Questions tagged [epidemiology]

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

Filter by
Sorted by
Tagged with
0
votes
0answers
23 views

Would this be classified as a cross-sectional study design?

Let's say I'm conducting a study in which persons recently diagnosed with an infectious disease were recruited to provide a variety of different specimens and answer standardized clinical survey ...
-1
votes
1answer
74 views

Why do some viruses get deadlier over time?

I was wondering what reasons are that make some viruses become more lethal over time. By "more lethal", I am not referring to acquiring more mutations which make the virus more infectious ...
-2
votes
1answer
71 views

Fluctuations in disease burden of respiratory viruses (especially influenza/coronaviruses)

Compared to peaks in terms of disease burden (morbidity and mortality, or incidence of severely symptomatic cases and deaths caused by a viral strain within a population), is the relatively light ...
1
vote
1answer
33 views

How can the recurrence risk ratio be calculated?

The recurrence risk ratio is calculated as follows: $$ \lambda_s = \frac{\text{risk of sibling}}{\text{risk in population}}$$ where the risk of sibling refers to the risk that a sibling has to get the ...
4
votes
2answers
194 views

Why there aren't any pandemic diseases by prions?

Learning biology in school, I became interested in the fact that there aren't any diseases by prions which are globally infectious (as far as I know), unlike diseases by viruses (ex. COVID-19, SARS ...
-2
votes
1answer
57 views

Virus variant transmissibility: empirical data or spike protein shape?

Well first I am not in the field of Biology or Medical Sciences. Since these days we are waiting scientists to tell us if the Indian variant of SARS Cov 2 is more transmissible than the original virus,...
4
votes
2answers
105 views

Which viruses still present today caused a deadly pandemic/epidemic in the past?

The current Covid-19 pandemic and its virus Sars-Cov-2 can be dangerous, especially for vulnerable groups like the elders. But however, I have seen studies that this virus become less dangerous in the ...
0
votes
1answer
43 views

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, ...
0
votes
0answers
57 views

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 ...
-5
votes
2answers
58 views

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 ...
3
votes
1answer
221 views

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 ...
3
votes
0answers
83 views

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 ...
0
votes
1answer
87 views

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-...
4
votes
1answer
145 views

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$...
0
votes
0answers
20 views

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 ...
0
votes
1answer
81 views

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 ...
7
votes
1answer
696 views

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 ...
4
votes
1answer
260 views

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 ...
-1
votes
1answer
89 views

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 ...
1
vote
1answer
58 views

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 ?
2
votes
0answers
83 views

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 ...
7
votes
1answer
218 views

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 ...
58
votes
2answers
12k views

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. ...
0
votes
2answers
84 views

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 ...
1
vote
0answers
72 views

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 ...
2
votes
2answers
65 views

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 $\...
2
votes
2answers
209 views

Can Coronaviridae mutate into something as dangerous as Flioviridae? [closed]

Can coronaviruses mutate to an extent to get as dangerous as fliovirusues such as Marburg viruses, Ravn or Ebola Zaire?
3
votes
2answers
162 views

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., ...
0
votes
1answer
87 views

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 ...
-1
votes
1answer
48 views

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 ...
21
votes
2answers
4k views

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 ...
1
vote
1answer
30 views

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 ...
0
votes
2answers
105 views

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 ...
1
vote
1answer
102 views

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?
0
votes
2answers
48 views

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 ...
34
votes
4answers
5k views

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 ...
0
votes
1answer
53 views

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 ...
0
votes
1answer
53 views

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 ...
1
vote
1answer
62 views

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 ...
46
votes
2answers
6k views

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 ...
3
votes
2answers
74 views

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 ...
13
votes
2answers
677 views

Why are bats the source of dangerous coronavirus pandemics?

Why do coronaviruses come from bats? I mean, why precisely coronaviruses and not (for instance) herpesviruses? It looks like bats host more zoonotic viruses (per species) than rodents, although they ...
0
votes
1answer
45 views

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 ...
7
votes
1answer
200 views

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 ...
10
votes
2answers
5k views

How exactly does alcohol solution kill or neutralize viruses?

To reduce the risk of infection by viruses (including 2019-nCoV) the CDC suggests: Wash your hands often with soap and water for at least 20 seconds. Use an alcohol-based hand sanitizer that contains ...
7
votes
1answer
91 views

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 ...
9
votes
1answer
953 views

Is COVID-19 claimed to get less deadly over time? If so, why?

From a TV news report of a press conference from (I think) the German Robert Koch Institute, I remember hearing an expert declare that he was expecting COVID-19 to get less deadly over time. ...
-1
votes
1answer
123 views

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 : ...
3
votes
1answer
504 views

Is the Basic Reproduction Number in epidemiology dependent on population size?

I am assuming that the basic reproduction number $R_0$ of a disease depends on the population size (or the number of susceptible individuals). When $R_0$ is reported it seems to be without such ...
0
votes
2answers
164 views

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 ...