HIV facts

HIV facts

• The human immunodeficiency virus (HIV) is a type of virus called a retrovirus, which infects humans when it comes in contact with tissues such as those that line the vagina, anal area, mouth, or eyes, or through a break in the skin.
• HIV infection is generally a slowly progressive disease in which the virus is present throughout the body at all stages of the disease.
• Three stages of HIV infection have been described.
1. The initial stage of infection (primary infection), which occurs within weeks of acquiring the virus, and often is characterized by a flu- or mono-like illness that generally resolves within weeks.
2. The stage of chronicasymptomatic infection(meaning a long duration of infection without symptoms) lasts an average of eight to 10 years.
3. The stage of symptomatic infection, in which the body's immune (or defense) system has been suppressed and complications have developed, is called the acquired immunodeficiency syndrome (AIDS). The symptoms are caused by the complications of AIDS, which include one or more unusual infections or cancers, severe loss of weight, and intellectual deterioration (called dementia).
• When HIV grows (that is, by reproducing itself), it acquires the ability to change (mutate) its own structure. This mutation enables the virus to become resistant to previously effective drug therapy.
• The goals of drug therapy are to prevent damage to the immune system by the HIV virus and to halt or delay the progress of the infection to symptomatic disease.
• Therapy for HIV includes combinations of drugs that decrease the growth of the virus to such an extent that the treatment prevents or markedly delays the development of viral resistance to the drugs.
• The best combination of drugs for HIV has not yet been defined, but one of the most important factors is that the combination be well tolerated so that it can be followed consistently without missing doses.

Dementia facts*

• Dementia is a term that describes a collection of symptoms that include decreased intellectual functioning that interferes with normal life functions and is usually used to describe people who have two or more major life functions impaired or lost such as memory, language, perception, judgment or reasoning; they may lose emotional and behavioral control, develop personality changes and have problem solving abilities reduced or lost.
• There are different classification schemes for dementias roughly based (and with overlap) on observed problems; some frequently used are cortical (memory, language, thinking, social) , subcortical (emotions, movement, memory), progressive (cognitive abilities worsen over time), primary (results from a specific disease such asAlzheimer's disease and secondary (occurs because of disease or injury).
• Alzheimer's disease (AD): is the most common cause of dementia in people over age 65 with cause possibly related to amyloid plaques and neurofibrillary tangles; almost all brain functions, including memory, movement, language, judgment, behavior, and abstract thinking, are eventually affected.
• Vascular dementia: is the second most common cause of dementia caused by brain damage from cerebrovascular or cardiovascular problems (strokes) or other problems that inhibit vascular function; symptoms similar to AD but personality and emotions effected only late in the disease.
• Lewy body dementia: is common and progressive where cells in the brain's cortex die and other contain abnormal structures (Lewy bodies); symptoms overlap with Alzheimer's disease but also include hallucinations, shuffling gait, and flexed posture with symptoms that may vary daily.
• Frontotemporal dementia: is dementia linked to degeneration of nerve cells in the frontal and temporal brain lobes and some evidence for a genetic factor (many have a family history of the disease); symptoms in patients (usually ages 40 – 65) have judgment and social behavior problems such as stealing, neglecting responsibilities,increased appetite, compulsive behavior and eventual motor skill problems and memory loss.
• HIV-associated dementia: is due to infection of the brain with HIV virus; symptoms include impaired memory, apathy, social withdrawal, and concentration problems.
• Huntington's disease: is a heredity disorder caused by a faulty gene and children of a person with the disorder have a 50% chance of getting the disease; symptoms begin in 30-40 year old people with personality changes such as anxiety, depression and progress to show psychotic behavior severe dementia and chorea - involuntary jerky, arrhythmic movements of the body.
• Dementia pugilistica: is also termed Boxer's syndrome, is due to traumatic injury (often repeatedly) to the brain; symptoms commonly are dementia and parkinsonism (tremors, gait abnormalities) and other changes depending where brain injury has happened.
• Corticobasal degeneration: is a progressive nerve cell loss in multiple areas of the brain; symptoms begin at about age 60 on one side of the body and include poor coordination and rigidity with associated visual-spatial problems that can progress to memory loss, hesitant speech and dysphagia (difficulty swallowing).
• Creutzfeldt-Jakob disease: is a rare disease that seems related to a gene mutation that causes rapid (death about one year after symptoms begin to develop) degenerative and fatal brain disease in people usually over 60 years old; personality changes and reduced coordination develop, rapidly followed by impaired judgment and vision and many patients develop a coma before they die.
• Other rare hereditary dementias: – Most of these diseases develop in people between 50 – 60 years old and most have variable symptoms of poor reflexes, dementia, hallucinations, paralysis and most develop coma before death; some of the names of these diseases are Gerstmann-Straussler-Scheinker disease, familial British dementia, familial Danish dementia and fatal familial insomnia.
• Secondary dementias: These dementias occur in patients with other disorders of movement such as Parkinson's disease or multiple sclerosis and may because by one or more problems listed above; these dementias may share symptoms with any of the above mentioned dementias but researchers are unsure if this is due to disease overlap or other causes.
• Dementias in children: While infections, trauma and poisoning can lead to dementia in both children and adults, there are some dementias that are unique to children but may result in mental problems, seizures, reduction or loss of motor skills, blindness, neurodegeneration and death; many are inherited disorders such as Niemann-Pick disease, Batten disease, Lafora disease and mitochondrial abnormalities.
• Other conditions that may cause dementia: Reactions to medications, endocrine and metabolic problems, nutritional deficiencies, infections, subdural hematomas, poisoning, brain tumors, anoxia (lack of oxygen), heart and lung problems.
• What conditions are not dementia: Although these conditions may resemble some aspects of dementia, they have different causes, usually are treatable and have better outcomes; examples are depression, delirium, mild cognitive impairment and age-related cognitive decline.
• Dementia causes: All causes of dementia result from death and damage of nerve cells in the brain; genetics and possibly the formation of different types of inclusions in the brain cells are likely the major causes, although some researchers suggest that certain inclusions may be only side effects of an underlying disorder.
• Risk factors for dementia include advancing age, genetics (family history), smoking, alcohol use, atherosclerosis, high cholesterol,diabetes, high plasma homocysteine levels, mild cognitive impairment,Down syndrome
• Dementia is diagnosed by using many methods such as patient's medical and family history, physical exam, neurological evaluations, cognitive and neuropsychological testing, CT's, MRI's and other brain scans, mental status exams, electroencephalograms, blood tests, psychiatric evaluations, and even some pre-symptomatic tests are available for some patients that may have a genetic link to dementia.
• Most treatments for dementia will neither reverse or stop the disease; however, there are treatments and medications that may reduce the symptoms and slow the disease progression; they are tightglucose control by persons with diabetes, intellectual stimulating activities, lowering cholesterol and homocysteine levels, regularexercise, education, controlling inflammation of body tissues, using NSAID's and possibly other medications.

Definition of Retrovirus

Retrovirus: A virus that is composed not of DNA but of RNA. Retroviruses have an enzyme, called reverse transcriptase, that gives them the unique property of transcribing their RNA into DNA after entering a cell. The retroviral DNA can then integrate into the chromosomal DNA of the host cell, to be expressed there. HIV is a retrovirus.

Flu (influenza, conventional, and H1N1) facts

• Influenza, commonly called "the flu," is caused by viruses that infect the respiratory tract.
• Influenza viruses are divided into three types, designated A, B, and C, with A types usually causing the most problems in humans.
• Most people who get the conventional or seasonal flu recover completely in one to two weeks, but some people develop serious and potentially life-threatening medical complications, such as pneumonia.
• Much of the illness and death caused by conventional or seasonal influenza can be prevented by annual influenza vaccination.
• Influenza A undergoes frequent antigenic changes that require new vaccines to be developed and people to obtain a new vaccination every year. New vaccine technology is being developed.
• In April 2009, a new flu virus termed novel H1N1 swine flu developed in Mexico, rapidly spread worldwide, and caused the WHO to declare a flu pandemic. Eventually, the WHO declared the pandemic over in 2010. In 2012, a new type of flu strain developed, H3N2v, but has not developed into any epidemic situations currently.
• Like the influenza virus, drug treatments are constantly changing and improving, but currently, timely vaccination is still considered to be the best defense against the flu. However, the CDC considers antivirals an important adjunct to flu vaccine in the control of the disease process.
• People should be aware that flu pandemics can cause severe flu symptoms and sometimes death in many individuals who may be more susceptible to the pandemic flu than the conventional flu; however the previous pandemic flu virus (H1N1) has been available in vaccines and is considered part of the conventional circulating flu viruses.
• Individuals should check with their doctors to determine if they are considered to be at higher risk of getting severe flu symptoms than the normally healthy population.

Infectious mononucleosis (mono) facts

• Infectious mononucleosis (mono) is a contagious illness caused by the Epstein-Barr virus (EBV).
• The infection can be spread by saliva, and the incubation period for mono is four to eight weeks.
• Most adults have laboratory evidence (antibodies against the EBV) indicative of a previous infection with EBV and are immune to further infection.
• The symptoms of mono include fever, fatigue, sore throat, and swollen lymph nodes.
• The diagnosis of mono is confirmed by blood tests.
• Mono can cause liver inflammation (hepatitis) and enlargement of the spleen.
• People who have had mono can continue to shed virus particles in their saliva during reactivations of the viral infection throughout their lifetime.
• Vigorous contact sports should be avoided in the illness and recovery phase to prevent rupture of the spleen.

What is infectious mononucleosis?

Infectious mononucleosis, "mono," "kissing disease," and glandular fever are all terms popularly used for the very common infection caused by the Epstein-Barr virus (EBV). EBV is a member of the herpesvirus family. The characteristic symptoms of infection with EBV include fever, fatigue, malaise, and sore throat. The designation "mononucleosis" refers to an increase in a particular type of white blood cells (lymphocytes) in the bloodstream relative to the other white blood cells as a result of the EBV infection.

The disease was first described in 1889 and was referred to as "Drüsenfieber," or glandular fever. The term infectious mononucleosis was first used in 1920 when an increased number of lymphocytes were found in the blood of a group of college students who had fever and symptoms of the condition.

Definition of Asymptomatic infection

Asymptomatic infection: An infection without symptoms. Also known as inapparent or subclinical infection.

Acquired immunodeficiency syndrome (AIDS) facts

• AIDS stands for "acquired immunodeficiency syndrome."
• AIDS is an advanced stage of infection with the human immunodeficiency virus (HIV). HIV usually is spread from person to person through contact with infected sexual secretions or infected blood.
• People with AIDS have weakened immune systems that make them vulnerable to selected conditions and infections.
• For people infected with HIV, the risk of progression to AIDS increases with the number of years the person has been infected. The risk of progression to AIDS is decreased by using highly effective treatment regimens called HAART.
• In people with AIDS, HAART therapy improves the immune system and substantially increases life expectancy. Many patients who are treated with HAART have near-normal life expectancies.
• HAART is a treatment that must be continued for life. It is not a cure.
• It is possible for HIV to become resistant to some of the HAART medications. The best way to prevent resistance is for the patient to take their HAART medications as directed. If the patient wants to stop a drug because of side effects, he or she should call the physician immediately.
• If a person is exposed to blood or potentially infectious fluids from a source patient with HIV, the exposed person can take medications to reduce the risk of getting HIV.
• Research is under way to try to find a vaccine and a cure for HIV.

What does AIDS stand for? What causes AIDS?

AIDS stands for "acquired immunodeficiency syndrome." AIDS is caused by the human immunodeficiency virus (HIV) and is the most advanced stage of HIV infection.

The virus is spread through contact with infected blood or infected fluids such as sexual secretions (stage 1). Over time, the virus attacks the immune system, focusing on special cells called "CD4 cells" which are important in protecting the body from infections and cancers, and the number of these cells starts to fall (stage 2). Eventually, the CD4 cells fall to a critical level and/or the immune system is weakened so much that it can no longer fight off certain types of infections and cancers. This advanced stage of infection (stage 3) with HIV is called AIDS.

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 medications.