Drug-resistance testing also has become a key tool in the management of HIV-infected individuals. Details of these tests will be discussed later. Clearly, resistance testing is now routinely used in individuals experiencing poor responses to HIV therapy or treatment failure. In general, a poor response to initial treatment would include individuals who fail to experience a decline in viral load of approximately hundredfold in the first weeks, have a viral load of greater than 500 copies per mL by week 12, or have levels greater than 50 copies per mL by week 24. Treatment failure would generally be defined as an increase in viral load after an initial decline in a person who is believed to be consistently taking his or her medications. Since drug-resistant virus can be transmitted, guidelines from the U.S. Department of Health and Human Services (DHHS) (https://aidsinfo.nih.gov/) and International Antiviral Society-USA (IAS-USA) have suggested that resistance testing be performed in individuals who have never been on therapy to determine if they might have acquired HIV that is resistant to drugs.
Candidiasis of esophagus CMV retinitis Disseminated mycobacterial infection–culture not required HIV encephalopathy HIV wasting syndrome Kaposi sarcoma Lymphoid interstital pneumonitis and/or pulmonary lymphoid hyperplasia < age 13 Pneumocystis cariniipneumonia Toxoplasmosis of the brain in Pts > 1 month of age
If an exposure occurs, the exposed person can reduce the risk of getting HIV by taking antiretroviral medications. Current recommendations suggest two or more antiretroviral medications, depending on the risk of transmission and type of exposure. Medications should be started as soon as possible, preferably within hours of exposure and should be continued for four weeks, if tolerated. People who have been exposed should be tested for HIV at the time of the injury and again at six weeks, 12 weeks, and six months after exposure.
Jump up ^ Pritchard, Laura K.; Vasiljevic, Snezana; Ozorowski, Gabriel; Seabright, Gemma E.; Cupo, Albert; Ringe, Rajesh; Kim, Helen J.; Sanders, Rogier W.; Doores, Katie J. (2015-06-16). “Structural Constraints Determine the Glycosylation of HIV-1 Envelope Trimers”. Cell Reports. 11 (10): 1604–1613. doi:10.1016/j.celrep.2015.05.017. ISSN 2211-1247. PMC 4555872 . PMID 26051934.
The only available drug in this class is called maraviroc (Selzentry, MVC), which is now approved for use in combination therapy in treatment-experienced and naïve patients who do not have detectable CXCR4-using virus as determined by a tropism assay. This is a unique drug in a new class that blocks viral entry by interacting with the CCR5 molecule on the surface of the CD4 cell. It is known that HIV first binds to the CD4 molecule on the surface of CD4 cells and then connects with the CCR5 or CXCR4 molecule. Only after this second step is the virus able to enter the cell. The CCR5 antagonist prevents viruses that use CCR5 from getting into the cell. What is unique about this drug compared to others is that 20%-50% of patients have viruses that are able to use the CXCR4 receptor. In these cases, CCR5 antagonists do not appear to be active at suppressing virus. Therefore, in order to know if the drug will work for a given patient, a new test needs to be performed, the so-called tropism assays. This test will tell the provider and patient whether there is virus that uses CXCR4, in which case the patient would not be a candidate for MVC, or if they only have viruses that use CCR5, in which case MVC should be an active drug. Without tropism results, it is impossible to know whether MVC will be an active drug for a given patient.
Human immunodeficiency virus (HIV), a member of the retrovirus family, is the causative agent of acquired immunodeficiency syndrome (AIDS). HIV invades various immune cells (e.g., CD4+ T cells and monocytes) resulting in a decline in CD4+ T cell numbers below the critical level, and loss of cell-mediated immunity − therefore, the body becomes progressively more susceptible to opportunistic infections and cancer.
One of the greatest advances in the management of HIV infection has been in pregnant women. Prior to antiviral therapy, the risk of HIV transmission from an infected mother to her newborn was approximately 25%-35%. The first major advance in this area came with studies giving ZDV after the first trimester of pregnancy, then intravenously during the delivery process, and then after delivery to the newborn for six weeks. This treatment showed a reduction in the risk of transmission to less 10%. There is strong data that women who have viral suppression during pregnancy have very low risk of transmitting HIV to their baby. Current recommendations are to advise HIV-infected pregnant women regarding both the unknown side effects of antiviral therapy on the fetus and the promising clinical experience with potent therapy in preventing transmission. In the final analysis, however, pregnant women with HIV should be treated essentially the same as nonpregnant women with HIV. Exceptions would be during the first trimester, where therapy remains controversial, and avoiding certain drugs that may cause greater concern for fetal toxicity, such as EFV.
Aaron Glatt, MD Professor of Clinical Medicine, New York Medical College; President and CEO, Former Chief Medical Officer, Departments of Medicine and Infectious Diseases, St Joseph Hospital (formerly New Island Hospital)
HIV invariably develops resistance to any of these drugs if they are used alone. Resistance develops after a few days to several months of use, depending on the drug and the virus. HIV becomes resistant to drugs because of mutations that occur when it replicates.
Jump up ^ Lyumkis, Dmitry; Julien, Jean-Philippe; de Val, Natalia; Cupo, Albert; Potter, Clinton S.; Klasse, Per-Johan; Burton, Dennis R.; Sanders, Rogier W.; Moore, John P. (2013-12-20). “Cryo-EM structure of a fully glycosylated soluble cleaved HIV-1 envelope trimer”. Science. 342 (6165): 1484–1490. doi:10.1126/science.1245627. ISSN 1095-9203. PMC 3954647 . PMID 24179160.
It is not known, however, why only some HIV-positive people develop these symptoms. It also is also not completely known whether or not having the symptoms is related in any way to the future course of HIV disease. Regardless, infected people will become symptom-free (asymptomatic) after this phase of primary infection. During the first weeks of infection when a patient may have symptoms of primary HIV infection, antibody testing may still be negative (the so-called window period). If there is suspicion of early infection based upon the types of symptoms present and a potential recent exposure, consideration should be given to having a test performed that specifically looks for the virus circulating in the blood, such as a viral load test or the use of an assay that identifies HIV p24 antigen, for example, the new fourth-generation antibody/antigen combination test. Identifying and diagnosing individuals with primary infection is important to assure early access into care and to counsel them regarding the risk of transmitting to others. The latter is particularly important since patients with primary HIV infection have very high levels of virus throughout their body and are likely to be highly infectious. There is no definitive data showing that initiation of antiretroviral therapy during this early stage of infection results in clinical benefits. Nevertheless, it is generally thought that the benefits of reducing the size of the HIV in the body, preserving select immune responses, and reducing transmissibility favors early treatment. Once the patient enters the asymptomatic phase, infected individuals will know whether or not they are infected if a test for HIV antibodies is done.
“Physical and sexual intimate partner violence is common in perinatally infected youth and is associated with adverse consequences for HIV onward transmission pointing to the need for targeted interventions in this high risk group..”–Dr. William Blattner, JAIDS Co-Editor-in-Chief
There is little evidence that HIV can be transferred by casual exposure, as might occur in a household setting. For example, unless there are open sores or blood in the mouth, kissing is generally considered not to be a risk factor for transmitting HIV. This is because saliva, in contrast to genital secretions, has been shown to contain very little HIV. Still, theoretical risks are associated with the sharing of toothbrushes and shaving razors because they can cause bleeding, and blood can contain large amounts of HIV. Consequently, these items should not be shared with infected people. Similarly, without sexual exposure or direct contact with blood, there is little if any risk of HIV contagion in the workplace or classroom.
Jump up ^ Orsi, F; d’almeida, C (May 2010). “Soaring antiretroviral prices, TRIPS and TRIPS flexibilities: a burning issue for antiretroviral treatment scale-up in developing countries”. Current Opinion in HIV and AIDS. 5 (3): 237–41. doi:10.1097/COH.0b013e32833860ba. PMID 20539080.
You can get HIV testing in most doctors’ offices, public health clinics, hospitals, and Planned Parenthood clinics. You can also buy a home HIV test kit in a drugstore or by mail order. Make sure it’s one that is approved by the Food and Drug Administration (FDA). If a home test is positive, see a doctor to have the result confirmed and to find out what to do next.
HIV is a very small virus that contains ribonucleic acid (RNA) as its genetic material. When HIV infects animal cells, it uses a special enzyme, reverse transcriptase, to turn (transcribe) its RNA into DNA. (Viruses that use reverse transcriptase are sometimes referred to as “retroviruses.”) When HIV reproduces, it is prone to making small genetic mistakes or mutations, resulting in viruses that vary slightly from each other. This ability to create minor variations allows HIV to evade the body’s immunologic defenses, essentially leading to lifelong infection, and has made it difficult to make an effective vaccine. The mutations also allow HIV to become resistant to antiretroviral medications.
Everybody knows everybody else in Jackson’s small, tight-knit black gay community, and most men will find their sexual partners in this network. Most scientists now believe that risk of contracting H.I.V. boils down to a numbers game rather than a blame game: If the virus is not present in your sexual network, you can have unprotected sex and not get infected. But if you are in a community, like Jackson, where a high percentage of gay and bisexual men are infected with H.I.V. — and many don’t know it and go untreated — any unprotected sexual encounter becomes a potential time bomb. This explanation of “viral load” helps dispel the stubbornly held notion that gay and bisexual black men have more sex than other men, a false perception embedded in the American sexual imagination and fueled by stereotypes of black men as hypersexual Mandingos dating back to slavery.
Some people infected with HIV are asymptomatic at first. Most people experience symptoms in the first month or two after becoming infected. That’s because your immune system is reacting to the virus as it rapidly reproduces.
Entry to the cell begins through interaction of the trimeric envelope complex (gp160 spike) on the HIV viral envelope and both CD4 and a chemokine co-receptor (generally either CCR5 or CXCR4, but others are known to interact) on the target cell surface. Gp120 binds to integrin α4β7 activating LFA-1, the central integrin involved in the establishment of virological synapses, which facilitate efficient cell-to-cell spreading of HIV-1. The gp160 spike contains binding domains for both CD4 and chemokine receptors.
Jump up ^ Beck, CR; McKenzie, BC; Hashim, AB; Harris, RC; Zanuzdana, A; Agboado, G; Orton, E; Béchard-Evans, L; Morgan, G; Stevenson, C; Weston, R; Mukaigawara, M; Enstone, J; Augustine, G; Butt, M; Kim, S; Puleston, R; Dabke, G; Howard, R; O’Boyle, J; O’Brien, M; Ahyow, L; Denness, H; Farmer, S; Figureroa, J; Fisher, P; Greaves, F; Haroon, M; Haroon, S; Hird, C; Isba, R; Ishola, DA; Kerac, M; Parish, V; Roberts, J; Rosser, J; Theaker, S; Wallace, D; Wigglesworth, N; Lingard, L; Vinogradova, Y; Horiuchi, H; Peñalver, J; Nguyen-Van-Tam, JS (September 2013). “Influenza vaccination for immunocompromised patients: summary of a systematic review and meta-analysis”. Influenza and other respiratory viruses. 7 Suppl 2: 72–5. doi:10.1111/irv.12084. PMID 24034488. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]