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 Table of Contents  
Year : 2021  |  Volume : 8  |  Issue : 2  |  Page : 76-78

Mass screening of COVID-19 cases by sputum testing: An Indian perspective

1 Independent Public Health Researcher, J&K, India
2 Visiting Consultant, Institute of Child Health, Kolkata, India
3 Independent Public Health Researcher, Dehradun, Uttarakhand, India

Date of Submission05-Sep-2020
Date of Decision20-Apr-2021
Date of Acceptance05-Jul-2021
Date of Web Publication27-Oct-2021

Correspondence Address:
Sudip Bhattacharya
Jolly Grant, Dehradun
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/cjhr.cjhr_130_20

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SARS CoV 2 virus is detected in the respiratory tract by using nasal/oropharyngeal and nasal mid-turbinate swabs, nasopharyngeal wash and aspirate, and an oral aspirate. The anterior nares are the most common place to collect samples due to its ease and little invasiveness. Sample collection requires experienced hands, and if the appropriate technique isn't followed, it might lead to false negative results and alter the final conclusion. Because of its size and robustness, India's healthcare system has over 700 districts each running National Tuberculosis Elimination Program (NTEP) and experts in India have proposed modifying the CBNAAT machines used in NTEP program for COVID 19 testing by utilizing a new cartridge. After a second wave of COVID-19 cases, the number of cases in India is on the rise again. When dealing with a highly contagious disease, healthcare professionals are constrained by a lack of personal protective equipment, logistics, and infrastructure. The nasopharyngeal specimen and the procedure involved, make it a more difficult and riskier affair for healthcare practitioners to perform. If COVID-19 is combated with the NTEP's current infrastructure, human resources, and logistics, we believe that early detection of cases and overall containment will be maximized. Sputum samples can be self-collected in small plastic containers and sent to the nearest tuberculosis unit for CBNAAT analysis instead of using the professional technique of collecting nasopharyngeal swabs in Viral Transport Media. Sputum sample collection is a simple operation. Be it in urban tertiary care facilities or a rural subcentre. To collect sputum, healthcare staff can simply assist. In the current phase of the pandemic in India, where the majority of COVID-19 infections are asymptomatic, mass screening at the community level using effective testing specimens and methodologies becomes critical and the only choice. It would make sense to collect COVID-19 samples at the community level based on the scientific evidence in such a scenario, especially for a country with a population of over 1.3 billion people.

Keywords: COVID-19, mass screening, sputum

How to cite this article:
Saleem SM, Ghatak N, Bhattacharya S. Mass screening of COVID-19 cases by sputum testing: An Indian perspective. CHRISMED J Health Res 2021;8:76-8

How to cite this URL:
Saleem SM, Ghatak N, Bhattacharya S. Mass screening of COVID-19 cases by sputum testing: An Indian perspective. CHRISMED J Health Res [serial online] 2021 [cited 2022 Jan 20];8:76-8. Available from: https://www.cjhr.org/text.asp?2021/8/2/76/329445

As the world was in a continuous fight with SARS-CoV-2 Virus for the past 18 months, the COVID-19 cases slowly came under the cloud, totally overstretching our health care system. After a steady phase of some weeks and mutant transformations of the virus, we are now witnessing the second wave of the so-called 21st century pandemic. COVID cases are rising at a breakneck pace from all parts of the country. Over 1000 cases of mortality are reported each day. Both the central and the state governments are doubling their efforts to bring down the situation under control.[1] With cases rising continuously and rapidly, this time the pandemic appears to be a bigger threat than it did during the first wave. To break the chain, determination of those who are diseased is an important aspect of the disease control in COVID-19.

Centre for Disease Control, US recommends detection of SARS-CoV-2 virus either from the upper respiratory tract or from the lower respiratory tract.[2] The specimen may include a nasopharyngeal/Oropharyngeal swab, nasopharyngeal wash/aspirate, an oral aspirate, and a nasal mid turbinate swab. Specimen from the anterior nares are usually collected from the upper respiratory tract while bronchoalveolar lavage, tracheal aspirate, pleural fluid, lung biopsy, and sputum sample can be collected from the lower respiratory tract. Most of the countries follow this method because of the simplicity and less invasive procedure involved in nasopharyngeal/oropharyngeal swab collection for viral detection. Only known drawback is that the sampling requires expertise hands and if the right technique is not followed while sample collection, it may lead to false-negative results and affect the overall ultimate outcome.[3] We know that a poor technique can cause aerosol formation, and if a patient sneezes or vomits, that is totally something we do not want in between to happen during the procedure. Here, we want to ask a question. Is there any other effective sampling method which is totally safe, effective with greater sensitivity and specificity which requires less expertise, and is safe for the handlers also?

Chen et al. conducted a study on 545 samples from China collected from 22 COVID-19 positive cases taken over some time. During the study, the samples taken included 209 pharyngeal samples, 262 sputum samples, and 74 fecal samples. Over the period, it was observed that the pharyngeal samples turned out to be negative among the cases, but sputum and fecal samples collected from them were tested positive for SARS-CoV-2 on Reverse transcription-polymerase chain reaction (RT-PCR) on days 13 and 39, respectively.[4] On a similar note, Wyllie et al. in a study on a comparison of nasopharyngeal versus salivary samples reported that salivary samples are an appealing alternative to the former one in the detection of SARS-CoV-2 Virus. These are noninvasive methods and easy to administer.

RT-PCR detection of respiratory pathogens suggests comparable diagnostic sensitivity between the two sample types. The findings indicated that SARS-CoV-2 can be detected from the saliva of COVID-19 patients and self-collected saliva samples have comparable SARS-CoV-2 detection sensitivity to nasopharyngeal swabs collected by healthcare workers from mild and subclinical COVID-19 cases.[3] Chen et al. in their study collected over 1070 specimens from 205 patients with COVID-19 reported sensitivity of 93% for bronchoalveolar lavage, 72% for sputum sample, 63% for nasal swabs, 46% for fibro bronchoscope brush biopsy, 32% from pharyngeal swabs, 29% for feces, and 15% blood, respectively.[4]

It is quite evident from the above studies that appropriate technique and sampling methods play an important and pivotal role in diagnosis and the detection of COVID-19. Additional feature of the analysis of COVID-19 cases is the willingness of the healthcare system to incorporate changes within it to test more and detect more cases. As we know that the Indian healthcare system is one of the largest and robust healthcare three-tier networks (primary, secondary, and tertiary) all over the globe spreads over 700 districts.[5] In the Indian health system, for every endemic disease, there is a specific national program running at the national level. Here for the discussion, one of them is the National Tuberculosis Elimination Program (NTEP), previously called RNTCP. The unique features of NTEP are that there are supervisory staffs at the sub-district level and a sub-district unit for a population of 5 lakh each. The unique feature of the program is that it is decentralized with full community participation. The screening of the cases of tuberculosis is done almost at the doorsteps of the patient's home. One unique feature is also that there is regular monitoring of the patients who are on the drug therapy with sputum microscopy and CBNAAT (cartridge-based nucleic acid amplification test). Furthermore, there is also a network of more than 2000 CBNAAT machines in India.[6] Recently, experts from India were of the view to modify these CBNAAT machines for COVID-19 testing using a different cartridge. This decision was taken given limited testing facilities for COVID-19 in India.[7] As the cases of COVID-19 are on the rise in India following a second wave. The scarcity of personal protective equipment and limited logistics and infrastructure make it cumbersome for the healthcare professional to deal with such a highly communicable disease.[8] The nasopharyngeal specimen and the technique involved make it more difficult and a risky affair for healthcare workers. We hypothesize that using the current infrastructure, manpower, and logistics of the NTEP in the fight against COVID-19 will result in maximum effectiveness in the early detection of cases and overall containment of the disease. Instead of the expert technique of collecting nasopharyngeal swabs and transporting them in Viral Transport Media, a simple sputum sample can be self-collected by those with symptoms of influenza-like illness in small plastic containers and get that delivered to the nearest tuberculosis unit for CBNAAT analysis. The collection of sputum samples is a simple procedure. Be it in tertiary care centers of urban areas or a sub-center of a rural area. Healthcare workers can easily aid in collecting sputum samples.

In the current part of the pandemic in India, wherever over the majority of cases of COVID-19 are symptomless, it becomes imperative, and a solely option to choose the mass screening at the community level using effective testing specimens and techniques. For such a scenario, considering a group of sputum samples for investigation of COVID-19, at the community level supported by the above-named scientific proof is going to be a good option for the country with over 1.3 billion population and limited resources.


The authors would like to thank all the authors of those books, articles, and journals that were referred in preparing this manuscript.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

India COVID Second Wave: How and why India's Covid Situation Turned Grimmer than Ever Before | India News-Times of India. Available from: https://timesofindia.indiatimes.com/india/why-is-indias-second-covid-wave-way-more-severe-than-irst/articleshow/82102250 cms. [Last accessed on 2021 Apr 21].  Back to cited text no. 1
Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention; 2020. Available from: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/social-distancing.html. [Last accessed on on 2020 Apr 24].  Back to cited text no. 2
Wyllie AL, Fournier J, Casanovas-Massana A, Campbell M, Tokuyama M, Vijayakumar P, et al. Saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs. medRxiv [Internet]. 2020 Jan 1;2020.04.16.20067835. Available from: http://medrxiv.org/content/early/2020/04/22/2020.04.16.20067835.abstract  Back to cited text no. 3
Chen C, Gao G, Xu Y, Pu L, Wang Q, Wang L, et al. SARS-CoV-2-positive sputum and feces after conversion of pharyngeal samples in patients with COVID-19. Ann Intern Med 2020;172:832-4.  Back to cited text no. 4
Chokshi M, Patil B, Khanna R, Neogi SB, Sharma J, Paul VK, et al. Health systems in India. J Perinatol 2016;36:S9-12.  Back to cited text no. 5
Guidelines: Central TB Division. Available from: https://tbcindia.gov.in/index1.php?lang=1&level=1&sublinkid=4571&lid=3176. [Last accessed on 2020 May 01].  Back to cited text no. 6
Porecha M. ICMR Approves TB Machines for COVID-19 Testing. @businessline. Available from: https://www.thehindubusinessline.com/news/icmr-approves-tb-machines-for-covid-19-testing/article31258604.ece. [Last accessed on 2020 May 01].  Back to cited text no. 7
Bhattacharya S, Hossain MM, Singh A. Addressing the shortage of personal protective equipment during the COVID-19 pandemic in India-A public health perspective. AIMS Public Health 2020;7:223-7.  Back to cited text no. 8


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