Virus
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A virus is defined as any of a various number of submicroscopic parasites that can infect any animal, plant or bacteria and often lead to very serious or even deadly diseases. A virus consists of a core of RNA or DNA, generally surrounded by a protein, lipid or glycoprotein coat, or some combination of the three. No virus can replicate without the help of a host cell, and though they can be spread, viruses lack the ability of self-reproduction and are not always considered to be living organisms in the regular sense.Some of the most common or best known viruses include the human immunodeficiency virus (HIV), which is the virus that causes AIDS, the herpes simplex virus, which causes cold sores, smallpox, multiple sclerosis, and the human papilloma virus, now believed to be a leading cause of cervical cancer in adult women. The common human cold is also caused by a virus.Since a great deal of mystery still surrounds the origins of most modern viruses, ways to cure these viruses and the diseases they cause are still in the very early stages of development.
Explore Viruses, Infections & Disease
Latest about Viruses, Infections & Disease
![Underwater photo of a child swimming in a freshwater pond; only the child's body is visible, as his head is out of the water](https://cdn.mos.cms.futurecdn.net/bDZxGPEDZK6JkkxaTmHagn-320-80.jpg)
'Brain-eating' infections could become more common, scientists warn
By Jennifer Zieba published
Researchers think climate change will soon cause an increase in the incidence of Naegleria fowleri infections, a "brain-eating" disease.
![Water is pouring out of a silver tap into a glass, which is already almost full with water. A person's hand is shown as they hold the glass under the tap.](https://cdn.mos.cms.futurecdn.net/E5Q2CUvDVMVepgZF3x82Zc-320-80.jpg)
Can you get a brain-eating amoeba from tap water?
By Emily Cooke published
In the U.S., tap water is generally safe and not a likely source of brain-eating-amoeba infections, experts told Live Science.
![A pencil drawing showing brain eating amoebas entering a boy's nose, and an artistic representation of the boy's brain breaking down](https://cdn.mos.cms.futurecdn.net/U9Vuh3K746SGpu6vifPerc-320-80.jpg)
'Brain-eating' amoebas kill nearly 100% of victims. Could new treatments change that?
By Stephanie Pappas published
Doctors are pulling out new techniques and drugs in an effort to cure devastating brain infections.
![An electron microscope image of flu virus particles, depicted in yellow and orange](https://cdn.mos.cms.futurecdn.net/zTipaAATgmyWEuAvTQgJbK-320-80.jpg)
Scientists find secret 'back door' flu viruses use to enter cells
By Michael Schubert published
Flu viruses that can use a second cellular entry point may move more effectively between animals and humans, scientists say.
![Illustration of the bacteria streptococcus pyogenes. The bacterial cells look like fluorescent light green-ish blue balls that are bunched together in a diagonal line across the image and in a cluster in the top-right-hand corner of the image. The background is undulating and a mixture of dark purple, green and yellow colors.](https://cdn.mos.cms.futurecdn.net/MUyZKK7VgGwjFyUQNCtNoc-320-80.jpg)
New, faster sepsis test could save lives, scientists say
By Emily Cooke published
Preliminary experiments suggest that a new test could diagnose bacterial infections that cause sepsis days faster than conventional approaches, with potentially lifesaving consequences.
![A gloved hand holds a petri dish with a culture of yeast](https://cdn.mos.cms.futurecdn.net/iipui4znZ6XwceMU5K6rm-320-80.jpg)
New fungal infection discovered in China
By Emily Cooke published
Scientists uncovered a species of fungi that had never before been seen in humans. They say warmer temperatures could drive its evolution, for the worse.
![a patient in a hospital gown, mask and hair net lays down while getting an ultrasound screening and a physician is checking the image on a laptop](https://cdn.mos.cms.futurecdn.net/q4fgDoN85WtN4ZEoL2GVWd-320-80.jpg)
Black patients may be missed on common cancer screening, study suggests
By Kristel Tjandra published
An early screening test for endometrial cancer may be missing the disease in many Black patients.
![An artist's rendering of the HIV virus, depicted in pinks and purples](https://cdn.mos.cms.futurecdn.net/UMYvSFLdnJRdksKquWFHA-320-80.jpg)
HIV prevention drug found 100% effective in clinical trial
By Linda-Gail Bekker published
The drug, lenacapavir, provided better protection than other preventive medications.
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