Impact of super-spreaders on COVID-19: systematic review

Rambo, Ana Paula Schmitz; Gonçalves, Laura Faustino; Gonzáles, Ana Inês; Rech, Cassiano Ricardo; Paiva, Karina Mary de

doi:10.1590/1516-3180.2020.0618.r1.10122020

Cited by 14 publications

(9 citation statements)

References 14 publications

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“…We used our epi-econ model to compare two distinct control strategies—physical distancing versus testing with self-isolation—using a common set of assumptions and parameter values. The model includes the possibility of transmission by superspreading to allow a comparison of control strategies when a disproportionate share of secondary transmissions are caused by a small fraction of infected individuals, as seems to be indicated for COVID-19 17 , 21 – 23 .…”

Section: Introductionmentioning

confidence: 99%

Physical distancing versus testing with self-isolation for controlling an emerging epidemic

Newbold

Ashworth

Finnoff

et al. 2023

Sci Rep

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Two distinct strategies for controlling an emerging epidemic are physical distancing and regular testing with self-isolation. These strategies are especially important before effective vaccines or treatments become widely available. The testing strategy has been promoted frequently but used less often than physical distancing to mitigate COVID-19. We compared the performance of these strategies in an integrated epidemiological and economic model that includes a simple representation of transmission by “superspreading,” wherein a relatively small fraction of infected individuals cause a large share of infections. We examined the economic benefits of distancing and testing over a wide range of conditions, including variations in the transmissibility and lethality of the disease meant to encompass the most prominent variants of COVID-19 encountered so far. In a head-to-head comparison using our primary parameter values, both with and without superspreading and a declining marginal value of mortality risk reductions, an optimized testing strategy outperformed an optimized distancing strategy. In a Monte Carlo uncertainty analysis, an optimized policy that combined the two strategies performed better than either one alone in more than 25% of random parameter draws. Insofar as diagnostic tests are sensitive to viral loads, and individuals with high viral loads are more likely to contribute to superspreading events, superspreading enhances the relative performance of testing over distancing in our model. Both strategies performed best at moderate levels of transmissibility, somewhat lower than the transmissibility of the ancestral strain of SARS-CoV-2.

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Section: Introductionmentioning

confidence: 99%

Physical distancing versus testing with self-isolation for controlling an emerging epidemic

Newbold

Ashworth

Finnoff

et al. 2023

Sci Rep

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“…The heterogeneity in individual age and the reaction to biological and environmental changes that have been observed in COVID-19 dynamics in terms of different reactions to vaccination by age group, severity of infection per age group, hospitalization, and intensive care unit (ICU) records show different patterns, which is why it is important to improve mathematical models for COVID-19 pandemic prediction to account for different proportions of ages in the population, which is a major factor in epidemic history [ 25 ]. In some age classes (namely young and adult classes), all infectious are neither symptomatic nor reported and some models incorporating asymptomatic [ 26 ], unreported [ 27 ], and super-spreaders [ 28 ] have been proposed for the COVID-19 outbreak. Many authors have also included age in their models as a gravity factor [ 29 , 30 , 31 , 32 , 33 ], but here, the originality is to propose an improvement of the classical Ross and Kermack-McKendrick model and use it for giving a theoretical and numerical framework for interpreting the relationship between demographic parameters such as age pyramid, fertility and mortality, and epidemiological parameters such as the basic reproduction number R 0 and vaccination rate.…”

Section: Introductionmentioning

confidence: 99%

Age Dependent Epidemic Modeling of COVID-19 Outbreak in Kuwait, France, and Cameroon

et al. 2022

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Revisiting the classical model by Ross and Kermack-McKendrick, the Susceptible–Infectious–Recovered (SIR) model used to formalize the COVID-19 epidemic, requires improvements which will be the subject of this article. The heterogeneity in the age of the populations concerned leads to considering models in age groups with specific susceptibilities, which makes the prediction problem more difficult. Basically, there are three age groups of interest which are, respectively, 0–19 years, 20–64 years, and >64 years, but in this article, we only consider two (20–64 years and >64 years) age groups because the group 0–19 years is widely seen as being less infected by the virus since this age group had a low infection rate throughout the pandemic era of this study, especially the countries under consideration. In this article, we proposed a new mathematical age-dependent (Susceptible–Infectious–Goneanewsusceptible–Recovered (SIGR)) model for the COVID-19 outbreak and performed some mathematical analyses by showing the positivity, boundedness, stability, existence, and uniqueness of the solution. We performed numerical simulations of the model with parameters from Kuwait, France, and Cameroon. We discuss the role of these different parameters used in the model; namely, vaccination on the epidemic dynamics. We open a new perspective of improving an age-dependent model and its application to observed data and parameters.

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“…Several studies have found vaccination to be linked with the reduced number of cases and severity of infection (6)(7)(8)(9)(10). However, the widespread disparity in distribution and access of the vaccines (11,12) as well as the lack of adherence to public health measures to control the spread (13)(14)(15) saw unchecked community spread in different geographical locations. This constellation of factors gave rise to multiple mutations in the genetic make-up of the pathogen, resulting in different variants (16).…”

Section: Introductionmentioning

confidence: 99%

COVID-19 Recovery Patterns Across Alpha (B.1.1.7) and Delta (B.1.617.2) Variants of SARS-CoV-2

Kumar

Quadri

Alawadhi³

et al. 2022

Front. Immunol.

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BackgroundB.1.1.7 (alpha) and B.1.617.2 (delta) variants of concern for SARS-CoV-2 have been reported to have differential infectivity and pathogenicity. Difference in recovery patterns across these variants and the interaction with vaccination status has not been reported in population-based studies.ObjectiveThe objective of this research was to study the length of stay and temporal trends in RT-PCR cycle times (Ct) across alpha and delta variants of SARS-CoV-2 between vaccinated and unvaccinated individuals.MethodsParticipants consisted of patients admitted to national COVID-19 treatment facilities if they had a positive RT-PCR test for SARS-CoV-2, and analysis of variants was performed (using whole genome sequencing). Information on vaccination status, age, sex, cycle times (Ct) for four consecutive RT-PCR tests conducted during hospital stay, and total length of hospital stay for each participant were ascertained from electronic medical records.ResultsPatients infected with the delta variant were younger (mean age = 35years vs 39 years for alpha, p<0.001) and had lesser vaccination coverage (54% vs 72% for alpha, p<0.001). RT-PCR Ct values were similar for both variants at the baseline test; however by the fourth test, delta variant patients had significantly lower Ct values (27 vs 29, p=0.05). Length of hospital stay was higher in delta variant patients in vaccinated (3 days vs 2.9 days for alpha variant) as well as in unvaccinated patients (5.2 days vs 4.4 days for alpha variant, p<0.001). Hazards of hospital discharge after adjusting for vaccination status, age, and sex was higher for alpha variant infections (HR=1.2, 95% CI: 1.01–1.41, p=0.029).ConclusionPatients infected with the delta variant of SARS-CoV-2 were found to have a slower recovery as indicated by longer length of stay and higher shedding of the virus compared to alpha variant infections, and this trend was consistent in both vaccinated and unvaccinated patients.

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Impact of super-spreaders on COVID-19: systematic review

Cited by 14 publications

References 14 publications

Physical distancing versus testing with self-isolation for controlling an emerging epidemic

Physical distancing versus testing with self-isolation for controlling an emerging epidemic

Age Dependent Epidemic Modeling of COVID-19 Outbreak in Kuwait, France, and Cameroon

COVID-19 Recovery Patterns Across Alpha (B.1.1.7) and Delta (B.1.617.2) Variants of SARS-CoV-2

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