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Seroprevalence
of Human Herpesvirus 8 (HHV-8) Infection in Northern Thailand
Human
herpesvirus 8 (HHV-8) is associated with Kaposi
sarcoma (KS) in patients with AIDS and
KS, classical KS, or endemic KS. Because HIV
infections and HIV/AIDS are common in Thailand
but KS is very rare (only 0.2% of reported
patients with AIDS in Thailand had KS), researchers
determined the HHV-8 seroprevalence among populations
who were HIV positive or at risk of HIV
infection.
A total of
992 persons from 2 populations underwent testing
for lytic antibodies to HHV-8 using an immunofluorescence
assay involving a BCBL-1 cell line at serum
dilutions of 1 : 50 and 1 : 100.
Serum specimens
with positive results were titered to end
points.
Subjects included
 400 married
couples in which the husband was HIV positive
and the wife was HIV positive (200 couples)
or HIV negative (200 couples). In addition,
200 HIV-negative men from a sexually transmitted
diseases (STD) clinic were studied.
Results
The antibody prevalence
was 24.2% in the total population. The prevalence
was higher among HIV-negative men (13.0%)
but was similar among HIV-positive women (27.9%)
and HIV-negative women (23.8%).
The HHV-8 seroprevalence
among wives whose husbands were HIV-1 positive
did not differ according to their husband's
HHV-8 status. There was no association between HHV-8
seroprevalence and reported sexual behavior or STD history.
Conclusion
Despite the rarity
of KS among patients with AIDS in Thailand,
HHV-8 infections are common and do not appear
to be frequently transmitted sexually in these
populations.
Commentary by
S D Hudnell
In this issue
of Clinical Infectious Diseases (October 1, 2004),
Chen et al. report on HHV-8 seroprevalence
in northern Thailand, a region notable for a
very low incidence of KS despite a relatively
high incidence of HIV/AIDS, and lend further support
to the related concepts that HHV-8 infection is
not uncommon in HIV-negative adults in regions
of the world in which KS is not endemic
and that transmission of HHV-8 often occurs by
nonsexual means.
Using a sensitive
lytic IFA, Chen et al. report an overall HHV-8
seroprevalence among 400 HIV-negative men and
women of 20.5%, a result that is remarkably
similar to those described elsewhere for US blood
donors.
Perhaps the most
curious result in this report is the finding
that HHV-8 seroprevalence among HIV-negative female
subjects (23.8%) is significantly higher than that
among HIV-negative male subjects (13%).
Not only
is this intriguing result difficult to explain,
but it contrasts with results of studies involving
HIV-negative US blood donors, in which no
sex-based difference in seroprevalence were noted.
Another interesting
finding reported by Chen et al. is the
lack of correlation between the relatively high
incidence of HIV/AIDS and HHV-8 infection and the
very low incidence of KS.
As the authors
suggest, it is very likely that there are
unrecognized cofactors involved in KS pathogenesis
that have yet to be accounted for.
The issues brought
forth by the results of Chen et al. are important
and only further deepen the mystery of the
complex relationship between HHV-8 and KS.
We certainly have
much more to learn from this peculiar herpesvirus.
Department
of Epidemiology, Johns Hopkins
University, Bloomberg School of
Public Health, Baltimore, Maryland;
Department of Pathology, University
of Pittsburgh, Pennsylvania; Research
Institute for Health Sciences,
Chiang Mai University, Chiang
Mai, Thailand; and Centers
for Disease Control and
Prevention, Atlanta, Georgia.
Index
of all HIV/AIDS articles by topic.
09/24/04
References
N Chen and
others. Seroprevalence
of Human Herpesvirus 8
Infection in Northern Thailand.
Clinical Infectious Diseases 39(7):
1052-1058. October 1, 2004.
S D Hudnall. Crazy 8: Unraveling
Human Herpesvirus 8 Seroprevalence
(Editorial Commentary).
Clinical Infectious Diseases 39(7): 1059-1061. October 1, 2004.
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