Two studies led by researchers at the Johns Hopkins Bloomberg School of Public
Health found
that people infected with HIV in Thailand die from the
disease significantly sooner than those with
HIV in other parts of the world.
According to the researchers, the shorter survival
time measured in the studies suggests that
HIV subtype E, which is the most common HIV subtype in
Thailand, may be more virulent than other
subtypes of the virus.
Both studies are published in a special issue of the
journal AIDS.
The first study followed 228 men over a 14-year period
starting in 1991. All the men were
serving in the Thai military and were HIV-negative when
they enrolled in the study. The researchers
tested for HIV every six months to determine approximately
when the men acquired HIV. They were
diagnosed at a time before combination antiretroviral drug
therapy was available.
The researchers compared the group of Thai men to a
group of similar HIV-positive men living
in North America and Europe who were included in another
study. The median time from HIV infection
to death for the Thai men was 7.8 years compared to 11
years for HIV-positive men living in North
America and Europe. The survival rate for the Thai men also
was lower than in studies of similar
populations living in low- and middle-income countries in
sub-Saharan Africa where subtypes A, C, D
and G circulate. The shorter survival after HIV infection
among persons in Africa infected with
subtype D, however, was similar to the survival among the
Thai men.
"We were surprised to learn that the young military
recruits from Thailand appeared to develop
AIDS more quickly and have shorter survival after their HIV
infection than persons in Africa who
were carefully followed," said lead author Ram Rangsin,
assistant professor of community and military
medicine at Phramongkutklao College of Medicine in Bangkok,
Thailand, who conducted the research
while studying at the Bloomberg School of Public Health.
"Fortunately, the men who have survived
after their infection are now receiving treatment with
effective antiviral drugs and doing very well."
For the second study, researchers followed a small
group of male blood donors and their wives
from 1992 to 2007. All the men and women were determined to
have acquired HIV less than two years
prior to enrolling in the study. The median survival rate
from infection to death was 7.8 years for the
men and 9.6 years for the women. Again, the survival rate
was lower than the 11 years reported for
HIV-positive men in developed countries.
"The fact that both young military conscripts and
blood donors and their wives in Thailand had
similarly shortened survival compared to persons in the
U.S. and Africa — except those infected with
subtype D viruses — suggests that viral subtypes D
and E may be more virulent than many other viral
subtypes," said Kenrad E. Nelson, a senior author of both
studies and professor in the departments of
Epidemiology and International Health at the Bloomberg
School. "If we could understand better the
virulence characteristics of these viruses, we might learn
something more about why those with HIV
infection progress to AIDS, usually many years after they
are infected."
"The Natural History of HIV-1 Subtype E Infection in
Young Men in Thailand With Up to 14
Years of Follow-up" was written by Rangsin, Phunlerd
Piyaraj, Thira Sirisanthana, Narongrid
Sirisopana, Onsri Short and Nelson. The research was
supported by the Office of AIDS Research at
the National Institutes of Health and by the Thailand
Research Fund. Funding was also provided by
the Fogarty International Center of the National Institutes
of Health.
"Survival of Blood Donors and Their Spouses with HIV-1
Subtype E Infection in Northern
Thailand 1992-2007" was written by Nelson, Caroline
Costello, Vinai Suriyanon, Supaluk Sennun and
Ann Duerr. The research was supported by the Centers for
Disease Control and Prevention through
the CONRAD program at East Virginia Medical School.
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