In this study, it was found that 33.1% of the patients were in a presymptomatic state, and four (8%) of them died. This significant proportion could mean an eventual silent transmission, contributing to increased cases in the epidemic associated with SARS-CoV-2 [9].
Regarding the clinical manifestations related to gender, we evidence a more significant musculoskeletal commitment in the female gender in this study. This could be related to what has been published by Jeong et al. [10], who observed that musculoskeletal disorders such as myalgias are a frequent clinical manifestation in presymptomatic individuals. However, this research would infer that this clinical manifestation would have greater clinical relevance in women infected with SARS-CoV-2.
On the other hand, it is essential to mention that in developing countries such as Colombia, the diagnosis of these individuals is generally late, so they become the primary transmitters of this new virus and the perfect hosts for the generation of new variants SARS-CoV-2. On the other hand, our findings demonstrated that the most common clinical manifestations in individuals who evolved to symptoms were headache, fever, and anosmia. These findings agree with Fu et al. [11], who found that the main clinical manifestations of COVID-19 are fever, headache, cough, and dyspnea.
According to age, in the bivariate analysis, we observed that cough was a predominant clinical manifestation in presymptomatic adults, which agrees with Arons et al. [12]. They showed that cough was present in 54% of a group of presymptomatic adults. However, in the analysis of principal components, we were able to describe these presymptomatic individuals’ symptoms better, and it was observed that the most common symptoms were anosmia and arthralgia in young people. Young individuals do not seem to have significantly lower respiratory tract involvement. However, SARS-CoV-2 infection affects the upper respiratory tract, mainly causing neurological manifestations such as olfactory dysfunction, lasting up to 28 days [13]. Anosmia can be a pathognomonic clinical manifestation that could be used by healthcare personnel to differentiate SARS-CoV-2 infection from other respiratory viruses such as influenza [14]. Another study in Korea also evidenced anosmia as a frequent symptom in 3,191 young people with COVID-19 and was characteristic in mild forms of the disease [15].
The most important clinical manifestations in adults were cough, ageusia, and odynophagia, consistent with published [16]. It is striking to show that another neurological manifestation such as ageusia is one of the most frequent clinical symptoms during SARS-CoV-2 infection, which could be associated with greater involvement of the virus on the glossopharyngeal facial, and vagus nerves in this age group [17]. Therefore, ageusia could serve as a pathognomonic symptom to diagnose the adult population.
In the elderly, the clinical manifestations were epigastric pain, dyspnea, and headache. Dyspnea was in the present work a specific manifestation of older adults infected by SARS-CoV-2 [18]. Dyspnea should be considered a clinical symptom with a poor prognosis, mainly in patients with comorbidities such as hypertension, cardiovascular disease, and kidney disease [19].
Regarding the Cq values between the different clinical groups, our data are similar to those published by Quiroga et al. [20], who did not show relevant differences between the Cqs of symptomatic (37.35) and asymptomatic (35.24) individuals. In addition, it should be noted that the patients who died had a higher viral load (Cq 29.93), consistent with the work of Fajnzylber et al. [21], who showed a higher viral load induces a more significant inflammatory response and a worse prognosis. Clinical practice in those infected with SARS-CoV-2.
Declarations
The present study has some limitations; first, we do not know how long asymptomatic individuals were infected while in contact with other individuals before diagnosis. The study also did not include data on the observed incubation period, and our data could be limited mainly to the Colombian Caribbean population, in contrast to [22]. Furthermore, the information reported here is retrospective and extrapolated mainly to the clinical behavior of SARS-CoV-2 in the year 2020.
