Ayurvedic intervention and COVID-19: A systematic review of case studies and case reports

Hetalben Amin; Mehul Barai

doi:10.4103/ijoyppp.ijoyppp_19_21

REVIEW ARTICLE

Year : 2022 | Volume : 10 | Issue : 1 | Page : 50-61

Ayurvedic intervention and COVID-19: A systematic review of case studies and case reports

Hetalben Amin¹, Mehul Barai²
¹ Hetalben Amin, Central Council for Research in Ayurvedic Sciences, Ministry of AYUSH, Government of New Delhi, India
² Ayurveda, Meghdhara Ayurveda Hospital, Jamnagar, Gujarat, India

Date of Submission	14-Sep-2021
Date of Acceptance	05-Feb-2022
Date of Web Publication	26-Apr-2022

Correspondence Address:
Dr. Hetalben Amin
Central Council for Research in Ayurvedic Sciences, Ministry of AYUSH, Government of India, D-Block, Janak Puri, New Delhi - 110 058
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijoyppp.ijoyppp_19_21

Abstract

Ayurveda focuses on the diet, lifestyle, herbal medicines, and herbo-mineral medicines as per the specific constitution (Prakriti) of an individual. In this COVID-pandemic, various healthcare systems dynamically respond to combat the disease. Ayurveda also has evidence on case studies and case reports treated through Ayurvedic intervention. Therefore, there is a need for systematic review of all studies of COVID-19 and Ayurvedic intervention. The aim of this study was to systematically review the available case studies and case reports on Ayurvedic formulations/interventions in COVID-19. The published data were retrieved from MEDLINE, Embase, Science Direct, Scopus, Web of Science, Google Scholar, MedRxiv, and OSF on July 1, 2021. The search did not include any restrictions. Case reports and case studies published for COVID-19 through Ayurvedic formulation/intervention. Standard method for data extraction and coding was developed for the analysis of the eligible case studies and case reports. A total of 59 studies were collected from different databases; among them, extractions were made for repetitive studies; after extraction, only 17 studies were taken. The present systematic review proves that Ayurveda science is safe and effective without an adverse effect in treating COVID-19 even in high-risk, comorbid, vulnerable conditions. Adaptation of Ayurveda in the COVID-19 pandemic is the positive hope for the management of COVID-19.

Keywords: Ayurveda, case reports, case studies, COVID-19

How to cite this article:
Amin H, Barai M. Ayurvedic intervention and COVID-19: A systematic review of case studies and case reports. J Appl Conscious Stud 2022;10:50-61

How to cite this URL:
Amin H, Barai M. Ayurvedic intervention and COVID-19: A systematic review of case studies and case reports. J Appl Conscious Stud [serial online] 2022 [cited 2023 Oct 4];10:50-61. Available from: http://www.jacsonline.in/text.asp?2022/10/1/50/343851

Introduction

Fast increase in COVID-19–positive cases and less evidence of safety and efficacy of Ayurvedic intervention are the major challenges to reduce the global burden in this pandemic. In this novel coronavirus pandemic (COVID-19), various health-care systems dynamically respond to combat the disease.

Ayurveda has described epidemiology which is based upon the physical and spiritual sciences. Adopting ethical code of conduct (Sadvritta) and rejuvenation therapies (Rasayana), etc., is suggested to combat the epidemics. As we all know, COVID-19 has taken precious lives in this pandemic. Almost all scientific bodies are engaged in the solution of COVID-19. Ayurveda is the oldest medical Indian system over 5000 years and is recognized as a complete medical system that may have solution for respiratory diseases which might carry potential and effective treatment for COVID-19. Therefore, large-scale public health studies of Ayurveda is needed to be a responsible path forward (Acharyya, 2020). Epidemic disease inflicts the persons having dissimilar constitution, food habits, bodily strength, suitability, mind, and age (Hetalben & Shukla, 2020). It is also observed that isolation and panic situation of COVID-19 affect the high psychological distress of patients. For this situation, Satvavajaya Chikitsa (Ayurvedic psychotherapy) can be utilized for strengthening psychological aspect. Ayurveda has pharmacological along with nonpharmacological strategies for the prevention and cure of diseases. Pharmacological strategies include plant-based medicines and herbomineral medicines, whereas nonpharmacological strategies include daily lifestyle (Dinacharya), seasonal lifestyle (Ritucharya), rejuvenating conducts (Achara Rasayana), diet, lifestyle, and behavioral code and conducts (Sadvritta).

Almost all studies were conducted in India except one in New York performed on nonresidential Indians (Girija & Sivan, 2022). This systematic review presents case studies and case reports on COVID-19 and Ayurvedic intervention [Table 1].

Table 1: Details of all studies

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Materials and Methods

In the present study, we searched case studies and case reports of COVID-19 and Ayurvedic intervention. We conducted systematic review and followed the PRISMA guideline. There were no exposures, interventions, and comparison groups.

Information sources and search

We used data sources such as MEDLINE, Embase, ScienceDirect, Scopus, Web of Science, Google Scholar, MedRxiv, and OSF on July 1, 2021. The search did not include any restrictions.

Search strategy

Search terminologies were case studies and case reports without any specific outcomes as we aimed to analyze and describe all case studies and case reports of COVID-19 and Ayurveda.

Study selection and data collation

Two reviewers have reviewed independently the titles, abstracts, and full-texts and piloted it with one report. Extracted information included epidemiological background, disease information, sign and symptoms, and laboratory tests. The data were collected by one reviewer and complimented by others.

Synthesis of results

The extracted information was analyzed qualitatively.

We did not conduct the meta-analysis for quantitative synthesis.

Ethics

The present study is a systematic review of published case studies and case reports. The present work did not need any authorization by an ethics committee as no humans were involved in this study nor any personal information of patients is studied.

Results

We found seven reports in Embase, 17 in MEDLINE, 13 in ScienceDirect, 15 in PMC, 19 in Google Scholar, and 69 in Web of Science [Figure 1]. Among them, six reports were from Google Scholar, and three were the preprint articles. A total of nine case studies (Akhila, 2022; Balkrishna et al., 2021; Dutt et al., 2021; Joshi & Puthiyedath, 2022; Pandey et al., 2021; Rais et al., 2020; Rastogi, 2022; Rastogi et al., 2022; Vaidya et al., 2021) were found whereas 8 case series (Balkrishna et al., 2021; Bentur et al., 2021; Dutt et al., 2021; Girija et al., 2022; Gupta & Singhal, 2021; Kumar et al., 2020a, 2020b; Patil 2021) were identified. The PRISMA diagram is depicted in [Figure 1].

Figure 1: PRISMA diagram

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Balkrishna et al., described that 83.33% of patients were got relief with Ayurvedic treatment alone whereas Allopathy + Ayurveda group found 43.78% of relief (Rais et al., 2020). Dutt et al., also found that Ayurvedic intervention got faster relief than Allopathy medication in mild symptoms patients (Dutt et al., 2021). A study evaluated the clinical outcome in COVID-19 confirmed asymptomatic to mild symptomatic patients who had received Ayurveda and compared with control (who has not received Ayurveda or any support therapy) found that Guduchi Ghan Vati, a common and widely used Ayurvedic preparation, could benefit treating asymptomatic COVID-19 patients (Girija et al., 2022). Patil has done his research on morbid patients with maximum symptoms with only Ayurvedic treatment (herbomineral combination of medicine) and found recoveries without any complications; they reduced all their symptoms, drastic reduction in their CRP, and corrections in their hemograms (Balkrishna et al., 2021). Ayurveda and Yoga, along with government-mandated compulsory modern western medicine treatment, were found effective in a patient of 55 years aged having diabetes mellitus, hypertension, hypothyroidism, and chronic kidney disease (Hetalben & Shukla, 2020). An ICU-admitted COVID-19–positive patient having COVID-19 infection RT-PCR test positive with a chest severity score of 18/25 treated with Ayurvedic intervention for 19 days along with standard ICU care for 2 months found complete relief with Ayurvedic herbomineral medication (Girija & Sivan, 2022). All case studies found that COVID-19–positive cases treated with Ayurvedic intervention with either herbomineral or pure plant-based medicines found no any adverse drug reaction.

Results of individual studies and synthesis

All case studies and case series of Ayurvedic intervention were done in India (Akhila, 2022; Balkrishna et al., 2021; Dutt et al., 2021; Girija et al., 2022; Girija & Sivan, 2022; Gupta & Singhal, 2021; Hetalben & Shukla, 2020; Joshi & Puthiyedath, 2022; Kumar et al., 2020a, Mishra et al., 2021; Pandey et al., 2021; Patil, 2021; Rais et al., 2020; Rastogi, 2022; Rastogi et al., 2022; Vaidya et al., 2021) except one, i.e., New York (Mishra et al., 2021). Majority studies, i.e., eight studies, were conducted on both genders (Balkrishna et al., 2021; Bentur et al., 2021; Dutt et al., 2021; Girija et al., 2022; Gupta & Singhal, 2021; Kumar et al., 2020a, 2020b; Patil, 2021) whereas six studies on male patients (Akhila, 2022; Girija & Sivan, 2022; Mishra et al., 2021; Rastogi, 2022; Rastogi et al., 2022; Vaidya et al., 2021) and three studies on female patients (Joshi & Puthiyedath, 2022; Pandey et al., 2021; Rais et al., 2020) were found. Three studies on asymptomatic patients (Balkrishna et al., 2021; Kumar et al., 2020a, 2020b) and 10 studies on mild symptomatic patients (Akhila, 2022; Dutt et al., 2021; Girija & Sivan, 2022; Gupta & Singhal, 2021; Kumar et al., 2020; Mishra et al., 2021; Pandey et al., 2021; Rastogi, 2022; Rastogi et al., 2022; Vaidya et al., 2021) were conducted. Two studies were reported on moderate-to-severe COVID-19 patients (Joshi & Puthiyedath, 2022; Rastogi et al., 2022), and two studies were reported on symptomatic patients with comorbidities (Bentur et al., 2021; Girija et al., 2022). Mid age group (18–60 years) was taken for the majority of the studies among them, while one study reported for the age group of 4–92 years with high-risk category along with multiple comorbidities (Girija et al., 2022). Different case studies for various age group were found such as age group of 18–75 years (Vaidya et al., 2021), 68-year-old patient (Balkrishna et al., 2021), age group 60 years and above (Bentur et al., 2021), and age group of 10–80 years (Balkrishna et al., 2021), one study in the age group 60 years and above (Bentur et al., 2021), and one study found in the age group of 10–80 years (Balkrishna et al., 2021). Laboratory investigations were done in all studies to assess the effect of Ayurvedic intervention for COVID-19. Two studies reported moderate-to-severe symptoms of COVID-19 (Balkrishna et al., 2021; Mishra et al., 2021) and one case study was done on post-COVID-19 condition. Two studies were conducted on symptomatic patients with high-risk comorbidities (Bentur et al., 2021; Girija et al., 2022).

Management of COVID-19 was found through only Ayurvedic interventions in five studies (Akhila, 2022; Dutt et al., 2021; Girija and Sivan, 2022; Pandey et al., 2021; Patil 2021) and three studies were found in which the management of COVID-19 was done through Ayurveda along with other therapies (Bentur et al., 2021; Gupta & Singhal, 2021; Mishra et al., 2021). Ayurveda along with Allopathy standard care treatment was given in five studies (Balkrishna et al., 2021; Joshi & Puthiyedath, 2022; Rais et al., 2020; Rastogi et al., 2022; Vaidya et al., 2021). Ayurveda treatment in an ICU patient was given in a study (Kumar et al., 2020b), whereas Ayurvedic intervention was given among multiple comorbid patients who had taken Allopathy treatment for their comorbidities (Girija et al., 2022).

All patients in all selected reports were treated within 5–14 days, and in one study, patients were treated for 2 months along with ICU care (Kumar et al. 2020b). Ayurvedic Rasaushadhis (herbomineral formulations) was used to treat COVID-19 patients in seven studies (Akhila, 2022; Joshi & Puthiyedath, 2022; Pandey et al., 2021; Patil, 2021; Rais et al., 2020; Rastogi 2022; Rastogi et al., 2022). No study was found to have ADR/AE with Ayurveda treatment in COVID-19 patients.

Discussion

Ayurveda is the science that mainly focuses on the diet, lifestyle, herbal medicines, and herbomineral medicines as per the specific constitution of an individual. It is very essential to explore the Ayurveda system of medicine to manage COVID-19 (Garg, 2020). Hence, while different treatment modalities are being used to manage COVID-19, it might be wise to adopt Ayurveda for prophylactic and therapeutic strategies, which have no adverse effect to date reported. Lot of expectations from the world community from India is emerged by using its indigenous medical system Ayurveda, to handle the critical situation of this pandemic (Garg, 2020).

About 80% of COVID-19 cases have mild symptoms, 15% of cases require urgent medical attention, and 5% of critical cases require hospitalization equipped with ICU (Zhou et al., 2020). The present review found all these types of cases treated with Ayurvedic formulations, which may prove the efficacy of Ayurveda with no side effects reported in mild, moderate, and severe cases of COVID-19.

The comorbidities act as the risk factor with high risk and mortality (Wu et al., 2020). The present report also found the studies that are managed through Ayurvedic interventions in high-risk comorbidities with maximum symptoms (Balkrishna et al., 2021; Dutt et al., 2021; Gupta & Singhal, 2021; Hetalben & Shukla 2020). 5% of cases require intensive care and require about 9–10 days to progress from symptoms of upper respiratory tract infection to acute respiratory distress syndrome (Wu & McGoogan, 2020). Reduced peripheral capillary oxygen saturation (SpO₂) below 90% is also a risk indicator in apparently mild cases (World Health Organization, 2020). Ayurveda along with ICU care and other treatments modalities also has potential to treat ICU patients with hypoxia.

Age is the major factor that affects the prognosis of the disease as the change in pulmonary function is also associated with poor prognosis. Studies also reported that older COVID-19 patients are at an increased risk of death (Basile et al., 2020; Ikizler, 2020; Kliger et al., 2020; Kliger & Silberzweig, 2020). Studies on 60 years and above patients of COVID-19 treated with Ayurvedic intervention found that there is no adverse effect of Ayurvedic intervention (Dutt et al., 2021; Gupta & Singhal, 2021; Pandey et al., 2021; Patil, 2021; Rais et al., 2020). Moreover, one case study was found of pregnant woman having COVID-19 symptoms After consuming, Ayurvedic intervention, she was treated in 7 days without any complication with (Acharyya, 2020). As we all know, pregnant women are more prone to the risks such as adverse maternal and neonatal complications due to the change in immune system (Qiao, 2020).

Ayurveda medicines have been reported safe and efficacious, applicable for broad-spectrum, easily available, long-term practiced, easy to administer, and easily affordable (Saggam et al., 2020). Ayurvedic treatment regimen facilitated expedited recovery from SARS-CoV-2 infection without any observed adverse effects by employing traditional Indian Ayurvedic medicine in treating COVID-19 (Devpura et al., 2021). Ayurveda gives an utmost importance to personalized therapy under Purusham Purusham Vikshya (an individualized approach) principle (Amin & Sharma, 2015b). It is also established that Prakriti has effects on biochemical and hematological parameters too (Amin & Sharma, 2015a, 2015b). Therefore, present review was planned to identify case studies and case series which proves the safety and efficacy of Ayurvedic intervention in COVID-19 in mild-to-severe, high-risk, comorbid patients treated without any side effect. Moreover, interdisciplinary approach of AYUSH can also reduce the severe and fatal condition of the COVID-19.

Conclusion

The present systematic review proves that Ayurveda science is safe and effective without an adverse effect in treating COVID-19 even in high-risk, comorbid, vulnerable conditions. Adaptation of Ayurveda in the COVID-19 pandemic is the positive hope for the management of COVID-19. Experiences shared by physicians through documentation and published evidence are needed to validate the Ayurvedic intervention safe and effective in this pandemic which may nurtured the science in the future. This can help society by reducing burden on the health-care workers; this could fill gaps and unmet needs to the current pandemic challenge. Further studies can be performed with large sample size and as randomized control studies with standardized outcome measures to explore the effect of Ayurvedic interventions in COVID-19 patients in various vulnerable groups.

Limitations

Lack of standardized outcome measures of COVID-19 and fewer studies are performed to identify the Ayurvedic intervention are the major limitations of the present review. More evidences are needed in various vulnerable cases for analyzing the effect of Ayurvedic intervention in COVID-19.

Registration

The study is submitted in the PROSPERO International Prospective Register of Systematic Reviews ID 266859 on July 1, 2021.

Financial support and sponsorship

Central Council for Research in Ayurvedic Sciences, Ministry of AYUSH, New Delhi, India, supported the study.

Conflicts of interest

There are no conflicts of interest.

References

1.	Acharyya, A., (2020). Prospect of Ayurveda system of medicine in recent COVID-19 pandemic in India. International Journal of Ayurveda and Traditional Medicine, 2(2), 26-29.
2.	Akhila, V. G., (2022). Management of Sannipata Jwara w.s.r to COVID-19 – Case report. Journal of Ayurveda and Integrative Medicine, 13(1), 100416. doi: 10.1016/j.jaim. 2021.02.007.
3.	Amin, H., & Sharma, R., (2015a). Biochemical and anthropometric profile of obese subjects of different Prakriti (Constitution) at Jamnagar District, Gujarat, India. International Journal of Clinical and Experimental Physiology, 2(1), 16. doi: 10.4103/2348-8093.155505.
4.	Amin, H., & Sharma, R., (2015b). Biochemical and anthropometric profiles of different Prakriti (Ayurvedic Constitution) patients of non-insulin dependent diabetes mellitus. Journal of Obesity and Metabolic Research, 2(2), 120. doi: 10.4103/2347-9906.156533.
5.	Balkrishna, A., Bhatt, A. B., Singh, P., Haldar, S., & Varshney, A., (2021). Comparative retrospective open-label study of Ayurvedic medicines and their combination with allopathic drugs on asymptomatic and mildly-symptomatic COVID-19 patients. Journal of Herbal Medicine, 29, 100472. doi: 10.1016/j.hermed. 2021.100472.
6.	Basile, C., Combe, C., Pizzarelli, F., Covic, A., Davenport, A., Kanbay, M.,… Mitra, S., (2020). Recommendations for the prevention, mitigation and containment of the emerging SARS-CoV-2 (COVID-19) pandemic in haemodialysis centres. Nephrology Dialysis Transplantation, 35 (5), 737-741. doi: 10.1093/ndt/gfaa069.
7.	Bentur, S. A., Mishra, A., Kumar, Y., Thakral, S., & Garg, R., (2021). Integrative Therapy based on Yoga, Ayurveda and Modern Western Medicine for Treatment of High-risk Cases of COVID-19: A Telemedicine-Based Case Series.
8.	Devpura, G., Tomar, B. S., Nathiya, D., Sharma, A., Bhandari, D., Haldar, S.,… Varshney, A., (2021). Randomized placebo-controlled pilot clinical trial on the efficacy of Ayurvedic treatment regime on COVID-19 positive patients. Phytomedicine, 84, 153494. doi: 10.1016/j.phymed. 2021.153494.
9.	Dutt, J., Ganatra, B., Suthar, N., Malek, M., Shukla, B., Shukla, K.,… Bhalani, M., (2021). A randomized and comparative study to assess safety and efficacy of supplemental treatment of a herbal formulation – Aayudh Advance comprising essential oils in patients with corona virus 2019 (COVID-19). Contemporary Clinical Trials Communications, 22, 100755. doi: 10.1016/j.conctc. 2021.100755.
10.	Garg, G., (2020). COVID-19 pandemic: The Ayurvedic perspective. International Journal of Ayurveda and Traditional Medicine, 2(2), 1-2.
11.	Girija, P. L. T., & Sivan, N., (2022). Ayurvedic treatment of COVID-19/SARS-CoV-2: A case report. Journal of Ayurveda and Integrative Medicine, 13 (1), 100329. doi: 10.1016/j.jaim. 2020.06.001.
12.	Girija, P. L. T., Sivan, N., Naik, P., Murugavel, Y. A., Ravindranath, T. M., & Krishnaswami, C. V., (2022). Standalone Ayurvedic treatment of high-risk COVID-19 patients with multiple co-morbidities: A case series. Journal of Ayurveda and Integrative Medicine, 13(1), 100466.
13.	Gupta, K., & Singhal, A., (2021). Clinical study in the management of post COVID syndrome. International Journal of Multidisciplinary Research and Growth Evaluation, 2(3), 222-225.
14.	Hetalben, A., & Shukla, A., (2020). Ayurveda approach to combat epidemic diseases. Journal of Ayurvedic and Herbal Medicine, 6(3), 185-188. doi: 10.31254/jahm. 2020.6315.
15.	Ikizler, T. A., (2020). COVID-19 and dialysis units: What do we know now and what should we do? American Journal of Kidney Diseases, 76(1), 1-3. doi: 10.1053/j.ajkd. 2020.03.008.
16.	Joshi, J. A., & Puthiyedath, R., (2022). Outcomes of Ayurvedic care in a COVID-19 patient with hypoxia – A case report. Journal of Ayurveda and Integrative Medicine, 13(1), 100363. doi: 10.1016/j.jaim. 2020.10.006.
17.	Kliger, A. S., Cozzolino, M., Jha, V., Harbert, G., & Ikizler, T. A., (2020). Managing the COVID-19 pandemic: International comparisons in dialysis patients. Kidney International, 98(1), 12-16. doi: 10.1016/j.kint. 2020.04.007.
18.	Kliger, A. S., & Silberzweig, J., (2020). Mitigating risk of COVID-19 in dialysis facilities. Clinical Journal of the American Society of Nephrology, 15 (5), 707-709. doi: 10.2215/CJN.03340320.
19.	Kumar, A., Prasad, G., Srivastav, S., Gautam, V. K., & Sharma, N., (2020a). A retrospective study on efficacy and safety of Guduchi Ghan Vati for COVID-19 asymptomatic patients. MedRxiv, 2020a. doi: 10.1101/2020.07.23.20160424.
20.	Kumar, A., Prasad, G., Srivastav, S., Gautam, V. K., and Sharma, N., Efficacy and Safety of Guduchi Ghan Vati in the Management of Asymptomatic COVID-19 Infection: An Open Label Feasibility Study, medRxiv. 2020b, doi:10.1101/2020.09.20.20198515.
21.	Mishra, A., Bentur, S. A., Thakral, S., Garg, R., & Duggal, B., (2021). The use of integrative therapy based on Yoga and Ayurveda in the treatment of a high-risk case of COVID-19/SARS-CoV-2 with multiple comorbidities: A case report. Journal of Medical Case Reports, 15 (1), 95. doi: 10.1186/s13256-020-02624-1.
22.	Pandey, M., Kajaria, D., Sharma, C., & Kadam, S., (2021). Ayurvedic management of pregnant woman infected with SARS-CoV-2–A case report. Journal of Ayurveda and Integrative Medicine, In press, 100423. doi: 10.1016/j.jaim.2021.03.005.
23.	Patil, S., (2021). A case series sharing novel experience of treating viral pandemic cases of morbid, mid aged, mild, moderate & severe grade with only Ayurvedic Medicines. Journal of Ayurveda and Integrative Medicine, In press, 100420. doi: 10.1016/j. jaim. 2021.03.002.
24.	Qiao, J., (2020). What are the risks of COVID-19 infection in pregnant women? The Lancet, 395 (10226), 760-762. doi: 10.1016/S0140-6736(20) 30365-2.
25.	Rais, A., Kumar, T., Yadav, A., & Negi, D., (2020). Management of a mild COVID-19 infection through Ayurvedic intervention: A case report. Journal of Ayurveda Case Reports, 3 (3), 91. doi: 10.4103/jacr.jacr_58_20.
26.	Rastogi, S., (2022). Ayurveda co-interventions have supported complete recovery in severe COVID-19 infection with a chest severity score 18/25: A case report. Journal of Ayurveda and Integrative Medicine, 13(2), 100417. doi: 10.1016/j.jaim. 2021.02.008.
27.	Rastogi, S., Rastogi, R., & Kharbanda, A., (2022). Time when a physician turned out to be a patient: A case study on how an Ayurvedic physician cured himself from COVID-19. Journal of Ayurveda and Integrative Medicine, 13 (1), 100411. doi: 10.1016/j.jaim.2021.02.002.
28.	Saggam, A., Tillu, G., Dixit, S., Chavan-Gautam, P., Borse, S., Joshi, K.,… Patwardhan, B., (2020). Withania somnifera (L.) Dunal: A potential therapeutic adjuvant in cancer. Journal of Ethnopharmacology, 255, 112759. doi: 10.1016/j.jep.2020.112759.
29.	Vaidya, M. S., Deodatt, P. G., & Jagtap, P. G., (2021). Role of Dhanyapanchak Kwatha in abdominal manifestation in COVID-19 case – A single case study. The Healer, 2(1), 136-140. doi: 10.51649/healer. 21.
30.	World Health Organization. (2020). Clinical management of severe acute respiratory infection (SARI) when COVID-19 disease is suspected. Interim guidance. Pediatria i Medycyna Rodzinna, 16(1), 9-26. doi: 10.15557/PiMR.2020.0003.
31.	Wu, C., Chen, X., Cai, Y., Xia, J., Zhou, X., Xu, S.,… Song, Y., (2020). Risk factors associated with acute respiratory distress syndrome and death in patients with coronavirus disease 2019 pneumonia in Wuhan, China. JAMA Internal Medicine, 180(7), 934. doi: 10.1001/jamainternmed. 2020.0994.
32.	Wu, Z., & McGoogan, J. M., (2020). Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China. JAMA, 323(13), 1239. doi: 10.1001/jama. 2020.2648.
33.	Zhou, F., Yu, T., Du, R., Fan, G., Liu, Y., Liu, Z.,… Cao, B., (2020). Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: A retrospective cohort study. The Lancet, 395(10229), 1054-1062. doi: 10.1016/S0140-6736(20) 30566-3.