“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

Herpes linked to Alzheimer's: Antivirals may help

A new commentary by scientists at the Universities of Manchester and Edinburgh on a study by Taiwanese epidemiologists supports the viability of a potential way to reduce the risk of Alzheimer's disease.

When the Taiwanese authors looked at subjects who suffered severe herpes infection and who were treated aggressively with antiviral drugs, the relative risk of dementia was reduced by a factor of 10.

Manchester's Professor Ruth Itzhaki and Edinburgh's Professor Richard Lathe say the paper, by Tzeng et al. and published in Neurotherapeutics in February 2018, also shows that herpes simplex virus type 1 (HSV1) leads to an increased risk of developing the disease.

"This article and two others by different research groups in Taiwan provide the first population evidence for a causal link between herpes virus infection and Alzheimer's disease, a hugely important finding," said Professor Itzhaki.

They publish a commentary in the Journal of Alzheimer's Disease on the three articles, arguing that they provide the strongest evidence yet for a causal link between herpes infection and Alzheimer's disease, backing 30 years of research by Professor Itzhaki.

Professor Itzhaki said: "I believe we are the first to realise the implications of these striking data on this devastating condition which principally affects the elderly. No effective treatments are yet available.

"Almost 30 million people worldwide suffer from it and sadly, this figure will rise as longevity increases.

"But we believe that these safe and easily available antivirals may have a strong part to play in combating the disease in these patients.

"It also raises the future possibility of preventing the disease by vaccination against the virus in infancy.

"Successful treatment by a specific drug, or successful vaccination against the putative microbe, are the only ways to prove that a microbe is the cause of a non- infectious human disease."

Most Alzheimer's disease researchers investigate its main characteristics -- amyloid plaques and neurofibrillary tangles; however, despite the vast amount of research, the causes of their formation are unknown.

HSV1 infects most humans in youth or later and remains lifelong in the body in dormant form within the peripheral nervous system.

From time to time the virus becomes activated and, in some people, it then causes visible damage in the form of cold sores.

The Taiwanese study identified 8,362 subjects aged 50 or more during the period January to December 2000 who were newly diagnosed with severe HSV infection.

The study group was compared to a control group of 25,086 people with no evidence of HSV infection.

The authors then monitored the development of dementia in these individuals over a follow-up period of 10 years between 2001 and 2010.

The risk of developing dementia in the HSV group was increased by a factor of 2.542. But, when the authors compared those among the HSV cohort who were treated with antiviral therapy versus those who did not receive it, there was a dramatic tenfold reduction in the later incidence of dementia over 10 years.

Professor Richard Lathe added: "Not only is the magnitude of the antiviral effect remarkable, but also the fact that -- despite the relatively brief duration and the timing of treatment -- in most patients severely affected by HSV1 it appeared to prevent the long-term damage in brain that results in Alzheimer's.

Professor Itzhaki said: "It was as long ago as 1991 when we discovered that, in many elderly people infected with HSV1, the virus is present also in the brain, and then in 1997 that it confers a strong risk of Alzheimer's disease in the brain of people who have a specific genetic factor.

"In 2009, we went on to show that HSV DNA is inside amyloid plaques in Alzheimer's patients' brains.

"We suggested that the virus in brain is reactivated by certain events such as stress, immunosuppression, and infection/inflammation elsewhere.

"So we believe the cycle of HSV1 reactivation in the brain eventually causes Alzheimer's in at least some patients."

Source: https://www.sciencedaily.com/releases/2018/07/180712100515.htm