Acquired Immunodeficiency Syndrome(AIDS)

AIDS [Acquired Immunodeficiency Syndrome]

Think about the life of a socially isolated young boy whose mother died of AIDS recently. A number of social stigma and false beliefs are associated with the most dreadful disease –AIDS, a viral disease occurs due to reduction in number of helper T- cells which stimulate B- cells to produce antibodies. Occurrence of AIDS was first noticed amongst homosexuals in 1981 from USA and from prostitutes of Chennai , India in 1986.

AIDS virus also called Human Cell Leukaemia Virus III ( HCLV III) was first isolated by Robert Gallo (1986) but was named Human Immunodeficiency Virus (HIV) by ICVN in 1986. HIV belongs to group retrovirus characterized by the presence of RNA as genetic material and enzyme reverse transcriptase. It is believed that HIV may have passed from monkey host to human population during 1960s in Africa. Francoise Barre-Sinousi & Luc Montagnier were awarded Noble Prize in 2008 for AIDS research.

Structure & Life cycle of HIV:

Structurally HIV looks like a wheel having many radiating spokes with clubbed terminals with diameter of 90-120 nm. Each virus contains two single stranded RNA filaments associated with enzymes reverse transcriptase, protease& Integrase  and two protein coats(Core capsid P-24 and Matrix protein P-17) enveloped by lipid bilayer with projecting glycoprotein spikes   (transmembrane glycoprotein Gp-41 &surface glycoprotein Gp-120) derived from host cell membrane.

After entering into host, the virus infects macrophages where viral RNA replicates to form viral DNA with the help of enzyme Reverse Transcriptase. Now this viral DNA gets incorporated into host genome and starts producing new viral RNAs. Thus macrophages act like HIV Factory. The recognition of the specific host cell is due to the presence of glycoprotein CD-4 and co receptor in host membrane (CXCR-4 in T cells and CCR-5 in macrophages). Simultaneously HIV also enters into helper T- cells where it multiplies to produce and release new virions that lead to decrease in number of T- lymphocytes. AS a result of immune deficiency the patient fails to protect himself against any infection. Once HIV has weakened our immune system, series of multiple infections lead to AIDS.

Incubation period of HIV ranges from 6 months to 12 years. The progression of HIV includes Window period (2-12 weeks), symptomatic period (3-12 years) and AIDS period (2-3 years).

Transmission:

HIV spreads rapidly among people having multiple sex partners and injecting drugs through shared syringe. Women are biologically and socially more vulnerable to HIV infection because of periodical menstrual discharge through reproductive tract, larger vaginal surface for contact, cervical erosions and low status in society. AIDS viruses can be transmitted by various means like – Transfusion of infected blood, Sexual intercourse with infected person, Use of infected syringe /needle or razors, from mother to child through placenta and even organ transplants.

Symptoms:

It is quite difficult to identify AIDS as HIV infection leads to one or more symptoms which can be easily mistaken for many other diseases. Among those most common symptoms of AIDS include painless swollen glands in neck and armpit region, severe weight loss , persistent fatigue, night sweats, persistent diarrhea , fever lasting for several weeks, nausea and oral thrash etc.

Diagnosis:

HIV can be detected only by testing of blood samples. Diagnostic tests developed for AIDS are  ELISA ( Enzyme Linked Immuno Sorbent Assay) and Western Blotting. Western Blotting is used for the confirmation of ELISA positive cases.

Prevention & Control

It is very difficult to control AIDS because no effective drug or vaccine has been developed so far. Some anti retroviral drugs viz. Zidovudine /AZT( Azidothymidine), Didanosine ( Dideoxyionosine) are administered alone or in combination which slow down by interfering replication process of HIV. Thus prolonging the life of the HIV infected patient.

World Health Organization (WHO) , National AIDS Control Organization (NACO)and various NGOs are actively engaged in preventing the AIDS through various programmes which include many steps like educating people about AIDS, ensuring use of disposable and sterile syringe /needle, Blood testing before blood transfusion, avoiding sexual contact with multiple partners, need of safe sexual intercourse by using condoms, avoiding tatoos, ear and nose piercing from unqualified people etc. Every year December 1 is celebrated as World AIDS Day to  make aware and educate the people about AIDS so that social stigma, false beliefs  and alarming situation can be controlled in order to establish a healthy society.

Recap: AIDS-most dreadful viral disease caused by HIV –a retrovirus containing two single stranded RNA molecules associated with reverse transcriptase enzyme.Incubation period ranges from 6 months to 12 years. HIV is transmitted by Transfusion of infected blood, Sexual intercourse with infected person, Use of infected syringe /needle or razors, from mother to child through placenta. Most common symptoms include painless swollen glands in neck and armpit region, severe weight loss , persistent fatigue, night sweats, persistent diarrhea , fever lasting for several weeks & nausea. Diagnostic test for AIDS is ELISA. Some antiretroviral drugs viz. Zidovudine /AZT( Azidothymidine), Didanosine ( Dideoxyionosine) are administered to control AIDS.  NACO and WHO are actively engaged in preventing the AIDS through various programmes which include many steps like educating people about AIDS, ensuring use of disposable syringe and blood testing before transfusion.