**3.2 Neurologic and neurocognitive symptoms**

Cognitive symptoms such as difficulty concentrating, attention problems, and memory failure have been described frequently. These symptoms tend to improve in the long term after performing neurocognitive rehabilitation [31].

Symptomatic treatment should be offered to people with headaches, with the one usually employed for the primary headache they present, depending on the tension or migraine type [31].

There is no pharmacological treatment to speed up smell recovery or to attenuate parosmia. In the case of myalgias, the treatment is symptomatic, where Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are commonly administered [31].

#### **3.3 Psychological and emotional problems**

For those presenting with mild to moderate anxiety and depression, Selective Serotonin Reuptake Inhibitors (SSRIs) should be initiated progressively to maintenance doses with a reassessment every 3–4 weeks [31].

In the case of neuropathic pain or a history of diabetes mellitus, duloxetine would be the antidepressant of choice. If the existing clinical picture includes diarrhea or digestive disorders, the chosen treatment would be paroxetine [31].

#### **3.4 Dyspnea and cough**

For mild symptoms of dyspnea that do not require oxygen and do not have a cardiac etiology, they may benefit from breathing exercises and respiratory physiotherapy.

The following is recommended for cough: antitussives such as dextromethorphan or guaifenesin, bronchodilators such as inhaled therapies, bronchodilators, or inhaled glucocorticoids [31].

#### **3.5 Olfactory-gustatory symptoms**

If symptoms do not resolve after 2 months, evaluation by an otolaryngologist may be necessary [31].

Treatment consists of olfactory rehabilitation. The use of oral or topical corticosteroid therapy for 15 days, vitamin D, sodium citrate, or theophylline is evaluated, recommending the performance of olfactometry [31].

They could benefit from the stimulation or rehabilitation of smell through occupational therapy or speech therapy [32].

## **4. Long COVID-19 studies in Mexico and Latin America**

In Mexico, a case–control study carried out in the state of Zacatecas with 219 patients found a relative risk of 2 to 33 times higher for developing persistent symptoms such as dyspnea, nausea, and anosmia [20].

An ongoing longitudinal study of neurological syndromes associated with COVID-19 in Mexico City found a high frequency of neurological manifestations during hospitalization in patients with COVID-19, suggesting a higher number of short- and long-term sequelae for these patients [24].

In a follow-up study of patients discharged from a temporary hospital dedicated to COVID-19 in Mexico, the groups of symptoms that presented in more than 30% of the participants 90 days after discharge were neurological, dermatological, and mood disorders. In this study, women presented persistent symptoms more frequently than men, consistent with studies in Wuhan, showing a relationship between the female sex and the symptoms of prolonged COVID-19 [25].

Alvarez-Moreno et al. [33] reported that the most persistent symptoms in Bogotá, Colombia, were headache, fatigue, and insomnia. Likewise, they emphasize that their results are like those reported in other studies. Also, they suggest that there may be an underreporting effect in Latin America that could accentuate social inequalities.

In the study by González-Hermosillo et al. [34], patients who have persistent fatigue for 3 to 6 months were associated with ages between 40 and 50 years.

Patients with fatigue have a high prevalence of other symptoms such as bradypnea, cognitive decline, sleep problems, autonomic dysregulation, and psychological stress. In Mexican studies, the depression and anxiety prevalence among previous COVID-19 patients are up to 15.7% and 22.6%, respectively [34].

The prevalence of symptoms has a progressive decrease with time. A 6-month follow-up study in patients who recovered from the COVID-19 infection showed a reduction in fatigue prevalence—from 53 to 46.9%.

Gonzalez-Hermosillo et al. [34] found that 40.4% of the patients presented persistent symptoms. Of them, 9.1% had a progressive reduction after 4 weeks [34].
