Human immunodeficiency virus (HIV) can lead to acquired immunodeficiency syndrome (AIDS), in which the immune system begins failing, leading to life-threatening opportunistic infections. HIV is present as both free virus particles and virus within infected immune cells in the body of the infected individual. HIV infection is now declared pandemic.

 

Three main transmission routes for HIV -1 are there. HIV-2 is transmitted less frequently from pregnant mother her child and sexual route than HIV-1. Various modes of transmission of HIV are -

 

Sexual

Most of HIV infections are by unprotected sexual relationship. Transmission occurs when infected secretions of one person come into contact with the genital, oral, or rectal mucous membranes of other person. The use of latex condoms reduces the risk of sexual transmission of HIV by more than 85%. Spermicides may increase the transmission rate of HIV. It has been found that medical circumcision may reduce the risk of contracting the disease. 

Blood or blood product

Transmission through this route is common in intravenous drug users, hemophiliacs and those who receive blood transfusions and blood products. Health care workers like nurses, doctors, tattooing, piercings etc. are high risk behavior and can lead to infection by HIV. 

Pregnant Mother to Child

The transmission of the HIV from the mother to the child can occur during pregnancy, during childbirth or through breast milk. The risk of transmission to the child is high in absence of treatment. With treatment the rate and extent of transmission of the infection in newborn and fetus reduces dramatically. For prophylaxis antiretroviral drugs are prescribed to infants also. 

Other routes 

HIV can also be transmitted by saliva, tears and urine of infected individuals but at present no data is available.