Human Immunodeficiency Virus (HIV)



Overview (Microbiological Features and Global Epidemiological Situation)

HIV is the virus which causes Acquired Immunodeficiency Syndrome (AIDS) and one of the world's most serious health issues. According to the WHO in 2017, approximately 36.7 million people are living with HIV globally and more than 35 million people have lost their lives until 2017 due to HIV–related causes. In annual basis, about 1.8 million people get infected by HIV, while 1.0 million die (2016).

HIV is an enveloped retrovirus and surrounded by a membrane made of fatty materials which are dotted with small spikes of proteins. HIV attacks the CD4 cells that protect the immune system to fight with infection in human bodies. When HIV is untreated, the number of CD4 cells reduces due to HIV attacks and it becomes harder and harder for the body to fight off infectious microorganisms including resident bacteria which is usually not harmful for healthy people.

HIV can be controlled by proper treatment, though there is no effective cure currently.

Transmission Route

HIV is spread by contact with body fluids of infected persons through such as ;
  • Sexual intercourse,
  • Use of contaminated syringes and needles,
  • Blood transfusion, and
  • Infected mother to an unborn child.


According to the WHO, symptoms depend on the stage of the disease.

Stage 1: Asymptomatic
The lymph node enlarges persistently but there is no other symptoms.

Stage 2: Mild symptoms
Developing symptoms due to weakened immune system such as moderate weight loss (<10 %), repeated upper respiratory tract infections and oral ulceration.

Stage 3: Advanced symptoms
The symptoms become severe while reducing CD4 cells such as severe weight loss (10 %<), chronic diarrhea, continuous fever and pulmonary tuberculosis.

Stage 4: Severe symptoms
In the last stage, severe HIV-related diseases emerge such as HIV wasting syndrome, kaposi sarcoma and central nervous system toxoplasmosis.

Prevention Methods in Healthcare Facilities

HIV requires comprehensive infection prevention and control procedures in healthcare facilities as other healthcare associated infections. WHO recommended primary prevention precautions are ;
  • Strengthening safe blood transfusion services,
  • Preventing unsafe injections,
  • Implementing standard precautions which are the series of basic infection control procedures,
  • Promoting occupational health to avoid hazards from working place,
  • Improving emergency and essential surgical care in primary healthcare facilities, and
  • Strengthening safe waste disposal to avoid transmission of pathogen through contaminated wastes such as needles.
When exposed to the risk of infection due to failing of primary precautions, apply post exposure prophylaxis for HIV which includes first aid, counselling, HIV test and administration of antiretroviral drugs.

Reference List

World Health Organization (2007) Prevention of HIV Transmission in Health Care Settings. Available at: (Accessed on: 9th March 2018)

World Health Organization (2007) WHO case definitions of HIV for surveillance and revised clinical staging and immunological classification of HIV-related disease in adults and children. Available at: (Accessed on: 9th March 2018)

World Health Organization (2017) HIV/AIDS Fact sheet, updated November 2017. Available at: (Accessed on: 9th March 2018)