/ 28 February 2002

New immunodeficiency virus found in African monkeys

FRANCIS TEMMAN, Seattle | Thursday

AN international team of researchers has identified a new simian immunodeficiency virus (SIV) in a species of monkey from Cameroon, relaunching the debate on the origin of the Aids virus.

The new virus, dubbed VISgsn after the greater spot-nose monkeys, or Ceropithecus nictitans, was identified in 19 monkeys in Cameroon by researchers from the Research Institute for Development (IRD) at Montpellier, southwest France.

The research was presented at the ninth Conference on Retroviruses and Opportunistic Infections, being held here until Thursday.

The virus is similar to the VIScpz virus in chimpanzees, and HIV-1, a strain of the human immunodeficiency virus (HIV) which causes Aids in humans.

The discovery of the virus has “relaunched hypotheses on the origin of the Aids virus and may be the missing link” in a theory that it is more ancestral than that of chimpanzees, said lead researcher in the study, the IRD’s Eric Delaporte.

The fact that “chimpanzees eat these little white-nosed monkeys,” indicates they are not, in fact, natural hosts of HIV-1 as was believed.

The research suggests infection could be via other, smaller monkeys.

To date, numerous strains of SIV, regrouped into six types, have been identified in around 30 species and sub-species of African monkeys. Unlike humans, monkeys are natural carriers of the virus without developing Aids.

The two existing strains of HIV: HIV-1 and HIV-2, originate in simian viruses through ape-human transmission; the first is the chimpanzee virus VIRspz, the second carrier is the mangabey monkey.

The fact that the new virus has a regulating gene “Upu” crucial to its replication a new discovery for a smaller species broadens the Aids virus’s zoonotic potential its transferability to other species, Delaporte said.

Noting that the white-nosed monkey is highly sought after for its meat, he said that even if the risk were slight, transmission to humans was possible, for instance if someone cut themselves while preparing meat.

“The virus … could therefore very well be transmitted to humans, or other monkeys, to create either new strains of divergent HIV viruses, or it could combine with existing viruses thus complicating the virological spectre of HIV,” he warned.

Delaporte, a French researcher working in conjunction with the government of Cameroon, said the next step would be to develop tests to screen all simian viruses to evaluate the risk to people. – AFP