PDF file - Department of Health and Ageing

National Notifiable Diseases Surveillance System, 2004
Annual report
Following the deliberate release of anthrax spores
in the United States of America in 2001, anthrax
became a nationally notifi able disease in Australia.
In 2004, no cases of anthrax were notifi ed. The
last reported human cases of anthrax in Australia
(both cutaneous anthrax) occurred in July 1998 and
February 1997.
Anthrax is a notifi able animal disease subject to
compulsory government control strategies including:
vaccination of susceptible livestock located on sites
with a known history of anthrax; epidemiological
investigation of outbreaks; quarantine and decontamination
of affected premises; and safe disposal of
carcases. Certain rural areas in central New South
Wales and northern and north-eastern Victoria are
associated with recurring cases of anthrax in cattle
and sheep. In these endemic areas, anthrax has a
low and decreasing prevalence. Cases only occur
sporadically, mostly in partially vaccinated animals.
In 2004, 15 outbreaks of anthrax were reported in
livestock (13 from New South Wales and 2 from
Victoria). Only one of these outbreaks was from outside
the known anthrax endemic areas, on a farm
that was part of an old stock route leading to the
endemic zone in New South Wales. In all instances
the usual protocols of quarantine, disinfection of
contaminated ground, carcass incineration, and
vaccination of the herd and neighbouring herds
were implemented. All animal movements from
affected properties were traced and there was no
risk of further spread of disease.
Australian bat lyssaviral and lyssaviral
(unspecified) infections
Case defi nition – Lyssavirus (unspecifi ed)
Only confirmed cases are reported AND only
where there is insuffi cient evidence to meet a
case defi nition for Australian bat lyssavirus or
rabies.
Confirmed case: Requires positive fl uorescent
antibody test result for lyssaviral antigen on
fresh brain smears, OR specifi c immunostaining
for lyssaviral antigen on formalin fi xed
paraffi n sections of central nervous system
tissue, OR presence of antibody to serotype 1
lyssavirus in the cerebrospinal fl uid, OR detection
of lyssavirus-specifi c RNA (other than to
Australian bat lyssavirus or rabies).
Case defi nition – Australian bat lyssavirus
Only confirmed cases are reported.
Confirmed case: Requires isolation of
Australian bat lyssavirus confi rmed by
sequence analysis, OR detection of Australian
bat lyssavirus by nucleic acid testing.
No new cases of either Australian bat lyssaviral
or lyssaviral (unspecifi ed) infections were notifi
ed during 2004. Two cases of human infection
with Australian bat lyssavirus, in 1996 and 1998,
occurred following close contact between bat-handlers
and infected bats. Both resulted in the death of
the infected person.
There are two strains of Australian bat lyssavirus
known: one circulates in frugivorous bats, suborder
Megachiroptera, and the other circulates in
the smaller, mainly insectivorous bats, sub-order
Microchiroptera. Each strain has been associated
with one human fatality. Surveillance indicates
infected bats are widespread at a low frequency on
the Australian mainland. 37 Research into the genetic
sequences of lyssaviruses isolated from different
groups of bats using molecular methods suggests
that the virus has been associated with bats in
Australia for more than 1,500 years. 38 That is, the
virus was well established before European colonisation,
and its recent ‘emergence’ is in all likelihood
due to changes in human behaviour and encroachment
on bat habitats.
Brucellosis
Case defi nition – Brucellosis
Only confirmed cases are reported.
Confirmed case: Requires isolation of
Brucella species, OR IgG seroconversion
or a signifi cant increase in antibody level or
a fourfold or greater rise in titre in Brucella
agglutination titres or complement fi xation titres
between acute and convalescent phase serum
samples. (Where possible both tests should be
conducted at the same laboratory), OR a single
high Brucella agglutination titre.
AND Acute encephalomyelitis with or without
altered sensorium or focal neurological signs.
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