Background and purpose Neurological complications of SARS‐CoV‐2 infection are noticed among critically ill patients soon after disease onset. Information on delayed neurological sequelae of SARS‐CoV‐2 infection is nil. Following a longitudinal study design, the occurrence of cognitive decline among individuals with a history of mild symptomatic SARS‐CoV‐2 infection was assessed. Methods Stroke‐ and seizure‐free Atahualpa residents aged ≥40 years, who had pre‐pandemic cognitive assessments as well as normal brain magnetic resonance imaging and electroencephalogram recordings, underwent repeated evaluations 6 months after a SARS‐CoV‐2 outbreak infection in Atahualpa. Patients requiring oxygen therapy, hospitalization, and those who had initial neurological manifestations were excluded. Cognitive decline was defined as a reduction in the Montreal Cognitive Assessment (MoCA) score between the post‐pandemic and pre‐pandemic assessments that was ≥4 points greater than the reduction observed between two pre‐pandemic MoCAs. The relationship between SARS‐CoV‐2 infection and cognitive decline was assessed by fitting logistic mixed models for longitudinal data as well as exposure‐effect models. Results Of 93 included individuals (mean age 62.6 ± 11 years), 52 (56%) had a history of mild symptomatic SARS‐CoV‐2 infection. Post‐pandemic MoCA decay was worse in seropositive individuals. Cognitive decline was recognized in 11/52 (21%) seropositive and 1/41 (2%) seronegative individuals. In multivariate analyses, the odds for developing cognitive decline were 18.1 times higher among SARS‐CoV‐2 seropositive individuals (95% confidence interval 1.75–188; p = 0.015). Exposure‐effect models confirmed this association ( β = 0.24; 95% confidence interval 0.07–0.41; p = 0.006). Conclusions This study provides evidence of cognitive decline among individuals with mild symptomatic SARS‐CoV‐2 infection. The pathogenesis of this complication remains unknown.

Antibodies to SARS-CoV-2 were detected in 303/673 rural Ecuadorian adults (45%), 77% of whom had compatible clinical manifestations. Seropositivity was associated with the use of open latrines. Our findings support the fears of mass spread of SARS-CoV-2 in rural Latin America and cannot exclude a contributing role for fecal-oral transmission.

Background and purpose Cognitive decline is a recognized manifestation of long COVID, even among patients who experience mild disease. However, there is no evidence regarding the length of cognitive decline in these patients. This study aimed to assess whether COVID‐19‐related cognitive decline is a permanent deficit or if it improves over time. Methods Cognitive performance was evaluated by means of the Montreal Cognitive Assessment (MoCA) in COVID‐19 survivors and noninfected individuals. All study participants had four cognitive evaluations, two of them before the pandemic and the other two, 6 and 18 months after the initial SARS‐CoV‐2 outbreak infection in the village. Linear mixed effects models for longitudinal data were fitted to assess differences in cognitive performance across COVID‐19 survivors and noninfected individuals. Results The study included 78 participants, 50 with history of mild COVID‐19 and 28 without. There was a significant—likely age‐related—decline in MoCA scores between the two prepandemic tests (β = −1.53, 95% confidence interval [CI] = −2.14 to −0.92, p < 0.001), which did not differ across individuals who later developed COVID‐19 when compared to noninfected individuals. Six months after infection, only COVID‐19 survivors had a significant decline in MoCA scores (β = −1.37, 95% CI = −2.14 to −0.61, p < 0.001), which reversed after 1 additional year of follow‐up (β = 0.66, 95% CI = −0.11 to 1.42, p = 0.092). No differences were noticed among noninfected individuals when both postpandemic MoCA scores were compared. Conclusions Study results suggest that long COVID‐related cognitive decline may spontaneously improve over time.

Data on SARS-CoV-2 transmission in rural communities is scarce or non-existent. A previous cross-sectional study in middle-aged and older adults enrolled in the Atahualpa Project Cohort demonstrated that 45% of participants had SARS-CoV-2 antibodies, 77% of whom were symptomatic. Here, we assessed the incidence of SARS-CoV-2 infection in the abovementioned rural population. One month after baseline testing, 362 of 370 initially seronegative individuals were re-tested to assess incidence of seroconversion and associated risk factors. Twenty-eight of them (7.7%) became seropositive. The overall incidence rate ratio was 7.4 per 100 person months of potential virus exposure (95% C.I.: 4.7-10.2). Six seroconverted individuals (21.4%) developed SARS-CoV-2-related symptomatology. The only covariate significantly associated with seroconversion was the use of an open latrine. Predictive margins showed that these individuals were 2.5 times more likely to be infected (95% C.I.: 1.03-6.1) than those using a flushing toilet. Therefore, along one month, approximately 8% of seronegative individuals became infected, even after almost half of the population was already seropositive. Nevertheless, a smaller proportion of incident cases were symptomatic (21% versus 77% of the earlier cases), and no deaths were recorded. Whether this decreased clinical expression resulted from a lower viral load in new infections cannot be determined. Increased seroconversion in individuals using latrines is consistent with a contributory role of fecal-oral transmission, although we cannot rule out the possibility that latrines are acting as a proxy for poverty or other unknown interacting variables.

High social risk, as measured by the social determinants of health (SDH), may increase the risk of SARS-CoV-2 infection. However, this association has not been studied in rural communities. Using the Atahualpa Project cohort, we aimed to assess the association between SDH and SARS-CoV-2 seropositivity in community-dwelling older adults living in rural Ecuador. SARS-CoV-2 antibodies were determined in 319 individuals aged ≥ 60 years that completed a validated field instrument to assess their social risk before the introduction of this novel pandemic. Multivariate models were fitted to assess the independent association between SDH—and each of their components—and SARS-CoV-2 seropositivity, after adjusting for relevant covariates. According to the Gijon scale, 102 (32%) individuals had a high social risk (≥ 10 points). A total of 141 (44%) individuals were seropositive to SARS-CoV-2. A fully-adjusted logistic regression model showed an independent) association between social risk and SARS-CoV-2 positivity (OR 1.15; 95% CI 1.04–1.27; p = 0.008). For every unit of the total SDH score, the odds of SARS-CoV-2 seropositivity increased 15% (95% CI 3.7–27%). In addition, multivariate models showed that the individual component of SDH more strongly associated with SARS-CoV-2 seropositivity was housing, which suggested that lack of basic home facilities may increase the risk of SARS-CoV-2 infection. Knowledge on the association between high social risk and SARS-CoV-2 infection is indispensable for the development of cost-effective preventive strategies for controlling modifiable factors that are in the path of SARS-CoV-2 infection among older adults living in underserved communities.