Original Article

Clinical-epidemiological characteristics of COVID-19 patients from Pinar del Rio

Daniel Barreras Sixto^{1  *} 
http://orcid.org/0000-0003-3464-0500

Odalys Orraca Castillo² 
http://orcid.org/0000-0002-1742-610X

Liana Valdés Lanza¹ 
http://orcid.org/0000-0002-8514-6046

Carlos Alberto Miló Valdés¹ 
http://orcid.org/0000-0003-1527-4541

Alberto Lugo Hernández¹ 
http://orcid.org/0000-0003-2294-550X

Yusleivy Martínez Carmona¹ 
http://orcid.org/0000-0002-5172-7440

¹University of Medical Sciences of Pinar del Río. Pepe Portilla Provincial Pediatric Hospital. Pinar del Río, Cuba.

²University of Medical Sciences of Pinar del Río. Ernesto Che Guevara de la Serna Faculty of Medical Sciences. Pinar del Río, Cuba.

ABSTRACT

Introduction:

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus, which can cause acute respiratory syndrome and is currently an international public health emergency.

Objective:

to identify the epidemiological clinical factors of COVID-19 in the period from March 2020 to May 2021 in Pinar del Rio.

Methods:

a descriptive cross-sectional study was conducted in Pinar del Rio province. Data collected from the statistical reports of the Provincial Unit of Hygiene and Epidemiology of COVID-19 discharged patients were explored. Clinical and epidemiological variables were identified.

Results:

the age groups 41-50 years, 51-60 years represented 17,16 % for both, followed by the group 21-30 years which represented 16,23 %. Male sex predominated over the female sex, representing 52,82 %. Cases with asymptomatic evolution predominated, representing 53,28 %. The symptomatic course of the disease predominated in the age groups 21-30 and 51-60 years old. The most predominant symptoms were cough and fever, followed by rhinorrhea and odynophagia. Hypertension was the most frequent disease followed by asthma and type 2 diabetes mellitus. The Pinar del Rio municipality presented the highest number of positive cases.

Conclusions:

there was a slight predominance of asymptomatic patients. Fever and respiratory symptoms prevailed. The most frequent chronic diseases were hypertension and asthma. Pinar del Rio municipality was the most affected region.

MeSH: COVID-19; EPIDEMIOLOGY; RESPIRATORY SYNDROME

INTRODUCTION

Coronaviruses are a family of respiratory viruses that cause disease in humans. In 2002, the emergence of severe acute respiratory syndrome (SARS) due to coronaviruses was first reported worldwide in Southeast Asia, and 10 years later (2012) another severe disease outbreak was identified in Saudi Arabia and named as eastern Mediterranean respiratory syndrome (MERS). In December 2019, a new coronavirus responsible for severe acute respiratory failure syndrome 2019 (SARS-CoV-2) appeared in Wuhan, China. COVID-19 was declared on January 30, 2020 as a public health emergency by the World Health Organization (WHO) and as a pandemic in March 2020.^1,2

Until May 2021, 190 countries and 30 territories reported cases of COVID-19, with a record of more than 160 million confirmed cases, with more than three million deaths, for a case fatality rate of 2.08%.^1,3

In the same period, 67 million confirmed cases were reported in the Americas, representing 40 % of the cases reported in the world, with more than one million deaths, for a case fatality rate of 2.44 %.³

Cuba reported approximately 136 628 confirmed cases, while Pinar del Río accumulated 6 451 confirmed cases, which represented 5,7 % of the total number of confirmed cases on the island.⁴

This potentially fatal disease probably affects 1 in every 1,000 infected persons under 50 years of age without underlying conditions, but more than 1 in 10 patients over 80 years of age with multiple comorbidities. Hence, it is important to understand the factors involved in the severe course of the disease.⁵

The main clinical features of the disease are similar to those of other CoV infections in humans. SARS-CoV-2 infection is dominated by upper respiratory tract involvement with high viral loads in secretions.⁶

In 80 % of patients, respiratory symptoms are mild, 15 % severe, and 5 % require intensive care, according to reviewed studies; an unquantified number of cases are asymptomatic.⁷

The asymptomatic form and mild presentations are more common in children, adolescents and young adults, while severe forms predominate in those over 65 years of age and in people with chronic diseases such as diabetes, chronic obstructive pulmonary disease (COPD), cardiovascular or cerebrovascular disease, and arterial hypertension.^6,8

Those affected by COVID-19 commonly present with fever, cough, sore throat, headache, fatigue, myalgia, and shortness of breath, and therefore it is indistinguishable from other respiratory infections.⁶

Conjunctival injection, hemoptysis and diarrhea are also described. Anorexia manifests in 25% of cases, and is more frequent from the second week of the disease onwards. Alterations of the senses of taste (ageusia) and smell (anosmia) are also frequent. Dyspnea can occur from the second day to 17 days; late onset is usually associated with more severe outcomes.^6,9

Gastrointestinal symptoms are associated with indicators of severity. Previous studies with SARS indicated that CoV may have a tropism for the gastrointestinal tract.^10,11

By the end of the first week the disease may progress to pneumonia, respiratory failure and death. This progression is directly associated with the extreme increase of inflammatory mediators as a consequence of Cytokine Storm Syndrome (CSS).¹² According to the number of patients reported by the province of Pinar del Río, the aim is to identify the clinical-epidemiological factors of CoVID-19, in the period from March 2020 to May 2021.

METHODS

A descriptive cross-sectional study was conducted in the province of Pinar del Río. The data were taken from the statistical reports of the Provincial Directorate of Hygiene, Epidemiology and Microbiology, of patients discharged by COVID-19 in the period from March 2020 to May 2021. The universe consisted of all confirmed cases of SARS-CoV virus in Pinar del Río. The sample consisted of 5 379 patients discharged by COVID-19.

Statistical reports were reviewed to search for the following variables: municipality of origin, age group, sex, course of the disease, frequency of symptoms, number and frequency of comorbidities, municipality of origin.

The principles of medical ethics and the aspects established in the Declaration of Helsinki were complied with.

RESULTS

A predominance of confirmed patients was observed in the municipality of Pinar del Río, followed by Minas de Matahambre, which represented 1,54 % and 1,02 % respectively. In addition, the municipalities with the lowest incidence of cases were Mantua (0,19%) and Viñales (0,27 %). (Table 1)

Table 1 Distribution by municipalities of patients with COVID-19, Pinar del Río, March 2020 - May 2021 

Municipality	Total population		Positives discharged
	No.	%	No.	%
Sandino	35 968	6,17	286	0,80
Mantua	23 593	4,05	44	0,19
Minas de Matahambre	31 527	5,41	321	1,02
Viñales	29 002	4,97	78	0,27
La Palma	33 798	5,80	241	0,71
Los Palacios	38 186	6,55	170	0,45
Consolación del Sur	88 222	15,13	555	0,63
Pinar del Río	192 675	33,05	2969	1,54
San Luis	31 658	5,43	178	0,56
San Juan y Martínez	42 918	7,36	264	0,62
Guane	35 490	6,09	273	0,77
Total	583 037	100	5379	0,92

Source: Hygiene, Epidemiology and Microbiology database.

A predominance of the disease was observed in the age groups 41-50 years, 51-60 years which represented 17,16 % for both, followed by the group of 21-30 years which represented 16,23 %. The male sex predominated, accounting for 52,82 % of the total number of cases. In particular, a slight predominance of the female sex was observed in the 1-10 and 51-60 age groups (Table 2).

Table 2 Distribution of patients with COVID-19 according to age and sex. 

Age group	Male		Female		Total
	No.	%	No.	%	No.	%
<1 año	25	0,46	17	0,32	42	0,78
1-10	132	2,45	162	3,01	294	5,47
11-20	423	7,86	239	4,44	662	12,31
21-30	470	8,74	403	7,49	873	16,23
31-40	423	7,86	361	6,71	784	14,58
41-50	485	9,02	438	8,14	923	17,16
51-60	452	8,40	471	8,76	923	17,16
61-70	229	4,26	220	4,09	449	8,35
71≤	202	3,76	227	4,22	429	7,98
Total	2841	52,82	2538	47,18	5379	100,00

Source: Hygiene, Epidemiology and Microbiology database.

According to the course of the disease, there was a predominance of cases with asymptomatic evolution, which represented 53,28 % of the total number of patients. The symptomatic course predominated in the age groups corresponding to 21-30 and 51-60 years of age (Table 3).

Table 3 Distribution of patients with COVID-19 according to age and presence of symptoms. 

Age group	Asymptomatic		Symptomatic Total		Total
	No.	%	No.	%	No.	%
<1 año	16	0,30	26	0,48	42	0,78
1-10	189	3,51	105	1,95	294	5,47
11-20	339	6,30	323	6,00	662	12,31
21-30	438	8,14	435	8,09	873	16,23
31-40	416	7,73	368	6,84	784	14,58
41-50	527	9,80	396	7,36	923	17,16
51-60	485	9,02	438	8,14	923	17,16
61-70	237	4,41	212	3,94	449	8,35
71≤	219	4,07	210	3,90	429	7,98
Total	2866	53,28	2513	46,72	5379	100

Source: Hygiene, Epidemiology and Microbiology database.

The most frequent symptoms were cough and fever, representing 30.20% and 30.9% respectively, followed by rhinorrhea (22.6%) and odynophagia (13.33%). While the age groups most affected by these symptoms were 51-60 years and 21-30 years respectively, children under one year of age were the least affected (Table 4).

Table 4 Frequency of symptoms in symptomatic patients diagnosed with COVID-19. 

Legend: GS: general syndrome (includes asthenia, anorexia and malaise; PGO: loss of taste and/or smell; GIT: gastrointestinal disorders (includes diarrhea, abdominal pain, vomiting and gastritis). Percentage values based on total symptomatic patients (n=2513).

Source: Hygiene, Epidemiology and Microbiology database.

Overall, the most frequent comorbidities were arterial hypertension (4.16%), asthma (1.21%) and type 2 diabetes mellitus (1.06%); the female sex was slightly more affected than the male sex. (Table 5).

Table 5 Frequency of personal pathological history of SARS-CoV 2 positive patients according to sex. 

APP	Male		Female		Total
	No.	%	No.	%	No.	%
Diabetes mellitus type 2	21	0,39	36	0,67	57	1,06
Hyperthyroidism	1	0,02	11	0,20	12	0,22
Hypothyroidism	1	0,02	11	0,20	12	0,22
Thyroiditis	1	0,02	1	0,02	2	0,04
Hyperuricemia/gout	3	0,06	1	0,02	4	0,07
Arterial hypertension	109	2,03	115	2,14	224	4,16
Obesity	2	0,04	6	0,11	8	0,15
Heart failure	1	0,02	2	0,04	3	0,06
Ischemic heart disease	21	0,39	11	0,20	32	0,59
Asthma	32	0,59	33	0,61	65	1,21
Thrombopathies	4	0,07	0	0	4	0,07
Cerebrovascular accidents	10	0,19	0	0	10	0,19
Psychiatric disorders	16	0,30	13	0,24	29	0,54
Alcoholism	6	0,11	1	0,02	7	0,13
Smoking	2	0,04	1	0,02	3	0,06
Allergies	7	0,13	6	0,11	13	0,24
Psoriasis	0	0	1	0,02	1	0,02
Genetic diseases	1	0,02	2	0,04	3	0,06
Ulcer/gastritis	12	0,22	5	0,09	17	0,32
HIV infection	1	0,02	1	0,02	2	0,04
COPD	4	0,07	5	0,09	9	0,17
Nephropathies	7	0,13	4	0,07	11	0,20
cancer	7	0,13	10	0,19	17	0,32

Frequency of personal pathological history of SARS-CoV 2 positive patients according to sex,

Legend: HIV: human immunodeficiency virus; COPD: chronic obstructive pulmonary disease.

Source: Hygiene, Epidemiology and Microbiology database.

DISCUSSION

The municipality of Pinar del Río constitutes the capital of the province, coincides with the highest population density, the highest degree of urbanization and also the highest number of positive cases, a direct spatial correlation between population density and incidence of COVID-19.¹³ However, a study carried out in Santiago de Cuba does not consider the density variable alone with direct correlation to incidence. It demonstrates by mathematical regression model that the link in combination with the entry of travelers does not confer value to it in isolation.

The average age of the confirmed cases in the province is 42 years old, which discretely disagrees with the national behavior of the pandemic, because the average age of the confirmed cases in the country is 37 years old. In COVID-19, worldwide research shows senescence as a risk group for contracting the disease, however, in Pinar del Río the incidence in older adults is low, which speaks in favor of the accurate and effective measures implemented by the provincial health directorate and provincial defense councils that protect the elderly.^13,14

As for the predominance of the male sex, it is shown that female individuals develop stronger immune responses and are relatively more resistant to virus infections than male individuals. The difference in the copy number of X-linked genes involved in the immune response and the presence of genes involved in disease susceptibility in males and females may explain these sex differences. The androgen receptor, as well as the ACE2 gene loci, are on the X chromosome.¹⁵

Sex hormones are suggested to be potential mediators of the sex dysmorphism described in SARS-CoV-2 infection by virtue of their ability to modulate the immune response. Testosterone suppresses innate immune responses, whereas estrogens have immunosuppressive effect at higher levels, and immunostimulatory activity at lower levels, with functions involved in counteracting viral replication in nasal epithelial cells. In addition, they theoretically link the hyperandrogenic phenotype to increased COVID-19 viral load, disease dissemination and severity.^13,16,17

The asymptomatic course of the disease predominated in the population of Pinar del Río and the country according to the national reports of the Ministry of Public Health, in contrast to international records, which could be due to the active screening of cases implemented in Cuba that detects the asymptomatic person. On the other hand, reports at world level are made by the arrival of symptomatic patients to health services.¹⁸

A clinical characterization of patients with COVID-19 in China showed fever as the most frequent symptom during admission, followed by cough. These results coincide with the research presented,¹⁵ in the work of Roblejo and Marcheco,(17) on a study of 431 patients with COVID-19 in Havana; fever was determined as the most frequent symptom in all age groups. In addition, very similar results were found regarding the higher frequency of personal pathological history of arterial hypertension and asthma in patients with COVID-19.

It is concluded that the clinical-epidemiological behavior of SARS-CoV-2 disease in Pinar del Río province is similar to that described in national and international reports. There were symptoms associated to the upper respiratory tract with satisfactory evolution. There was a slight predominance of asymptomatic patients among the total diagnosed, which indicates the effectiveness of early diagnosis in primary health care. Fever and respiratory symptoms were predominant; although other symptomatologies (neurological and digestive) were found less frequently. Arterial hypertension and asthma were reported as frequent chronic diseases. Most of the cases in the province were concentrated in the head municipality because of its higher population density.

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Received: February 16, 2022; Accepted: April 12, 2022