Abstract
The percentage of asymptomatic COVID-19 cases worldwide is estimated at 18-50%; 53% in Cuba specifically, and 58% in Havana, the Cuban capital and the 2020 epicenter of the country's COVID-19 epidemic. These figures, however, do not represent the transmission capacity or behavior of asymptomatic cases. Understanding asymptomatic transmission's contribution to SARS-CoV-2 spread is of great importance to disease control and prevention. Identify the epidemiological implications of asymptomatic SARS-CoV-2 infection in Havana, Cuba, during the first wave of the epidemic in 2020. We carried out a cross-sectional study of all confirmed COVID-19 cases diagnosed in Havana, Cuba, from March 16 through June 30, 2020. The information was obtained through review of the standardized form for investigation of suspected and confirmed cases. Examined variables included age, sex, occupation, case type and source of infection. Cases were divided into asymptomatic and symptomatic groups, and transmission was characterized through the creation of a contact matrix. Analysis was carried out in Epidat and R. We studied 1287 confirmed cases, of which 57.7% (743) were asymptomatic, and 42.3% (544) were symptomatic. Symptomatic presentation was the most common for both imported and introduced cases, while asymptomatic presentation was more common in autochthonic cases and infections from an undetermined source. Asymptomatic infection was more common in groups aged ⟨20 and 20-59 years, while symptomatic infection was more common in those aged ⟩60 years. In the contact matrix, 34.6% of cases (445/1287) were not tied to other cases, and 65.4% (842/1287) were infectious-infected dyads, with symptomatic-symptomatic being the most common combination. The majority of primary cases (78.5%; 1002/1276) did not generate secondary cases, and 85.6% (658/743) of asymptomatic cases did not lead to other cases (although one asymptomatic superspreader led to 90 cases in a single event). However, 63.2% (344/544) of symptomatic primary cases generated secondary cases, and 11 symptomatic superspreaders spawned 100 secondary cases in different events. Asymptomatic SARS-CoV-2 infection was the most common form of COVID-19 in Havana during the study period, but its capacity for contagion was lower than that of symptomatic individuals. Superspreader events under specific conditions played an important role in sustaining the epidemic.
Highlights
INTRODUCTION SARSCoV-2 infection can produce endothelial injury and microvascular damage, one cause of the multiorgan failure associated with COVID-19
Patients recovered from SARS-CoV-2 infection showed decreased cerebral hemodynamic reserve and breath-holding index regardless of the disease’s clinical severity or presence of neurological symptoms
These abnormalities may be associated with endothelial damage caused by COVID-19
Summary
INTRODUCTION SARSCoV-2 infection can produce endothelial injury and microvascular damage, one cause of the multiorgan failure associated with COVID-19. Endothelial dysfunction can be evaluated by using transcranial Doppler ultrasound to study cerebral hemodynamic reserve, but there are few of these studies in patients with COVID-19, and the technique is not included in COVID-19 action and follow-up guidelines nationally or internationally. Direct or immune-mediated viral infection results in endothelial and microvascular dysfunction, one cause of multiple organ involvement in COVID-19.[1,2]. IMPORTANCE Cerebral hemodynamic reserve, an expression of endothelial involvement, is altered in recovered COVID-19 patients. This alteration, which increases stroke risk, can be detected via transcranial Doppler ultrasound. The cerebral microcirculatory damage that causes endotheliitis in SARS-CoV-2 infection can be diagnosed at a patient’s bedside by evaluating cerebral hemodynamic reserve (CHR) through transcranial Doppler ultrasound. The technique is not included in international or domestic action guidelines for addressing acute SARS-CoV-2 infection or recovery, and research on the matter is limited
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
