“AIDS-defining” conditions

HIV is a virus that attacks CD4 cells (T cells). These white blood cells serve as helper cells for the immune system. CD4 cells send a biological SOS signal to other immune system cells to go on the offensive against infections.

When a person contracts HIV, the virus merges with their CD4 cells. The virus then hijacks and uses the CD4 cells to multiply. As a result, there are fewer CD4 cells to fight infections.

Opportunistic infections and diseases

With HIV, a weakened immune system increases vulnerability to several opportunistic infections, cancers, and other conditions. The CDC refers to these as “AIDS-defining” conditions. If someone has one of these conditions, the HIV infection has advanced to stage 3 HIV (AIDS), regardless of the number of CD4 cells in their blood.

Following are some of the more common opportunistic diseases. Becoming knowledgeable about these health risks is the first step in protecting against them.

Candidiasis

Candidiasis encompasses several infections in different areas of the body caused by Candida, a genus of fungi. These infections include oral thrush and vaginitis. A fungal infection is considered AIDS-defining when found in the esophagus, bronchi, trachea, or lungs.

Powerful and sometimes quite toxic antifungal medications are used to treat candidiasis. A healthcare provider will recommend a specific medication based on the location of infection.

For instance, they may prescribe these medications for vaginitis caused by candidiasis:

• butoconazole (Gynazole)
• clotrimazole
• miconazole (Monistat)

If systemic infection is present, treatment may include medications like:

• fluconazole (Diflucan)
• itraconazole (Sporanox)
• posaconazole (Noxafil)
• micafungin (Mycamine)
• amphotericin B (Fungizone)

Cryptococcal meningitis

Cryptococcus is a common fungus found in soil and bird droppings. Some varieties also grow in areas surrounding trees, and one variety particularly prefers eucalyptus trees. If inhaled, Cryptococcus may cause meningitis. This is an infection of the membranes around the brain and spinal cord.

Very potent (and quite often toxic) antifungal medications are used to initially treat cryptococcal meningitis, as are frequent spinal taps. These medications may include in combination:

• amphotericin B
• flucytosine (Ancobon)
• fluconazole
• itraconazole

This condition can be fatal if not treated promptly. Long-term suppressive therapy is often used with somewhat less toxic medications for people with HIV.

Cryptosporidiosis

A tiny parasite that lives in the intestines of humans and animals is responsible for cryptosporidiosis. Most people get the disease by drinking contaminated water or eating contaminated produce.

Cryptosporidiosis is an unpleasant diarrheal illness for healthy people. However, for those who are HIV-positive, it can last longer and cause more severe symptoms.

A medication called nitazoxanide (Alinia) is normally prescribed to treat the disease.

Cytomegalovirus

Cytomegalovirus (CMV) is virus most commonly thought of as causing serious eye disease in people with weakened immune systems. It can potentially lead to blindness.

CMV can also lead to illness in other areas of the body, such as the digestive tract and parts of the nervous system.

There are currently no medications to cure CMV. However, several powerful antiviral medications can treat the infection. These include:

• gancliclovir (Zirgan)
• valgancilovir (Valcyte)
•  foscarnet (Foscavir) 
• cidofovir (Vistide)

In people with severely weakened immune systems, these CMV medications often need to be given at significant doses over the long term.

However, the damage from CMV infection may slow with the use of antiretroviral therapy. This can result in the rebuilding of the immune system (as demonstrated by clinically significant rises in CD4 count). Anti-CMV therapy may potentially be changed to easier-to-tolerate suppressive treatments.

Herpes simplex viruses

Herpes simplex virus (HSV) is characterized by sores on the mouth, lips, and genitals. Anyone can get herpes, but people with HIV experience increased frequency and severity of outbreaks.

There is no cure for herpes. However, relatively easy-to-tolerate medications, taken long term, can alleviate symptoms of the virus.

Pneumocystis pneumonia

Pneumocystis pneumonia (PJP) is a fungal pneumonia that can be fatal if it’s not diagnosed and treated early. PJP is treated with antibiotics. The risk of a person with HIV developing PJP rises so high that preventive antibiotic therapy may be used if their CD4 count drops below 200 cells per microliter (cells/µL).

Salmonella septicaemia

Commonly referred to as “food poisoning,” salmonellosis is a bacterial infection of the intestines. The bacteria responsible is most often transmitted via food or water that has been contaminated with feces.

The U.S. Food and Drug Administration (FDA) reports that those with weakened immune systems, such as people living with HIV, have at least a 20 times greater risk of salmonellosis. Salmonellosis can spread into the blood, joints, and organs.

Antibiotics are commonly prescribed to treat this infection.

Toxoplasmosis

Toxoplasmosis is caused by parasites in contaminated food. The disease can also be contracted from cat feces.

The risk of significant disease from toxoplasmosis infection rises substantially once the CD4 count drops below 100 cells/µL. An HIV-positive person should ideally avoid all contact with cat feces or any other source of toxoplasmosis exposure.

People who have severely weakened immune systems (less than or equal to 100 CD4 cells/µL) should receive the same preventive antibiotic therapy as that for PJP.

Toxoplasmosis is treated with antimicrobial medications such as trimethoprim-sulfamethoxazole (Bactrim).

Tuberculosis

Tuberculosis (TB) may seem like a disease from the past, but it’s actually the leading cause of death for individuals who have HIV.

TB is caused by Mycobacterium tuberculosis bacteria and is spread through the air. TB generally affects the lungs and has two forms: latent TB and active TB disease.

Individuals with HIV are more likely to become sick with TB.

The disease is treated over the course of six to nine months with a combination of several medications, including:

• isoniazid (INH)
• rifampin (Rifadin)
• ethambutol (Myambutol)
• pyrazinamide

With treatment, both latent and active TB can be managed, but without treatment, TB can lead to death.

Mycobacterium avium complex (MAC)

Mycobacterium avium complex (MAC) organisms are present in most everyday environments. They rarely cause problems for people with healthy immune systems. For those with weakened immune systems, however, MAC organisms can make their way into the body through the GI system and spread. When the organisms spread, they may lead to MAC disease.

This disease causes symptoms such as fever and diarrhea, but it usually isn’t fatal. It can be treated through antimycobacterials and antiretroviral therapy.

Opportunistic cancers

Invasive cervical cancer

Cervical cancer begins in the cells lining the cervix. The cervix is located between the uterus and vagina. Cervical cancer is known to be caused by the human papillomavirus (HPV). Transmission of this virus is extremely common among all sexually active women. But studies have clearly demonstrated that the risk of contracting HPV rises substantially as HIV progresses.

For this reason, HIV-positive women should undergo regular pelvic exams with Pap tests. Pap tests can detect early cervical cancer.

Cervical cancer is considered invasive when it spreads outside the cervix. Treatment options include surgery, radiation therapy, or chemotherapy.

Kaposi sarcoma

Kaposi sarcoma (KS) is linked to infection by a virus called human herpes virus 8 (HHV-8). It causes cancerous tumors of the body’s connective tissues. Dark, purplish skin lesions are associated with KS.

KS isn’t curable, but its symptoms often improve or resolve completely with antiretroviral therapy. Several other treatments are available for people with KS. These include radiation therapy, intralesional chemotherapy, systemic chemotherapy, and retinoids.

Non-Hodgkin’s lymphoma

Non-Hodgkin’s lymphoma (NHL) is a cancer of lymphocytes, cells that are part of the immune system. Lymphocytes are found throughout the body in such places as the lymph nodes, digestive tract, bone marrow, and spleen.

Various treatments are used for NHL, including chemotherapy, radiation therapy, and stem cell transplants.

Source: https://www.healthline.com/health/hiv-aids/opportunistic-infections

Novel method for dating 'hibernating' HIV strains

Researchers at the BC Centre for Excellence in HIV/AIDS (BC-CfE) and Simon Fraser University (SFU), in partnership with University of British Columbia (UBC) and Western University, have developed a novel way for dating "hibernating" HIV strains, in an advancement for HIV cure research in the province. Published in the Proceedings of the National Academy of Sciences (PNAS), the BC-CfE's first major scientific contribution to the area of HIV cure research confirms that dormant HIV strains can persist in the body for decades.

"If you can't identify it, you can't cure it. This research provides further essential clues in the pursuit of an HIV cure -- which will ultimately require the complete eradication of dormant or 'latent' HIV strains," said Dr. Zabrina Brumme, Director, Laboratory with BC-CfE and lead author on the study. "Scientists have long known that strains of HIV can remain essentially in hibernation in an individual living with HIV, only to reactivate many years later. Our study confirms that the latent HIV reservoir is genetically diverse and can contain viral strains dating back to transmission."

 

"The BC-CfE has consistently been a national and global leader on research on HIV and on the implementation of its pioneering Treatment as Prevention® strategy. The addition of molecular biologist Dr. Zabrina Brumme as Director of the innovative BC-CfE Laboratory ensures the BC-CfE will play a significant role in HIV cure research," said Dr. Julio Montaner, Director of the BC-CfE. "Curative strategies will need to address this new study's key findings. I want to acknowledge the study participants and thank them for helping to increase our knowledge on the origins of the latent HIV reservoir."

"By creating family trees of viruses using a technique called molecular phylogenetics, we can reconstruct the evolutionary history of HIV within a person," said Brad Jones, a Ph.D. student with UBC at the BC-CfE and the first author on the study. "In essence, we created a highly calibrated 'time machine' that gives us a specific time stamp for when each dormant HIV strain originally appeared in a person."

Dormant HIV strains, which have integrated their DNA into that of the body's cells, can persist for years and are unreachable by antiretroviral treatments and the immune system. They can reactivate at any time, which is why HIV treatment needs to be maintained for life.

Through advances in antiretroviral therapy, an individual living with HIV can now live a longer, healthier life on treatment. Treatment works by stopping HIV from infecting new cells. On sustained treatment, individuals can achieve a level of virus that is undetectable by standard blood tests. An undetectable viral load means improved health and that the virus is not transmittable to others -- the concept behind Treatment as Prevention®.

"Previous research had already revealed that the HIV reservoir was genetically complex. With our method, we can now understand that complexity with greater granularity, pinpointing exactly when each unique HIV strain originally appeared in a person," said Dr. Jeffrey Joy, Research Scientist at the BC-CfE and co-author on the study.

"In order to eradicate HIV from a person's body, you first need to know the characteristics of HIV in the latent reservoir," said Dr. Art Poon, Assistant Professor in Pathology and Laboratory Medicine at Western University, also a co-author on the study. "We are providing a method for better measuring the timeline of virus latency and evolution within an individual living with HIV."

In order to "date" dormant HIV strains within the viral reservoir, researchers needed to compare these strains to those that evolved within an individual living with HIV over the entire history of their infection. The BC-CfE is one of a handful of institutions worldwide capable of such research, thanks to its maintenance of a historical repository of blood specimens from individuals diagnosed with HIV in BC. These specimens date back to 1996 and were originally collected for viral load and drug resistance testing. The BC-CfE Laboratory has provided HIV drug resistance genotyping for virtually all Canadian provinces and territories since 1998, as well as for many countries worldwide.

This research was funded by the Canadian Institutes of Health Research (CIHR) in partnership with the Canadian Foundation for AIDS Research (CANFAR) and the International AIDS Society (IAS) through its support of the Canadian HIV Cure Enterprise (CanCURE), as well as the US National Institutes of Health (NIH) through its support of the Martin Delaney BELIEVE Collaboratory.

To be a speaker at STD 2018 Conference being held at Toronto, Canada, submit your abstracts here: https:/std-hiv-aids.cmesociety.com/abstract-submission 

 

Source: https://www.sciencedaily.com/releases/2018/09/180905142037.htm