HIV is the most deadly and contagious infection closely linked with the sexual behaviour of individuals. HIV and AIDS are interchangeably used though there is a slight difference between them. The first case of AIDS was recognized in India in the year 1982. There are various forms of HIV infection encompassing 10 subtypes. They are classified as type-A, type-B, type C and up to type-J. there is one more distinct and unusual type of HIV known as type -O.HIV is a global health problem, with African countries and a few European counties in the priority list. India shares a good percentage of the cases, however, the preventive protocols from the past 10 years has brought in some reduction in the prevalence rate of the disease.  HIV is abbreviated as human immunodeficiency virus and AIDS stands for acquired immunodeficiency syndrome. Most often people get confused about the difference between HIV and AIDS. HIV is the causative factor for AIDS, whereas, AIDS is the most advanced stage of illness with prominent symptoms. HIV is one of the most challenging diseases in the world today. This is because of the nature of the illness that involves multi-system damage. Because of the involvement of all body systems, it is very difficult to completely cure the infection. On the other hand, the HIV virus is a highly resistant organism against any antibiotics. However, modern medicines are capable to keep a check against the viral load to some extent which helps in Atlas prolonging the survival period of the hosts.

1. Introduction

2. Morphology of HIV

​3. How HIV works

4. Transmission of HIV

5. Difference between HIV and AIDS

6. Symptoms of AIDS 

7. Prevention and control of HIV

Morphology of HIV

HIV is the most virulent and highly resistant virus. It has the capacity to survive in any adverse environment making it the most challenging disease for many decades. As the name suggests, HIV works by attacking the immune system which in turn results in poor immunity in the body. Human Immunodeficiency Virus (HIV) is an RNA virus belongs to the genus Lentivirus and the family of retroviridae. It measures approximately 1oo nm encompassing 72 external spikes generated through envelopes. There are 2 major glycoprotein envelopes surrounding the organism namely,  gp120 and gp41. Based on the variation in the surface proteins, HIV is classified into 2 major types, namely, HIV- 1 and HIV-2. The major serological differences reside in the surface protein gp120. Depending upon the variability in the V3 (variable region) HIV-1 and HIV-2 are further divided into subtypes called clads. There is also a lipid bilayer with a number of host-cell proteins. The looks like cone-shaped, having a dense nucleocapsid that contains core protein p24. This nucleocapsid produces 2 similar copies of single-stranded positive polarity RNA genome measuring 9.8 kb. The genome is known by names viral enzymes reverse transcriptase (RT), integrase RNase H, and protease. There is a matrix surrounded by the envelope. Within the matrix, there is a viral core, made up of p24. There is a capsid that is shaped like an icosahedron. There are small isohedral subunits that cover the entire capsid that finally change into a shape resembling a bullet. HIV proteases are the type of enzyme that assists in breaking down the complex proteins into smaller. These smaller proteins combine with the genetic material of HIV to form a new HIV virus.


Structure of HIV Virion-image by NIAID


How HIV works

The main mechanism of HIV is, attacking the immune system which results in gradual debilitation of all the body systems, ultimately the organs suffer systems infections. In many cases that disease will be identified only after the patient reached an advanced stage, hence, early diagnosis plays a vital role in managing HIV. HIV has a  unique genetic material made up of RNA that has an ability to easily combine with the normal cells of the body, This makes the immune system very difficult to identify the virus.


Transmission of HIV

HIV is transmitted in three ways: sexually, by anal or vaginal intercourse and the last one by blood transfusion with contaminated blood.  Among these, transfusion with contaminated blood is a highly efficient means of transmission. Transmission by heterosexual (vaginal) intercourse is of 0.1% to 1%. But this is not the case always. If either one or both the partners suffered from vaginal disease, ulcers then the rate of transmission is way too high. Pregnant mothers suffering from HIV can easily transmit the infection to newborn, however, the recent medical advancements made it possible to block the transmission from mother to child.


Difference between HIV and AIDS

HIV is the state of having some viral load in the blood whereas AIDS is an advanced stage where the patient is in danger due to high viral load (percentage per ML of blood). AIDS is probably a case of high risk and the sufferer must be inching close towards death.


Symptoms of AIDS 

AIDS is a multi-system disorder that affects various systems in the body causing complete failure of organs when the end stage of the disease reached. A person suffering from AIDS might experience being always tired, swelling of lymph glands and nodes, chronic fever that lasts for more than 10 days, excessive night sweats, sudden loss of weight, anaemia, loss of hunger, variations in the sugar levels and multi-system damage.


Prevention and control of HIV

Because there is no known cure or vaccine for HIV infection, prevention and control strategies are extremely important. The main approaches towards AIDS prevention is

1. Promotion of safer sexual behaviours: Since the onset of the pandemic, information, education, and communication campaigns have been vital in reducing behaviours that put individuals at high risk for infection. These campaigns are of two types: broad mass communication for the general public, and targeted, more intensive behavioural change communication strategies aimed at vulnerable groups. Person-to-person education programs are important for certain vulnerable groups because such programs increase the level of knowledge about AIDS and high-risk behaviours.

2. Promotion of condom use: The promotion of safer sexual behaviours, including the use of condoms, is an integral part of prevention and control strategies. Condom use is encouraged through programs that involve market research, product importation, brand name packaging, advertising, media promotion, distribution, and management.

3. Measures to the prevention and treatment of STDs: Conventional STDs facilitate the transmission of HIV. Because of its adverse effect on the immune system, HIV infection can alter the incidence, natural history, and response to treatment of other STDs. In addition, these diseases rank among the top 10 of the most important health problems in the semi-urban and rural populations. The early diagnosis and treatment of sexually transmitted diseases combined with behavioural intervention is recommended.

4. Prevention of unsafe drug use behaviour: Conduct some outreach programs that include education regarding the need to eliminate needle sharing, instructions regarding sterilization of needles and the use of packed ( sterile packed) injection needles.

5. Provision of a safe blood supply: Transfusion-induced HIV infection can be prevented by safe blood screening initiatives. The donor blood must be thoroughly examined for HIV and related viruses. Yet, as many as 3% to 5% of HIV-infected individuals in sub-Saharan Africa and parts of Asia become infected by contaminated blood. 

6. Targeted interventions: For individuals at high risk of HIV infection, and epidemiologically sound set of preventive activities (interventions) are put together as a package. These interventions not only are easy to implement but they are cost-efficient and their impact is measurable.