Researchers have identified HIV-1 group N in a
57-year-old man residing in France who reported recent travel to Togo, where
infection was suspected to have originated, according to a case report
published in The Lancet.
According to background information in the report, HIV-1
group N was first identified in 1998 in a Cameroonian woman with AIDS, and it
has since been reported in HIV-infected patients from Cameroon only.
“Until now, HIV-1 group N was considered to be
like a wild virus, and with very limited cross-species transmission, only 10 to
12 cases have been reported despite thousands of HIV-infected patients tested
in Cameroon to differentiate between M, N or O groups,” François
Simon, MD, of Hospital Saint Louis in Paris, told Infectious Disease
News. “The report of a group N primary infection indicates that the
virus is still circulating today, and the contamination in Togo indicates that
HIV-1 group N is getting out of Cameroon and is no longer confined to this
François Simon, MD
In the current case, the patient reported sexual contact
with a Togalese partner while visiting Togo. Subsequent symptoms surfaced 8
days after returning to Paris, which led the researchers to infer that the
infection was acquired in Togo.
According to Simon, HIV-1 group N was thought to have
limited potential to grow at the epidemic level, particularly the viral protein
U (Vpu), which was considered unable to down regulate the CD4 expression.
“This lack of down regulation was the best explanation for the low
prevalence of the strain,” he said.
However, this new case is particularly important because
of severe CD4 depletion and high viral load. “The story must be more
complicated, which is important for ongoing research,” Simon said.
Although a five-drug antiretroviral combination showed
good initial efficacy, the researchers said long-term immunological and
virological follow-up is needed.
“This case of HIV-1 group N primary infection
indicates that this rare group is now circulating outside Cameroon, which
emphasizes the need for rigorous HIV epidemiological monitoring,” they
Disclosure: The researchers report no relevant