Written by Dr. Sangamithra, MBBS | 
Medically Reviewed by Dr. Sunil Shroff, MBBS, MS, FRCS (UK), D. Urol (Lond) on Sep 16, 2014

AIDS Distribution Pattern

Worldwide AIDS surveillance is coordinated by GPA at WHO in Geneva. Reports are received from collaborating centers, including CDC in the United States, the WHO Collaborating Centre in Paris, and WHO regional offices and ministries of health. Accuracy and completeness of AIDS reporting vary in different areas of the world.

Epidemiologic studies indicate three broad yet distinct geographic patterns of transmission.

Pattern I is typical of industrialized countries with large numbers of reported AIDS cases, such as North America, Western Europe, Australia, New Zealand, and parts of Latin America. In these areas, most cases occur among homosexual or bisexual males and urban IV drug users. Heterosexual transmission is responsible for only a small percentage of cases but is increasing.

Pattern II is observed in areas of central, eastern, and southern Africa and in some Caribbean countries. In these areas, most cases occur among heterosexuals; the male to female ratio is approximately 1:1 and perinatal transmission is relatively more common than in other areas. IV drug use and homosexual transmission either do not occur or occur at a very low level.

Pattern III is found in areas of Eastern Europe, the Middle East, Asia, and most of the Pacific. HIV appears to have been introduced into these areas in the early to mid-1980s, and only small numbers of cases have been reported. Homosexual and heterosexual transmission has only recently been documented. Generally, cases have occurred among persons who have traveled to endemic areas or who have had sexual contact with individuals from endemic areas, such as homosexual men and female prostitutes.


  1. Currie, Edwina. The Observer, 15 February 1987
  2. HIV - (https://www.who.int/hiv/en/)
  3. HIV InSite Knowlege Base - (http://hivinsite.ucsf.edu/InSite.jsp?page=KB)
  4. HIV / AIDS - (https://www.niaid.nih.gov/diseases-conditions/hivaids)

Latest Publications and Research on AIDS/HIV - Worldwide distribution and Risk of Transmission


bijaykumar107 Thursday, January 24, 2013

iwant to ask if there is no infectioninthe blood is there no risk of aids if two different groups of blood are tranfued if there is there and not the aids then waht is it \. can u please tell me

www.plwha.org Thursday, April 21, 2011

HIV travel restrictions and retreats: www.plwha.org

hivprevention Wednesday, February 23, 2011

I find it frusterating that hiv screening can only detect the antibodies as opposed to the actual virus. Our governments need to allocate further investment into research so we can work towards more effective hiv prevention

trayfie Sunday, December 25, 2011

You can get a HIV DNA test. This test checks for the presence of the virus itself not the antibodies. This test can be taken 28 days after suspected exposure and the test results are highly accurate. Look it up for more information.

rkwat Wednesday, November 5, 2008

AIDS is the silent tsunnami of asia.

guest Friday, June 27, 2008

Very useful information but difficult to cite, especially in APA style. Would be helpful to include author's name and publication date.

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