Inverted Covariate Effects for First versus Mutated Second Wave Covid-19: High Temperature Spread Biased for Young

Abstract

(1) Background: Here, we characterize COVID-19’s waves, following a study presenting negative associations between first wave COVID-19 spread parameters and temperature. (2) Methods: Visual examinations of daily increases in confirmed COVID-19 cases in 124 countries, determined first and second waves in 28 countries. (3) Results: The first wave spread rate increases with country mean elevation, median population age, time since wave onset, and decreases with temperature. Spread rates decrease above 1000 m, indicating high ultraviolet lights (UVs) decrease the spread rate. The second wave associations are the opposite, i.e., spread increases with temperature and young age, and decreases with time since wave onset. The earliest second waves started 5–7 April at mutagenic high elevations (Armenia, Algeria). The second waves also occurred at the warm-to-cold season transition (Argentina, Chile). Second vs. first wave spread decreases in most (77%) countries. In countries with late first wave onset, spread rates better fit second than first wave-temperature patterns. In countries with ageing populations (for example, Japan, Sweden, and Ukraine), second waves only adapted to spread at higher temperatures, not to infect the young. (4) Conclusions: First wave viruses evolved towards lower spread. Second wave mutant COVID-19 strain(s) adapted to higher temperature, infecting younger ages and replacing (also in cold conditions) first wave COVID-19 strains. Counterintuitively, low spread strains replace high spread strains, rendering prognostics and extrapolations uncertain.

Summer COVID-19 third wave: faster high altitude spread suggests high UV adaptation

“…We applied this method for the 42 second waves detected for the USA (Dis, Table 2). Most of the onset dates determined by running windows (62%) are within five days of the date determined visually, in line with similar previous analyses for other countries (Seligmann et al 2020).…”

“…Previously, it was shown that first wave spread, when comparing different countries, decreases with mean annual temperature (Demongeot et al 2020). The opposite trend with temperature occurs for second wave spread parameters (Seligmann et al 2020). This is in line with observations on variation in spread across different regions of Italy, in March 2020 (first wave period, negative correlation with temperature) and in May 2020 (second wave period, positive correlation with temperature) (Malki et al 2020).…”

“…Unexpectedly, second wave slopes decrease with population density (r = -0.459, two-tailed P = 0.0022, Figure 2B). This unexplained inversion of patterns between first and second waves has been reported for covariates such as temperature, time since wave onset and median population age when comparing different countries (Seligmann et al 2020). The decrease of slopes with density in the USA is foremost astounding because it does not at all fit with any knowledge on disease spread.…”

“…We therefore use a simplified method. Statistical analyses based on calculating Pearson correlation coefficients r for a running window of 20 days determine a local maximum for r within five days of the second wave onset date determined visually for 80 percent of the countries examined (Seligmann et al 2020). Figure 1B plots these r values for Wisconsin as a function of the first day included in the running window.…”

Validity of Clinical Symptoms Score to Discriminate Patients with COVID-19 from Common Cold Out-Patients in General Practitioner Clinics in Japan

“…The medical records of patients who visited the SUC between 1 and 14 August 2020, during the second wave of the COVID-19 pandemic in Japan [ 11 ], were collected. The data included demographic information, medical history, exposure to patients with COVID-19, symptoms, signs, number of people around the patient in the past week and the places visited in the past two weeks which were possible transmission routes (interviewed and examined by seven medical doctors).…”