Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

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Dr Mohan Z Mani

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I wish all success to your journal and look forward to sending you any suitable similar article in future"

Dr Mohan Z Mani,
Professor & Head,
Department of Dermatolgy,
Believers Church Medical College,
Thiruvalla, Kerala
On Sep 2018

Prof. Somashekhar Nimbalkar

"Over the last few years, we have published our research regularly in Journal of Clinical and Diagnostic Research. Having published in more than 20 high impact journals over the last five years including several high impact ones and reviewing articles for even more journals across my fields of interest, we value our published work in JCDR for their high standards in publishing scientific articles. The ease of submission, the rapid reviews in under a month, the high quality of their reviewers and keen attention to the final process of proofs and publication, ensure that there are no mistakes in the final article. We have been asked clarifications on several occasions and have been happy to provide them and it exemplifies the commitment to quality of the team at JCDR."

Prof. Somashekhar Nimbalkar
Head, Department of Pediatrics, Pramukhswami Medical College, Karamsad
Chairman, Research Group, Charutar Arogya Mandal, Karamsad
National Joint Coordinator - Advanced IAP NNF NRP Program
Ex-Member, Governing Body, National Neonatology Forum, New Delhi
Ex-President - National Neonatology Forum Gujarat State Chapter
Department of Pediatrics, Pramukhswami Medical College, Karamsad, Anand, Gujarat.
On Sep 2018

Dr. Kalyani R

"Journal of Clinical and Diagnostic Research is at present a well-known Indian originated scientific journal which started with a humble beginning. I have been associated with this journal since many years. I appreciate the Editor, Dr. Hemant Jain, for his constant effort in bringing up this journal to the present status right from the scratch. The journal is multidisciplinary. It encourages in publishing the scientific articles from postgraduates and also the beginners who start their career. At the same time the journal also caters for the high quality articles from specialty and super-specialty researchers. Hence it provides a platform for the scientist and researchers to publish. The other aspect of it is, the readers get the information regarding the most recent developments in science which can be used for teaching, research, treating patients and to some extent take preventive measures against certain diseases. The journal is contributing immensely to the society at national and international level."

Dr Kalyani R
Professor and Head
Department of Pathology
Sri Devaraj Urs Medical College
Sri Devaraj Urs Academy of Higher Education and Research , Kolar, Karnataka
On Sep 2018

Dr. Saumya Navit

"As a peer-reviewed journal, the Journal of Clinical and Diagnostic Research provides an opportunity to researchers, scientists and budding professionals to explore the developments in the field of medicine and dentistry and their varied specialities, thus extending our view on biological diversities of living species in relation to medicine.
‘Knowledge is treasure of a wise man.’ The free access of this journal provides an immense scope of learning for the both the old and the young in field of medicine and dentistry as well. The multidisciplinary nature of the journal makes it a better platform to absorb all that is being researched and developed. The publication process is systematic and professional. Online submission, publication and peer reviewing makes it a user-friendly journal.
As an experienced dentist and an academician, I proudly recommend this journal to the dental fraternity as a good quality open access platform for rapid communication of their cutting-edge research progress and discovery.
I wish JCDR a great success and I hope that journal will soar higher with the passing time."

Dr Saumya Navit
Professor and Head
Department of Pediatric Dentistry
Saraswati Dental College
On Sep 2018

Dr. Arunava Biswas

"My sincere attachment with JCDR as an author as well as reviewer is a learning experience . Their systematic approach in publication of article in various categories is really praiseworthy.
Their prompt and timely response to review's query and the manner in which they have set the reviewing process helps in extracting the best possible scientific writings for publication.
It's a honour and pride to be a part of the JCDR team. My very best wishes to JCDR and hope it will sparkle up above the sky as a high indexed journal in near future."

Dr. Arunava Biswas
MD, DM (Clinical Pharmacology)
Assistant Professor
Department of Pharmacology
Calcutta National Medical College & Hospital , Kolkata

Dr. C.S. Ramesh Babu
" Journal of Clinical and Diagnostic Research (JCDR) is a multi-specialty medical and dental journal publishing high quality research articles in almost all branches of medicine. The quality of printing of figures and tables is excellent and comparable to any International journal. An added advantage is nominal publication charges and monthly issue of the journal and more chances of an article being accepted for publication. Moreover being a multi-specialty journal an article concerning a particular specialty has a wider reach of readers of other related specialties also. As an author and reviewer for several years I find this Journal most suitable and highly recommend this Journal."
Best regards,
C.S. Ramesh Babu,
Associate Professor of Anatomy,
Muzaffarnagar Medical College,
On Aug 2018

Dr. Arundhathi. S
"Journal of Clinical and Diagnostic Research (JCDR) is a reputed peer reviewed journal and is constantly involved in publishing high quality research articles related to medicine. Its been a great pleasure to be associated with this esteemed journal as a reviewer and as an author for a couple of years. The editorial board consists of many dedicated and reputed experts as its members and they are doing an appreciable work in guiding budding researchers. JCDR is doing a commendable job in scientific research by promoting excellent quality research & review articles and case reports & series. The reviewers provide appropriate suggestions that improve the quality of articles. I strongly recommend my fraternity to encourage JCDR by contributing their valuable research work in this widely accepted, user friendly journal. I hope my collaboration with JCDR will continue for a long time".

Dr. Arundhathi. S
MBBS, MD (Pathology),
Sanjay Gandhi institute of trauma and orthopedics,
On Aug 2018

Dr. Mamta Gupta,
"It gives me great pleasure to be associated with JCDR, since last 2-3 years. Since then I have authored, co-authored and reviewed about 25 articles in JCDR. I thank JCDR for giving me an opportunity to improve my own skills as an author and a reviewer.
It 's a multispecialty journal, publishing high quality articles. It gives a platform to the authors to publish their research work which can be available for everyone across the globe to read. The best thing about JCDR is that the full articles of all medical specialties are available as pdf/html for reading free of cost or without institutional subscription, which is not there for other journals. For those who have problem in writing manuscript or do statistical work, JCDR comes for their rescue.
The journal has a monthly publication and the articles are published quite fast. In time compared to other journals. The on-line first publication is also a great advantage and facility to review one's own articles before going to print. The response to any query and permission if required, is quite fast; this is quite commendable. I have a very good experience about seeking quick permission for quoting a photograph (Fig.) from a JCDR article for my chapter authored in an E book. I never thought it would be so easy. No hassles.
Reviewing articles is no less a pain staking process and requires in depth perception, knowledge about the topic for review. It requires time and concentration, yet I enjoy doing it. The JCDR website especially for the reviewers is quite user friendly. My suggestions for improving the journal is, more strict review process, so that only high quality articles are published. I find a a good number of articles in Obst. Gynae, hence, a new journal for this specialty titled JCDR-OG can be started. May be a bimonthly or quarterly publication to begin with. Only selected articles should find a place in it.
An yearly reward for the best article authored can also incentivize the authors. Though the process of finding the best article will be not be very easy. I do not know how reviewing process can be improved. If an article is being reviewed by two reviewers, then opinion of one can be communicated to the other or the final opinion of the editor can be communicated to the reviewer if requested for. This will help one’s reviewing skills.
My best wishes to Dr. Hemant Jain and all the editorial staff of JCDR for their untiring efforts to bring out this journal. I strongly recommend medical fraternity to publish their valuable research work in this esteemed journal, JCDR".

Dr. Mamta Gupta
(Ex HOD Obs &Gynae, Hindu Rao Hospital and associated NDMC Medical College, Delhi)
Aug 2018

Dr. Rajendra Kumar Ghritlaharey

"I wish to thank Dr. Hemant Jain, Editor-in-Chief Journal of Clinical and Diagnostic Research (JCDR), for asking me to write up few words.
Writing is the representation of language in a textual medium i e; into the words and sentences on paper. Quality medical manuscript writing in particular, demands not only a high-quality research, but also requires accurate and concise communication of findings and conclusions, with adherence to particular journal guidelines. In medical field whether working in teaching, private, or in corporate institution, everyone wants to excel in his / her own field and get recognised by making manuscripts publication.

Authors are the souls of any journal, and deserve much respect. To publish a journal manuscripts are needed from authors. Authors have a great responsibility for producing facts of their work in terms of number and results truthfully and an individual honesty is expected from authors in this regards. Both ways its true "No authors-No manuscripts-No journals" and "No journals–No manuscripts–No authors". Reviewing a manuscript is also a very responsible and important task of any peer-reviewed journal and to be taken seriously. It needs knowledge on the subject, sincerity, honesty and determination. Although the process of reviewing a manuscript is a time consuming task butit is expected to give one's best remarks within the time frame of the journal.
Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
Timely publication of journal: Publication of manuscripts and bringing out the issue in time is one of the positive aspects of JCDR and is possible with strong support team in terms of peer reviewers, proof reading, language check, computer operators, etc. This is one of the great reasons for authors to submit their work with JCDR. Another best part of JCDR is "Online first Publications" facilities available for the authors. This facility not only provides the prompt publications of the manuscripts but at the same time also early availability of the manuscripts for the readers.
Indexation and online availability: Indexation transforms the journal in some sense from its local ownership to the worldwide professional community and to the public.JCDR is indexed with Embase & EMbiology, Google Scholar, Index Copernicus, Chemical Abstracts Service, Journal seek Database, Indian Science Abstracts, to name few of them. Manuscriptspublished in JCDR are available on major search engines ie; google, yahoo, msn.
In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
It is well said that "happy beginning is half done" and it fits perfectly with JCDR. It has grown considerably and I feel it has already grown up from its infancy to adolescence, achieving the status of standard online e-journal form Indian continent since its inception in Feb 2007. This had been made possible due to the efforts and the hard work put in it. The way the JCDR is improving with every new volume, with good quality original manuscripts, makes it a quality journal for readers. I must thank and congratulate Dr Hemant Jain, Editor-in-Chief JCDR and his team for their sincere efforts, dedication, and determination for making JCDR a fast growing journal.
Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."

Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
On May 11,2011

Dr. Shankar P.R.

"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."

Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
On April 2011

Dear team JCDR, I would like to thank you for the very professional and polite service provided by everyone at JCDR. While i have been in the field of writing and editing for sometime, this has been my first attempt in publishing a scientific paper.Thank you for hand-holding me through the process.

Dr. Anuradha
On Jan 2020

Important Notice

Original article / research
Year : 2022 | Month : April | Volume : 16 | Issue : 4 | Page : LC06 - LC09 Full Version

Considerations for Testing of COVID-19 in Travellers under Quarantine- A Retrospective Study from Palakkad district, Kerala, South India

Published: April 1, 2022 | DOI:
C Sreedevi, N Divyamol, Shilu Mariam Zachariah, MG Deepak

1. Assistant Professor, Department of Community Medicine, Government Medical College, Palakkad, Kerala, India. 2. Assistant Professor, Department of Community Medicine, Government Medical College, Palakkad, Kerala, India. 3. Associate Professor, Department of Community Medicine, Government Medical College, Palakkad, Kerala, India. 4. Professor, Department of Community Medicine, Karuna Medical College, Chittur, Palakkad, Kerala, India.

Correspondence Address :
Dr. N Divyamol,
Assistant Professor, Department of Community Medicine, Government Medical College,
Palakkad, Kerala, India.


Introduction: Until sufficient herd immunity is generated in the population, contact tracing, testing, and quarantining should be continued as key interventions in breaking the chain of transmission of Coronavirus Disease 2019 (COVID-19).

Aim: To identify appropriate strategies for testing of the travellers, who were coming from high-risk areas by analysing patterns of testing among COVID-19 positive returnees.

Materials and Methods: A retrospective cohort study was conducted in Community Medicine Department, Government Medical College, Palakkad, Kerala, India, during 25th September 2020 to 15th October 2020, using the secondary data available from the database of COVID-19 Contact Tracing Cell (CCTC) to determine the testing pattern among the laboratory confirmed cases of COVID-19 positive returnees in Palakkad district. Only COVID-19 positive travellers returning to Palakkad district in May 2020 were included in the study, thus the sample size obtained was 122. Data regarding age, gender, co-morbidity, presence of symptom and time of its onset, time of swab collection and reporting of results which were collected by CCTC were analysed. The Statistical Package for the Social Sciences (SPSS) version 20.0 was used to analyse the data collected by CCTC. Quantitative variables were summarised as means with standard deviations and median with interquartile ranges. Qualitative variables were summarised as percentages.

Results: Between arrival and swab collection there was mean duration of 6.9±3.8 days and a median duration of seven days among the total positive returnees. Among the asymptomatic cases, the mean duration was found to be 7.4±3.6 days for the same. Between day 10 and day 12 of quarantine, 79%-91% of the cases have given swabs for Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing. This had yielded 90% positive reporting within 14 days of quarantining. Total 10 cases were diagnosed after 14 days of quarantine due to late swab collection while in quarantine. Mean duration between symptom onset and swab collection among 22 symptomatic cases was 1.9±1.6 days (median=2 days).

Conclusion: Testing of asymptomatic returnees from high risk area may be initiated (swab collection) by day 10 as swabs collected around 10th day of quarantine capture maximum number of positive cases. A delayed initiation for testing may prolong the time taken for diagnosis. Those who have tested negative during 14 days of quarantine should self-monitor for symptoms and reduce contact with high risk persons for one more week.


Coronavirus disease 2019, High risk persons, Pandemics, Reverse transcription polymerase chain reaction

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was first reported from patients presented with pneumonia, who were linked to Wuhan Sea food market in China in December 2019 (1). It soon spread to various countries and was declared pandemic by World Health Organisation (WHO) on 11th March 2020 (2).

Kerala reported the first Coronavirus Disease 2019 (COVID-19) case in India on January 27, 2020 (3). In the two years after then, the state recorded 53,78,831 total cases with a 97.11% recovery rate and 0.95% fatality rate as of 17th January 2022 (4). In the state, vaccination programmes are still running strong. As of 17th January 2022, Kerala had achieved coverage of 99.8% of the first dose and 82.3% of the second dosage of COVID-19 vaccine for those aged 18 and higher (4). The state has begun administering precautionary vaccine doses to adults over the age of 60 and frontline workers. So far, the COVID-19 vaccination has been administered to 76.9% of Kerala’s population (4).

Meanwhile, the emergence of novel genetic mutations and variants poses a substantial threat to public health (5). Breakthrough infections and immune escape mechanisms are still being researched. Contact tracing, testing and quarantining and isolating positive cases should remain as important methods for halting transmissions until the population has developed considerable herd immunity against the emerging strains of SARS-CoV-2 (6).

Quarantining, testing, and tracing the contacts of positive patients were important strategies of state’s response to COVID-19, when interstate and non resident Keralites returned to the state throughout the early phases of the epidemic (7). As per the guidelines existing then, all high risk contacts were advised quarantine for a period of 28 days and low risk contacts were advised quarantine for a period of 14 days (8).

The district of Palakkad, which shares the state’s border with Tamil Nadu, was at significant danger due to the enormous number of interstate travellers (9). Researches analysing the testing pattern are not reported from the state of Kerala. The current study aimed to investigate the testing pattern and suggest appropriate testing strategies for COVID-19 positive returnees in Central Kerala’s Palakkad district.

Material and Methods

A retrospective cohort study was done by Community Medicine Department, Government Medical College, Palakkad, Kerala, India, during the period 25/09/20-15/10/20, using the secondary data available from the database of COVID-19 Contact Tracing Cell (CCTC) to determine the testing pattern among the laboratory confirmed cases of COVID-19 positive returnees in the month of May 2020, in Palakkad district. The research was approved by the Institutional Ethics Committee (IEC) GMC Palakkad (vide letter no. IEC/GMCPKD/15/20/69).

Inclusion and Exclusion criteria: Only COVID-19 positive travellers who returned to Palakkad district in May 2020 were included in the study. Those cases with incomplete data required for study were excluded from the study.


COVID-19 Contact Tracing Cell (CCTC) had been functioning under the Department of Community Medicine, Government Medical College (GMC), Palakkad for tracing the contacts of COVID-19 cases positive cases in the district. CCTC collected information about demographic variables, clinical characteristics and co-morbidities, testing, travel, contacts made during period of incubation, assessed risk of the contacts and advised measures according to risk categorisation by doing telephonic interviews.

As expatriates returned and the borders were re-opened in May 2020, allowing returnees to enter the state, the cases reported in Palakkad district during that month (May) were investigated (10),(11). Travellers returning to Palakkad accounted for 122 cases (87%) of the total 140 COVID-19 positive cases reported in the district in May 2020. Only COVID-19 positive travellers who returned to Palakkad district were included in the study, thus the sample size obtained was 122.

Variables regarding co-morbidity, presence of symptoms with time of onset, time of swab collection and time of reporting were investigated as these were important parameters for timely diagnosis, isolation and case management. Those cases with incomplete data on the above mentioned variables were planned to be excluded from analysis.

Statistical Analysis

The Statistical Package for the Social Sciences (SPSS) version 20.0 was used to analyse the data collected by CCTC. Quantitative variables were summarised as means with standard deviations and median with interquartile ranges. Qualitative variables were summarised as percentages.


There were 122 COVID-19 positive travellers in the month of May 2020 in Palakkad district. Total 22 positive returnees (18%) had symptoms such as fever, cough, sore throat and myalgia. The baseline characteristics of the returnees in given in (Table/Fig 1). All the returnees were following quarantine as per guideline (8).

Pattern of testing: Among all study participants, COVID-19 was diagnosed by RT-PCR testing of nasal swabs (12). Swabs were taken at the nearest Government Health Facility and forwarded to the nearest tertiary care centre having an RT-PCR laboratory for testing. (Table/Fig 2) shows some patterns of timings with respect to diagnosis of COVID-19 among the positive returnees.

Among the 22 symptomatic travellers, the mean and median duration between last day of travel (assuming it to be the last day of exposure) and symptom onset was 4.1±2.6 days and three days, respectively. Among 100 asymptomatic travellers, mean duration between arrival and swab collection was 7.4±3.6 days. Among 22 symptomatic travellers, mean duration between arrival and swab collection was 4.9±3.9 days. Mean duration between symptom onset and swab collection among 22 symptomatic cases was 1.9±1.6 days. The results were reported after mean duration of 2.4±0.7 days following swab collection in all cases. The distribution of time of onset of symptom, the time of swab collection, the time of diagnosis (reporting) with respect to day in quarantine is given in (Table/Fig 3),(Table/Fig 5), respectively.

Among total 122 COVID-19 positive returnees, there were 10 cases whose results were positive after 14 days of quarantine. Certain characteristics pertaining to testing of the 10 cases are shown in (Table/Fig 6).

Only two cases out of 10 showed symptoms before swab collection. Among those cases reported after 14 days majority of the cases (7 out of 10), testing was initiated on or after 14th day of quarantine. This was coupled with 2-4 days delay in reporting. Mean days for reporting after swab collection was 2.5 days. Case no: 5 may be identified as a false negative result on first testing done on 9th day which was later turned positive on 15th day swab as he was retested when his co-traveller turned positive.


Majority of Kerala’s COVID-19 positive cases were from the returnees to the state from abroad and other states within India during the months May 2020 to June 2020 (11). Similar trend was observed in the current study; 87% of total cases reported in the month of May in Palakkad district were returnees.

An 82% of returnees in the present study were asymptomatic. These results are in line with many other researches published globally where the proportion of asymptomatic COVID-19 was more than 50% (13),(14),(15). The WHO also suggests 80% of infections are mild or asymptomatic (16). But certain studies have identified the prevalence of asymptomatic COVID-19 cases below 50% also (17),(18),(19). A series of systematic reviews and meta-analysis revealed that the proportion of tested positive for COVID-19 who never developed symptoms ranged from 8.44% to 39% (17),(18),(20). This variation may be explained by differences in definition of asymptomatic cases, accuracy of testing methods and duration of follow-up (21).

Among symptomatic travellers the mean and median time duration between day of travel (assuming it to be the last day of exposure) and symptom onset was 4.1±2.6 days and 3 (IQR 2-7) days respectively. This may be considered as a proxy indicator of incubation period for the disease among returnees. Different studies have reported ranges of mean incubation periods varying from 4.6 to 6.4 days which were based on different methods of assessment like earliest exposure to onset, exposure interval to onset and other methods (22),(23),(24). In majority of the published literature, mean/median incubation period is reported to be around five days (24),(25),(26). Because of lack of confirmation with respect to day of exposure, the current study assumed the day of travel to Kerala as the day when exposure would have happened. None of the travellers were symptomatic on the day of travel.

Mean duration of time between arrival and swab collection was 6.9±3.8 with median of seven days among the total positive returnees. Among the asymptomatic cases the same was found to be 7.4±3.6 days. By day 10 and day 12 of quarantine 79%-91% of the cases have given swabs for RT-PCR testing. This had yielded 90% positive reporting within 14 days of quarantining allowing for an average two days time for reporting from nearest Government Tertiary Care Centre.

Mean duration between symptom onset and swab collection among 22 symptomatic cases was 1.9±1.6 days (Median 2, IQR 0-3.25) which indicates testing was initiated on second day after symptom onset. Median duration of symptom onset to sample collection 8was two days (IQR 1-4) among positive results in a study based on Indian Council of Medical Research laboratory surveillance network in India from March 2020 to January 2021 (27). From a systematic review of individual participant data, regarding time during infection when COVID-19 is detectable by RT-PCR, the highest percentage virus detection was from nasopharyngeal sampling between 0 and 4 days postsymptom onset at 89% {95% Confidence Interval (CI) 83 to 93} dropping to 54% (95% CI: 47 to 61) after 10 to 14 days (28). In all symptomatic returnees, testing should be initiated immediately with symptom onset. This will help in early diagnosis, reducing the complications and interrupting the transmissions (29). All the symptomatic returnees had a milder course of disease and short duration of stay in hospital.

Mean duration between swab collection and reporting was 2.4±0.7 (Median 2, IQR 2-3) in the present study. Median duration between testing to data entry for positive results was 0 days (IQR 0-1) across different states in India from March 2020 to January 2021 (27). The state of Kerala had a median duration of five days (IQR 1-15) for entering positive results according to the same study (27).

Results of 10 cases came positive after 14 days of quarantine. Among them testing was initiated on or after 14th day of quarantine for seven persons. From the findings in the current study, the authors are of the opinion that, testing of asymptomatic returnees, if done around 10 days of quarantine would cover double the median incubation period. This will help to capture the positive cases early among the returnees. Positivity mandates isolation, which will limit further spread of disease.

A single negative result may not rule out the disease status of returnees; as the test is not 100% sensitive (30). It is to be noted that the pretest probability of the disease is high especially among people from red zone areas and those who are symptomatic. Case no: 5 may be identified as a false negative result on first testing done on 9th day due to only moderate sensitivity (around 63% positive rate for nasal swab of COVID-19 patients) (31); or it could be an outlier with regard to duration of infection following exposure as evidenced by positive second swab result on 17th day. Infection could have happened around or outside the maximum incubation period of 14 days in the case as an outlier; the chance for this is as low as 101/10000 cases (14). These evidences reinforce the point; a negative result around 12 days of quarantine should not impart a false sense of security in high-risk suspects (32).

From the sociological point of view, being asymptomatic is a reason for breach in quarantine restrictions observed among the returnees (33). This can increase the number of primary and secondary contacts. A late testing coupled with delayed reporting may increase the onward transmission; thus the burden on the system and families (34).

Strict quarantine of minimum 14 days is to be ensured when testing all returnees is not feasible. Considering the possibility of false negative results, negative person should self-monitor for symptoms and reduce close contact with high-risk persons for one more week.

Testing of asymptomatic returnees may be initiated (swab collection) early around 10-12 days of quarantine as it will cover double the incubation period and capture maximum number of positive cases. It will also prevent the patient from making unintentional contacts after 14 days and lower the risk of contact transmission. Even if tested negative by RT-PCR while in quarantine, all asymptomatic returnees need to strictly self-monitor for symptoms and reduce contact with high risk people for one more week owing to the possibility of a false negative result. Further investigation into the probability of transmission beyond 14 days following exposure is recommended, and for those who are not tested while in quarantine, extending its duration beyond the authorised period may be considered accordingly.


As the study was based on secondary data, the information regarding clinical characteristics and co-morbidities could not be verified by the investigators. Impact of delayed testing could not be estimated by the present investigation.


Majority of the COVID-19 positive returnees were asymptomatic. Average duration between symptom onset and swab collection among symptomatic cases was two days. Among the total COVID-19 positive returnees, swabs were collected for RT-PCR testing on day 7 of quarantine (median duration). By day 10 and day 12 of quarantine 79%-91% of the cases had given swabs for RT-PCR testing. This had yielded 90% positive reporting within 14 days of quarantining.


Authors acknowledge the District Health Authority, Palakkad, Principal, Director, Head of Department and faculty of Community Medicine (GMC Palakkad), Medico-social workers, JHI/JPHNs and volunteer medical students (GMC Palakkad), nodal officer of COVID 19 control cell, Nodal officers of COVID First Line Treatment Centres (CFLTCs), and most importantly our patients for the support and valuable inputs.


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DOI and Others

DOI: 10.7860/JCDR/2022/55065.16193

Date of Submission: Jan 19, 2022
Date of Peer Review: Feb 02, 2022
Date of Acceptance: Mar 23, 2022
Date of Publishing: Apr 01, 2022

• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? NA
• For any images presented appropriate consent has been obtained from the subjects. NA

• Plagiarism X-checker: Jan 20, 2022
• Manual Googling: Jan 31, 2022
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