Questions tagged [test]
This tag should be used for questions about Biomedical tests used in diagnosis of health conditions.
65
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12 views
Litmus test for decay fluids
Assume a body is in the first 3 days of decay. Is there a test (like luminal for blood) to test for any bodily decay fluids on the floor?
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35 views
Which is the best test to confirm a Lidocaine allergy?
As per my study, there are two tests which are performed to confirm/dispute a Lidocaine allergy.
Patch test
Intradermal Test
Which is the most conclusive of the above? Are there any other tests?
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23 views
Covid-19: what's (usually) the probability of getting a negative PCR result conditioned on getting a positive antigen test result first?
It's been pointed out to me that most studies comparing antigen with PCR tests either consider these as independent tests carried out over the whole sample (and report concordance/discordance that way,...
2
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2answers
97 views
Antigen vs PCR test
In the Czech Republic there is now mandatory testing for factory employees.
Anecdotally I am now being told by people I am acquainted with, who run medium sized firms here, that their employees are ...
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19 views
What's the difference between rt-PCR COVID-19 test using different lengths of nose swab?
I read:
Our nose swabs only enter the nose ½ inch, not all the way up the nostril, ensuring no pain or damage.
A few months ago, I had a COVID-19 test with a nose swabs that looked like ~5cm.
What's ...
0
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1answer
45 views
Covid19 Rapid serological tests and Vaccine
Let's say that once I'm vaccinated I try the rapid serological test and the result is negative. My question is: let's admit that the reliability of the test is 100%; does it mean that the vaccine didn'...
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19 views
Is there a simple way to quantify viral content beeing exhaled by a person potentially independent of the specific virus type?
As far as I have understood it, persons who have contacted virusses (that are to a substantial part transmitted through the air, such as covid-19) tend to be only or most strong infectuous during a ...
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14 views
Can an individual who has had a covid-19 vaccination test positive and is that a problem?
Can an individual who has had a covid-19 vaccination test positive and is that a problem?
Up to now and for some time to come, testing has been important to help control the spread of this disease.
...
0
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1answer
71 views
Do having multiple COVID tests decrease the chance of a false negative? [closed]
With my work we're required to get frequent COVID tests. Sometimes it happens we get COVID tested twice before the first day of work. So for example if I'm working Saturday I may get tested the ...
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30 views
why isn't this finger stick antibody test (for covid) in more common use?
I had some concerns about going to the dentist, because dental treatment involves a lot of aerosolized droplets and seems like a good way to get a high dose of covid.
My dentist's office (in Manhattan)...
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53 views
Are COVID-19 patients infectious even if test results are negative?
With Covid-19, are people infectious in the first days after infection before they test positive on a Covid test?
I have learned that Covid-19 tests are ineffective in the first few days after being ...
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20 views
How does ELISA test for COVID antibodies detect antibodies specific to SARS-CoV-2?
I know how ELISA can be used to detect particular antigens by using antibodies specific to the antigen.
How is it being used to detect SARS-CoV-2 specific antibodies?
I realise that one possible ...
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0answers
45 views
Does the stool test for Helicobacter pylori show only acute infections?
There are four options when being tested for Helicobacter pylori - blood test, stool test, breath test and scope test. (Helicobacter pylori (H. pylori) infection)
Scope test is definitely the most ...
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0answers
30 views
Who's RNA does the rRT-PCR test for SARS-CoV-2 target?
The official guide for laboratory testing for coronavirus disease in suspected human cases by the WHO explains the procedure for testing a sample. On page two it states that the test
is based on ...
1
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3answers
431 views
What is the principal goal in pooled COVID-19 testing?
Pooled testing for COVID-19 is being considered as a method to ramp up testing Stat News. Apparently this is being considered by the White House coronavirus team.
It's not clear to me what the goal of ...
5
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2answers
117 views
Has China announced any results from their massive (new) COVID-19 testing program in Wuhan?
About 10 days ago China announced a plan to test the entire population (~11 million) of Wuhan. And more recently they've announced testing over 1 million per day in the city. But have any results been ...
1
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1answer
60 views
Why does CDC's RT-PCR protocol for Covid-19 use the N gene, but the Charite one the E gene and RdRp?
The Charite protocol mentioned among other things that
Of note, the N gene assay also performed well but was not subjected to intensive further validation because it was slightly less sensitive.
...
2
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1answer
22 views
What's the margin of error for the estimate on the percentage of people infected with latent tuberculosis?
According to a 2011 (news) article in Science
More than a third of the world's population is estimated to be infected with Mycobacterium tuberculosis. Most people's immune system can keep the ...
2
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0answers
61 views
Is there a possibility of transmission of COVID-19 during sample collection process?
Is there a possibility of transmission of COVID-19 during sample collection process from safety kits worn by sample collecting person to the suspected infected person whose sample is being collected?
...
10
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1answer
78 views
Can the specificity of a COVID-19 antibody test be improved by testing twice?
My question is fairly simple: There is a COVID-19 antibody test with a worst-case specificity of 98%, meaning that it yields potentially up to 2% false positives.
While that number is not bad it is ...
2
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1answer
39 views
How often is a Ct of 30 (or more) using the Charité protocol a false positive for Covid-19?
A French case report that has received widespread media attention suggests (actually stated in pretty strong terms in the paper) that Covid-19 was already spreading in France in December 2019. (In ...
2
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1answer
64 views
Is there a graph over time of Covid-19 test positivity rate in the US?
Back in mid-April some commentary/news was that the US was not doing enough testing as evidenced by the test positivity rate:
America’s 20 percent positivity rate is disquieting. The U.S. did almost ...
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1answer
31 views
COVID-19: Is it possible to use the specimen collected through swabs for multiple tests
I am an engineer and currently doing some modeling of COVID-19 testing from a math perspective. I was reading through COVID-19 articles related to testing and I had the following doubt:
If a ...
2
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1answer
127 views
Are there methods available to determine ongoing cell damage in Covid-19 survivors?
It took years for many of those first infected with Hepatitis-C, to learn that it was destroying their livers. It took years for those with HIV to learn their immune systems were being destroyed.
Is ...
2
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0answers
46 views
Is there a colorblindness test for non-verbal children?
The colorblindness tests that I have seen have all relied on getting a verbal answer from the test subject. Examples are "What number do you see in this picture?".
Most people can follow a test ...
2
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0answers
50 views
Can having other coronaviruses like HCoV-OC43 give positive results when testing for SARS-CoV-2? [closed]
Is it possible that a person having coronaviruses other than SARS-CoV-2 test positive for SARS-CoV-2 in rapid (antibody testing kits) as well as RT PCR tests? Searching around the internet didn't ...
2
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1answer
131 views
Why isn't saliva sampling used when sampling for the presence of respiratory diseases?
Previously I've asked a question focused on COVID-19: Why did countries initially presume that detecting COVID-19 requires a deep nasal swab?
@Fizz provided the following response:
So clearly it was ...
0
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1answer
45 views
Ratio of PCR to antibodies positive Covid-19 tests in studies outside USA?
CNN reported:
Two studies involving antibody blood tests in California -- one in Los Angeles County and the other in Santa Clara County -- so far have suggested that the number of people already ...
3
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0answers
42 views
Have cases of Covid-19 virus “reactivation” been noticed in countries besides China and South Korea?
April 10 news:
South Korean officials on Friday reported 91 patients thought cleared of the new coronavirus had tested positive again. [...]
Jeong Eun-kyeong, director of the Korea Centers for ...
6
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1answer
233 views
Why were so many Covid-19 negative tests among close contacts of the early Chinese cases?
In an ECDC report from Jan 17, it is said that
In China, 763 close contacts have been identified and monitored. Of these, 644 have completed the observation
period, while 119 remain under medical ...
2
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1answer
190 views
Are false positives from Cellex’s Coronavirus antibody test systemic?
The FDA just approved the first antibody test for the Coronavirus, made by Cellex. The test has a significant false positive rate though (see here). Now for a lot of tests, false positives can be ...
2
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2answers
377 views
Is South Korea doing “random” testing to combat covid-19 epidemic?
It is well-known that South-Korea has developed a powerful system of drive-through testing allowing them to test hundreds of thousands of person in the past two months. I was wondering whether the ...
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1answer
53 views
Why is the US not implementing large scale random Covid-19 testing to isolate asymptomatic people? [closed]
For this question, we will define surveillance as large scale random Covid-19 testing.
It is my understanding that:
surveillance enables the sorting of asymptomatic patients to be immediately ...
3
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2answers
888 views
Is it possible that COVID-19 virus exist in a human body, but be absent from samples taken from nose and back of throat?
As specified in this link, COVID-19 tests start with taking samples from the nose or back or throat of people.
Based on growth rate of this disease, I thought what if those samples are not positive (...
2
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1answer
35 views
What is the best protocol and criteria or policy for COVID-19 novel coronavirus testing?
What is the best protocol and criteria or policy for COVID-19 novel coronavirus testing?
During early U.S. infections, the criteria have been stringent due to limited test availability. As tests ...
4
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2answers
157 views
Can the capacity for COVID-19 tests be amplified by testing multiple samples mixed together and testing each only if positive?
If I understand it right, the following steps are to be taken into account:
Taking the sample: for the proposed method more samples would have to be taken.
Transporting the sample: more samples ...
2
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1answer
257 views
Is there a way to test for covid 19 after recovery?
I had symptoms that could have been corona symptoms last week. Unfortunately the testing capacity in my country (Germany) is not sufficient to test every person with symptoms at the moment, so only ...
2
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1answer
62 views
Which tests for Coronavirus/COVID19 are available and why seem they be so different?
Lately I'm reading about the good Coronavirus-Tests in South Korea, the faulty tests in the USA and the tests in Indonesia which are according to some Singapore newspapers not even working.
I wonder ...
5
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5answers
303 views
Why are people with COVID-19 symptoms being denied tests in the US?
I have heard several times now, from both people I personally know and from others who have posted their stories online that they do not qualify for COVID-19 testing.
From the stories I have heard, ...
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0answers
29 views
Pandemic: what is the term for the phenomenon of diffusion of tests and the spreading of the virus itself?
Context: from the "discovery" of the virus to its spreading
Before the discovery of sars-2 people died from sars-1, flu or pneumonia.
On the one hand, we have a new, previously unknown virus that is ...
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1answer
84 views
Having tested positive for COVID-19, will future tests be positive?
The World Health Organization indicates the COVID-19 genome is detected in assays. Once a patient tests positive, is there any reason not to expect that future instances of the same assay will result ...
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36 views
Tilt table test and beta blockers
Is tilt table test indicative with beta blockers for dysautonomia diagnosis? Or is it require drug withdrawal?
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0answers
169 views
Is there any figure about the accuracy of COVID-19 tests? [duplicate]
Recently I saw the local media (Romania) presenting a case that was initially considered COVID-19 positive and two subsequent tests led to negative results. As far as I know no official bothered to ...
6
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1answer
112 views
How do they test COVID-19 in drive-thru labs?
I've read that SARS-CoV-2 virus which causes COVID-19 disease can be tested with RT-qPCR.[1] It seems a somewhat lengthy procedure.
Then it's unclear to me: how do they test the virus in drive-...
3
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2answers
139 views
Technology prospects for genome sequencing at home and data protection
Ever since the end of the Human Genome project we have been witnessing the steady advance of genome sequencing technology and the decline of the price required to perform it. This lead to the advent ...
6
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1answer
163 views
What is the “best” or most accurate way to measure bodily hydration?
We all know that there are important benefits to good hydration. No question there.
I recently heard about a study (unfortunately I didn't catch the author's name) concluding that water is not close ...
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0answers
54 views
Are blood pressure numbers recorded during an office visit really meaningful?
On a recent visit to my primary care doctor the staff did the perfunctory BP reading. I had just sat down a few seconds prior. The reading was done only once.
Is such a reading at all meaningful?
I ...
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0answers
38 views
How often is a microscope used
I am planning on studying Graduate Entry into Medicine (4 years instead of 6 for people that already have a degree) in the UK.
Microscopes really irritate my eyes. I think in the UK we still have to ...
1
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2answers
59 views
Is there a convenient self test for Glaucoma?
I was identified as a glaucoma suspect and told to get rechecked for glaucoma annually. Knowing that glaucoma can move more quickly than that I was spooked and wound up creating my own self test. If ...
3
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1answer
35 views
Is there an inexpensive test (IE: perhaps a form of litmus paper?) for keeping tabs on oral pH at home?
My initial research into the effect of oral pH on health I came across an article that suggests that using fluoride products in an acidic environment has many negative effects on health and that 32% ...
