HIV AND AIDS

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HIV and AIDS:

HIV and AIDS PROF.DR-MOHAMMED EMAM

HIV:

HIV Human immunodeficiency virus (HIV) is a lentivirus (a member of the retrovirus family) that causes acquired immunodeficiency syndrome (AIDS), AIDS: a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to flourish. Infection with HIV occurs by the transfer of blood , semen , vaginal fluid , pre-ejaculate , or breast milk

: The four major routes transmission :

: The four major routes transmission unsafe sex , contaminated needles, breast milk, transmission from an infected mother to her baby at birth ( perinatal transmission ).

Sexual:

Sexual The majority of HIV infections are acquired through unprotected sexual relations . Sexual transmission can occur when infected sexual secretions of one partner come into contact with the genital , oral , or rectal mucous membranes of another

Blood products :

Blood products In general, if infected blood comes into contact with any open wound , HIV may be transmitted. This transmission route can account for infections in intravenous drug users , hemophiliacs , and recipients of blood transfusions

Mother-to-child :

Mother-to-child The transmission of the virus from the mother to the child can occur in utero (during pregnancy), intrapartum (at childbirth ), or via breast feeding However, where combination antiretroviral drug treatment and Cesarian section are available, this risk can be reduced to as low as one percent. Postnatal mother-to-child transmission may be largely prevented by complete avoidance of breast feeding

Epidemiology:

Epidemiology HIV infection in humans is considered pandemic by the World Health Organization (WHO). From its discovery in 1981 to 2006, AIDS killed more than 25 million people. HIV infects about 0.6% of the world's population. In 2009, AIDS claimed an estimated 1.8 million lives, down from a global peak of 2.1 million in 2004. Approximately 260,000 children died of AIDS in 2009. A disproportionate number of AIDS deaths occur in Sub-Saharan Africa , retarding economic growth and increasing poverty. In 2005, it was estimated that HIV would infect 90 million people in Africa, resulting in a minimum estimate of 18 million orphans . [

Pathogenesis:

Pathogenesis HIV infects primarily lymphocytes that function as helper T cells . These helper T cells are characterized by specific receptors called , CD4 + T. In addition to helper cells ,this receptors is present in 10-20% of monocytes , macrophages ,Langerhans cells in dermis, and dendritic cells ,

Pathogenesis:

Pathogenesis HIV infection leads to low levels of CD4+ T cells through three main mechanisms: First , direct viral killing of infected cells ; Second , increased rates of apoptosis in infected cells; Third , killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. When CD4+ T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

Pathogenesis:

Pathogenesis Upon entry into the target cell, the viral RNA genome is converted (reverse transcribed) into double-stranded DNA by a virally encoded reverse transcriptase The resulting viral DNA is then imported into the cell nucleus and integrated into the cellular DNA by a virally encoded integrase and host co-factors. Once integrated, the virus may become latent , allowing the virus and its host cell to avoid detection by the immune system. Alternatively , the virus may be transcribed , producing new RNA genomes and viral proteins that are packaged and released from the cell as new virus particles that begin anew replication cycle .

:

Most untreated people infected with HIV-1 eventually develop AIDS. These individuals mostly die from opportunistic infections or malignancies associated with the progressive failure of the immune system. HIV progresses to AIDS at a variable rate affected by viral, host, and environmental factors; most will progress to AIDS within 10 years of HIV infection: some will have progressed much sooner, and some will take much longer.

Types of HIV:

Types of HIV Two types of HIV have been characterized: HIV-1 and HIV-2. HIV-1 is the virus that was initially discovered and termed both LAV and HTLV-III. It is more virulent , more infective , and is the cause of the majority of HIV infections globally. . Because of its relatively poor capacity for transmission, HIV-2 is largely confined to West Africa .

CLASSIFICATION:

CLASSIFICATION WHO/CDC CLASSIFICAION: 3 Stages ,well or asymptomatic HIV related disease AIDS Combined with 3 stages of immunodeficiency, accorrding to number of CD4 (more than 500,200-500 and less than 200) or number of lymphocytes(more than 2000, 1000-2000 and less than 1000)

CLINICAL FEATURES OF HIV:

CLINICAL FEATURES OF HIV The stages of HIV infection are 1- Acute infection (also known as primary infection ) 2 - Latency 3 - AIDS. 1 -Acute infection lasts for several weeks and may include symptoms such as fever , lymphadenopathy , pharyngitis , rash , myalgia ., malaise , and mouth and esophageal sores.

CLINICAL:

CLINICAL . 2- The latency stage involves few or no symptoms and can last from two weeks to twenty years or more, depending on the individual. 3 -AIDS, the final stage of HIV infection, is defined by low CD4+ T cell counts (fewer than 200 per micro liter), various opportunistic infections , cancers and other conditions

WHO clinical staging of HIV disease in adults(2006):

WHO clinical staging of HIV disease in adults(2006 ) In poor communities, medical facilities are sometimes poorly equipped, and it is not possible to use CD4 and viral load test results to determine the right time to begin antiretroviral treatment. The World Health Organization (WHO) has therefore developed a staging system for HIV disease based on clinical symptoms, which may be used to guide medical decision making .

WHO clinical staging of HIV disease in adults(2006):

WHO clinical staging of HIV disease in adults(2006 ) Clinical Stage I I : Asymptomatic Persistent generalized lymphadenopathy Clinical Stage II : Moderate unexplained* weight loss (under 10% of presumed or measured body weight)** Recurrent respiratory tract infections (sinusitis, tonsillitis, otitis media, pharyngitis ) Herpes zoster Angular chelitis Recurrent oral ulceration Papular pruritic eruptions Seborrhoeic dermatitis Fungal nail infections

Clinical Stage III: :

Clinical Stage III: Unexplained* severe weight loss (over 10% of presumed or measured body weight)** Unexplained* chronic diarrhea for longer than one month Unexplained* persistent fever (intermittent or constant for longer than one month) Persistent oral candidiasis Oral hairy leukoplakia Pulmonary tuberculosis Severe bacterial infections (e.g. pneumonia, empyema , pyomyositis , bone or joint infection, meningitis, bacteraemia ) Acute necrotizing ulcerative stomatitis , gingivitis or periodontitis Unexplained* anaemia (below 8 g/dl), neutropenia and/or chronic thrombocytopenia .

Clinical Stage IV (AIDS):

Clinical Stage IV (AIDS) HIV wasting syndrome Pneumocystis pneumonia Recurrent severe bacterial pneumonia Chronic herpes simplex infection ( orolabial , genital or anorectal of more than one month’s duration or visceral at any site) Oesophageal candidiasis (or candidiasis of trachea, bronchi or lungs) Extrapulmonary tuberculosis Kaposi sarcoma Cytomegalovirus infection (retinitis or infection of other organs) Central nervous system toxoplasmosis HIV encephalopathy :

Clinical Stage IV:

Clinical Stage IV Extrapulmonary cryptococcosis including meningitis Disseminated non- tuberculous mycobacteria infection Progressive multifocal leukoencephalopathy Chronic cryptosporidiosis Chronic isosporiasis Disseminated mycosis ( extrapulmonary histoplasmosis , coccidiomycosis ) Recurrent septicaemia (including non- typhoidal Salmonella) Lymphoma (cerebral or B cell non-Hodgkin) Invasive cervical carcinoma Atypical disseminated leishmaniasis Symptomatic HIV-associated nephropathy or HIV-associated cardiomyopathy :

Examples of opportunistic infections and cancers:

Examples of opportunistic infections and cancers Respiratory system Pneumocystis jirovecii Pneumonia (PCP) Tuberculosis (TB) Kaposi's Sarcoma (KS) Gastro-intestinal systemCryptosporidiosis Candida Cytomegolavirus (CMV) Isosporiasis Kaposi's Sarcoma Central/peripheral Nervous system Cytomegolavirus Toxoplasmosis Cryptococcosis Non Hodgkin's lymphoma Varicella Zoster Herpes simplex SkinHerpes simplex Kaposi's sarcoma Varicella Zoste r

HIV test:

HIV test Antibody tests Window period Antibody tests may give false negative (no antibodies were detected despite the presence of HIV) results during the window period , an interval of three weeks to six months between the time of HIV infection and the production of measurable antibodies to HIV seroconve rsion :

HIV TESTS:

HIV TESTS During the window period , an infected person can transmit HIV to others although their HIV infection may not be detectable with an antibody test.

ANTIBODY TESTS:

ANTIBODY TESTS ELISA The enzyme-linked immunosorbent assay (ELISA), or enzyme immunoassay (EIA), was the first screening test commonly used. Western blot Like the ELISA procedure, the western blot is an antibody detection test. However, unlike the ELISA method, the viral proteins are separated first and immobilized employed for HIV test. It has a high sensitivit y

ANTIBODY TESTS:

ANTIBODY TESTS Rapid or point-of-care tests The positive predictive value of Rapid Antibody Tests in low-risk populations has not been evaluated

Interpreting antibody tests :

Interpreting antibody tests ELISA testing alone cannot be used to diagnose HIV, even if the test suggests a high probability that antibody to HIV-1 is present. ELISA results are not reported as "positive" unless confirmed by a Western Blot

Antigen tests :

Antigen tests * The p24 antigen test detects the presence of the p24 protein of HIV (also known as CA), the capsid * Nucleic acid-based tests (NAT ) Nucleic-acid-based tests amplify and detect one or more of several target sequences located in specific HIV genes, such as HIV-I GAG, HIV-II GAG, HIV- env , or the HIV- pol protein of the virus eg. RT PCR- or branched DNAtest .

Other tests used in HIV treatment :

Other tests used in HIV treatment The CD4 T-cell count :. A CD4 count does not check for the presence of HIV. It is used to monitor immune system function in HIV-positive people. Declining CD4 T-cell counts are considered to be a marker of progression of HIV infection.

Accuracy of HIV testing:

Accuracy of HIV testing The accuracy of serologic testing has been verified by isolation and culture of HIV and by detection of HIV RNA by PCR , which are widely accepted " gold standards " in microbiology . the combination of ELISA and Western Blot used for the diagnosis of HIV is remarkably accurate, with very low false-positive and -negative rates as described above.

TREATMENT:

TREATMENT Until now , There is currently no publicly available vaccine or cure for HIV or AIDS. However, a vaccine that is a combination of two previously unsuccessful vaccine candidates was reported in September 2009 to have resulted in a 30% reduction ininfections . [

Post-exposure prophylaxis:

Post-exposure prophylaxis a course of antiretroviral treatment administered immediately after exposure, referred to as post-exposure prophylaxis , is believed to reduce the risk of infection if begun as quickly as possible In July 2010, a vaginal gel containing tenofovir , a reverse transcriptase inhibitor , was shown to reduce HIV infection rates by 39 percent

PROPHYLAXIS:

PROPHYLAXIS However, due to the incomplete protection provided by the vaccine and/or post-exposure prophylaxis, the avoidance of exposure to the virus is expected to remain the only reliable way to escape infection for some time yet

HAART:

HAART Current treatment for HIV infection consists of highly active antiretroviral therapy , or HAART. This has been highly beneficial to many HIV-infected individuals e.g tenofovir, ritonavir and atripla, atazanavir ,combivire,abacavire

HAART COCKTAILS:

HAART COCKTAILS Current HAART options are combinations (or "cocktails") consisting of at least three drugs belonging to at least two types, or "classes ," of antiretroviral agents. Typically, these classes are two nucleoside analogue reverse transcriptase inhibitors (NARTIs or NRTIs) plus either a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor (NNRTI) .

WHEN TO STRAT treatment ?:

WHEN TO STRAT treatment ? Antiretroviral therapy should be initiated in all patients with a CD4 count less than 350, with treatment also recommended for patients with CD4 counts between 350 and 500. However, for patients with CD4 counts over 500, the expert Panel was evenly divided, with 50% in favor of starting antiretroviral therapy at this stage of HIV disease, and 50% viewing initiating therapy at this stage as optional

HAART:

HAART HAART neither cures the patient nor uniformly removes all symptoms; high levels of HIV-1, often HAART-resistant, return if treatment is stopped . Moreover, it would take more than a lifetime for HIV infection to be cleared using HAART. [ Despite this, many HIV-infected individuals have experienced remarkable improvements in their general health and quality of life , which has led to a large reduction in HIV-associated morbidity and mortalit y

Entry inhibitors:

Entry inhibitors New classes of drugs such as entry inhibitors provide treatment options for patients infected with viruses already resistant to common therapies, although they are not widely available and not typically accessible in resource-limited settings. Because AIDS progression in children is more rapid and less predictable than in adults, in particular, in young infants, more aggressive treatment is recommended for children than adults

HAART:

HAART Anti-retroviral drugs are expensive, and the majority of the world's infected individuals do not have access to medications and treatments for HIV and AIDS

PROGNOSIS:

PROGNOSIS Without treatment, the net median survival time after infection with HIV is estimated to be 9 to 11 years, The median survival rate after diagnosis of AIDS in resource-limited settings where treatment is not available ranges between 6 and 19 months

بِسْمِ اللهِ الرَّحْمنِ الرَّحِيمِ:

بِسْمِ اللهِ الرَّحْمنِ الرَّحِيمِ وَالْحَافِظِينَ فُرُوجَهُمْ وَالْحَافِظَاتِ" ( الأحزاب):35

قال تعالى: {قد أفلح المؤمنون الذين هم في صلاتهم خاشعون والذين هم عن اللغو معرضون والذين هم لفروجهم حافظون إلا على أزواجهم أو ما ملكت أيمانهم فإنهم غير ملومين فمن ابتغى وراء ذلك فأولئك هم العادون} [المؤمنون: 1-5]. وقد وعد الله هؤلاء المفلحين بقوله: {أولئك هم الوارثون * الذين يرثون الفردوس هم فيها خالدون}. :

قال تعالى: {قد أفلح المؤمنون الذين هم في صلاتهم خاشعون والذين هم عن اللغو معرضون والذين هم لفروجهم حافظون إلا على أزواجهم أو ما ملكت أيمانهم فإنهم غير ملومين فمن ابتغى وراء ذلك فأولئك هم العادون} [المؤمنون: 1-5]. وقد وعد الله هؤلاء المفلحين بقوله: {أولئك هم الوارثون * الذين يرثون الفردوس هم فيها خالدون}.

قال الله تعالى لنبيه ::

قال الله تعالى لنبيه : ( قل للمؤمنين يغضوا من أبصارهم ويحفظوا فروجهم ذلك أزكى لهم إن الله خبير بما يصنعون وقل للمؤمنات يغضضن من أبصارهن ويحفظن فروجهن..) وفي مواضع أخرى من كتابه العزيز وعد الحافظين فروجهم بالأجر العظيم فقال: ( والحافظين فروجهم والحافظات أعد الله لهم مغفرة وأجرا عظيما ).

كما أكد النبي هذا المعنى في العديد من أحاديثه فقال: :

كما أكد النبي هذا المعنى في العديد من أحاديثه فقال : "إذا صلت المرأة خمسها، وصامت شهرها، وحفظت فرجها، وأطاعت زوجها، قيل لها: ادخلي الجنة من أي أبواب الجنة شئت". (رواه أحمد وصححه الألباني).

وقال ::

وقال : "اضمنوا لي ستًا من أنفسكم أضمن لكم الجنة: اصدقوا إذا حدثتم، وأوفوا إذا وعدتم، وأدوا إذا اؤتمنتم، واحفظوا فروجكم، وغضوا أبصاركم، وكفوا أيديكم". ( رواه أحمد وابن حبان والحاكم وصححه).

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