of HV-1 Subtype C over Time in African Countries.
HIV-1 subtype C was first discovered in Ethiopia, South Africa and
Malawi in the early 1980s and has since spread to Southern Africa as
well as other countries in Europe (e.g. Russia;1), Asia (e.g. India, China; 2, 3
) and South America (Brazil; 4) where subtype C has become most
predominant. Concomitant with the increase in subtype C in the
different countries, there has been a corresponding increase in HIV
prevalence rates (as shown in the UNAIDS maps) implying a causal
relationship between the two observations.
In previous investigations aimed at
correlating HIV prevalence rates and subtype C prevalence, it was found
that HIV prevalence rate was lower in
Malawi during the early years of the epidemic (2% in 1989) when the
of subtype C was at low levels. The rate has now increased to about 18%
(2001) and this is at >90% subtype C prevalence (5). This
observation supports the hypothesis of the causal relationship between
C prevalence and HIV prevalence rates.
Based on an estimation of the
of subtype C over the years since the disease was first reported in the
(sequence data), the distribution and numbers of this subtype have
and spread throughout most countries in Africa. Subtype C increased
dramatically in the early 1990s where countries with a subtype C
of >80% increased from 3 in the previous years to 5 in the early
and more in the Southern African countries in recent years.
molecular epidemiology information available for countries such as
Lesotho and Swaziland, but it is believed that subtype C is the major
circulating subtype in these countries as well.
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A, Kingsley L, Harrison L, Mullins JI, Gupta P. 2001. Human
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