Published Date: 2006-05-18 00:00:00
Subject: PRO/AH> Rabies, antelope - Namibia
Archive Number: 20060518.1397
RABIES, ANTELOPE - NAMIBIA
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Thu, 18 May 2006
From: Merritt Clifton <email@example.com>
Source: The New Era, Windhoek 16 May 2006 [edited]
Namibia's flagship trophy game species, the kudu, is under threat from
rabies that have already devastated record numbers of the antelope and
sources in the industry have voiced concern that the outbreak could impact
negatively on the hunting season that is due. [For a picture of the kudu,
Two veterinarians, Dr Otto Zapke and Dr Beate Voights, confirmed the
outbreak, with Dr Zapke saying probably "thousands" of kudu died in the
Omaruru area where recently no cases of the contagious disease have been
brought to his attention.
Dr Zapke said the Okahandja and Windhoek areas are showing more prevalence
of rabies, while Dr Voights said there is a tendency among farmers not to
report cases of the deadly viral disease that can affect all warm-blooded
animals and has various known strains.
With over 5000 trophy hunters, the hunting industry directly generates NAD
100 million [USD 16 million] for the country each year, and NAD 200 million
[USD 32 million] is generated indirectly as secondary revenue.
Namibia Professional Hunting Association (NAPHA) affiliated sources
revealed the contagion was initially detected at a farm in the Wilhelmstal
area before it spread north via farms at Omaruru, Otjiwarongo and then it
spread eastwards and scattered southwards.
Cases of the communicable disease have been reported at Omitara, from where
it spread towards Botswana. Some farms around Windhoek have also reported
cases of strange behaviour in this antelope, such as frothing at the mouth
and not being afraid of people.
There was one strange case in which this beast had to be shot inside a
house and one farmer who requested anonymity cited several cases of rabid
kudu. Though the meat from the affected animals can be consumed provided
the necessary precautions are taken, one of the beasts shot near Windhoek
was destroyed because of the severity of the infection.
One 12 000 hectare farm suffered game losses of 400 beasts over the past 2
years of the present outbreak, and other farmers are said to have incurred
huge losses of the antelope that is preferred by high-spending trophy
hunters who like its majestic, spiral horns.
Sources are saying the present outbreak whose magnitude compares to the
contagion that affected the game industry over a 7 year wave in Namibia
lasting from 1975 to 1982, is being caused by kudu populations that have
increased over the past several years. [See commentary].
The outbreak has been underreported because some farmers are afraid of the
negative effects that bad publicity could generate in light of the
closeness of the hunting season.
New Era was told kudus that have weakened immunity to rabies when compared
to dogs and other animals get infected by eating affected vegetation, while
the virus could also get into their bodies through lesions in their mouths
caused by shrubs and thorns.
Kudu infected by the virus (with an incubation period varying from 21 to
365 days) tend to hang their heads lower, but the most important clinical
characteristic of the preliminary phase is behavioural change during which
the animal appears tame, salivates excessively, loses appetite, and
urinates frequently. After this phase sick animals may either become
aggressive or show signs of paralysis.
Kudu are found throughout Namibia except in the Namib Desert.
[byline: Chrispin Inambao]
Editor, ANIMAL PEOPLE
PO Box 960
Clinton, WA 98236
[A unique outbreak of rabies in kudu antelope (_Tragelaphus strepsiceros_)
began in central Namibia in 1977, apparently involving oral spread of
infection between individuals. It peaked in 1980 and eventually subsided in
1985, by which time it caused an estimated loss of 30-50 000 antelope, or
20 per cent of the population.
During 2002 there was another substantial outbreak in kudu, during which an
estimated 2500 animals on more than 81 farms in Namibia died. This outbreak
continued into 2003.
The social behaviour of kudu was believed to be related to the spread of
rabies, and it is thought that mouth lesions from the browsing of
thorn-bushes may have been a contributing factor due to the presence of the
rabies virus in saliva. The kudu epizootics in Namibia have provided an
example of non-bite transmission, with horizontal spread between kudus.
Recent molecular studies in a panel of 37 rabies virus isolates originating
in Namibia between 1980 and 2003 suggested that these viruses were all of
the canid rabies biotype of southern Africa. The viruses from kudu were
closely associated with jackal, bat-eared fox and domestic dog isolates.
Further reading: Karen Mansfield, et al. A molecular epidemiological study
of rabies epizootics in kudu (_Tragelaphus strepsiceros_) in Namibia. BMC
Vet Res 2006; 2: 2. - Mod.AS]