dadra And Nagar Haveli20 | 3,393 2 | 11 2 | 3,380 | 2 |
DistrictCases Lakshadweep District0 | 30 9 | 30 9 | 0 | 0 |