Questions tagged [epidemiology]

The study of the distribution, incidence, and potential control of a disease.

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University Curriculum Using NEXTSTRAIN.ORG [closed]

I seek undergraduate-level curricula (i.e. lab activities) which utilize the website NEXTSTRAIN.ORG. Any good examples out there?
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Relationship between BMI and age?

I'm trying to study how age as a confounder may affect the relationship between commute mode and BMI (and design a research proposal). To explain age as a potential confounder, I compared age to ...
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Covid-19 is a respiratory illness. So how could you catch it by touch?

The U.S. department of agriculture put out a statement in February 2021 in which they wished to underscore that at the time there is no epidemiologic or scientific information that COVID-19 spreads ...
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The probability meaning of Covid variants

In the CDC webpage about Covid-19's variants the next sentence appears: This (the United Kingdom) variant spreads more easily and quickly than other variants. In the ECDC paper about Covid-19's ...
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How are vaccines mass-produced?

I have a background in product design and so am familiar with with how most things are mass-produced — food, machines, etc. But I've been able to find very little information on how vaccines are mass-...
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What is the consensus in the scientific community over COVID-19's mode of transmission?

I've read from many news and scientific sources that COVID spreads primarily through respiratory droplets, but I've also read multiple sources that have said we don't entirely know yet. Is it fomites, ...
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Do partial (nighttime) curfews curb the spread of epidemics (and via which mechanisms)? [closed]

Do partial (e.g., nighttime) curfews curb the spread of epidemics? What is the (epidemiological) mechanism by which partial curfews curb the spread of epidemics? Is there evidence from past or present ...
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Can an epidemic span multiple countries?

Can an epidemic centralised in one area be still considered an epidemic if it spans multiple countries? If so what is the limit to the number of countries a disease can infect in one region before it ...
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Are there any examples of viruses that have jumped from reptile to human?

I know that there are plenty of examples of zoonosis occurring from reptiles to humans that involve bacterial pathogens, (e.g. Salmonella) but are there any instances of viruses being transferred from ...
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1answer
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COVID-19 deaths by year of birth?

Are there (global, country, etc.) data of COVID-19 deaths (or hospitalization) by year of birth? I was able to found them only by "age group", the meaning of this being usually an interval ...
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How are latence period and duration of infectiosity defined?

I assume that infectiosity of an individual is not a binary property but a quantity that grows and decays gradually, very much like the number of infected or infectious individuals in a population. ...
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What kind of people are more likely to catch COVID-19?

It is well known that people of old age or with respiratory problems are more vulnerable by the effects of COVID-19. However, I wasn't able to find information on any similar trends on catching the ...
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About how many covid-19 virus particles is required in the human body before infection and sickness follows?

Our immune systems are often able to destroy germs and virus particles. About how many of them does it take to make a 70 year old healthy male sick ? Any ideas ?
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Why is there no herd immunity against common cold coronaviruses?

In discussions of herd immunity against SARS-CoV-2 the underlying assumption usually appears to be that the virus basically stops spreading once a sufficient percentage of the population has overcome ...
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Estimate parameters from epidemic curve: how to proceed?

I am trying to build an epidemic model based upon the SIRD model, but I need to estimate the parameters for this model (α = infection rate, β = recovery rate and γ = mortality rate). What is the ...
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How to fit simulated with measured data having systematic errors?

Consider a given time series of measured data, i.e. the number of persons tested positive for COVID-19. And consider a simulation - consisting of a model, possibly fed with some parameters estimated a ...
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Are the social-distancing measures implemented against SARS-CoV-2 also suppressing the spread of other viruses?

With social-distancing measures being implemented in many countries I would expect other viruses, like the ones that cause seasonal flus, to have also a hard time propagating in these circumstances. ...
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Factors of infection rate

I refer to J.H. Jones' Notes on R0. Preliminaries The standard SIR model consists of a system of three differential equations $$ds/dt = -\beta s i$$ $$di/dt = \beta s i - \nu i$$ $$dr/dt = \nu i$...
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Interpreting the reciprocal of $R_0$

$R_0$ is the average number of secondary cases arising from a single infectious individual in a fully susceptible population. In many of the compartmental models for epidemiology, the parameter $\...
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How to model social structure in SIR models

I refer to J.H. Jones' Notes on R0. More details in this question at Mathematics SE: How does the reproduction number depend on characteristics of the physical contact graph of a population? The ...
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The role of duration of contact in SIR models

I refer to J.H. Jones' Notes on R0. The basic SIR model - as described in Jones' Notes - considers three factors that make up the reproduction number: $\tau$ = the transmissibility (i.e., ...
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The role of duration of infectiousness in SIR models

I refer to J.H. Jones' Notes on R0. The basic SIR model - as described in Jones' Notes - considers three factors that make up the reproduction number: $\tau$ = the transmissibility (i.e., ...
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Why are men more susceptible to severe COVID-19?

It seems that globally, men are more susceptible to severe COVID-19 than women: https://www.theguardian.com/world/2020/mar/26/men-are-much-more-likely-to-die-from-coronavirus-but-why This is seen in ...
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Do we know if dogs are asymptomatic transmiters of sars-cov-2?

Dogs do not use mask when going for a walk nor they observe the security distance. On the contrary, they frequently join their noses, and put their noses where other dogs had put them before or had ...
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COVID-19 Infection rate related to population size?

Recently, in the UK's daily government briefing they started showing the graphs that compare national death rates, adjusted by the population size of each country. I understand the various reasons ...
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Is there a vaccine against the plague (Yersinia pestis)?

There seems to be recurrent events of infections of the plage (Yersinia pestis), from the well known Justinian plague to the Black Death and to recent years. In fact, two cases were reported in China ...
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What does (deaths / (resolved + deaths)) describe in an emerging epidemic?

It would seem in a emerging epidemic, where the time to resolve a disease is long, an evaluation might be used such as: (predictive mortality rate) = (deaths) / (deaths + resolved) Is this a ...
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What happens to a virus SARS-CoV-2 on an object?

Many articles say that "the coronavirus" — they probably speak of the SARS-CoV-2 — can "remain alive" for so many hours on some surfaces, so many days on some other surfaces. For example, "the virus ...
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Why does the SARS-CoV2 virus not remain infectious forever? Or does it?

Given that the majority of biologists do not currently consider viruses to be alive, a virus can never die. It can, however, get destroyed by long exposures to soapy water, alcohol, and apparently ...
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How verified experimentally is the Marginal Value Theorem for viruses?

Reading some Stanford notes on R0, they get to MVT and optimal virulence: Consider a directly-transmitted infection from which there is no recovery (e.g., Herpes Simplex). The population ...
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Can swarming locusts act as a vector for any human pathogens?

What human pathogens can the locusts currently swarming in Africa act as a vector for? E.g. can the locust swarm 'become a reservoir for' SARS-CoV-2? Measles? Ebola?
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Why do some viruses cease being a problem even though no vaccine or cure is found?

No vaccine or cure has been found for SARS-CoV or MERS-CoV yet the world is not too concerned about them. How can it be? Did all people who had those viruses die or do viruses just randomly decide to ...
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Could an exposure to a small amount of viruses result in an easier course of the disease?

According to Gunther Hartmann (Professor of Clinical Chemistry and Pharmacology at the University of Bonn) cited in this article (Süddeutsche Zeitung, in German) Die Zahl der Erreger hat bei ...
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Are specific primers or detectors, or both, used in COVID-19 tests?

I am trying to learn about the rRT-PCR testing procedure used to test for COVID-19, but I am slightly confused on one point. Are highly specific primers used with a non-specific detector, or are ...
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How likely is to develop an infection from a single virion entering a single cell? [closed]

Is there any research (including mathematical or computational modelling) regarding how likely it is to infect an organism starting from a single virion entering a single cell? I am interested in any ...
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1answer
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Does the Abbott ID NOW coronavirus test return a positive result if you take it while you're still in the incubation period? [closed]

It seems like Abbott's ID Now test works by detecting the virus directly as opposed to checking for antibodies? If the test result is negative does that mean you don't have the virus? Or does that not ...
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If rabies always kills its hosts, must there be some animal that is an asymptomatic carrier?

I searched a lot on the Internet, but I am not clear about the spread of the rabies virus. As I understand, rabies kills any animal it infects—cats, dogs, foxes, bats, humans. If it kills all of its ...
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Do we know of any “species ending bugs”?

Are we aware of a "bug" (virus, bacterium, prion, ...) that has completely exterminated an entire species? Either through direct observation or maybe some form of archeological evidence? If not, are ...
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Can far-UVC light be safely used as germicide? (help understanding a paper)

I've been trying to familiarize myself with the literature on far UVC light as a germicide. My question mostly pertains to figure 4 of this paper. The paper investigates the efficacy of 207 nm light ...
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1answer
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Covid-19: Is it possible to get to r0 < 1 through social distancing measures? [closed]

I'm trying to wrap my head around some of the information I'm reading about how to fight Covid-19 and conflicting opinions about how much "social distancing" is required to avert a disaster, or ...
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If every person between 15-60 had an immune system equal to the healthiest people, would this affect the spread of coronavirus? [closed]

Has anyone calculated the speed or breadth of the spread of something like coronavirus (or any cold, flu, airborne pathogen) based on how well the population can master the virus with their immune ...
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Would “Pox Parties” of the young/healthy (while isolating the vulnerable) be an effective method of combating the COVID-19 outbreak?

It is commonly said that most people, especially the healthiest would only develop mild syndromes. Therefore, shouldn’t we, instead of confining all the population as a whole proceed as follows : ...
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Is there any biological evidence corroborating a historians' claim that the 1918 “Spanish flu” originated from China?

A 2014 History article says According to new research by a Canadian historian, the 1918 flu outbreak that killed 50 million people originated in China. [...] Humphries found medical records ...
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If the covid-19 appeared once, could it reappear anytime?

Governments are imposing confinement measures on their populations, trusting that if there is no more transmission the virus will die out. But since this coronavirus appeared a first time, what could ...
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Is COVID-19 more deadly than swine flu?

I have a question about the novel coronavirus and swine flu. How do the death rates compare between the two diseases? How do the transmissions and rate of transmission compare? Was a vaccine ...
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Is a nightly curfew an effective intervention strategy for limiting the spread of an infectious disease? [closed]

The governing bodies of several geographic areas hit by disease outbreaks will sometimes impose a nightly curfew on their citizens, restricting or limiting the ability of their citizens from going ...
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How can we calculate the constants of the SIR model?

I am not a biologist by profession, but I am attempting to implement a simple SIR model from the following paper. The paper assumes the following constants are known: rc = growth rate of ...
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Are all emerging viral diseases of the past 100 years zoonoses?

From my basic understanding: The viruses causing Ebola, Sars and Covid-19 are all the result of a zoonosis, meanings that the viruses have passed from animals to humans. So my question is: Are all ...
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1answer
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What percentage of individuals infected with COVID-19 don't have symptoms?

There are various statistics estimating mortality of COVID-19 infections, based on how many diagnosed people have died. These numbers are used by various media to extrapolate how many people will die ...
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Could total 2020 flu deaths be low due to Covid19 countermeasures?

A working assumption is that Covid19 countermeasures will also reduce seasonal flu transmission and mortality. Could this effect be so large that the 2020 total global deaths from both causes will be ...