Pathophysiology of hiv-

These special cells help the immune system fight off infections. This damage to the immune system makes it harder and harder for the body to fight off infections and some other diseases. Opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS. HIV stands for human immunodeficiency virus. It is the virus that can lead to acquired immunodeficiency syndrome or AIDS if not treated.

Pathophysiology of hiv

Pathophysiology of hiv

Pathophysiology of hiv

HIV infection can be staged based on the CD4 count. Learn more about our commitment to Global Medical Knowledge. Sexual transmission of HIV Needle- and instrument-related transmission Maternal transmission Transfusion- and transplant-related transmission. Direct retinoscopy. Cervical cancerinvasive. Antiretroviral drugs.

Adult audition musical ontario theater. HIV primary infection and disease progression

Show references Pathophysiology of hiv DL, et al. But sometimes, even with this treatment, it lasts for decades. This illness, known as Pathopnysiology or acute HIV infection, may last for a few weeks. HIV infection weakens your immune system, making you much more likely to develop numerous yiv and certain types of cancers. Continuous HIV replication results in a state of generalized immune activation persisting Pathoophysiology the chronic phase. Share on: Facebook Twitter. HIV remains in the body and in infected white blood cells. Complete list of donor screening assays for infectious agents and HIV diagnostic assays. Hewlitt packard employs nurses prophylaxis PrEP. Human immunodeficiency virus disease: AIDS and related disorders. This content does not have an Arabic version. It can spread through sexual contact or blood, or from mother to child during pregnancy, childbirth or breast-feeding. Sax Pathophysiology of hiv. Philadelphia, Pa.

Over the past three decades of intense research on the contribution of viral and host factors determining the variability in HIV-1 infection outcome, HIV pathogenesis is still a fascinating topic that requires further study.

  • HIV is commonly transmitted via unprotected sexual activity , blood transfusions , hypodermic needles , and from mother to child.
  • Acquired immunodeficiency syndrome AIDS is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus HIV.
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These special cells help the immune system fight off infections. This damage to the immune system makes it harder and harder for the body to fight off infections and some other diseases. Opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS. HIV stands for human immunodeficiency virus. It is the virus that can lead to acquired immunodeficiency syndrome or AIDS if not treated.

So once you get HIV, you have it for life. Untreated, HIV reduces the number of CD4 cells T cells in the body, making the person more likely to get other infections or infection-related cancers. These opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS, the last stage of HIV infection. No effective cure currently exists, but with proper medical care, HIV can be controlled. If it stays undetectable, they can live long, healthy lives and have effectively no risk of transmitting HIV to an HIV-negative partner through sex.

Today, someone diagnosed with HIV and treated before the disease is far advanced can live nearly as long as someone who does not have HIV. Scientists identified a type of chimpanzee in Central Africa as the source of HIV infection in humans.

They believe that the chimpanzee version of the immunodeficiency virus called simian immunodeficiency virus, or SIV most likely was transmitted to humans and mutated into HIV when humans hunted these chimpanzees for meat and came into contact with their infected blood.

Studies show that HIV may have jumped from apes to humans as far back as the late s. Over decades, the virus slowly spread across Africa and later into other parts of the world.

We know that the virus has existed in the United States since at least the mid to late s. Medicine to treat HIV, known as antiretroviral therapy ART , helps people at all stages of the disease if taken as prescribed.

Treatment can slow or prevent progression from one stage to the next. Within 2 to 4 weeks after infection with HIV, people may experience a flu-like illness, which may last for a few weeks. When people have acute HIV infection, they have a large amount of virus in their blood and are very contagious. If you think you have been exposed to HIV through sex or drug use and you have flu-like symptoms, seek medical care and ask for a test to diagnose acute infection.

During this phase, HIV is still active but reproduces at very low levels. People may not have any symptoms or get sick during this time. However, people who take HIV medicine as prescribed and get and keep an undetectable viral load or stay virally suppressed have effectively no risk of transmitting HIV to their HIV-negative sexual partners. As this happens, the person may begin to have symptoms as the virus levels increase in the body, and the person moves into Stage 3.

People with AIDS have such badly damaged immune systems that they get an increasing number of severe illnesses, called opportunistic illnesses. Without treatment, people with AIDS typically survive about 3 years. Common symptoms of AIDS include chills, fever, sweats, swollen lymph glands, weakness, and weight loss. People with AIDS can have a high viral load and be very infectious.

The only way to know for sure whether you have HIV is to get tested. Knowing your status is important because it helps you make healthy decisions to prevent getting or transmitting HIV.

Some people may experience a flu-like illness within 2 to 4 weeks after infection Stage 1 HIV infection.

But some people may not feel sick during this stage. Flu-like symptoms include fever, chills, rash, night sweats, muscle aches, sore throat, fatigue, swollen lymph nodes, or mouth ulcers. These symptoms can last anywhere from a few days to several weeks. During this time, HIV infection may not show up on an HIV test, but people who have it are highly infectious and can spread the infection to others. Each of these symptoms can be caused by other illnesses. But if you have these symptoms after a potential exposure to HIV, see a health care provider and tell them about your risk.

No effective cure currently exists for HIV. But with proper medical care, HIV can be controlled. Download Consumer Info Sheet pdf icon. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Section Navigation. Minus Related Pages. On This Page. What is HIV?

Where did HIV come from? What are the stages of HIV? To find places near you that offer confidential HIV testing, Visit gettested. You can also use a home testing kit, available for purchase in most pharmacies and online. Is there a cure for HIV? More HIV Topics. Follow HIV. Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.

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Nature Medicine. From Wikipedia, the free encyclopedia. Cell Reports. The virus, entering through which ever route, acts primarily on the following cells: [15]. In: Ferri's Clinical Advisor But sometimes, even with this treatment, it lasts for decades. National Institutes of Health.

Pathophysiology of hiv

Pathophysiology of hiv

Pathophysiology of hiv

Pathophysiology of hiv

Pathophysiology of hiv

Pathophysiology of hiv. The HIV Life Cycle

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Initial infection may cause nonspecific febrile illness. HIV can directly damage the brain, gonads, kidneys, and heart, causing cognitive impairment, hypogonadism, renal insufficiency, and cardiomyopathy.

Screening should be routinely offered to all adults and adolescents. Retroviruses are enveloped RNA viruses defined by their mechanism of replication via reverse transcription to produce DNA copies that integrate in the host cell genome. Infection with human T-lymphotropic virus HTLV 1 or 2 can cause T-cell leukemias and lymphomas, lymphadenopathy, hepatosplenomegaly, skin lesions, and immunocompromise.

In some areas of West Africa, both viruses are prevalent and may coinfect patients. HIV-1 originated in Central Africa in the first half of the 20th century, when a closely related chimpanzee virus first infected humans. Epidemic global spread began in the late s, and AIDS was recognized in In , about 1.

In many sub-Saharan African countries, incidence of HIV infection is declining markedly from the very high rates of a decade before; nevertheless, important gaps remain to meet the World Health Organization's Fast-Track strategy to end the AIDS epidemic by In , 39, cases were diagnosed.

Certain cancers eg, Kaposi sarcoma , non-Hodgkin lymphoma to which defective cell-mediated immunity predisposes. Candidiasis of esophagus. Cervical cancer , invasive. Coccidioidomycosis , disseminated or extrapulmonary. Cryptococcosis , extrapulmonary. Histoplasmosis , disseminated or extrapulmonary. Kaposi sarcoma.

Lymphoma, Burkitt or equivalent term. Lymphoma , primary, of brain. Mycobacterium avium complex MAC or Mycobacterium kansasii , disseminated or extrapulmonary.

Mycobacterium tuberculosis of any site, pulmonary, disseminated, or extrapulmonary. Progressive multifocal leukoencephalopathy. Transmission of HIV requires contact with body fluids—specifically blood, semen, vaginal secretions, breast milk, saliva, or exudates from wounds or skin and mucosal lesions—that contain free HIV virions or infected cells. Transmission is more likely with the high levels of virions that are typical during primary infection, even when such infections are asymptomatic.

Transmission by saliva or droplets produced by coughing or sneezing, although conceivable, is extremely unlikely. Needle- or instrument-related: Sharing of blood-contaminated needles or exposure to contaminated instruments. Sexual practices such as fellatio and cunnilingus appear to be relatively low risk but not absolutely safe see table HIV Transmission Risk for Several Sexual Activities. Risk does not increase significantly if semen or vaginal secretions are swallowed.

However, open sores in the mouth may increase risk. The sexual practices with the highest risks are those that cause mucosal trauma, typically intercourse. Anal-receptive intercourse poses the highest risk. Mucous membrane inflammation facilitates HIV transmission; sexually transmitted diseases, such as gonorrhea, chlamydial infection, trichomoniasis, and especially those that cause ulceration eg, chancroid, herpes, syphilis , increase the risk several-fold.

Other practices that cause mucosal trauma include fisting inserting most or all of the hand into the rectum or vagina and using sexual toys. Recent evidence shows that HIV infected people in whom antiretroviral therapy has reduced their viral load below the current detectable level virally suppressed do not sexually transmit the virus to their partners. Undetectable virus equals an untransmittable virus. Vaginal or anal intercourse with or without ejaculation if a condom is not used or is not used correctly.

Risk appears to be higher if the wound is deep or if blood is inoculated eg, with a contaminated hollow-bore needle. Risk is also increased with hollow-bore needles and with punctures of arteries or veins compared with solid needles or other penetrating objects coated with blood because larger volumes of blood may be transferred. Thus, sharing needles that have entered the veins of other injection drug users is a very high risk activity. Risk of transmission from infected health care practitioners who take appropriate precautions is unclear but appears minimal.

However, extensive investigations of patients cared for by other HIV-infected physicians, including surgeons, have uncovered few other cases. Transmission rates can be reduced dramatically by treating HIV-positive mothers with antiretroviral drugs while they are pregnant, in labor, and breastfeeding.

Cesarean delivery and treatment of the infant for several weeks after birth also reduce the risk. However, in many developing countries, where blood and blood products are not screened for HIV, the risk of transfusion-transmitted HIV infection remains high.

Infection has developed in recipients of kidney, liver, heart, pancreas, bone, and skin—all of which contain blood—but screening for HIV greatly reduces risk of transmission. HIV transmission is even more unlikely from transplantation of cornea, ethanol-treated and lyophilized bone, fresh-frozen bone without marrow, lyophilized tendon or fascia, or lyophilized and irradiated dura mater.

Some cases of infection occurred in the early s, before safeguards were introduced. In the United States, sperm washing is considered an effective method of reducing the risk of partner insemination from a known HIV-positive sperm donor.

Male homosexual intercourse or contact with infected blood eg, through sharing needles in injection drug users; before effective screening of donors, through transfusions.

In most countries, both patterns occur, but the first pattern usually predominates in developed countries; the second pattern predominates in Africa, South America, and southern Asia. In areas where heterosexual transmission is dominant, HIV infection follows routes of trade, transportation, and economic migration to cities and spreads secondarily to rural areas.

In Africa, particularly southern Africa, the HIV epidemic has killed tens of millions of young adults, creating millions of orphans. Factors that perpetuate spread include. Deficient systems of medical care that do not provide access to HIV testing and antiretroviral drugs. However, through international efforts, as of , an estimated Many opportunistic infections that complicate HIV are reactivations of latent infections.

Thus, epidemiologic factors that determine the prevalence of latent infections also influence risk of specific opportunistic infections. In many developing countries, prevalence of latent TB and toxoplasmosis in the general population is higher than that in developed countries. Dramatic increases in reactivated TB and toxoplasmic encephalitis have followed the epidemic of HIV-induced immunosuppression in these countries. Similarly in the United States, incidence of coccidioidomycosis, common in the Southwest, and histoplasmosis, common in the Midwest, has increased because of HIV infection.

Human herpesvirus 8 infection, which causes Kaposi sarcoma , is common among homosexual and bisexual men but uncommon among other HIV patients in the United States and Europe. These HIV proteins are assembled into HIV virions at the host cell inner membrane and budded from the cell surface within an envelop of modified human cell membrane.

Each host cell may produce thousands of virions. After budding, protease, another HIV enzyme, cleaves viral proteins, converting the immature virion into a mature, infectious virion.

HIV protease cleaves viral proteins, converting the immature virion to a mature, infectious virion. Virions have a plasma half-life of about 6 hours. In moderate to heavy HIV infection, about 10 8 to 10 9 virions are created and removed daily. The high volume of HIV replication and high frequency of transcription errors by HIV reverse transcriptase result in many mutations, increasing the chance of producing strains resistant to host immunity and drugs.

The humoral immune system is also affected. Hyperplasia of B cells in lymph nodes causes lymphadenopathy, and secretion of antibodies to previously encountered antigens increases, often leading to hyperglobulinemia. Total antibody levels especially IgG and IgA and titers against previously encountered antigens may be unusually high. However, antibody response to new antigens eg, in vaccines decreases as the CD4 count decreases.

Abnormal elevation of immune activation may be caused in part by absorption of components of bowel bacteria. HIV also infects nonlymphoid monocytic cells eg, dendritic cells in the skin, macrophages, brain microglia and cells of the brain, genital tract, heart, and kidneys, causing disease in the corresponding organ systems. HIV strains in several compartments, such as the nervous system brain and CSF and genital tract semen , can be genetically distinct from those in plasma, suggesting that they have been selected by or have adapted to these anatomic compartments.

Thus, HIV levels and resistance patterns in these compartments may vary independently from those in plasma. During the first few weeks of primary infection, there are humoral and cellular immune responses:. But rapid mutation of viral antigens that are targeted by lymphocyte-mediated cytotoxicity subvert control of HIV in all but a small percentage of patients.

For every 3-fold 0. Eventually, AIDS almost invariably develops in untreated patients. Initially, primary HIV infection may be asymptomatic or cause transient nonspecific symptoms acute retroviral syndrome. Acute retroviral syndrome usually begins within 1 to 4 weeks of infection and usually lasts 3 to 14 days.

Symptoms and signs are often mistaken for infectious mononucleosis or benign, nonspecific viral syndromes and may include fever, malaise, fatigue, several types of dermatitis, sore throat, arthralgias, generalized lymphadenopathy, and septic meningitis.

After the first symptoms disappear, most patients, even without treatment, have no symptoms or only a few mild, intermittent, nonspecific symptoms for a highly variable time period 2 to 15 years.

Symptoms during this relatively asymptomatic period may result from HIV directly or from opportunistic infections. The following are most common:. Asymptomatic, mild-to-moderate cytopenias eg, leukopenia, anemia, thrombocytopenia are also common. Some patients experience progressive wasting which may be related to anorexia and increased catabolism due to infections and low-grade fevers or diarrhea.

Some patients present with cancers eg, Kaposi sarcoma, B-cell lymphomas that occur more frequently, are unusually severe, or have unique features in patients with HIV infection see Cancers Common in HIV-Infected Patients.

In other patients, neurologic dysfunction may occur. Disseminated mycobacterial infections. Cryptococcus neoformans infection. Infections that also occur in the general population but suggest AIDS if they are unusually severe or frequently recur include. Herpes zoster. Herpes simplex. Vaginal candidiasis.

Kaposi sarcoma KS is a vascular tumor caused by herpesvirus type 8 infection. Lesions appear as bluish to violaceous macules, plaques, or tumors.

Pathophysiology of hiv

Pathophysiology of hiv