South African AIDS policy tied to 330,000 lives lost
Harvard School of Public Health study reveals human cost of policy choices
More than 330,000 lives were lost to HIV/AIDS in South
Africa from 2000 and 2005 because a feasible and timely antiretroviral
(ARV) treatment program was not implemented, assert researchers from
the Harvard School of Public Health (HSPH) in a study published by the Journal of Acquired Immune Deficiency Syndromes (JAIDS).
In addition, an estimated 35,000 babies were born with HIV during that
same period in the country because a feasible mother-to-child
transmission prophylaxis program using nevirapine (an anti-AIDS drug)
was not implemented, the authors write.
(The paper in full is available here under the “What’s New” heading.)
The study estimates the consequences of the HIV/AIDS policies
followed by the South African government for a five-year period when
neighboring countries ramped up their HIV-prevention programs. The
paper may have broader implications for the evaluation of consequences
of public health programs.
Pride Chigwedere, MD, SD, lead author of the paper, and
colleagues estimated what they described as the ARV benefits lost that
were attributable to government policies restricting or delaying the
use of ARV treatment in South Africa. For comparison, the authors used
Botswana and Namibia, neighboring countries facing epidemics of similar
scale and dynamics and with similar resources per capita. Chigwedere led the analysis while earning his doctoral degree in
immunology and infectious diseases from HSPH, graduating in June 2008.
He came to HSPH from Zimbabwe, where he was a practicing physician
treating AIDS patients. Prof. Max Essex, head of the HSPH AIDS Initiative, supervised the research and was senior author on the paper.
South Africa is one of the countries most severely affected by the AIDS
epidemic. The authors cite UNAIDS data that the prevalence of HIV/AIDS
in the adult population is 18.8 percent, with approximately 5.5 million
persons infected with HIV. Under the leadership of Thabo Mbeki, who was
president of South Africa during the period examined in the paper, the
government restricted use of donated nevirapine and blocked funds for
more than a year from the Global Fund to Fight AIDS, Tuberculosis, and
Malaria awarded to the South African province KwaZulu Natal, the
authors recount. Mbeki formally resigned in September 2008.
The authors estimated the lost benefits of ARV drug use for two
groups: AIDS patients and children born to HIV-infected mothers. The
research team framed those lost benefits as “person-years,” meaning the
number of years of life lost due to premature death from HIV/AIDS. The
team chose a limited time period for examination to estimate only the
ARV benefits already lost and to avoid speculation about the future
direction of ARV policies in South Africa.
For background, the pharmaceutical company Boehringer Ingelheim
announced in July 2000 that it would offer nevirapine free of charge
for five years for the prevention of mother-to-child transmission of
HIV-1 in developing economies. South Africa restricted the availability
of nevirapine to two pilot sites per province until December 2002, said
Chigwedere. The country’s government launched a national program
for the prevention of mother-to-child transmission in August 2003 and a
national ARV treatment program in 2004. By 2005, the authors estimated,
there was 23 percent ARV treatment coverage and less than 30 percent prevention of
mother-to-child transmission coverage in South Africa.
By comparison,
neighboring Botswana began a program for the prevention of
mother-to-child transmission in 1999 and a national ARV treatment
program in 2001. Using WHO “3×5” initiative data, the authors estimated
that there was 85 percent ARV treatment coverage in Botswana and 71percent in
Namibia by 2005. Both Botswana and Namibia achieved a prevention
rate of mother-to-child transmission of greater than 70 percent by 2005.
To estimate the lost benefits, the research team compared the actual
number of persons who received ARVs for treatment or for prevention of
mother-to-child transmission between 2000 and 2005 with what was
reasonably feasible in the country during that period. They then
multiplied the difference by the average efficacy of ARV treatment or
prevention of mother-to-child transmission prophylaxis.
“The analysis is robust,” said Pride Chigwedere. “We used a transparent
and accessible calculation, publicly available data, and, where we made
assumptions, we explained their basis. We purposely chose very
conservative assumptions and performed sensitivity analyses to test
whether the results would qualitatively change if a different
assumption were used.”
In conclusion, the authors write: “Access to appropriate public health
practice is often determined by a small number of political leaders. In
the case of South Africa, many lives were lost because of a failure to
accept the use of available ARVs to prevent and treat HIV/AIDS in a
timely manner.”
In addition to Pride Chigwedere, and Max Essex, the study’s authors include HSPH faculty members George Seage III, ScD, MPH, Sofia Gruskin, JD, MIA, and Tun-Hou Lee, ScD.
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How the researchers made their calculations
To determine the person-years lost because of AIDS deaths, the authors first estimated the number of persons who were eligible to
receive ARV treatment by obtaining the number of deaths from AIDS in
South Africa for the period 2000-2005 from UNAIDS. Patients with AIDS
who died without getting treatment lost the entire average benefit of
ARV therapy. Data regarding individuals who received ARV therapy in
South Africa between 2000 and 2005 were obtained from the UNAIDS and
WHO ‘‘3 by 5′ records (23percent in 2005, less than 10 percent in 2004, 3 percent in 2003,
and less than 3 percent for preceding years). The authors propose that South
Africa could have started an ARV treatment program in 2000, covering
not more than 5 percent of persons who needed therapy but ramping up the
coverage as drugs became less expensive and more international
resources became available to 50 percent coverage by 2005. This estimate is
lower that the coverage achieved by both Botswana and Namibia. Then
they estimated the average life-years that ARV therapy adds to patients
with AIDS in Africa, based on primary studies, a meta-analysis, and a
comparison with developed countries. The authors calculated that 2.2
million person-years were lost in South Africa from 2000 to 2005 by not
implementing a feasible and timely ARV treatment program.
In order to calculate the person-years lost through mother-to-child transmission prevention failure, the authors estimated the number of children infected with HIV through
vertical transmission, using data from the Actuarial Society of South
Africa AIDS and Demographic Model and reducing that number to account
for HIV prevalence in South Africa with population growth in mind. They
estimated mother-to-child transmission prevention coverage using data
from the PMTCT Task Team in South Africa and the Health Systems Trust.
The research team assumed that it was feasible for South Africa to
start a mother-to-child transmission prevention program in 2000, given
that nevirapine was available for free, and estimated a ramping up to
about 55 percent coverage by 2005. This estimate is less than the coverage
achieved by both Namibia and Botswana. They used the HIV Network for
Prevention Trials 012 trial, which showed that single-dose nevirapine
decreased transmission by 47 percent compared with oral ZDV in a breastfeeding
population. To estimate the person-years lost per case of HIV
transmitted, the authors assumed a life expectancy of 48 years and then
subtracted the average survival of an HIV-infected baby without ARV
treatment. The authors estimated that 1.6 million person-years were
lost in South Africa from 2000 to 2005 by not implementing a
mother-to-child transmission prophylaxis program using nevirapine.