106 votes
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What's the evidence against SARS-CoV-2 being engineered by humans?

At the moment, there is very little scientific literature about this, but I found two papers that address the problem and are fairly easy to understand. You can find them in the references. Reference ...
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56 votes

What is the benefit of fever during infections?

Fever is a trait observed in warm and cold-blooded vertebrates that has been conserved for hundreds of millions of years (Evans, 2015). Elevated body temperature stimulates the body's immune ...
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47 votes
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Is the Common Cold an Immune Overreaction?

Can someone die of the common cold? No. The common cold is a clinical syndrome restricted to upper respiratory tract involvement. By clinical syndrome, I mean it is the constellation of symptoms (...
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38 votes
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Why don't we develop immunity against common cold?

Long lasting immunity is obtained by means of the adaptive immune system, and mainly involves the development of antibodies that identify specific parts (epitopes) of the pathogen's proteins. Common ...
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37 votes
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Why don't viruses cause wounds?

A virus does not destroy that many cells before it is exterminated by the immune system or before the host dies. Perhaps even more crucially, viruses typically target a very specific type of cell — ...
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35 votes
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Has there even been a clinical study where healthy volunteers consented to be infected with a pathogen?

This is a great biological question! It asks a lot about how empirical science is done in the field of modern biology. I'm glad we encourage such questions from curious people who want to learn more. ...
27 votes

Why don't we develop immunity against common cold?

First, I want to note that ddiez has a good answer, but I thought this was good question to have a more expanded answer on immunology and pathogenesis. The First thing we need to establish what is a &...
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26 votes
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Did the Zika virus mutate?

There is one main answer to this question: The Zika virus spreads so fast because it never emerged in this part of the world. Hence there is no natural immunity available in the population and a lot ...
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24 votes
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Why was disease transfer to the Americas one-way?

In "Guns, Germs, and Steel" Jared Diamond includes quite a bit on this topic. His conclusion is that Europeans, and old world humans in general were much more exposed to their farm animals, often ...
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24 votes

What's the evidence against SARS-CoV-2 being engineered by humans?

If you need more [counter]evidence, there's a newer paper "The proximal origin of SARS-CoV-2" by Andersen et al. (March, 17) that touches on the same topic. The paper brings up two reasons ...
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19 votes

Why was disease transfer to the Americas one-way?

There is at least one important exception - it is generally thought that syphilis came to Europe from the Americas.
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18 votes

Has there even been a clinical study where healthy volunteers consented to be infected with a pathogen?

Yes, Dr Barry Marshall self administered Helicobacter pylori to investigate whether it causes stomach ulcers. He won a Nobel Prize for it. https://en.wikipedia.org/wiki/Barry_Marshall
17 votes
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How the conjunctivitis virus spread just by seeing a person's eye who is infected

You can't catch conjunctivitis by looking at someone, but you can spread it around by touching your eye and touching something else, which then can pass the virus to someone else (viral conjunctivitis ...
16 votes

Did the Zika virus mutate?

A mutation isn't necessary to explain the outbreak in the Americas, given the low immunity of the population, but there is tentative evidence that this strain of the Asian lineage of the virus may ...
15 votes
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To what extent is Ebola airborne? (aerosols)

Interesting question and hard to answer definitively. First of all: It seems still pretty clear that the major (and by far most important) infection route comes from direct contact with infected ...
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14 votes
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Septic Shock: I'll kill myself before you kill me

The important thing to recognize about the host response to sepsis is that it is actually a generalization of mechanisms used in local infection response by the innate immune system. When an animal ...
12 votes
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How long does the Ebola virus remain infectious on contaminated items or surfaces?

This really depends on the environment, one study (listed below as reference 1) found that the Ebola virus can survive under ideal conditions on flat surfaces in the dark for up to six days - see the ...
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12 votes
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Does a microwave oven disinfect food?

Microwave ovens can indeed kill bacteria in food by heating them to high temperatures. For example, this article found that microwave heating could kill all of the Salmonella bacteria in a chicken ...
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12 votes

Why don't viruses cause wounds?

The innate immune system is remarkably good at providing a first line of defense. Viruses don't just march into your body uncontested. They basically have to fight for every square centimeter of ...
11 votes
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Why does a Urinary Tract Infection cause a strong, persistent urge to urinate?

Nerve endings exist in a more or less homeostatic interstitial fluid medium which when disturbed in certain ways result in depolarization. This is a very simple explanation, but basically correct. ...
11 votes

Has there even been a clinical study where healthy volunteers consented to be infected with a pathogen?

All the time! For example Flucamp does research on influenza, rhinovirus and (non-SARS) coronaviruses, that involves deliberate infection of paid volunteers. When the trial starts, we only ...
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10 votes

If ants have an antibiotic gland, how can they spread hospital infections?

I have worked in hospitals (US) most of my life, treating both community-acquired, and more pertinently to this question, nosocomial (hospital acquired) infections, and have read many articles on the ...
10 votes

Is the Common Cold an Immune Overreaction?

The common cold is not the result of a single virus. Over 200 viruses can cause a cold, so specific symptoms could vary depending on the virus in question. However, in the absence of an immune ...
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9 votes
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Acquiring Covid-19 vaccination through kissing with viral vector vaccinated person

No, this is not possible, as the vectors used for the vaccination cannot replicate anymore. Some of the genes necessary for this step have been removed from the viral genome to prevent the ...
  • 49.4k
9 votes

How does the first organism infected by a disease get infected?

Viruses evolve like all other biological species. The family of SIVs that gave rise to HIV goes back millions of years across many hosts. Just like you can build a "family tree" out of ...
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8 votes

Why don't viruses cause wounds?

Smallpox, now eradicated, caused severe lesions. In those who survived: the lesions often turned into scars.
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7 votes

If ants have an antibiotic gland, how can they spread hospital infections?

Ants can and do carry loads that are several times their own weight. I grew up in an area with a lot of ants, and a common scene was a long trail of ants acting as a food supply line. Once a morsel is ...
7 votes

What is the benefit of fever during infections?

Fever normally under hypothalamic heat center's control which stays at limbic system of brain . Hypothalamus sets its own set point 36.4-37.2 in healthy peoples by some molecules named exogenous and ...
7 votes

Why are the bacteria that cause hospital-acquired infections resistant to many antibiotics?

Hospitals have certain features: They are full of people immunocompromised in some way (old, exposed tissue, on steriods etc.) They are full of people with pathogens They are full of doctors who will ...
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7 votes

Do organisms use detergents to fight off viruses?

To answer your question, consider why soap is effective against bacteria and viruses. The chemistry of detergents allows them to interrupt the lipid layer that surrounds cells and some viruses. ...
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