what is the natural course of the infection

Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. For example, untreated infection with HIV causes a spectrum of clinical problems beginning at the time of seroconversion (primary HIV) and terminating with AIDS and usually death.

Full Answer

What is an infection?

Infection occurs when an organism, such as a virus or bacterium, invades the body. The infectious agent rapidly multiplies in the body’s tissues. Although not all infections result in disease, some can trigger the immune system, causing symptoms of illness. There are five stages of infection:

What is the natural course of untreated HIV infection?

The natural course of untreated HIV infection varies widely with some HIV-positive individuals able to maintain high CD4 cell counts and/or suppressed viral load in the absence of ART. Although similar, the underlying mechanistic processes leading to long-term nonprogression and viral control are likely to differ.

What are the stages of infection?

Infection typically occurs in five stages. The incubation stage occurs right after exposure and before symptoms develop. This stage can range from hours for some infections to days, weeks, or even years for other infections. The next stage is prodromal, which involves mild, nonspecific symptoms.

Do all infections result in disease?

Although not all infections result in disease, some can trigger the immune system, causing symptoms of illness. There are five stages of infection: This article will explain each of the five stages of infection in detail, describing how long they can last and giving examples of infections.

What is the natural history of an infection?

Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. For example, untreated infection with HIV causes a spectrum of clinical problems beginning at the time of seroconversion (primary HIV) and terminating with AIDS and usually death.

What infections are permanent?

Persistent Infections by Organ SystemImmune System. ... Human Immunodeficiency Virus. ... Human T-Cell Leukemia Viruses. ... Epstein-Barr Virus. ... Human Cytomegalovirus. ... Human Herpesviruses 6 and 7. ... Nervous System. ... Herpes Simplex Virus Types 1 and 2.More items...

What is acute retroviral?

Acute retroviral syndrome (ARS) is the first stage of infection with the human immunodeficiency virus (HIV). Symptoms of acute retroviral syndrome are similar to the flu (such as headache, nausea, diarrhea, and body aches) and disappear on their own within weeks.

What is human immunodeficiency virus?

HIV stands for human immunodeficiency virus. It weakens a person's immune system by destroying important cells that fight disease and infection. There is currently no effective cure for HIV.

How long can infection last?

Acute infections, which are short-lived. Chronic infections, which can last for weeks, months, or a lifetime. Latent infections, which may not cause symptoms at first but can reactivate over a period of months and years.

What happens if you have an infection for a long time?

An untreated bacterial infection can also put you at risk for developing a life-threatening condition called sepsis. Sepsis occurs when an infection causes an extreme reaction in your body. The bacteria most likely to cause sepsis include Staphylococcus aureus, E. coli, and some types of Streptococcus.

What is a person who is infectious but has subclinical disease called?

Such persons who are infectious but have subclinical disease are called carriers. Frequently, carriers are persons with incubating disease or inapparent infection. Persons with measles, hepatitis A, and several other diseases become infectious a few days before the onset of symptoms.

What is the stage of subclinical disease?

This stage of subclinical disease, extending from the time of exposure to onset of disease symptoms, is usually called the incubation period for infectious diseases, and the latency period for chronic diseases.

What is a timeline in medical terminology?

Description: Timeline shows state of susceptibility, exposure, subclinical disease in which pathologic changes takes place, onset of symptoms, followed by usual time of diagnosis, clinical disease, followed by recovery, disability, or death. Return to text.

What is the difference between pathogenicity and infectivity?

For an infectious agent, infectivity refers to the proportion of exposed persons who become infected. Pathogenicity refers to the proportion of infected individuals who develop clinically apparent disease.

What is the definition of virulence?

Virulence refers to the proportion of clinically apparent cases that are severe or fatal. Because the spectrum of disease can include asymptomatic and mild cases, the cases of illness diagnosed by clinicians in the community often represent only the tip of the iceberg.

What is natural history?

Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. For example, untreated infection with HIV causes a spectrum of clinical problems beginning at the time of seroconversion ...

How long does it take for AIDS to develop?

It is now recognized that it may take 10 years or more for AIDS to develop after seroconversion. ( 43) Many, if not most, diseases have a characteristic natural history, although the time frame and specific manifestations of disease may vary from individual to individual and are influenced by preventive and therapeutic measures.

What happens during the first phase of a virus?

During the first phase of the infection, the virus is multiplying itself very fast. The CD4 lymphocytes may decrease, but stabilise again later. The immune system begins to produce antibodies against the virus in this first phase following the infection.

What are the symptoms of HIV?

Symptoms such as oral and genital trush, fever, diarrhoea or shingles occur.

How long does asymptomatic HIV last?

Nevertheless, many patients feel well and do not recognize the infection, although they might be already infected for a long time. This phase lasts normally a couple of years.

What does AIDS stand for?

AIDS. AIDS is the abbreviation for “Acquired Immune Deficiency Syndrome”. If the immune system is heavily compromised, life-threatening diseases will arise. Certain diseases have been defined which are considered as AIDS-defining-diseases.

Can HIV be removed with treatment?

Hence, the course of infection is delayed. These drugs cannot remove HIV from the body, meaning, a cure is not possible.

What is the prodromal stage?

The prodromal stage refers to the period after incubation and before the characteristic symptoms of infection occur. People can also transmit infections during the prodromal stage. During this stage, the infectious agent continues replicating, which triggers the body’s immune response and mild, nonspecific symptoms.

What is the term for an organism that invades the body?

Illness. Decline. Convalescence. In HIV. Summary. Infection occurs when an organism, such as a virus or bacterium, invades the body. The infectious agent rapidly multiplies in the body’s tissues. Although not all infections result in disease, some can trigger the immune system, causing symptoms of illness.

How long does hepatitis B last?

Certain infections can last several weeks or even years. Symptoms of hepatitis B can last several weeks#N#Trusted Source#N#. It can also develop into a chronic disease if the infection continues for more than 6 months.

What is stage 2 HIV?

Stage 2: Chronic HIV infection. If left untreated, acute HIV infection progresses to chronic HIV, which can last for decades. In chronic HIV, the virus continues to replicate and destroy CD4 cells. People may not experience symptoms at this stage.

What is the last stage of HIV?

The decline stage occurs when the number of infectious microbes declines and symptoms resolve. The final stage is convalescence. During this stage, symptoms disappear, and the body starts to recover. HIV has three stages of infection: acute, chronic, and AIDS. Last medically reviewed on March 3, 2021.

How long does it take for a virus to develop?

The incubation stage occurs right after exposure and before symptoms develop. This stage can range from hours for some infections to days, weeks, or even years for other infections. The next stage is prodromal, which involves mild, nonspecific symptoms.

What happens during the decline stage of the immune system?

During the decline stage, the immun e system mounts a successful defense against the pathogens, and the number of infectious particles decreases. Symptoms will gradually improve. However, a person can develop secondary infections during this stage if the primary infection has weakened their immune system.