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 IMVS Call Centre Metropolitan–8222 3000 IMVS Newsletter Number 50 Winter 2003

Strong evidence exists that pigs are the

source for new mammalian influenza A

reassortants and subsequent spread to

humans. The practice of closely inte-

grated farming of poultry and pigs in

China is one of the strong contributors

to potential new emerging strains of 

influenza A.

Other emerging viruses, for example

Rift Valley fever virus from East Africa,

have resulted from the increase in

construction of large dams and

irrigation systems driven by

increased agriculture.

This mosquito-borne

 virus, is like many

other arboviruses, an

emerging virus.

The increased use of 

open water storage systems

for consumption or flood irrigations of 

rice fields, has led to increased breeding

of mosquitoes and is one of the major

contributors to emerging Dengue and

Japanese Encephalitis viruses in Asia.

The high population densities of many

 Asian countries has further contributed

to the ease of transmission of these

 viruses by mosquitoes and caused severe

morbidity and mortality throughout

 Asia. Dengue has also spread to the

 Americas as a result of increased trade

and travel. The arboviruses have thus

found a new host range by using

humans as a vehicle for its spread.

Preliminary findings

have implicated the

civet cat (a member

of the squirrel

family) as a likely

reservoir for the SARS

coronavirus. Close contacts,

perhaps with farming of this

animal for human consumption

or extraction of its anal glands for

the manufacture of perfume may have

lead to this emergence. If subsequently

confirmed, this provides another

example of how emerging viruses may

arise from human contacts/invasion of 

new animal territories.

The spread of HIV, an emergent virus

first recognised in 1981, has been

assisted by increased social interactions

– sexual behaviour and exchange of 

infected needles amongst drug abusers.

in the news

Spinal research awardFor the third time IMVS

researchers have been

awarded the world’s most

prestigious prize for

spinal research by the

International Society forthe Study of Lumbar

Spine.

The Advertiser (7th May

2003) reported that

studies at the IMVS

Adelaide Centre for

Spinal Research

involved mapping

nerves in the spine.

Researchers found

that discs normally

have only a meagresupply of nerves

distributed around

their periphery but may

acquire additional nerves

following damage to the

outer regions. These findings

suggest that back pain

cannot originate from the

central region of the disc because

of the lack of a nerve supply

essential for carrying the sensation.

The study concluded that treatmentof disc pain should focus on the

outer region of the disc. This work

is expected to lead to improved

treatments for back pain.

The experimental work was a

collaborative effort involving the

IMVS, RAH and University of 

Adelaide.

Continued from page 9

There are now more than 40 million

people infected with this virus world-

 wide. With its ability to integrate in

the host chromosome and thereby

contribute to vertical, as well as

horizontal transmission, the AIDS

 virus has used humans as vectors for

its global spread.

What can we do? We cannot predict when new emerging

 viruses will cause such sudden out-

breaks like SARS, influenza pandemics,

 AIDS, etc. The provision and use of 

rapid virus detection/ 

identification methods

are essential for

patient management,public health

surveillance and control

measures. The recent SARS outbreak

has clearly shown the additional severe

impact on business and trade, as well

as the infinite cost of loss of human

lives should we not be sufficiently

prompt in recognising, detecting,

identifying and controlling these

outbreaks.

These preventative approaches require

multi-disciplinary interactions betweenthe clinicians, laboratory, public health

personnel, basic research and govern-

ments. Vaccines have proved effective

in the prevention and control of many

 viral infections, e.g. influenza, measles,

polio, smallpox, etc. However, the

successful development and intro-

duction of vaccines requires

more research into under-

standing of the basic

biology of the specific

 virus and its interactions

 with the host.

The dilemma of emerging

 viruses provides yet another

example of the intimate integration of 

humans with the whole planetary

environment, a fact easily overlooked

in our highly urbanised cities.♦

10

Did youknow 

Total SARS cases

to July 3rd 8439,

deaths 812.

Did youknow 

Most emergent

viruses are

zoonotic.