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Journal of Theoretical Biology Jul 2022The many respiratory viruses that cause influenza-like illness (ILI) are reported and tracked as one entity, defined by the CDC as a group of symptoms that include a...
The many respiratory viruses that cause influenza-like illness (ILI) are reported and tracked as one entity, defined by the CDC as a group of symptoms that include a fever of 100 degrees Fahrenheit, a cough, and/or a sore throat. In the United States alone, ILI impacts 9-49 million people every year. While tracking ILI as a single clinical syndrome is informative in many respects, the underlying viruses differ in parameters and outbreak properties. Most existing models treat either a single respiratory virus or ILI as a whole. However, there is a need for models capable of comparing several individual viruses that cause respiratory illness, including ILI. To address this need, here we present a flexible model and simulations of epidemics for influenza, RSV, rhinovirus, seasonal coronavirus, adenovirus, and SARS/MERS, parameterized by a systematic literature review and accompanied by a global sensitivity analysis. We find that for these biological causes of ILI, their parameter values, timing, prevalence, and proportional contributions differ substantially. These results demonstrate that distinguishing the viruses that cause ILI will be an important aspect of future work on diagnostics, mitigation, modeling, and preparation for future pandemics.
Topics: Epidemics; Humans; Influenza, Human; Rhinovirus; Virus Diseases; Viruses
PubMed: 35490763
DOI: 10.1016/j.jtbi.2022.111145 -
PloS One 2021Intensity and duration of the COVID-19 pandemic, and planning required to balance concerns of saving lives and avoiding economic collapse, could depend significantly on...
IMPORTANCE
Intensity and duration of the COVID-19 pandemic, and planning required to balance concerns of saving lives and avoiding economic collapse, could depend significantly on whether SARS-CoV-2 transmission is sensitive to seasonal changes.
OBJECTIVE
Hypothesis is that increasing temperature results in reduced SARS CoV-2 transmission and may help slow the increase of cases over time.
SETTING
Fifty representative Northern Hemisphere countries meeting specific criteria had sufficient COVID-19 case and meteorological data for analysis.
METHODS
Regression was used to find the relationship between the log of number of COVID-19 cases and temperature over time in 50 representative countries. To summarize the day-day variability, and reduce dimensionality, we selected a robust measure, Coefficient of Time (CT), for each location. The resulting regression coefficients were then used in a multivariable regression against meteorological, country-level and demographic covariates.
RESULTS
Median minimum daily temperature showed the strongest correlation with the reciprocal of CT (which can be considered as a rate associated with doubling time) for confirmed cases (adjusted R2 = 0.610, p = 1.45E-06). A similar correlation was found using median daily dewpoint, which was highly colinear with temperature, and therefore was not used in the analysis. The correlation between minimum median temperature and the rate of increase of the log of confirmed cases was 47% and 45% greater than for cases of death and recovered cases of COVID-19, respectively. This suggests the primary influence of temperature is on SARS-CoV-2 transmission more than COVID-19 morbidity. Based on the correlation between temperature and the rate of increase in COVID-19, it can be estimated that, between the range of 30 to 100 degrees Fahrenheit, a one degree increase is associated with a 1% decrease-and a one degree decrease could be associated with a 3.7% increase-in the rate of increase of the log of daily confirmed cases. This model of the effect of decreasing temperatures can only be verified over time as the pandemic proceeds through colder months.
CONCLUSIONS
The results suggest that boreal summer months are associated with slower rates of COVID-19 transmission, consistent with the behavior of a seasonal respiratory virus. Knowledge of COVID-19 seasonality could prove useful in local planning for phased reductions social interventions and help to prepare for the timing of possible pandemic resurgence during cooler months.
Topics: COVID-19; Hot Temperature; Humans; Meteorological Concepts; Pandemics; SARS-CoV-2; Seasons; Weather
PubMed: 33596214
DOI: 10.1371/journal.pone.0246167 -
SAGE Open Medical Case Reports 2021Clinicians and researchers have reported an array of neurological abnormalities in coronavirus disease 2019 (COVID-19), and while serotonin excess has been observed we...
Clinicians and researchers have reported an array of neurological abnormalities in coronavirus disease 2019 (COVID-19), and while serotonin excess has been observed we are unaware of reports of central nervous system serotonin toxicity in COVID-19. We present two cases that resemble serotonin syndrome in COVID-19, but without identifiable inciting medications. A 54-year-old with multiple sclerosis and diabetes mellitus presented with altered mental status. His altered sensorium was attributed to diabetic ketoacidosis, but his condition quickly deteriorated with fever to 105 degrees Fahrenheit, rigidity in all extremities, inducible clonus, and hyperreflexia. He was intubated and was treated for possible meningitis and seizure. Neurologic workup was negative for acute pathology. Despite acetaminophen, his core temperature remained elevated to 105 degrees Fahrenheit. He was treated with external cooling and cyproheptadine and within 48 h, his fever, rigidity, hyperreflexia, and clonus resolved. He was extubated and discharged home on day 14. A 72-year-old with hyperlipidemia was admitted with tremors, 4 days after testing positive for COVID-19. His symptoms rapidly worsened, and he was transferred to the Intensive Care Unit on day 3 , febrile to 104.4 degrees Fahrenheit, heart rate of 180 beats per minute, and apparent whole body myoclonus. He was intubated and developed fever refractory to acetaminophen requiring external cooling. Extensive neurologic workup was negative. He received cyproheptadine and slowly improved. He was extubated and discharged to rehab on day 11. These cases represent a unique presentation in COVID-19 that must be considered and requires a high index of suspicion.
PubMed: 34290872
DOI: 10.1177/2050313X211032089