What is Infection: Definition and 36 Discussions

An infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection.
Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response.
Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths). The branch of medicine that focuses on infections is referred to as infectious disease.

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  1. pinball1970

    Potentially fatal dog parasite found in the Colorado River

    The paper https://www.mdpi.com/2076-0817/13/3/245 From the introduction. "Heterobilharzia americana is a schistosome trematode endemic to the Gulf Coast and South Atlantic region of North America, infecting raccoons, marsh rabbits, dogs, horses, nutria, bobcats, mountain lions, opossums, and...
  2. mktsgm

    Can synthetic viruses be created in a lab and become pathogenic?

    Today's technology is so advanced. Not only a part of a virus can be created in a lab, but with any viral genome, maybe it is possible now to assemble a complete and whole virus from the scratch. In such a case, if it is made to infect a human/animal, will it be able to replicate itself in the...
  3. jim mcnamara

    Multiple Sclerosis and Epstein-Barr virus infection

    Statnews article: https://www.statnews.com/2022/01/13/strong-new-evidence-suggests-virus-triggers-multiple-sclerosis/ Evidence from a colossal blood bank at Walter Reed Army Hospital allowed researchers to look over a long time span of samples for a huge number of US service men/women. The...
  4. morrobay

    SARS-CoV-2 Exposure without Infection

    From page 6: 'Close contacts who are Sars-Cov-2 exposed are often both NAT negative and antibody negative indicating that Sars-Cov-2 failed to establish a successful infection'. So the exposure generated memory T cells in absence of an infection. I wonder how quantitatively widespread in a...
  5. A

    COVID Vaccinating after an infection

    Since the time has come for me to consider a single shot of either the pfizer or moderna vaccine I was wondering can someone more knowledgeable please explain to me , how exactly does the vaccine change the antibodies already present in my system? I myself from the information I have understand...
  6. Wrichik Basu

    COVID "High" dose of steroids in mild infection may lead to viral pneumonia?

    This is again based on what was said by the Director of AIIMS in a press conference. He said that many people are self-medicating, and taking high dose of steroids even in mild COVID infection, which increases viral multiplication and leads to viral pneumonia. From this new article, Two...
  7. Wrichik Basu

    COVID Can MRI detect COVID infection in lungs?

    During this second wave of pandemic in our country, there have been several cases where the RT-PCR test is yielding false negatives. Many patients are being advised CT scans by doctors if the RT-PCR is negative, but the patient still shows symptoms of COVID. In many cases, this has given good...
  8. mktsgm

    COVID Those who had covid infection are also advised for vaccines. Why?

    Normally, when a person gets infected by a virus and subsequently recovers from it, it is understood that he had developed sufficient antibodies. One can surmise that his T-cell contribution also could be satisfactory in its fight against the infection. In my view, the vaccines are supposed to...
  9. gleem

    COVID Lingering effects of a COVID infection: Post COVID Syndrome

    It is becoming apparent that the COVID pandemic may be casusing more harm than originally thought. Months after recovering from noncritical infections from COVID people are developing medical conditions that are greatly affecting their lives. Symptoms include tremors, vertigo, double vision...
  10. L

    MHB COVID-19 in a Small Town: Probability of Infection

    Kindly assist with these questions: Data showed that 22% of people in a small town was infected with the COVID-19 virus. A random sample of six residents from this town was selected. 1) What is the probability that exactly two of these residents was infected? 2) What is the probability that at...
  11. jim mcnamara

    Post SARS-CoV-2 infection -psychiatric diagnoses

    https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(20)30462-4/fulltext Results Take away - It does not identify 'long haulers' - patients who have often severe symptoms of Covid-19 that persist for months after the infection has ended. Maybe there is some association there. But...
  12. E

    CV19 infection rates are increasing, but death rates are decreasing?

    CV19 infection numbers are increasing substantially throughout the world, but deaths from the virus are steadily decreasing, why is this? Does this mean that the virus is becoming less virulent?
  13. mktsgm

    Medical Necrosis vs Apoptosis: Exploring Disease Implications

    It is said that necrosis precipitates inflammation. It is also considered that inflammation causes most of the damage in any diseased condition. Comparatively, apoptosis doesn't trigger inflammation. I have the following doubts in this context. 1) Is necrotic (and/or apoptotic) cell death...
  14. V

    How does virus infection work?

    What is the probability that a healthy person with fully functional immunity will become infected when he receives a tiny amount of some (flu kind) virus on a) hands, b) eyes, c) lungs? I don't know how to define a small dose of a virus, but I guess if only one virus gets in my lungs, my immune...
  15. jim mcnamara

    Coronavirus infection rate + outcomes -versus bloodtypes

    https://www.scmp.com/news/china/society/article/3075567/people-blood-type-may-be-more-vulnerable-coronavirus-china-study This is a news report on a Chinese study, not a journal article Type O population of confirmed patients were disproportionately less like to die and less likely to become...
  16. Ygggdrasil

    Medical Bacteriophage treats antibiotic-resistant bacterial infection

    Bacteriophages, viruses that infect bacteria, have long interested scientists as a potential therapy for bacterial infections. Today, in the journal Nature Medicine, scientists report the first clinical use of genetically-engineered bacteriophages to treat an antibiotic-resistant bacterial...
  17. mktsgm

    Medical What Motivates Germs to Infect Our Bodies?

    I wonder what could be the motive for a bacteria or a virus to invade our body. If it finds food in us, what serves as food? What would have happened to that particular germ, had it not infected someone?
  18. M

    Probability virus question at different infection rates

    Homework Statement From various studies, it is known that once an individual is infected with a virus, they become infectious at rate λ. The individual will recover at rate λ, independent of the time it took for them to become infectious. Let X be the total amount of time an individual has this...
  19. mktsgm

    Is Pasteur's Infection Theory Still Valid in Modern Medicine?

    The whole edifice of Infectious diseases and their treatment lies on Louis's Pasteur's 150-year old theory. His contemporary Antoine Bechamp had entirely opposite ideas. Yet Pasteur prevailed. Though Pasteur's theory holds till now we face inadequacy of it (eg) lull and resurfacing of...
  20. K

    What would a virus do if it caused total extinction?

    Ok so I am thinking that it is not in the best interest of a virus to cause total extinction because after that you do not have anything else to infect and sustain your virus cycle. So isn't a virus's best interest to just infest a host and make it want to reproduce like crazy so it could have...
  21. G

    Ebola Virus Disease: Mechanism of infection

    I have looked in a lot of different websites for a explanation of the mechanism of the ebolavirus to infect our body: how it avoid our immunology system, what it exactly change from our DNA and the consequences in the body. I didn't found a clear information, can someone help me to understand ebola?
  22. B0b-A

    Any evidence bacteria can exist within mitochondria in humans?

    I heard a claim bacteria can exist within human mitochondria, is there any evidence that is true ?. mitochondria"']https://www.google.com/search?q="bacteria+within+mitochondria"[/URL] only gets one hit, and the examples given are not human.
  23. E

    Is it possible to be infected by the same cold virus twice?

    I am just getting over a relatively minor headcold, and I was curious if it was possible to get infected by the same bug you just got over. My keyboard, computer desk, and other objects are covered in these germs as I have touched them and sneezed on them countless times in the past 5-6 days...
  24. S

    Why secodary dengue infection more virulent?

    If u get infected with X serotype of dengue. And then you get infected again with Y serotype you get a severe infection. What is the exact pathology behind this. Also what happens if you get infected by X serotype again, do you get severe infection then as well. Thanks :smile:
  25. D

    Medical HIV question: risk of infection

    One website gives the risk of infection by HIV for a woman during unprotected vaginal intercourse with an infected male partner as "between 1/1000 and 1/100,000." The CDC estimated the number of undiagnosed persons in the greater U.S. with HIV in 2009 at a conference as 230,000. Using a very...
  26. D

    Medical Can a flight cause an ear infection?

    I understand how a pressure differential caused by an altitude change can cause temporary pain, but can it actually cause a lasting infection? There are two suspected cases in my entourage.
  27. D

    Cumulative probability of HIV infection

    I have read that the condom effectiveness in protecting from HIV infection is around 98%. Assuming the probability of contracting HIV from a single protected encounter is 2% the probability of getting nfected after 1000 protected encounters is (I took the math from here...
  28. H

    Medical Ear Infection & Chronic Pain: What to Do?

    I have an ear infection and it is chronic. I went to my doctor and he prescribed some drops. I have put these in at the morning and lunch. Now, at night, my ear has swollen canal has swollen shut and the pain is intense and I can't hear, what should I do.
  29. H

    HIV: Consistency, Color, Infection?

    Suppose you fill up a beaker with 1 mole of isolated HIV. What would be the consistency of this collection of HIV? Slimy? Liquid? What color would it have? If you would put your finger in it, would it infect you if you have no open wounds on your finger, i.o.w. does it penetrate through your...
  30. A

    Troubleshooting Webcam Software Infection

    I bought a webcam Wednesday, and now I can't get into the software to use the webcam, although I could get in the previous two days. I ran a virus scan, and the scan identified a file: C:\Documents and Settings\Family\Application...
  31. cronxeh

    EMS Infection Precautions for TB/HIV/Hepatitis Patients

    I'm currently undergoing training to become an EMT-B and as we were going over basic equipment it occurred to me that EMS uses an N95 mask for TB patients. Well I will assume bluntly that most TB's are also HIV patients. Those N95 masks are for non-oily particles of at least 300 nm in size...
  32. M

    Combatting Spyware & Adware: Proven Strategies to Avoid Infection

    I was thinking, since spy and adware seems to be running out of control nowadays, what methods have you come up with to aviod the intrusion/infection of such software. What programs have you found that actually work? I've tried several myself, Adaware and Spybot being about the best, but...
  33. S

    Fixing Damage from Virus Infection: Formatting an XP Hard Drive

    My dad gets that error on every exe he tries to open. He was infected with a virus, actually several. Is there any way to fix the damage? As far as we can tell, we got rid of all the infected files. If we can't, how would we format the hard drive? It's an XP system.
  34. Monique

    HIV needle stick infection rate

    A friend of my mother is a caretaker and accidentially stuck herself in the finger with a needle used on an HIV patient. It probably won't be until 6 mo from now until it can be diagnosed whether an infection has taken place. I was wondering, what are the chances that HIV is contracted and is...
  35. A

    Comparing USA and Iran HIV Infection Rates: Freedom or Slavery?

    Question: When comparing USA and Iran, we see that the USA has six times the HIV infection rate (as a percentage of the population) of Iran. It could be said that this is an indication of greater sexual freedom. In other words, it could be said that people in the USA have more freedom to...
  36. Ivan Seeking

    Alien Infection [from Mars]: Astrobiology magazine