Natural History of HIV Infection

Natural History of HIV Infection

The natural history of HIV infection is divided into following stages.

Acquisition of Infection
Primary HIV infection
Asymptomatic HIV infection
Early symptomatic infection
Late symptomatic infection
Advance HIV disease

Acquisition of Infection

The major routes of transmission of HIV are sexual contact, parenteral exposure to blood and blood products and transmission during pregnancy.

HIV is spread when blood, semen, or vaginal fluids from an infected person enter another person's body, usually in one of the following ways:

Sexual Contact: any type of sexual contact - anal, vagina, or oral.
Drug addicts sharing needles.
Tattooing and body piercing by un sterilized needles. Getting injected by un sterilized needles by quacks (especially in the underdeveloped countries.)
Accidental needle pricks to health workers or doctors.
Unsafe Blood or blood products.
Born to HIV positive mother. Pregnant female can transmit the virus to the newborn during pregnancy or during delivery or when she feeds her baby breast milk.

Primary HIV Infection

The initial infection with HIV is a subclinical type of infection and may not be of much consequence. A small part of the infected may develop within 2-3 weeks Rash, Fever and Lymphadenopathy. Some get pharyngitis, erythematous maculopapular rash, arthralgia, myalgia, retro orbital headache, malaise, diarrhea and vomiting. Opportunistic infections are not seen at this stage. A large majority remain asymptomatic. The majority of those infected do not give a history of this stage of infection because it goes unnoticed resembling routine infections.

Asymptomatic HIV infection

This is an asymptomatic phase of HIV infection and most of the patients maintaing normal health and unaware of the disease. This phase has a duration of several years - median duration being 10 years. The peripheral blood CD4 T-cell count is usually above 500 cells/mm³.

Early symptomatic HIV disease

At this stage symptoms including fever, unexplained weight loss, recurrent diarrhea, fatigue and headache. Cutaneous manifestations like seborrheic dermatitis, folliculitis, recurrent herpes simplex infections oral hairy leukoplakia may occur. During this period the CD4 T-cells count continues to come down. Usually anti retroviral therapy is started at this stage.

Late symptomatic HIV disease

As the CD4 count falls lower than 200 cells/mm³, the risk of developing AIDS related opportunistic infections or malignancy is very high. Pneumocystis carini pneumonia (PCP), Toxoplasma encephalitis, Disseminated mycobacterium avium complex (MAC), Esophageal candidiasis, Lymphoma and Kaposi sarcoma.

Advanced HIV disease

In advanced HIV disease state the CD4 cell count is less than 50 cells/mm³. The patients usually have multiple opportunistic infection and malignancies. With increased use of ART the survival among the advanced HIV disease patients has improved substantially.

	HIV infection
	Laboratory Tests for HIV Infection
	Manifestations of HIV
	Management of HIV infection

Sorry, your browser doesn't suppor Java.