I know... I know... Here we go talking about viruses again. I ́m sorry :( I don't want to make you "suffer" much more on this kind of subject, but I think it's also important to make it clear that the '80s wasn't a sea of roses, and I'm going to talk about one of the most striking issues of this decade, and deal with some details that might be unknown to some of you.
HIV, or Human Immunodeficiency Virus, is considered by some authors to be a global pandemic. However, who currently uses the term "global epidemic" to describe HIV.
What a lot of people don't know is that AIDS and HIV are two completely different things.
"AIDS" is an acronym meaning "Acquired Immunodeficiency Syndrome", that is a set of symptoms and events that occur due to weakening of immunity. The reason for this condition is an acquired infection, and there are many causes for the fall of immunity, but in the specific case of AIDS, it is caused by the HIV virus.
Now I'm going to talk in a more "biological" way: The Acquired Immunodeficiency Syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV) ( so far it's not too complicated, right?).
So let's go up one more ladder then.
During the initial infection, a person may experience a brief sick period, with flu-like symptoms. Usually this is followed by an extended period without any other symptoms. As the disease progresses, it interferes more and more in the immune system, making the person much more likely to have other types of diseases, such as opportunistic infections and cancer, that generally do not affect people with a healthy immune system.
But how was AIDS discovered?
AIDS was first observed clinically in 1981 in the United States. The initial cases occurred in a group of injecting drug users and homosexual men who had compromised immunity for no apparent reason. They had symptoms of pneumonia by the fungus Pneumocystis carinii (PCP), an uncommon opportunistic infection so far known to occur in people with a very weak immune system. Shortly thereafter, an unexpected number of gay men developed a type of rare skin cancer called Kaposi's sarcoma. Many more cases of PCP and Kaposi's sarcoma arose when an alert was given to the Centers for Disease Control and Prevention (CDC), which sent a task force to monitor the outbreak.
In 1983, two independent research groups led by Robert Gallo and Luc Montagnier declared that a new retrovirus could have infected AIDS patients and published their findings in the same issue of the journal Science.
Gallo's group called the newly isolated HTLV-III virus. At the same time, Montagnier's group isolated a virus from a patient who presented swelling of the lymph nodes of the neck and physical weakness, two characteristic symptoms of AIDS.
Contradicting the Gallo Group report, Montagnier and his colleagues showed that the virus core proteins were immunologically different from those of HTLV-I. Montagnier's group called the virus that isolated from lymphadenopathy-associated virus, LAV.
When, in 1986, it was discovered that these two viruses were the same, LAV and HTLV-III were renamed HIV, an acronym for Human Immunodeficiency Virus.
Origin
This is kind of weird but HIV-1 and HIV-2 viruses are believed to have originated in primates in Central West Africa and were transferred to humans in the early 20th century. HIV-1 appears to have originated in southern Cameroon through the evolution of SIV (cpz), the aide immunodeficiency virus (SIV), which infects wild chimpanzees (HIV-1 is descended from endemic SIVcpz in the subspecies of chimpanzees Pan troglodytes troglodytes.
There is evidence that humans who participated in wildlife activities, such as hunters or wild animal sellers, became infected with the SIV.
The oldest and most well-documented case of HIV in humans dates back to 1959 in the Democratic Republic of congo. The virus may have been present in the United States since 1966, but the vast majority of infections occurring outside sub-Saharan Africa (including the United States) can be traced back to a single unknown individual who became infected with HIV in Haiti and then brought the infection to the United States around 1969. The epidemic spread rapidly among high-risk groups (initially in men who had frequent sex with other men). In 1978, the prevalence of HIV-1 among male homosexuals living in New York and San Francisco was estimated at 5%, suggesting that several thousand people in the country were infected.
Progression and symptoms
There are three main phases of HIV infection: acute infection, clinical latency, and AIDS.
Acute infection
The initial period after HIV contamination is called acute infection or acute retroviral syndrome.
Symptoms occur between 40% and 90% of cases and usually include fever, swelling of the lymph nodes, inflammation of the throat (laryngitis or pharyngitis), rash, headache and/or mouth and genital sores. Skin rash, which occurs between 20% and 50% of cases, presents on the trunk in the form of maculopapular rash.
Due to their non-specific nature, these symptoms are often not recognized as signs of HIV infection.
Even cases that are evaluated by a family doctor or by a hospital are often diagnosed as one of the many common infectious diseases. Thus, it is recommended that HIV be considered in patients who have fever without apparent explanation and may have risk factors for contamination.
Clinical latency
Initial symptoms are followed by a phase of clinical latency called asymptomatic or chronic HIV. Without treatment, this second phase of HIV infection can last from three years to more than 20 years (on average, about eight years).
Although usually no symptoms appear at the beginning, near the end of this phase many people suffer with fever, weight loss, gastrointestinal problems and muscle pain. Between 50 and 70% of people also develop persistent generalized lymphadenopathy, characterized by unexplained and painless swelling of more than one group of lymph nodes (except in the groin) for a period of three to six months.
Acquired Immunodeficiency Syndrome
Acquired Immunodeficiency Syndrome is defined when cd4+ T-cell count is below 200 cells per μL of blood or by the occurrence of specific diseases in combination with an HIV infection. In the absence of specific treatment, about half of people infected with HIV develop AIDS about ten years after contamination.
The most common initial conditions that warn about the presence of AIDS are pneumocystosis (40%), cachexia (20%) and esophageal candidiasis. Other common signs include recurrent respiratory infections.
In addition, people with AIDS often have systemic symptoms such as prolonged fever, sweating (especially at night), swelling of the lymph nodes, chills, weakness and weight loss.
Transmission
HIV is transmitted in three main ways: sexual contact (the most common mode of HIV transmission and is carried out through sexual contact with an infected person), exposure to infected fluids (the second most frequent mode of HIV transmission, that is through blood and blood products and can occur by sharing syringes during injectable drug use, etc.) or body tissues (is the third most common form of HIV transmission in the world and it can be transmitted from mother to child during pregnancy, during childbirth or through breast milk).
Diagnosis
The diagnosis of AIDS in a person infected with HIV is based on the presence of certain signs or symptoms. Since June 5, 1981, many definitions have been developed for epidemiological surveillance. However, the clinical staging of patients was not a destination for these systems, as they are neither sensitive nor specific.
In developing countries, the World Health Organization staging system for HIV infection and the disease is used through clinical and laboratory data. In developed countries, the Centers for Disease Control and Prevention (CDC) classification system is used.
Prevention
Condom use reduces the risk of HIV transmission by about 80% in the long term. When condoms are used consistently by a couple in which one of the people is infected, the rate of HIV contamination is less than 1% per year. There is some evidence to suggest that female condoms may offer an equivalent level of protection.
Vaccination and cure
In 2012 there was still no effective vaccine for HIV/AIDS.
In 2007, doctors at a clinic in Germany were able to cure a patient with AIDS and leukemia. Doctors chose a donor who had a mutation in his DNA that could defend the system against HIV. After that, they performed bone marrow transplantation in the patients with EDAnd leukemia. The surprise came when doing further tests, when it was discovered that the HIV virus had disappeared from the patient's body. Currently the patient has been without the HIV virus for more than two years and without leukemia, however, the disease may still be hidden in his body.
In July 2019, scientists were able to eliminate AIDS DNA entirely from the genome of a living animal. The treatment suppressed HIV replication, followed by a round of gene editing therapy. When administered sequentially, this combination therapy eliminated HIV from the cells and organs of infected animals.
So, what did you think? I'm sorry for the big, detailed description, but I couldn't help it.
I don't want to scare you, but I hope this is a good warning to everyone.
Protect yourselves!
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