Self-reported periodontal disease, dental loss and COVID-19 in older adults

Research article


Self-reported periodontal disease, dental loss and COVID-19 in older adults

Autorreporte de enfermedad periodontal, pérdida dentaria y COVID-19 en adultos mayores


Yamilé Baganet-Cobas1
Alain-Manuel Chaple-Gil1,2*
Yilian Caballero-Guerra3
Dayana Chávez-Valdez3


1Universidad de Ciencias Médicas de La Habana. ICBP "Victoria de Girón". Departamento Carrera de Estomatología. La Habana, Cuba.
2Universidad Autónoma de Chile. Facultad de Ciencias de la Salud. Temuco, Chile.
3Clínica Estomatológica "Ana Betancourt". La Habana, Cuba.

*Author for correspondence. Email:




Introduction: Upon completion of this research, there was no evidence of studies addressing self-reported periodontal disease in Cuba, nor any antecedent of research relating it to COVID-19 in adults over 60.
Objective: To determine the relationship between self-reported periodontal disease, dental loss, and COVID-19 activity.
Methods: A descriptive cross-sectional investigation was carried out. The sample included 238 individuals aged over 60 who were infected with COVID-19, and survived. They gave their consent. The study was performed for over 1 year in Playa municipality of Havana, Cuba. Variables such as gender, age, COVID-19 evolutionary severity, comorbidities, and self-reported periodontal disease were used. A validated 4-question survey was applied to identify the periodontal disease and all data were processed in a database. Some variables were dichotomized to perform the odds ratio and Pearson's Chi-squared test, and determine the relationship between possible risk factors and the evolutionary severity of COVID-19.
Results: As a result, the odds ratio values ​​and confidence intervals for periodontal disease and advanced periodontal disease were 1.598 (0.261; 9.78) and 1.814 (0.296; 11.105) respectively, and the p-values were 0.609 and 0.514 respectively.
Conclusion: A relationship between periodontal disease and the evolutionary severity of COVID-19 cannot be established. However, a relationship was observed targeting dental loss and respiratory diseases as determinant risk factors in the severity of COVID-19.

Keywords: periodontal disease; self-report; COVID-19; patient acuity; aged.


Introducción: Hasta el momento de culminada esta investigación no se encontró evidencia de estudios que aborden el autorreporte de enfermedad periodontal en Cuba, ni antecedentes de estudios que la relacionen con la COVID-19 en adultos mayores de 60 años.
Objetivo: Determinar la relación entre el autorreporte de enfermedad periodontal, la pérdida dentaria y características de la COVID-19.
Métodos: Se realizó una investigación descriptiva transversal. La muestra fue de 238 individuos mayores de 60 años, que contrajeron la COVID-19 y sobrevivieron. Todos dieron su consentimiento informado. El estudio fue realizado en el período de 1 año en el municipio Playa, La Habana, Cuba. Las variables estudiadas fueron, sexo, edad, gravedad evolutiva de la COVID-19, comorbilidades y autorreporte de enfermedad periodontal. Se les aplicó una encuesta validada de 4 preguntas, para identificar enfermedad periodontal y los datos fueron procesados en una base de datos. Algunas variables fueron dicotomizadas para realizar la prueba de odds ratio y ji cuadrado de Pearson, para determinar la relación entre posibles factores de riesgo y la gravedad evolutiva de la COVID-19.
Resultados: Los valores de odds ratio e intervalos de confianza de la enfermedad periodontal y la enfermedad periodontal avanzada fueron de 1,598 (0,261; 9,78) y 1,814 (0,296; 11,105) y los valores de p de 0,609 y 0,514 respectivamente.
Conclusiones: No se comprueba que exista relación entre la enfermedad periodontal y la gravedad evolutiva de la COVID-19. Sin embargo, existe una relación que señala a la pérdida dentaria y las enfermedades respiratorias como factores de riesgo determinante en la gravedad de la COVID-19.

Palabras clave: enfermedad periodontal; autorreporte; COVID-19; gravedad del paciente; anciano.



Recibido: 07/02/2022
Aprobado: 21/04/2022




In recent years, periodontal disease (PD) has been widely studied due to its significant relationship with health. It emerges as a manifestation of systemic disorders, influences the etiology of diverse general diseases, and shares risk factors with current major chronic illnesses, such as cardiovascular,(1) rheumatic, renal, and neurological diseases - including Alzheimer's and Parkinson's,(2,3) cancer, chronic respiratory diseases,(4,5) obesity(6) and diabetes,(7,8) among others.(9,10,11,12,13) As a result of this relationship, and the aging population, an increase in the prevalence of periodontopathies, which in turn are the main cause of dental loss, is expected. Several studies associate edentulism with negative effects at the systemic level.(14,15,16)

The self-reported periodontal disease (SPD) has acceptable validity when compared to clinical excellence standards. Regarding painful gums, dental mobility, and people's opinions about whether they have gum disease, it can be classified as moderately to highly valid, according to Nelson's validity classification.(17)

On March 11th, 2020, the World Health Organization declared the COVID-19 pandemic,(18) caused by a novel coronavirus SARS-COV-2. It produces pulmonary damage and other organ failures, and like PD, features an exacerbated immune-inflammatory response, resulting in an excessive host immune reaction with cytokine storming, which is closely related to severity in the presence of chronic non-communicable diseases.(6,10,18,19,20)

The severity spectrum of COVID-19 ranges from asymptomatic to severe. While a significant proportion of SARS-CoV-2 positive individuals do not manifest symptoms or have only mild ones, some become seriously ill and develop a hyperinflammatory response leading to dysregulation of the involved organ metabolism, with potentially life-threatening consequences. Overall, the severity of COVID-19 increases with pre-existing comorbidities.(21) In this context, several hypothetical mechanisms may explain the strong associations observed between PD and COVID-19 severity.(20,22,23,24,25)

Up to the completion date of this research, there was no scientific evidence of SDP studies in Cuba, nor any antecedents of studies related to COVID-19 in adults over 60. For this reason, this research aims to determine the relationship between SDP, dental loss, and COVID-19 activity.

This research aims to determine the relationship between self-reported periodontal disease, dental loss, and COVID-19 activity.




Type of study: A cross-sectional descriptive research was conducted from April to September 2021. It was approved by the Ethics Committee of the Faculty of Stomatology at University of Medical Sciences of Havana as the main subject of the master's studies of one of the authors.

Inclusion and sample criteria: The sample consisted of 238 individuals aged over 60, who were infected with COVID-19 and survived it, from March 11th, 2020 to March 11th, 2021, and lived in Playa municipality in Havana, Cuba. They were all confirmed positive cases for COVID-19 according to the PCR test (Polymerase Chain Reaction).

Variables: The study variables were defined by gender (male/female), age groups (60-75 and 76-100), evolutionary severity of COVID-19 (asymptomatic, symptomatic, and severe), comorbidities (hypertension, diabetes mellitus, heart disease, chronic respiratory disease, and morbid obesity), dental loss (teeth and edentulous), and SPD (absence and presence of PD and presence of advanced periodontal disease (APD)).

Techniques and procedures: Credentials were submitted to governmental institutions to access the data required to develop the research. Then, personal data were collected from patients confirmed as COVID-19 positive. Individuals were presented with a 4-question survey to identify the presence of periodontal disease. This survey was validated in New Zealand,(26) and translated into Spanish for its usage. First, the absence of PD was determined when all four answers were negative; then, the presence of PD was determined in cases with two positive answers and if only the fourth one was also positive. Finally, the presence of SPD was determined when answers 2,3, and 4 were positive.

All data were collected through a Google form and stored in a database. General information, personal pathological background, and edentulous or dentate status were also recorded. All participants were visited and surveyed at their homes. All health protocol measures required by the relevant health organizations were followed, and the required protective equipment was used.

Data processing and analyses: Data regarding the evolutionary severity of COVID-19, the PD, and the SPD were dichotomized to process all variables and perform Pearson's odds ratio and the chi-square test. It aimed to determine the connection between their relationship (as possible risk factors) and the evolutionary severity of COVID-19. There was a 95 % confidence interval defined to establish this relation; besides, the p -value had to be less than 0.05 or equal to it to show any significance. All data were processed using Excel databases and imported into IBM SPSS® Statistics 25 for Windows. All statistical tests applied to the primary endpoints were assessed with a 95 % confidence interval. Similarly, this database is available in the Zenodo repository based on the principles of open sciences.(27)

Ethical aspects: The mediating institutions authorized using patient data through the official research document. All individuals received the informed consent document as per the Helsinki principles, which they signed voluntarily, and their identity and privacy were protected. They were informed of receiving information about the research results after its publication.




The population studied showed a slight predominance of female participants, and 72.3 % belonged to the early old age group. Among the comorbidities, there was a high prevalence of arterial hypertension (70.6 %), followed by diabetes mellitus and obesity. More than half of the total (58.4 %) had COVID-19 clinical symptoms, and a significant percentage of patients (81.9 % of the total) preserved their teeth despite their age (table 1).



The self-reported results of periodontal disease, even advanced periodontal disease, were high (between 48.7 % and 45.6 %) and did not have a statistically significant relationship regarding the evolutionary severity of COVID-19. This was evidenced by the ODDS ratio values and their confidence intervals 1.598 (0.261; 9.78) and 1.814 (0.296; 11.105) respectively, as well as the p -value of 0.609 and 0.514 for each of them. Besides, more than half of all of people affected by SPD presented clinical symptoms derived from COVID-19.

Dental loss p-values results were less than 0.05, and edentulous patients were statistically significant, suggesting the teeth loss as a risk factor for the evolutionary severity of COVID-19 with an ODDS ratio of 3.897 and confidence intervals between 1.001 and 15.173; supported by the p-value equal to 0.036 (table 2).

Likewise, there was a significant relationship between respiratory diseases and the severity of COVID-19, with an odds ratio of 6,833 and confidence intervals between 1,717 and 27,192 (table 2).




Dental loss might represent a risk factor contributing to the severity of COVID-19; however, there is no documented evidence in other articles connecting both situations. Recent studies suggest an association between edentulous diagnosed patients and lower respiratory capacity, a high incidence of chronic obstructive pulmonary diseases, greater susceptibility to hospitalizations due to pulmonary conditions, and even a higher risk of mortality derived from pneumonia, than toothed patients.(16,28,29,30,31) The biological mechanism relating the periodontal disease, dental loss, and edentulism to chronic diseases involves a local and systemic inflammation due to endothelial dysfunction, together with micro and macro-vascular impairment. In general, people with systemic diseases, elderly or not, have a weakened immune response.(14,28,32,33)

The relationship between the presence of respiratory diseases and the severity of COVID-19 was reaffirmed. It has been seen that, while suffering from COVID-19, patients with pre-existing respiratory illnesses have had an increased risk of serious complications and some have even died.(34,35,36,37) The underdiagnosis of all chronic respiratory diseases has been a universal characteristic, and despite reporting low prevalence among all chronic non-communicable diseases, according to Signes-Costa et al.(38) is the one with the greatest statistical relevance.(34)

Although the expected association between SPD and COVID-19 was not detected, recent studies from Qatar and England suggest an increased risk of severity, hospitalization, and death from COVID-19 when patients have periodontal disease.(39,40) This can be attributed to the lack of traditional procedures used for diagnosis, a limitation that all self-reported measures share when compared to the results of periodontal probing and radiographic examinations. Self-reported methods had a desirable use considering the epidemiological situation. Besides, the relationship among high blood pressure, diabetes mellitus, obesity, cardiovascular diseases, and the severity of COVID-19 were significant in this study, which differs from other results of several studies carried on in Cuba and the world.(41,42,43,44,45) This can be attributable to the low percentage of critically ill patients who made up the sample.

Self-reported diagnostic methods stated the presence of PD and can be used for epidemiological purposes. There is no relationship between SPD and the evolutionary severity of COVID-19 in the population studied. However, a relationship is observed targeting dental loss and respiratory diseases as determinant risk factors in the severity of COVID-19.




1. Larvin H, Kang J, Aggarwal VR, Pavitt S, Wu J. Risk of incident cardiovascular disease in people with periodontal disease: A systematic review and meta-analysis. Clinical and experimental dental research. 2021; 7(1):109-22. DOI: 10.1002/cre2.336

2. Piattelli A. Enfermedades periodontales y enfermedades sistémicas. Solemne acto de investidura como Doctor Honoris Causa 2016. [acceso: 31/03/2022]. Disponible en:

3. Villa Ocampo P. Enfoque salubrista de la enfermedad periodontal. Rev Iberoam CIencias. 2015 [acceso: 31/03/2022]; 2(4): [aprox. 11 pant.]. Disponible en:

4. Baldomero AK, Siddiqui M, Lo CY, Petersen A, Pragman AA, Connett JE, et al. The relationship between oral health and COPD exacerbations. International journal of chronic obstructive pulmonary disease. 2019; 14:881-92. DOI: 10.2147/copd.S194991

5. Vargas KF, Ferradas MC, Amaral MM, Reyes JC, Palacios MA. Enfermedad periodontal y enfermedades respiratorias: una revisión de ensayos clínicos y estudios observacionales. Rev Mex Periodontol. 2014 [acceso: 18/12/2021]; V(1): 36-40. Disponible en:

6. Halpern B, Louzada M, Aschner P, Gerchman F, Brajkovich I, Faria-Neto JR, et al. Obesity and COVID-19 in Latin America: A tragedy of two pandemics-Official document of the Latin American Federation of Obesity Societies. Obes Rev. 2021; 22(3):e13165. DOI: 10.1111/obr.13165

7. Roganović JR. microRNA-146a and -155, upregulated by periodontitis and type 2 diabetes in oral fluids, are predicted to regulate SARS-CoV-2 oral receptor genes. Journal of Periodontology. 2021; 92(7):35-43. DOI: 10.1002/jper.20-0623

8. Liccardo D, Cannavo A, Spagnuolo G, Ferrara N, Cittadini A, Rengo C, et al. Periodontal Disease: A Risk Factor for Diabetes and Cardiovascular Disease. International journal of molecular sciences. 2019; 20(6):1414. DOI: 10.3390/ijms20061414

9. Chatzopoulos GS, Cisneros A, Sanchez M, Wolff LF. Association between Periodontal Disease and Systemic Inflammatory Conditions Using Electronic Health Records: A Pilot Study. Antibiotics (Basel, Switzerland). 2021;10(4):386. DOI: 10.3390/antibiotics10040386

10. Pitones-Rubio V, Chavez-Cortez EG, Hurtado-Camarena A, Gonzalez-Rascon A, Serafin-Higuera N. Is periodontal disease a risk factor for severe COVID-19 illness? Medical Hypotheses. 2020 [acceso 4/7/2020]; 144(2020): [Aprox. 7 pp.] Disponible en:

11. Lim G, Janu U, Chiou LL, Gandhi KK, Palomo L, John V. Periodontal Health and Systemic Conditions. Dentistry journal. 2020; 8(4): [aprox. 10 pant.]. DOI: 10.3390/dj8040130

12. Ahmad P, Arshad AI, Della Bella E, Khurshid Z, Stoddart M. Systemic Manifestations of the Periodontal Disease: A Bibliometric Review. Molecules. 2020; 25(19):4508. DOI: 10.3390/molecules25194508

13. Hajishengallis G, Chavakis T. Local and systemic mechanisms linking periodontal disease and inflammatory comorbidities. Nature Reviews Immunology. 2021; 21(7):426-40. DOI: 10.1038/s41577-020-00488-6

14. Lauritano D, Moreo G, Della Vella F, Di Stasio D, Carinci F, Lucchese A, et al. Oral Health Status and Need for Oral Care in an Aging Population: A Systematic Review. International journal of environmental research and public health. 2019; 16(22):4558. DOI: 10.3390/ijerph16224558

15. López-Hernández D, Orozco-Campos N, Sam I, Blanco-Cornejo M. Necesidad de políticas de salud pública en población adulta mayor: indicadores de envejecimiento en un Instituto de Seguridad Social en México. Gaceta Médica de México. 2019; 155(Suppl 1):S10-s5. DOI: 10.24875/gmm.19005140

16. Al-Rafee M. The epidemiology of edentulism and the associated factors: A literature Review. 2020; 9(4):1841-3. DOI: 10.4103/jfmpc.jfmpc_1181_19

17. Abbood HM, Hinz J, Cherukara G, Macfarlane TV. Validity of Self-Reported Periodontal Disease: A Systematic Review and Meta-Analysis. Journal of periodontology. 2016; 87(12):1474-83. DOI: 10.1902/jop.2016.160196

18. Sukumar K, Tadepalli A. Nexus between COVID-19 and periodontal disease. The Journal of international medical research. 2021; 49(3):3000605211002695. DOI: 10.1177/03000605211002695

19. Huertos-Ochoa CC, Raffo-Peña MP, Sihuay-Torres K. La enfermedad periodontal podría ser una comorbilidad para la COVID-19. Revista Cubana de Investigaciones Biomédicas. 2021[acceso: 18/12/2021]; 40(1):6. Disponible en:

20. Gupta S, Sahni V. The intriguing commonality of NETosis between COVID-19 & Periodontal disease. Medical Hypotheses. 2020 [acceso: 4/07/2020]; 144: [Aprox. 1 pp.] Disponible en:

21. Hardy E, Fernandez-Patron C. Targeting MMP-Regulation of Inflammation to Increase Metabolic Tolerance to COVID-19 Pathologies: A Hypothesis. Biomolecules. 2021; 11(3):390. DOI: 10.3390/biom11030390

22. Takahashi Y, Watanabe N, Kamio N, Kobayashi R, Iinuma T, Imai K. Aspiration of periodontopathic bacteria due to poor oral hygiene potentially contributes to the aggravation of COVID-19. Journal of Oral Science. 2020; 63(1):1-3. DOI: 10.2334/josnusd.20-0388

23. Badran Z, Gaudin A, Struillou X, Amador G, Soueidan A. Periodontal pockets: A potential reservoir for SARS-CoV-2? Medical hypotheses. 2020; 143(2020):109907. DOI: 10.1016/j.mehy.2020.109907

24. Herrera D, Serrano J, Roldan S, Sanz M. Is the oral cavity relevant in SARS-CoV-2 pandemic? Clinical Oral Investigations. 2020; 2020(24): 2925-30. DOI: 10.1007/s00784-020-03413-2

25. Sahni V, Gupta S. COVID-19 & Periodontitis: The cytokine connection. Medical Hypotheses. 2020; 144(2020):[Aprox. 1 pp.] DOI: 10.1016/j.mehy.2020.109908

26. Foster Page LA, Thomson WM, Broadbent JM. Validity of self-reported periodontal questions in a New Zealand cohort. Clinical Oral Investigations. 2016; 20(3):563-9. DOI: 10.1007/s00784-015-1526-0

27. Chaple Gil A, Baganet Cobas Y. Dataset- Self-reported periodontal disease, dental presence and COVID-19, in older adults of the Playa municipality. [Dataset] Zenodo; 2021. Zenodo. DOI: 10.5281/zenodo.5791381

28. Casanova-Rosado AJ, Casanova-Rosado JF, Minaya-Sánchez M, Robles-Minaya JL, Casanova-Sarmiento JA, Márquez-Corona MdL, et al. Association of Edentulism with Various Chronic Diseases in Mexican Elders 60+ Years: Results of a Population-Based Survey. Healthcare. 2021; 9(4):404. DOI: 10.3390/healthcare9040404

29. Dwibedi N, Wiener RC, Findley PA, Shen C, Sambamoorthi U. Asthma, chronic obstructive pulmonary disease, tooth loss, and edentulism among adults in the United States: 2016 Behavioral Risk Factor Surveillance System survey. Journal of the American Dental Association (1939). 2020; 151(10): 735-44.e1. DOI: 10.1016/j.adaj.2019.07.032

30. Manabe K, Tanji F, Tomata Y, Zhang S, Tsuji I. Preventive Effect of Oral Self-Care on Pneumonia Death among the Elderly with Tooth Loss: The Ohsaki Cohort 2006 Study. The Tohoku Journal of Experimental Medicine. 2019; 247(4):251-7. DOI: 10.1620/tjem.247.251

31. Medeiros TCC, Areas ESA, Prates RC, Chapple I, Steffens JP. Association between tooth loss, chronic conditions and common risk factors - results from the 2019 brazilian health survey. J Periodontol. 2021. Online ahead of print. DOI: 10.1002/jper.21-0433

32. Pardo Romero FF, Hernández LJ. Enfermedad periodontal: enfoques epidemiológicos para su análisis como problema de salud pública. Revista de Salud Pública. 2018; 20(2): 258-64. DOI: 10.15446/rsap.v20n2.64654

33. Nieman DC. Coronavirus disease-2019: A tocsin to our aging, unfit, corpulent, and immunodeficient society. Journal of Sport and Health Science. 2020; 9(4):293-301. DOI: 10.1016/j.jshs.2020.05.001

34. Ng WH, Tipih T, Makoah NA, Vermeulen JG, Goedhals D, Sempa JB, et al. Comorbidities in SARS-CoV-2 Patients: a Systematic Review and Meta-Analysis. mBio. 2021; 12(1):e03647-20. DOI: 10.1128/mBio.03647-20

35. Kaeuffer C, Le Hyaric C, Fabacher T, Mootien J, Dervieux B, Ruch Y, et al. Clinical characteristics and risk factors associated with severe COVID-19: prospective analysis of 1,045 hospitalised cases in North-Eastern France, March 2020. Euro Surveill. 2020; 25(48): 2000895. DOI: 10.2807/1560-7917.Es.2020.25.48.2000895

36. Leong R, Lee TJ, Chen Z, Zhang C, Xu J. Global Temporal Patterns of Age Group and Sex Distributions of COVID-19. Infectious disease reports. 2021; 13(2):582-96. DOI: 10.3390/idr13020054

37. Bajgain KT, Badal S, Bajgain BB, Santana MJ. Prevalence of comorbidities among individuals with COVID-19: A rapid review of current literature. American Journal of Infection Control. 2021; 49(2):238-46. DOI: 10.1016/j.ajic.2020.06.213

38. Signes-Costa J, Núñez-Gil IJ, Soriano JB, Arroyo-Espliguero R, Eid CM, Romero R, et al. Prevalence and 30-day mortality in hospitalized patients with Covid-19 and prior lung diseases. Archivos de Bronconeumologia. 2021; 57(Suppl 2):13-20. DOI: j.arbres.2020.11.012

39. Larvin H, Wilmott S, Wu J, Kang J. The Impact of Periodontal Disease on Hospital Admission and Mortality During COVID-19 Pandemic. Frontiers in medicine. 2020; 7: 604980. DOI: 10.3389/fmed.2020.604980

40. Marouf N, Cai W, Said KN, Daas H, Diab H, Chinta VR, et al. Association between periodontitis and severity of COVID-19 infection: A case-control study. Journal of Clinical Periodontology. 2021; 48(4):483-91. DOI: 10.1111/jcpe.13435

41. Holt NR, Neumann JT, McNeil JJ, Cheng AC. Implications of COVID-19 for an ageing population. The Medical journal of Australia. 2020; 213(8): 342-4.e1. DOI: 10.5694/mja2.50785

42. Becerra-Muñoz VM, Núñez-Gil IJ, Eid CM, García Aguado M, Romero R, Huang J, et al. Clinical profile and predictors of in-hospital mortality among older patients hospitalised for COVID-19. Age and Ageing. 2021; 50(2): 326-34. DOI: 10.1093/ageing/afaa258

43. Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020; 395(10223):497-506. DOI: 10.1016/s0140-6736(20)30183-5

44. Maldonado Cantillo G. Comportamiento epidemiológico de la Hipertensión arterial en un Policlínico cubano. Horizonte Sanitario. 2020; 19(1):69-77. DOI: 10.19136/hs.a19n1.2899

45. Soeroto AY, Soetedjo NN, Purwiga A, Santoso P, Kulsum ID, Suryadinata H, et al. Effect of increased BMI and obesity on the outcome of COVID-19 adult patients: A systematic review and meta-analysis. Diabetes & Metabolic Syndrome. 2020; 14(6):1897-904. DOI: 10.1016/j.dsx.2020.09.029



Conflict of interests

The authors declare that they have no conflict of interests.
Funding: This research was not funded by any institution and was carried out upon the authors' own resources.


Authorship contribution

Conceptualization: Yamilé Baganet Cobas, Alain Manuel Chaple Gil.
Data curation: Alain Manuel Chaple Gil.
Formal analysis: Alain Manuel Chaple Gil.
Investigation: Yilian Caballero Guerra, Dayana Chávez Valdez.
Methodology: Yamilé Baganet Cobas, Alain Manuel Chaple Gil.
Project administration: Yamilé Baganet Cobas.
Supervision: Yamilé Baganet Cobas, Alain Manuel Chaple Gil.
Visualization: Yamilé Baganet Cobas, Alain Manuel Chaple Gil.
Writing - original draft: Yamilé Baganet Cobas, Alain Manuel Chaple Gil, Yilian Caballero Guerra, Dayana Chávez Valdez.
Writing - review and editing: Yamilé Baganet Cobas, Alain Manuel Chaple Gil, Yilian Caballero Guerra, Dayana Chávez Valdez.

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