Severe Acute Respiratory Syndrome Coronavirus 2 Transmission Potential, Iran, 2020

Muniz-Rodriguez, Kamalich; Fung, Isaac Chun Hai; Ferdosi, Shayesteh R.; Ofori, Sylvia K.; Lee, Yiseul; Tariq, Amna; Chowell, Gerardo

doi:10.3201/eid2608.200536

Cited by 40 publications

(37 citation statements)

References 7 publications

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“…This data reports cases aggregated at the country level and may suffer from a number of biases: it does not account for reporting delays; the growth over time in the number of cases may partly be ascribable to the increase in testing capacity; total cases represent the superimposition of different, asynchronous epidemics in multiple parts of the country, a majority of which coming from the highly urbanized Addis Abeba area 9 . However, we show that, assuming no restriction to school contacts, the reproduction number estimated by the model is in the range 1.87-2.18, just slightly lower than estimates of the SARS-CoV-2 basic reproduction number from other countries 25,26,27,28 . Moreover, our conclusions remain robust when considering a 20% increase or a 20% decrease of the reproduction number.…”

Section: Discussioncontrasting

confidence: 56%

Demography, social contact patterns and the COVID-19 burden in different settings of Ethiopia: a modeling study

Trentini

Guzzetta

Galli

et al. 2020

Preprint

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BackgroundCOVID-19 spread may have a dramatic impact in countries with vulnerable economies and limited availability of, and access to, healthcare resources and infrastructures. However, in sub-Saharan Africa a low prevalence and mortality have been observed so far.MethodsWe collected data on individuals’ social contacts in Ethiopia across geographical contexts characterized by heterogeneous population density, work and travel opportunities, and access to primary care. We assessed how socio-demographic factors and observed mixing patterns can influence the COVID-19 disease burden, by simulating SARS-CoV-2 transmission in remote settlements, rural villages, and urban neighborhoods, under the current school closure mandate.ResultsFrom national surveillance data, we estimated a net reproduction number of 1.62 (95%CI 1.55-1.70). We found that, at the end of an epidemic mitigated by school closure alone, 10-15% of the overall population would have been symptomatic and 0.3-0.4% of the population would require mechanical ventilation and/or possibly result in a fatal outcome. Higher infection attack rates are expected in more urbanized areas, but the highest incidence of critical disease is expected in remote subsistence farming settlements.ConclusionsThe relatively low burden of COVID-19 in Ethiopia can be explained by the estimated mixing patterns, underlying demography and the enacted school closures. Socio-demographic factors can also determine marked heterogeneities across different geographical contexts within the same country. Our findings can contribute to understand why sub-Saharan Africa is experiencing a relatively lower attack rate of severe cases compared to high income countries.

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Section: Discussioncontrasting

confidence: 56%

Demography, social contact patterns and the COVID-19 burden in different settings of Ethiopia: a modeling study

Trentini

Guzzetta

Galli

et al. 2020

Preprint

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“…Assumptions about the length of the infectious period ranged between 5.8 to 20 days and assumptions on the serial interval ranged between 4.4 to 14 days. Three studies applied methods to control for surveillance bias in case reporting [30][31][32], the potential occurrence of individual variation in transmission was included in two studies [30,33], and one study accounted for sub-exponential growth in the early stages of the outbreak [34].…”

Section: Overall Findingsmentioning

confidence: 99%

“…On the relationship between R0 and the generation time/serial interval: Several studies rely on the distribution of the generation time or its proxy the serial interval (time between the infection events or symptom onset of primary and secondary cases, respectively) in the estimation of R0 [30,34,37,41,44].…”

Section: Drivers Of Variation: I) Contextmentioning

confidence: 99%

“…The generalised growth model is capable of explicitly accounting for a subexponential growth phase [68,69]. One study applied this framework incorporating a scaling factor (the deceleration of growth parameter [68]) to account for the sub-exponential growth phase [34]. Although the effect of different scaling factor values on R0 was not explored, it is expected that the further that epidemic growth is from exponential, the lower R0 would be [68].…”

Section: Exponential Growthmentioning

confidence: 99%

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The basic reproduction number of SARS-CoV-2: a scoping review of available evidence

Barber

Griffin

Casey

et al. 2020

Preprint

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Background: The transmissibility of SARS-CoV-2 determines both the ability of the virus to invade a population and the strength of intervention that would be required to contain or eliminate the spread of infection. The basic reproduction number, R0, provides a quantitative measure of the transmission potential of a pathogen. Objective: Conduct a scoping review of the available literature providing estimates of R0 for SARS-CoV-2, provide an overview of the drivers of variation in R0 estimates and the considerations taken in the calculation of the parameter. Design: Scoping review of available literature between the 01 December 2019 and 07 May 2020. Data sources: Both peer-reviewed and pre-print articles were searched for on PubMed, Google Scholar, MedRxiv and BioRxiv. Selection criteria: Studies were selected for review if (i) the estimation of R0 represented either the initial stages of the outbreak or the initial stages of the outbreak prior to the onset of widespread population restriction (lockdown), (ii) the exact dates of the study period were provided and (iii) the study provided primary estimates of R0. Results: A total of 20 R0 estimates were extracted from 15 studies. There was substantial variation in the estimates reported. Estimates derived from mathematical models fell within a wider range of 1.94-6.94 than statistical models which fell between the range of 2.2 to 4.4. Several studies made assumptions about the length of the infectious period which ranged from 5.8-20 days and the serial interval which ranged from 4.41-14 days. For a given set of parameters a longer duration of infectiousness or a longer serial interval equates to a higher R0. Several studies took measures to minimise bias in early case reporting, to account for the potential occurrence of super-spreading events, and to account for early sub-exponential epidemic growth. Conclusions: The variation in reported estimates of R0 reflects the complex nature of the parameter itself, including the context (i.e. social/spatial structure), the methodology used to estimate the parameter, and model assumptions. R0 is a fundamental parameter in the study of infectious disease dynamics however it provides limited practical applicability outside of the context in which it was estimated, and should be calculated and interpreted with this in mind.

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“…Chinese scientists promptly identified the viral sequence isolated from patients and confirmed the human-to-human transmission of the virus. The R 0 (the basic reproduction number) of the virus was computed by scientists of various countries and declared to be about 2.2 and even higher (from 1.4 to 6.5) ( D’Arienzoa and Coniglio, 2020 ; Muniz-Rodriguez et al, 2020 ). Clinically, patients with COVID-19 showed respiratory symptoms that were initially very similar to those of other respiratory viral infections.…”

Section: Introductionmentioning

confidence: 99%

Association of vitamin D with the modulation of the disease severity in COVID-19

et al. 2020

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Severe Acute Respiratory Syndrome Coronavirus 2 Transmission Potential, Iran, 2020

Cited by 40 publications

References 7 publications

Demography, social contact patterns and the COVID-19 burden in different settings of Ethiopia: a modeling study

Demography, social contact patterns and the COVID-19 burden in different settings of Ethiopia: a modeling study

The basic reproduction number of SARS-CoV-2: a scoping review of available evidence

Association of vitamin D with the modulation of the disease severity in COVID-19

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