The most common human viral diseases. Types of computer viruses
The computer virus was distributed via email in an attached file, and after the user opened this file, the virus sent itself to the first 50 addresses in the email program's address book Microsoft Outlook.
Today " Melissa“You can’t scare anyone anymore. But they will remember her for a long time. Basically, the same as about the next nine viruses. About the latter, by the way, in honor of “ Melissa“And we remember. Read.
Brain
This virus is the most harmless in this hit parade. All because he was one of the first. Distributed via floppy disks. The development lies with the brothers Amjat and Basit Alvi ( Amdjat and Basit Faroog Alvi). These guys started it in 1986. But discover “ something's wrong“The specialists succeeded only a year later in the summer.
They say that in the US alone the virus infected more than 18 thousand computers. Fun fact: the development was based entirely on good intentions. That is, the brothers wanted to punish local pirates who were stealing their company's software.
And also Brain took pride of place as the world's first stealth virus. When trying to read an infected sector, it “ substituted“ his uninfected original. It was very difficult to catch one.
Source: securelist.com
Jerusalem
The second name is “ Friday 13“. And the first arose thanks to the country of its origin - Israel ( in 1988). Why is this dangerous? Friday“? The one that was downloaded from a floppy disk. And as soon as the time came X ( Friday 13) - the virus immediately deleted absolutely all data from the hard drive. In those days, few people believed in the existence of computer viruses. There were almost no anti-virus programs at all. That's why Jerusalem terrified users.
Source: classifieds.okmalta.com
Morris worm
And this one “ worm“ went on a rampage in November 1988. It blocked the operation of computers with its chaotic and uncontrolled reproduction. Because of him, in fact, the whole ( not too global for those times) Net. Please note: the failure did not last long, but it managed to cause serious damage. Experts valued them at $96 million.
Source: intelfreepress.com
Michelangelo (“March6“)
“Michelangelo“ was rowdy in 1992. It penetrated the boot sector of the disk through floppy disks, and sat quietly there until March 6th arrived. As soon as the time came for X, “ Mark“I immediately formatted the hard drive. Its appearance was beneficial to all companies developing anti-virus software. They then fanned the hysteria to incredible proportions. Although, the virus mocked only 10 thousand machines.
Source: macacosabetudo.com
Chernobyl (CIH)
It was created by a Taiwanese student ( in 1998). This malicious software was named after the latter’s initials. The essence of the software: through the Internet, email and disks, the virus entered the computer and hid inside other programs. And on April 26 it was activated. And it not only erased all the information on the hard drive, but also damaged the computer hardware.
Peak “ Chernobyl“came in April 1999. More than 300 thousand cars were damaged then ( mostly East Asia). And even after everyone trumpeted the information about the presence of such a pest, it hid on computers for a long time and continued its dirty deeds.
Source: softpedia.com
Melissa
We return again to “ Melissa“. It was created by then 30-year-old David Smith. The amount of damage caused to the programmer's brainchild is more than $100 million. For this, the attacker was put behind bars for a term of 46 to 57 months.
Then Smith was released on bail of $100 thousand, and the case began to be put on hold. The hearings have been postponed several times, and the prosecutors who launched the case so loudly have now remained silent. Jim Smith himself and his lawyer are also silent.
Source: jrwhipple.com
ILOVEYOU (“Letter of happiness”)
Someone in 2000 thought of writing a pretty cute virus. It arrived in the mail in the form of a message “I LOVE YOU” with an attached file. Users downloaded it and... A script settled on the hard drive that:
- randomly sent letters in incredible quantities;
- deleted important files on PC.
The results are simply shocking: the damage caused by this “ by letter“, “slammed“ 10% of all computers that existed at that time. In monetary terms it is $5.5 billion.
Name |
Pathogen |
Areas of the body affected |
Distribution method |
Type of vaccination | |||||||||||||||||||||||
Microvirus of one of three types - A, B and C - with varying degrees of virulence |
Respiratory tract: epithelium lining the trachea and bronchi. |
Droplet infection |
Killed virus: the strain of the killed virus must match the strain of the virus causing the disease | ||||||||||||||||||||||||
Cold |
The most different viruses, most often rhinoviruses (RNA - containing viruses) |
Airway: usually upper only |
Droplet infection |
Live or inactivated virus is administered by intramuscular injection; Vaccination is not very effective as there are many different strains of rhinoviruses | |||||||||||||||||||||||
Variola virus (DNA-containing virus), one of the smallpox viruses |
Airways, then skin |
Droplet infection (possible contagious transmission through skin wounds). |
A live weakened (attenuated) virus is introduced into a scratch on the skin; not currently applied. | ||||||||||||||||||||||||
Mumps (mumps) |
Respiratory tract, then generalized infection throughout the body through the blood; The salivary glands are especially affected, and in adult men also the testes |
Droplet infection (or contagious oral transmission with infectious saliva) |
Live attenuated virus | ||||||||||||||||||||||||
Xovirus (RNA - containing virus) |
Respiratory tract (from oral cavity to the bronchi), then passes to the skin and intestines |
Droplet infection |
Live attenuated virus | ||||||||||||||||||||||||
Measles rubella (rubella) |
Rubella virus |
Airways, cervical lymph nodes, eyes and skin |
Droplet infection |
Live attenuated virus | |||||||||||||||||||||||
Polio (infantile paralysis) |
Poliovirus (picornavirus; RNA-containing virus, three strains known) |
Throat and intestines, then blood; sometimes motor neurons of the spinal cord, then paralysis may occur |
Droplet infection or through human feces |
The live attenuated virus is given orally, usually on a sugar cube | |||||||||||||||||||||||
Yellow fever |
Arbovirus, i.e. arthropod-borne virus (RNA - containing virus) |
Blood vessel lining and liver |
Vectors are arthropods, such as ticks, mosquitoes |
Live attenuated virus (it is also very important to control the number of possible carriers) | |||||||||||||||||||||||
Influenza is not such a serious disease, but many millions of people get sick with it every year, and periodically pandemics (widespread epidemics) occur and claim many lives.
In 1886 and 1887, influenza was registered in Russia; In the summer of 1889, pathogen activity increased in Bukhara, and later that year the infection spread to other regions of Russia and Western Europe. Thus began the influenza pandemic of 1889-1890. During the second and third epidemics, the number of deaths progressively increased. The most ominous feature of this epidemic was that it apparently gave impetus to some kind of process, and now the flu is with us, or, as the epidemiologist Greenwood wrote, “we are not able to regain lost ground.”
In 1918, after the end of the First World War, an unprecedented influenza pandemic, called the “Spanish flu,” broke out.
In a year and a half, the pandemic has spread to all countries, affecting more than a billion people. The disease was extremely difficult: about 25 million people died - more than from injuries on all fronts of the First World War in four years.
Never later did influenza cause such a high mortality rate: the mortality rate was low during all subsequent epidemics and pandemics, although the percentage of deaths from influenza is low, the mass nature of the disease leads to the fact that during each major influenza epidemic, thousands of patients die from it, especially the elderly and children. It has been noted that during epidemics the mortality rate from diseases of the lungs, heart and blood vessels increases sharply.
Influenza remains the “king” of epidemics. No disease can reach hundreds of millions of people in a short time, and more than a billion people get sick with the flu during a pandemic! This was the case not only during the memorable pandemic of 1918, but relatively recently - in 1957, when the “Asian” flu pandemic broke out, and in 1968, when the “Hong Kong” flu appeared. There are several types of influenza virus known - A, B, C, etc.; under the influence of environmental factors, their number may increase. Due to the fact that immunity to influenza is short-term and specific, repeated illness is possible in one season. According to statistics, an average of 20-35% of the population suffers from influenza every year.
The source of infection is a sick person; Patients with a mild form of the virus are the most dangerous as spreaders of the virus, since they do not isolate themselves in a timely manner - they go to work, use public transport, and visit places of entertainment.
The infection is transmitted from a sick person to a healthy person through airborne droplets when talking, sneezing, coughing or through household items.
Smallpox is one of the oldest diseases. A description of smallpox was found in the Egyptian papyrus of Amenophis I, compiled 4000 BC. Smallpox lesions were preserved on the skin of a mummy buried in Egypt 3000 BC. The mention of smallpox, which the Chinese called “poison from the mother’s breast,” is contained in the oldest Chinese source - the treatise “Cheu-Cheufa” (1120 BC). The first classical description of smallpox was given by the Arab physician Rhazes.
Smallpox was the most common and most dangerous disease in the past. Its destructive power was not inferior to the power of the plague.
The first mention of smallpox in Russia dates back to the 4th century. In 1610, the infection was brought to Siberia, where a third of the local population died out. People fled to the forests of the tundra and mountains, displayed idols, burned scars on their faces like pockmarks in order to deceive this evil spirit - everything was in vain, nothing could stop the ruthless killer.
However, attempts to protect against smallpox are as ancient as smallpox itself. They were based on the observation that people who once had smallpox did not get sick again.
The first vaccination against smallpox in Russia was carried out in a solemn ceremony by Moscow University professor Efrem Mukhin in 1801. A child from an orphanage in Moscow was vaccinated with smallpox using the Jenner method and in honor of this was given the surname Vaccinov.
April 10, 1919 V.I. Lenin signed a decree on compulsory smallpox vaccination, which marked the beginning of mass vaccinations.
Poliomyelitis is a viral disease that affects the gray matter of the central nervous system. The causative agent of polio is a small virus that does not have an outer shell and contains RNA. The polio virus affects the limbs, that is, it changes the shape of the bones. Characteristic bone changes were found during excavations in Greenland on skeletons dating back to 500-600 BC. The incidence of polio has a number of characteristic features. Poliomyelitis is spread by intestinal diseases. With high levels of sanitation, children do not become infected at an early age, but become infected later. Poliomyelitis seems to mature, and in adults the disease is much more severe. An effective method of combating this disease is the live polio vaccine. The use of the polyvaccine made it possible to effectively extinguish outbreaks of infection, and the incidence rate sharply decreased. However, vaccination with a live vaccine does not mean eliminating the killer virus, but only replacing it with an artificial laboratory strain that is safe for humans.
Rabies is an infectious disease transmitted to humans from a sick animal through a bite or contact with the saliva of a sick animal, most often a dog. One of the main signs of developing rabies is hydrophobia, when the patient has difficulty swallowing liquids and develops convulsions when trying to drink water. The rabies virus contains RNA, packaged in a nucleocapsid of helical symmetry, covered with a shell, and when multiplying in brain cells, it forms specific inclusions, according to some researchers, “viral graveyards” called Babes-Negri bodies. The disease is incurable.
Tumor viruses - Over the years since the fact of the occurrence of viral sarcomas in chickens was first established, numerous researchers have discovered oncogenic viruses belonging to two groups in different species of vertebrates: DNA-containing and retroviruses. Oncogenic DNA viruses include pacovaviruses, adecoviruses, and herpesviruses. Of the RNA viruses, only retroviruses cause tumors.
The range of tumors caused by oncogenic viruses is unusually wide. Although the polyoma virus primarily causes tumors of the salivary glands, its very name indicates that it can cause many other tumors. Retroviruses cause mainly leukemia and sarcomas, which often cause tumors of the breast and a number of other organs. Although cancer is a disease of the whole organism, an essentially similar phenomenon, called transformation, is also observed in cell cultures. Such systems are used as models for studying oncogenic viruses. The ability to transform cells in vitro underlies methods for the quantitative determination of many oncogenic viruses. The same systems are also used for comparative studies of the physiology of normal and tumor cells.
Viruses and human malignant tumors - One of the arguments against the role of viruses in the occurrence of most malignant tumors in humans is the fact that in the vast majority of cases, malignant tumors are not contagious, whereas with a viral etiology, transmission from person to person can be expected. If, however, we assume that activation of heritable viruses by exogenous factors plays a role in the occurrence of tumors, then we should expect that facts of hereditary predisposition to malignant tumors will be revealed. Such a predisposition to the development of some tumors has indeed been discovered, but various explanations can be found for this. Despite 10 years of intensive work directed by special government programs, the connection between human malignancies and viruses still remains problematic. It seems extremely strange that oncogenic viruses, which play such an obvious role in the occurrence of tumors in a wide variety of animals, should somehow “bypass” humans.
AIDS - Acquired Immune Deficiency Syndrome - is a new infectious disease that experts recognize as the first truly global epidemic in the known history of mankind. Neither the plague, nor smallpox, nor cholera are precedents, since AIDS is decidedly unlike any of these and other known human diseases. The plague claimed tens of thousands of lives in the regions where the epidemic broke out, but never covered the entire planet at once. In addition, some people, having been ill, survived, acquired immunity and took on the work of caring for the sick and restoring the damaged economy. AIDS is not a rare disease that affects a few people by chance. Leading experts currently define AIDS as a “global health crisis”, as the first truly earthly and unprecedented epidemic of an infectious disease, which still, after the first decade of the epidemic, is not controlled by medicine and every infected person dies from it.
By 1991, AIDS was registered in all countries of the world except Albania. In the most developed country in the world - the United States - already at that time one out of every 100-200 people was infected, every 13 seconds another US resident was infected, and by the end of 1991, AIDS in this country had become third in mortality, overtaking cancer. So far, AIDS forces one to recognize itself as a fatal disease in 100% of cases.
The first people with AIDS were identified in 1981. During the past first decade, the spread of the pathogen virus occurred mainly among certain groups of the population, which were called risk groups. These are drug addicts, prostitutes, homosexuals, patients with congenital hemophilia (since the life of the latter depends on the systematic administration of drugs and donor blood).
However, by the end of the first decade of the epidemic, WHO had accumulated material indicating that the AIDS virus had spread beyond the named risk groups. He entered the general population.
The second decade of the pandemic began in 1992. It is expected that it will be significantly heavier than the first one. In Africa, for example, in the next 7-10 years, 25% of agricultural farms will be left without labor due to extinction from AIDS alone.
AIDS is one of the most important and tragic problems that arose before humanity at the end of the 20th century. The causative agent of AIDS, the human immunodeficiency virus (HIV), is a retrovirus. Retroviruses owe their name to an unusual enzyme - reverse transcriptase (retrovertase), which is encoded in their genome and allows the synthesis of DNA on an RNA template. Thus, HIV is capable of producing DNA copies of its genome in host cells, such as “helper” T-4 lymphocytes. Viral DNA is included in the genome of lymphocytes, where its presence creates conditions for the development of chronic infection. Even theoretical approaches to solving such a problem as cleaning the genetic apparatus of human cells from foreign (in particular, viral) information are still unknown. Without solving this problem, there will be no complete victory over AIDS.
Although it is now clear that the human immunodeficiency virus (HIV) is the cause of acquired immunodeficiency syndrome (AIDS) and related diseases, the origin of this virus remains a mystery. There is strong serological evidence that the infection appeared on the west and east coasts of the United States in the mid-1970s. However, cases of AIDS-associated diseases known in central Africa indicate that the infection may have appeared there even earlier (50-70 years). Be that as it may, it has not yet been possible to satisfactorily explain where this infection came from. Several human and monkey retroviruses have been discovered using modern cell culture techniques. Like other RNA viruses, they are potentially variable; therefore, they are quite likely to have such changes in the host spectrum and virulence that could explain the emergence of a new pathogen (there are several hypotheses: 1) the impact of unfavorable environmental factors on a pre-existing virus; 2) bacteriological weapons; 3) mutation of the virus as a result of radiation exposure from uranium deposits in the supposed homeland of the infectious pathogen - Zambia and Zaire).
Over the course of a lifetime, a person can get sick from so many different diseases and viruses that by old age he may not remember them all. Some diseases occur quickly and unnoticed, but others can be crippling. And to the question of which virus is the most dangerous, several dozen can be named.
What is a virus?
Translated from Latin, “virus” means “poison”. It is a cell-free organism that reproduces and lives only in the cells of living beings. Any virus consists of a protein shell containing DNA and RNA molecules.
Scientists know more than a hundred viruses that differ in shape and habitat. They mutate without problems and adapt to the characteristics of the organisms into which they have invaded. For viruses, life outside the cell does not exist. Microorganisms can cause many different diseases: measles, chickenpox, hepatitis, herpes, rabies, cancer, AIDS.
How do viruses spread?
All viruses that exist in nature can be divided into anthropotic (live in the human body) and zooanthropotic (live in the body of animals). You can pick up one or another virus in several ways.
- Through food (contaminated food, water).
- Through blood (surgery, transfusion, from mother to fetus, sexual intercourse, through the bites of infected insects or animals).
- By airborne droplets (through the respiratory tract).
- Contact and household (through hygiene items).
Almost all viruses have their own specific locations. Thus, hepatitis B and C enter the liver; chickenpox spreads across the skin; The staphylococcus virus can “at its own taste” infect the intestines, throat, heart and other vital organs. All viral infections are accompanied by individual symptoms and can affect the body in different ways. Each has its own specific therapy.
The most dangerous viruses in the world
Our life is very unpredictable. A successful, healthy and strong person can become practically disabled tomorrow; it is enough to be infected with the most terrible and incurable disease - AIDS. For many people, just the word itself causes horror and trembling.
So, the 10 most dangerous viruses:
- Human acquired immunodeficiency syndrome. It was opened in the early 80s of the twentieth century. The immunodeficiency virus attacks the human immune system, completely depriving it of its protective functions. So, people can die from a simple runny nose or a scratch on the arm. The disease is incurable.
- In second place in the “Most Dangerous Viruses” category is a relatively new disease - spongiform encephalopathy, which damages the human brain and causes dementia. The disease is incurable. Death occurs within two years.
- Rabies. Death can occur as early as five days after infection. The rabies virus is at the heart of hundreds of zombie films.
- African fever. A tropical infection that is accompanied by high fever, muscle pain and hemorrhages. Some types of this fever are incurable and result in death.
- Plague is an infection that in the 14th century killed everyone it came across. A third of Europe died from this disease. In our time, the treatment for plague is the Haffkine vaccine, discovered at the beginning of the last century.
- Anthrax. It is found in both humans and animals. Infection spores can persist in the soil for many years; they are very tenacious and can even withstand boiling. Without treatment, 90% of the disease is fatal.
- Cholera. A disease with a mortality rate of 85%. Transmitted through household contact. Causes vomiting, dehydration, diarrhea and cramps. Nowadays, a vaccine against this disease is actively used.
- Meningococcal infection. Affects the upper respiratory tract, nasopharynx. Inflammations end in hemorrhages. The infection can penetrate the brain. May be fatal.
- Tularemia. The fever is similar to typhoid fever.
- Malaria, African trypanosomiasis, tuberculosis, pneumonia and some others.
This list is not all of the most dangerous viruses in the world. This is only a small part known to mankind.
Animal viruses dangerous to humans
Viruses that infect animals also pose a significant danger to humans. Infections enter the human body along with food - milk, meat, eggs. They can develop serious, sometimes incurable diseases, and occur in people with complications.
Top most dangerous viruses that are transmitted from animals.
- Brucellosis.
- Tularemia.
- Toxoplasmosis.
- Rabies.
- Ringworm.
- Helminths.
- Trichinosis.
- Ancroceliosis.
Basic precautions can protect you from illness.
- Personal hygiene.
- High quality food processing.
- Vaccination of animals.
- Correct behavior with domestic and wild animals.
The most dangerous sexually transmitted human viruses
A person may not be aware of the presence of infections and diseases in his body for quite a long time. Thus, sexually transmitted infections can often occur without any symptoms. As a result, in the absence of a regular partner, the number of infected people may increase.
- AIDS is the first on the list of deadly infections. The virus can persist in the body for years and make itself felt after 7-10 years.
- Gonorrhea.
- Trichomonosis.
- Chlamydia.
- Syphilis.
- Genital herpes.
- Human papillomavirus.
All of the listed infections, except AIDS, are curable, but they leave their mark, affecting the internal organs and pelvic organs. One of the most terrible consequences is infertility.
You can protect yourself from such ailments with the help of a high-quality condom that has a valid expiration date. Anti-venereal drugs used in the first hours after sexual intercourse help with some sores. They are used to treat the mucous membranes of the genital organs, and the chance of infection is reduced several times.
And, of course, the best prevention is a regular sexual partner. It should be remembered that the most dangerous human viruses are not only those that end in death, but also all known viruses, because any treatment can be both expensive and lengthy.
The impact of viruses on human health
Once in the body, a viral infection can occur in two forms - acute and chronic. Often the disease develops covertly, when a person is unaware of it and becomes a carrier (herpes, AIDS).
There are many different ways of transmitting viruses, so you need to always be on guard. Having had one or another illness once, the body can develop immunity (chickenpox, Botkin's disease). Diseases often recur and return accompanied by serious complications. Sometimes vaccination can help alleviate the infection or avoid it altogether.
The most terrible consequence of viruses is damage to internal organs, the nervous system and brain, and mucous membranes. Some infections can provoke cancer, and the most dangerous viruses in the world often end in death.
Prevention of viral diseases
Of course, it is much safer and cheaper for people to carry out timely prevention of viruses. This way you can avoid not only expensive treatment and health complications, but also save lives.
- So, the best prevention is personal hygiene. You should always wash your hands before eating and after going outside.
- You should only eat well-processed food; be sure to wash vegetables and fruits. Products must be purchased in specialized stores.
- Strengthening the immune system should become a rule for every person.
- More positive - less stress!
- Infected people are indicated for quarantine and hospitalization.
- Don't forget about vaccination. Vaccinations are given against many diseases in childhood; there is no need to refuse them.
- Healthy lifestyle, proper nutrition and vitamins.
- Safe sex - some of the most dangerous viruses are transmitted through sexual contact.
Viruses that are best to get over in childhood
Viruses are one of the ancient forms of life on the planet. More than a thousand are known. Some exist quietly next to us, but some can cause serious damage to human health. Among all infections, there are some that are best dealt with in childhood. Children's diseases are the most dangerous viruses for adults, especially for pregnant women.
What children tolerate easily can cause complications for an adult. Pregnant women represent a special risk group, because the infection can affect not only the mother’s body, but also intrauterine life. Infections suffered during pregnancy cause serious defects and abnormalities of the fetus.
Top diseases that are best to get in childhood:
- Measles (consequences for adults - encephalitis, meningitis).
- Mumps (can cause mumps, infertility, brain diseases).
- Chickenpox, rubella (especially dangerous for expectant mothers. They cause cataracts, heart defects, and brain enlargement in the fetus).
- Polio. Your child must be vaccinated against this disease. When the disease appears in an adult, it almost always ends in a wheelchair or death.
Equipment also suffers from viruses
A virus is a microorganism with its own DNA that can live and reproduce only in another organism. A computer virus is no different from an ordinary one. It is a specially written program that infiltrates and attacks other programs and files.
A computer virus can erase absolutely any file on its own. There are several signs of infection:
- The program doesn't work.
- The program is not working correctly.
- Extraneous information appears on the screen.
- The files cannot be opened or read.
- The operating system does not load.
- There are more files on the disk, but less memory.
It is impossible to say for sure which is the most dangerous virus on a computer, because each of them harms files and programs.
Five common computer viruses:
- "Friday the 13th" (Jerusalem) - deletes all programs.
- "Cascade of falling letters."
- “Melissa” - an email arrives in the mail “The document that was requested...”.
- “Letter of confession” or “letter of happiness.” An email with a declaration of love.
- Nimda - creates administrator rights on the computer.
All viruses are created by experienced programmers for the purpose of hacking and personal gain. However, for every poison there is an antidote. The most dangerous computer viruses must be “treated” with antivirus programs or by formatting the hard drive.
For the purpose of prevention, you should use only licensed programs, visit only trusted sites and use “clean” media.
Conclusion
During his life, a person suffers a huge number of all kinds of ailments and viruses. To some, he develops lifelong immunity, and some can return again. Proper nutrition, personal hygiene and good immunity will help protect yourself from various diseases. Some of the most dangerous viruses come to humans from animals (rabies, anthrax, salmonellosis), so it’s worth taking care of them too. For example, vaccinating animals reduces the risk of getting an infection several times.
Viruses can cause a wide variety of diseases, depending on the type of infection and the characteristics of the infected tissue. What types of viruses do humans have? There are a huge number of them, and throughout their lives people come into contact with most infectious agents in one way or another. The diseases they cause range from relatively mild to deadly. The most common viruses in the world are colds, flu, and hepatitis.
Viruses and colds
The common cold (as they are commonly called influenza, ARVI, laryngitis, pharyngitis) remains one of the most common human ailments. In the United States alone, about a billion cases of acute respiratory viral infection are registered every year. A viral infection of the lining of the nasal passages leads to a runny nose, watery eyes, sore throat and sneezing. The course of the disease lasts from one to two weeks. According to statistics, more than 200 of the known strains can cause a cold. What types of viruses are the most common causative agents of ARVI? These are various rhinoviruses, adenovirus, coronavirus, Coxsackie virus, echovirus, enterovirus, orthomyxovirus, paramyxovirus and
Influenza virus
Influenza is caused by three types of microorganisms. Types A and B lead to seasonal infections, occurring during a period beginning in late fall and ending in early spring. Type C virus infections are less common and most often cause mild illness. The most common flu symptoms include body aches, fever, feeling tired, headache, sore throat, dry cough and nasal congestion. Flu vaccinations protect against types A and B viral infections.
Enteric viruses
What viruses are found in the digestive system and what are their characteristic symptoms? Microorganisms of this type penetrate the tissues of the stomach and intestines, causing viral gastroenteritis. Common symptoms of the disease include abdominal pain, colic, diarrhea, nausea and vomiting. In young children, including infants, gastroenteritis is often caused by rotavirus. This infection manifests itself in the form of fever, vomiting and watery diarrhea. Norovirus is an equally common causative agent of infectious diseases that affects both children and adults. However, in younger patients, diarrhea is almost always the predominant symptom of the disease, while incessant vomiting is more typical in adults. Other known enteric viruses include adenovirus, sapovirus, and astrovirus strains.
Hepatitis viruses
Infectious agents of this type infect the liver, initiating inflammatory processes. Science knows five different viruses that cause hepatitis; they were named based on the letters of the Latin alphabet from A to E. If you are interested in what types of hepatitis viruses exist in developed countries, then, according to statistical studies, in countries with developed infrastructure and medicine, types A, B and C predominate. The hepatitis A virus penetrates into the body when digesting food or water contaminated with feces. It causes one brief episode of hepatitis. Type B strains can cause acute or chronic liver infection. Microorganisms are found in blood and semen. The most common cases of hepatitis B infection include sexual intercourse, sharing the same syringes when using drugs, and transmission of the infection from mother to child during pregnancy and childbirth. Type C virus spreads through contact with the blood of a sick person. Repeated use of syringes by different people when using drugs is the most common method of transmission of infection. Hepatitis C, as a rule, becomes chronic, but adequate treatment in many cases can alleviate the disease.
Other viruses
What viruses do humans have besides the ones listed above? If you print a complete list of titles, you will have to publish several volumes of the list. Moreover: every year scientists discover new types, hitherto unknown. Some strains are very rare, but pose a great danger due to their potential lethality. These are, for example, the Ebola or rabies viruses. Other microorganisms are quite common and are the root cause of a huge number of diseases. For those who are interested in what types of viruses a person has, just open any popular medical reference book. Thus, a clear example of a common type of infection are herpes viruses that cause herpes simplex on the lips, genital herpes, infectious mononucleosis, chickenpox, shingles and many other ailments. The human papillomavirus causes not only the appearance of common warts on the skin, but also the development of cervical cancer.
What viruses have people been getting lately? Infections of the newest types - HIV, acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS coronavirus) - remain a serious problem, since today there is no truly effective treatment for these diseases.
Diagnostics
Diagnosis of a viral infection is mainly based on a primary medical examination and analysis of the medical history. For example, a disease such as influenza is fairly easy to recognize, and most people are familiar with its manifestations. Detection of some other infections, however, may require additional diagnostic tests.
Diagnostic testing options for viral infection
Since the answer to the question of what viruses a person has involves thousands of answers, sometimes it is not enough to simply examine the patient and study his medical history. In such cases, doctors will order one or more of the following tests:
- blood tests to check for antibodies to viruses or to detect antigens directly;
- culturing blood components, bodily fluids, and other materials collected from the affected area;
- spinal tap to analyze cerebrospinal fluid;
- a polymerase chain reaction technique to create multiple copies of viral genetic material for faster and more accurate identification of the virus;
- magnetic resonance imaging to detect inflammation in the temporal lobes of the brain.
Symptoms
What types of viruses do humans have? The list is incredibly extensive, but the symptoms of many infections can be systematized in order to compile a single list. Thus, signs of infection with the virus may include:
- increased body temperature;
- muscle pain;
- cough;
- sneezing;
- runny nose;
- chills;
- diarrhea;
- vomiting;
- skin rash;
- feeling of weakness.
More severe symptoms include:
- neck stiffness;
- dehydration;
- convulsions;
- paralysis of limbs;
- loss of orientation in space;
- back pain;
- loss of sensation;
- bladder and bowel dysfunction;
- drowsiness, which may progress to coma or death.
Infection: viral or bacterial?
What types of viruses do humans have? The names are unlikely to say anything to a non-specialist, but one should distinguish between viral and bacterial infections.
Infections of both types cause deterioration in health and the development of various diseases. However, there is a difference between them. A viral infection, as its name suggests, begins with the impact of a virus on the body - a tiny intracellular agent even smaller in size than a bacterium. In addition, it is in a protective shell, which means it is more difficult to destroy. The virus penetrates a living cell and integrates its genome into its genetic apparatus. Such infectious agents are non-cellular particles and require foreign cells to reproduce. If you are wondering what types of viruses there are, the names you will find in this article will most likely point you to the main sites of infection. These are the nose, throat and upper respiratory tract. Virus strains can cause both the common cold and AIDS.
To initiate a bacterial infection, the pathogenic bacterium must gain entry into the body through contaminated water, cuts in the skin, or contact with an infected person or contaminated objects. One of the fundamental differences between the two types of infections is that bacteria can enter the body through contact with inanimate objects, including door handles and table tops, while viruses cannot. Another difference is that nature is a cell and reproduces by division, while the virus dies without a host carrier. Most often, bacteria enter the body through the respiratory tract or gastrointestinal tract. Some bacterial infections are contagious (such as strep throat).
Cause of viral infection
The question of what viruses a person has is especially acute because the cells of the human body are susceptible to them. When exposed to viral particles, the immune system tries to destroy the source of danger and remove foreign strains from the body.
A person is most susceptible to various colds in the autumn and spring. Viral infectious diseases are a type of disease that is caused by an infection that has penetrated into a weakened body. They can develop in an acute form or in a sluggish form, but treatment must be carried out in both cases so as not to aggravate the situation and avoid dangerous complications. On average, a person gets sick from colds 2 to 3 times a year, but the disease always develops due to viral DNA.
Types of viruses
Symptoms of pathology can be caused by different types of bacteria, which differ in location, rate of development, and characteristics. Human viruses have a special classification; they are conventionally divided into fast and slow. The second option is very dangerous because the symptoms are very weak and the problem cannot be detected immediately. This gives it time to multiply and strengthen. Among the main types of viruses, the following groups are distinguished:
- Orthomyxoviruses- all influenza viruses.
- Adenoviruses and Rhinoviruses. They provoke ARVI - an acute respiratory viral infection that affects the respiratory system. Symptoms are very similar to the flu, but can cause complications (bronchitis, pneumonia)
- Herpesviruses– herpes viruses, which can live in the body for a long time asymptomatically, are activated immediately after the weakening of the immune system.
- Meningitis. It is provoked by a meningococcal infection, the brain mucosa is damaged, and the virus feeds on the cerebrospinal fluid (CSF).
- Encephalitis– affects the lining of the brain, causing irreversible disturbances in the functioning of the central nervous system.
- Parvovirus, which is the causative agent of polio. A very dangerous disease that can cause convulsions, inflammation of the spinal cord, and paralysis.
- Picornaviruses– causative agents of viral hepatitis.
- Orthomyxoviruses– cause mumps, measles, parainfluenza.
- Rotavirus– cause enteritis, intestinal flu, gastroenteritis.
- Rhabdoviruses- causative agents of rabies.
- Papoviruses– the cause of human papillomatosis.
- Retroviruses- the causative agents of AIDS, HIV develops first, and then AIDS.
List of human viral diseases
Medicine knows a huge number of contagious viruses and infections that can provoke various diseases in the human body. Below are only the main groups of diseases that you are likely to encounter:
- One of the largest groups of viral diseases is influenza (A, B, C), different types of colds that cause inflammation in the body, high fever, general weakness and sore throat. Therapy is carried out with the help of general restoratives, antiviral drugs, and, if necessary, antibacterial medications are prescribed.
Complex products help eliminate the unpleasant symptoms of influenza and ARVI, maintain efficiency, but often contain phenylephrine, a substance that increases blood pressure, which gives a feeling of vigor, but can cause side effects from the cardiovascular system. Therefore, in some cases, it is better to choose a drug without components of this kind, for example, AntiGrippin from Natur Product, which helps relieve the unpleasant symptoms of influenza and ARVI without causing an increase in blood pressure.
There are contraindications. It is necessary to consult a specialist.
- Rubella. A common childhood pathology, less common in adults. Symptoms include damage to the lining of the respiratory tract and skin. eyes, lymph nodes. The virus is transmitted by droplets and is always accompanied by high fever and skin rashes.
- Piggy. A dangerous viral disease affecting the respiratory tract, the salivary glands are severely affected. Rarely found in adult men, the testes are affected by this virus.
- Measles– often found in children, the disease affects the skin, respiratory tract, and intestines. Transmitted by airborne droplets, the causative agent is paramyxovirus.
- Poliomyelitis (infantile paralysis). The pathology affects the respiratory tract, intestines, and then penetrates the blood. Next, motor neurons are damaged, which leads to paralysis. The virus is transmitted by droplets, and sometimes a child can become infected through feces. In some cases, insects act as carriers.
- Syphilis. This disease is sexually transmitted and affects the genitals. Then it affects the eyes, internal organs and joints, heart, liver. Antibacterial agents are used for treatment, but it is very important to determine the presence of pathology immediately, because it may not cause symptoms for a long time.
- Typhus. It is rare and is characterized by a rash on the skin, damage to blood vessels, which leads to the formation of blood clots.
- Pharyngitis. The disease is caused by a virus that enters the human body along with dust. Cold air, streptococci, and staphylococci can also provoke the development of pathology. The viral illness is accompanied by fever, cough, and sore throat.
- Angina– a common viral pathology, which has several subtypes: catarrhal, follicular, lacunar, phlegmonous.
- Whooping cough. This viral disease is characterized by damage to the upper respiratory tract, swelling of the larynx is formed, and severe coughing attacks are observed.
The rarest human viral diseases
Most viral pathologies are contagious diseases that are transmitted sexually and by airborne droplets. There are a number of diseases that are extremely rare:
- Tularemia. The pathology, in its symptoms, strongly resembles the plague. Infection occurs after Francisella tularensis enters the body - it is an infectious bacillus. As a rule, it gets in with the air or through a mosquito bite. The disease is also transmitted from a sick person.
- Cholera. This disease is very rare in modern medical practice. The Vibrio cholerae virus, which enters the body through dirty water and contaminated food, causes symptoms of pathology. The last outbreak of the disease was recorded in 2010 in Haiti, the disease claimed the lives of more than 4,500 people.
- Creutzfeldt-Jakob disease. A very dangerous pathology that is transmitted through the meat of infected animals. The causative agent is considered to be a prion - a special protein that begins to actively destroy body cells after penetration. The insidiousness of the pathology lies in the absence of symptoms, the person begins to develop a personality disorder, develops severe irritation, and dementia. The disease cannot be cured and the person dies within a year.
Symptoms of the virus
Symptoms do not always appear immediately; some types of viral diseases can occur for a long time without obvious signs, which becomes a problem with further treatment. Every infectious disease goes through the following stages:
- incubation period;
- premonitory;
- the height of pathology;
- recovery.
The duration of the first stage always depends on the specific type of virus and can last from 2-3 hours to six months. Symptoms will differ depending on the developing disease, but, as a rule, the following manifestations are included in the general symptoms of viral pathologies:
- soreness, muscle weakness;
- slight chills;
- persistent body temperature;
- sensitivity of the skin to touch;
- cough, sore throat, watery eyes;
- dysfunction of some organs;
- enlarged lymph nodes.
Temperature due to viral infection
This is one of the body’s main reactions to the penetration of any pathogen. Temperature is a protective mechanism that activates all other immune functions to fight viruses. Most diseases occur with a high body temperature. Viral pathologies that provoke this symptom include:
- flu;
- ARVI;
- tick-borne encephalitis;
- childhood diseases: chickenpox, infectious mumps, rubella, measles;
- polio;
- infectious mononucleosis.
There are often cases of the development of diseases in which the temperature does not rise. The main symptoms are watery discharge with a runny nose and sore throat. The absence of fever is explained by insufficient activity of the virus or the immune system is strong, and therefore does not fully use all possible methods of fighting the infection. If growth has begun, then high rates remain, as a rule, for about 5 days.
Signs
Most viruses provoke the development of acute respiratory pathologies. There is some difficulty in identifying diseases that were caused by bacteria, because the treatment regimen in this case will be very different. There are more than 20 varieties of viruses that cause ARVI, but their main symptoms are similar. Primary signs include the following manifestations:
- rhinitis (runny nose), cough with clear mucus;
- low temperature (up to 37.5 degrees) or fever;
- general weakness, headaches, poor appetite.
How to distinguish a cold from a virus
There is a difference between these two concepts. A cold occurs during prolonged exposure to the cold, severe hypothermia of the body, which leads to a weakened immune system and the appearance of an inflammatory process. This is not the name of the disease, but only the cause of the development of other pathologies. Viral pathology often becomes a consequence of a cold, because the body does not have enough protective forces to resist the pathogen.
Virus diagnostics
When contacting a doctor, he must conduct a visual examination and collect anamnesis. As a rule. viral diseases are accompanied by fever, cough, runny nose, but after 3-4 days the person feels better. Specialists can determine the type of disease based on general symptoms or based on seasonal outbreaks of diseases, for example, influenza epidemics often begin in winter, and acute respiratory viral infections in the fall. Determining the exact type of virus will be required for specific treatment (HIV, syphilis, etc.). For this purpose, virological research is used.
This method in medicine is the “gold standard”, which is carried out in a special laboratory. As a rule, such methods are used during epidemic outbreaks of viral infectious diseases. Immunodiagnostic methods (immunoindication, serodiagnosis) are widely used for diagnosing pathogens. They are realized through various immune reactions:
- enzyme immunoassay (ELISA);
- radioisotope immunoassay (RIA);
- hemagglutination inhibition reaction;
- complement fixation reaction;
- immunofluorescence reaction.
Treatment of viral diseases
The course of therapy depends on the type of pathogen. For example, if it is necessary to treat ARVI, childhood viral pathologies (mumps, rubella, measles, etc.), then all medications are used to eliminate the symptoms. If you follow bed rest and diet, the body itself copes with the disease. Treatment of viruses is carried out in cases where they cause significant discomfort to a person. Apply for example:
- antipyretics if the temperature is above 37.5 degrees;
- vasoconstrictor drops are used to relieve nasal swelling;
- in rare cases, antibiotics (if a bacterial infection has occurred);
- NSAIDs that relieve pain and lower fever, for example, aspirin, paracetamol, ibuprofen.
During treatment, doctors recommend drinking more fluids to combat intoxication of the body, moderate nutrition, bed rest and room humidity of at least 50% where the patient is. Treatment for influenza is no different, but the doctor must monitor the patient, because this disease can cause serious consequences. One of them is pneumonia, which can lead to pulmonary edema and death.
If such complications begin, treatment must be carried out in a hospital using special medications (Zanamivir, Oseltamivir). When diagnosing the human papillomavirus, therapy consists of keeping the immune system in good shape, surgical removal of warts and condylomas. In cases of severe viral pathologies. For example, HIV requires a course of antiretroviral drugs. It cannot be completely eliminated, but it can be kept under control and prevent the spread of the disease.
If the genital organs are infected with herpes, it is necessary to take special medications; their maximum effectiveness has been confirmed in the first 48 hours. If you use the products later, their medicinal effect is significantly reduced and the course of treatment can last from several weeks to several months. Herpes on the lips needs to be treated with local remedies (ointments, gels), but even without them, the wound heals within a week.
Antiviral drugs
In medicine, there is a certain number of medications in this group that have proven their effectiveness and are used constantly. The entire list of drugs is divided into two types:
- Medicines that stimulate human immunity.
- Drugs that attack the detected virus are direct-acting drugs.
The first group refers to broad-spectrum drugs, but their use leads to serious complications. One example of such drugs is interferons, and the most popular of them is interferon alfa-2b. It is prescribed for the treatment of chronic forms of Hepatitis B, and was previously prescribed for hepatitis C. Patients had a hard time tolerating such therapy, which led to side effects from the central nervous system and the cardiovascular system. In some cases, pyrogenic properties appear and cause fever.
The second type of PPD medications is more effective and is easier to tolerate by patients. Among the popular medications, the following treatment options are distinguished:
- Herpes– acyclovir. Helps overcome the symptoms of the disease, but does not kill it completely.
- Flu– influenza neuraminidase inhibitors (Zanamivir, Oseltamivir). Modern influenza strains have developed resistance to previous medications (adamantanes), and they are not effective. Name of drugs: Relenza, Ingavirin, Tamiflu.
- Hepatitis. For the treatment of group B viruses, interferons are used together with Ribavirin. For hepatitis C, a new generation of drugs is used - Simeprevir. Its effectiveness reaches 80-91% of sustained virological response.
- HIV. It cannot be completely cured; antiretroviral drugs provide a lasting effect, cause remission, and the person cannot infect others. Therapy continues throughout life.
Prevention
Preventative measures may vary slightly depending on the type of virus. For example, to prevent infection with hepatitis or HIV, it is necessary to protect yourself during sexual intercourse. There are two main directions for the prevention of viral diseases:
- Specific. It is carried out to develop specific immunity in a person through vaccination. A person is injected with a weakened strain of the virus so that the body develops antibodies to it. This will help protect you from those with measles, flu, polio, and hepatitis (liver disease). Most life-threatening diseases can be prevented by vaccines.
- Nonspecific. Strengthening the human immune defense, a healthy lifestyle, physical activity and normal nutrition. A person must follow the rules of hygiene, which will protect him from intestinal infections, and use protection during sexual intercourse to prevent HIV infection.
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