Primate virus jumps species barrier to humans for 1st time in Asia

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SIMIAN FOAMY VIRUS, HUMAN - ASIA

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Fri 15 Jul 2005

Source: I-Newswire, 14 Jul 2005 [edited]

<http://i-newswire.com/pr36191.html> Primate virus jumps species

barrier to humans for 1st time in Asia

 

Scientists have identified the 1st reported case in Asia of

primate-to-human transmission of simian foamy virus (SFV), a retrovirus

found in macaques and other primates that so far has not been shown to

cause disease in humans.

 

The transmission of the virus from a monkey to a human took place at a

monkey temple in Bali, Indonesia, the researchers report in the July 2005

issue of the journal Emerging Infectious Diseases. Even though this

particular virus jumping to humans may not prove dangerous, the scientists

warn that the dense human and primate populations in Asia could lead to

other primate-borne viruses jumping the species barrier and causing human

disease.

 

" The issue of primate-to-human viral transmission has been studied

extensively in Africa, largely because that is where HIV originated, "

explains Dr Lisa Jones-Engel, lead author of the study and a research

scientist in the Division of International Programs at the Washington

National Primate Research Center. " But there has not been much work on the

topic in Asia, which has huge primate diversity and large human populations. "

 

Jones-Engel and her co-authors also argue for more research on diverse

contexts of human-primate contact. The vast majority of previous viral

transmission research focused on bushmeat hunting and consumption, a

practice in which local residents hunt monkeys for food [more commonly

practised in Africa].

 

HIV, the virus that causes AIDS in humans, is believed to have originated

as simian immunodeficiency virus (SIV), and jumped the species barrier to

humans when African bushmeat hunters came into contact with blood from

infected animals. Though bushmeat hunting and consumption may be a

significant factor in viral transmission in Africa, Jones-Engel says,

people in Asia have many other contexts in which they come into contact

with primates, including animal markets, primate pet ownership, urban

performing primates, and zoos. In addition, monkeys are significant symbols

in both Buddhism and Hinduism, and monkey temples -- places of religious

worship that have become refuges for populations of primates -- are common

throughout much of South and Southeast Asia. In these areas, protected

macaque populations have thrived alongside dense human settlement for

centuries.

 

On the island of Bali alone, there are more than 40 such temples, which are

frequented by tourists from around the world. About 700 000 international

tourists visit the island's 4 main monkey temples every year. Temple

workers and people who live near the temples also have a great deal of

contact with monkeys at the religious sites.

 

" In Asia, the amount of contact between humans and primates in temple

settings dwarfs the contact due to bushmeat hunting, " says Jones-Engel. For

this study, the researchers tested blood samples from 82 people who work in

or around a temple in Bali, as well as samples from macaques in the area.

They found antibodies for simian foamy virus in the blood of one 47 year

old farmer who visited the temple every day. They confirmed the tests by

performing a DNA analysis of the man's blood and found that the SFV strain

he carried was the same strain found in the temple's macaques. The man

denied owning a monkey as a pet, or hunting monkeys for food. He had been

bitten once and scratched more than once by the temple's macaques.

 

Researchers still don't know the long-term effects of SFV on humans. There

are about 40 known cases of people being infected through laboratory or zoo

contact or through bushmeat hunting in Africa. There are no known cases of

human disease yet.

 

However, Jones-Engel and her fellow researchers warn that there are other

primate viruses known to be harmful that could jump the species barrier.

They don't want people to be afraid of coming in contact with macaques or

other primates, but they do urge people to be cautious and careful when

interacting with monkeys. Feeding the animals, or even carrying food into a

temple, can greatly increase the risk of a bite or scratch, which can lead

to transmission of infection. Visitors occasionally engage in other risky

behavior, such as touching animals or trying to hold baby monkeys. Limiting

such behavior can reduce the risk of bites and scratches.

 

" If you look at free-ranging monkeys in Singapore's nature reserves, you

see that feeding by visitors is not allowed, and it is actively

discouraged, " says Gregory Engel, an attending physician at

Swedish/Providence Hospital in Seattle, Washington, a clinical instructor

of family medicine at the University of Washington, and a co-author on the

study. " Interspecies interaction there is very different, and rates of

human-monkey contact are much lower. "

 

Limiting dangerous contact between primates and humans can have other

benefits as well, such as reducing the transmission of human infections to

monkeys. Human measles, for instance, can cause disease in monkeys and can

even kill them. Other primate species have already seen significant

population losses because of infection by human illnesses.

 

Also participating in the study were researchers at the University of

Toronto; Udayana University in Denpasar, Bali, Indonesia; the University of

Notre Dame; the Southern Research Institute, Frederick, Maryland.; and the

Southwest Foundation for Biomedical Research, San Antonio, Texas.

 

[byline: Justin Reedy <jreedy]

 

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[The following is the summary from: Jones-Engel L, Engel GA, Schillaci MA,

Aida Rompis A, Putra A, Suaryana KG, et al. Primate-to-human retroviral

transmission in Asia. Emerg Infect Dis 2005; 11(7): Jul

<http://www.cdc.gov/ncidod/EID/vol11no07/04-0957.htm>:

 

Summary:

" We describe the 1st reported transmission to a human of simian foamy virus

(SFV) from a free-ranging population of nonhuman primates in Asia. The

transmission of an exogenous retrovirus, SFV, from macaques (_Macaca

fascicularis_) to a human at a monkey temple in Bali, Indonesia was

investigated with molecular and serologic techniques. Antibodies to SFV

were detected by Western blotting of serum from one of 82 humans tested.

SFV DNA was detected by nested polymerase chain reaction (PCR) from the

blood of the same person. Cloning and sequencing of PCR products confirmed

the virus's close phylogenetic relationship to SFV isolated from macaques

at the same temple. This study raises concerns that persons who work at or

live around monkey temples are at risk for infection with SFV. "

 

Foamy virus of non-human primates has been regarded as a virus without a

disease in humans from previous studies. The main reason for this is that,

so far, no unambiguous evidence of illness has been associated with

enzootic infection of humans with SFV. SFV belongs to the genus

_Spumavirus_ in the family _Retroviridae_. The current report has

demonstrated substantial proof of transmission of SFV from a primate to a

human in Asia. Epizootiology of SFV among free ranging primates, the

natural hosts, and humans remains largely unknown. More research is

definitely needed. - Mod.RY]

 

[see also:

2004

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Simian foamy virus, blood transmission - Canada 20041025.2889

Simian foamy virus, humans - Cameroon 20040319.0774

Simian foamy virus, humans - Cameroon (02) 20040322.0800

2001

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Simian foamy virus, humans - Canada 20010630.1245]

 

 

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