Africa Asia Middle East Français Português Subscribe IRIN Site Map
Global HIV/AIDS news and analysis
Advanced search
 Saturday 15 December 2007
Weekly reports 
In-Depth reports 
Country profiles 
Fact files 
Really Simple Syndication Feeds 
About PlusNews 
Contact PlusNews 
Print report
GLOBAL: New numbers give better picture of epidemic

Photo: Juda Ngwenya/PlusNews
Sub-Saharan Africa is still the region most severely affected by HIV/AIDS.
JOHANNESBURG, 20 November 2007 (PlusNews) - New HIV prevalence figures released on Tuesday suggest the global AIDS epidemic may be waning in many countries, but that UNAIDS also overestimated the number of people living with HIV in its earlier reports.

The 2007 AIDS epidemic update, jointly published by UNAIDS and the World Health Organisation (WHO), puts the number of people living with the virus at 33.2 million, a significant decrease from the 2006 estimate of 39.5 million. However, applying an "improved methodology", UNAIDS has also revised the 2006 figure to 32.7 million.

The overall percentage of people living with HIV appears to have levelled off, but because infected people are generally living longer, the global number continues to rise.

Based on "improvements in country data collection and analysis, as well as a better understanding of the natural history and distribution of HIV infection", the new report puts the annual number of new infections at 2.5 million, down from a peak of over 3 million a year in the late 1990s.

Critics have long accused UN officials of exaggerating the scale of the epidemic in order to secure more funding to combat the disease, but UNAIDS attributes the revisions mainly to the development of more sophisticated methodology for calculating HIV estimates, and more accurate and representative surveys for tracking infections.

Previously, epidemiologists relied mainly on data from antenatal clinics to calculate HIV prevalence rates, but the age groups of the women tested, and the fact they were clearly having unprotected sex, meant these numbers tended to overestimate HIV infections in the general population.

Many countries are now conducting more representative population-based household surveys, with the result that in India, for example, the estimated number of HIV infections has come down by more than half.

"The data for measuring the HIV epidemic ... has considerably expanded and improved in recent years," commented Ron Brookmeyer, Professor of Biostatistics at the US-based Johns Hopkins Bloomberg School of Public Health. "Nevertheless, there is a need to further improve the representativeness of the underlying data."

A better understanding of the natural dynamics of an epidemic has also helped to account for the lower estimates - HIV prevalence tends to reduce over time as the number of new infections in a population reaches a "saturation" point and deaths resulting from AIDS increase.

33.2 million people are living with HIV
There were 2.5 million new infections in 2007
There were 2.1 million AIDS-related deaths
68 percent of people living with HIV are in sub-Saharan Africa
8 countries in this region account for one-third of all new HIV infections
Source: 2007 AIDS Epidemic Update
The report attributes at least some of the drop in prevalence to HIV-prevention efforts. Infections among young pregnant women attending antenatal clinics have declined over the last five years in 11 of the 15 most affected countries, and studies looking at risk behaviour among young people also show encouraging results in countries such as Zimbabwe, Kenya, Botswana, Malawi and Zambia.

"Prevalence is dropping in a lot of countries," noted Prof John Hargrove, director of the Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA) at the University of Stellenbosch, South Africa. "There's absolutely no question, for example, that HIV prevalence in Zimbabwe has been dropping like a stone in recent years, but there is some resistance from people in the First World to accepting that."

UNAIDS officials were at pains to point out that the global AIDS epidemic still represented a public health crisis of devastating proportions, especially in the eight southern African countries where national adult HIV prevalence exceeded 15 percent.

"Unquestionably, we are beginning to see a return on investment," said UNAIDS head Dr Peter Piot in a statement. "But with more than 6,800 new infections and over 5,700 deaths each day due to AIDS, we must expand our efforts in order to significantly reduce the impact of AIDS worldwide."

Despite revised estimates for several sub-Saharan African countries, including Nigeria, Zimbabwe, Kenya and Angola, the region remains the one most affected by the epidemic, accounting for more than two-thirds of all people living with HIV and more than three-quarters of all AIDS deaths in 2007.

Unlike elsewhere in the world, the majority of people living with HIV in sub-Saharan Africa (61 percent) are women. Although access to life-prolonging antiretroviral treatment has improved, AIDS is still the region's number one cause of death.

According to Hargrove, many countries in the region still lack adequate HIV-prevalence data, and techniques for estimating the proportion of new infections in a cross-section of HIV-positive people are still not reliable enough. "The one thing we really need is to develop better methods for measuring the rate at which new infections are occurring."


See also, AFRICA: Falling HIV rates tell complex story

Theme(s): (IRIN) Aid Policy, (IRIN) HIV/AIDS (PlusNews), (IRIN) Prevention - PlusNews, (IRIN) Research - PlusNews


[This report does not necessarily reflect the views of the United Nations]
Print report
FREE Subscriptions
Your e-mail address:

Submit your request
 More on AFRICA
AFRICA: IRIN PlusNews Weekly Issue 366, 14 December 2007
GLOBAL: Many hands make healthcare more efficient
GLOBAL: IRIN PlusNews Weekly Issue 364, 7 December 2007
GLOBAL: Imams wake up to HIV/AIDS
GLOBAL: Positive fatwas - using religious rulings in the AIDS struggle
 More on HIV/AIDS (PlusNews)
AFRICA: IRIN PlusNews Weekly Issue 366, 14 December 2007
SWAZILAND: Risky business: report sheds new light on sex trade
GLOBAL: Many hands make healthcare more efficient
BURUNDI: HIV/AIDS programmes dealt a severe blow
SUDAN: Angelina Lino: "I tell people I have HIV so they can know it's real"
Back | Home page

Services:  Africa | Asia | Middle East | Radio | Film & TV | Photo | E-mail subscription
Feedback · E-mail Webmaster · IRIN Terms & Conditions · Really Simple Syndication News Feeds · About PlusNews · Bookmark PlusNews · Donors

Copyright © IRIN 2007
This material comes to you via IRIN, the humanitarian news and analysis service of the UN Office for the Coordination of Humanitarian Affairs. The opinions expressed do not necessarily reflect those of the United Nations or its Member States. Republication is subject to terms and conditions as set out in the IRIN copyright page.