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Bovine Papular Stomatitis (BPS)
AGENT:
DNA virus, genus Parapoxvirus, family Poxviridae; closely related
to contagious ecthyma virus
RECOGNITION
Syndrome:
Human:
Manifests as a cutaneous nodule or papule 3-8 mm in diameter at
the site of virus entry, usually on a finger or hand.
The lesion persists for about a month, gradually decreasing in size.
No systemic signs in humans.
Animal:
Only affects cattle, characterized by proliferative ulcers around the
lips and on mucous membranes of the mouth.
Lesions begin as small, hyperemic spots and rapidly progress into
ulcerous papules that last for a few days to a few weeks.
Although the course is generally mild,
it may last for several months.
Most animals experience only slight fever and little difficulty in
grazing,
but some develop diarrhea, hypersalivation, and teat lesions.
Incubation period: In humans, 3-8 days.
Case fatality rate: None.
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Confirmatory tests:
Resembles several, more severe, diseases of cattle, such as foot-
and-mouth disease and vesicular stomatitis, and it is important to
differentiate among these.
May isolate virus, or demonstrate by electron microscopy of
lesions.
Occurrence: In cattle,
worldwide distribution most often affecting young animals.
Only a few confirmed cases of human infection.
Because of the minimal lesions, many may go unreported.
Transmission:
Direct and indirect contact spread of the virus between animals.
Humans are infected from handling or examining infected cattle,
the virus usually entering the body through cuts or scratches on the
hand.
CONTROL AND PREVENTION
Individual herd:
Because BPS is of minimal economic significance, no control
measures are necessary for cattle.
Human infection can be prevented by the use of gloves, hand
washing, and general caution when working with infected animals.
Local\community: None.
National\international: None.
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Pseudocowpox
Milkers’ nodules, milkers’ wart, paravaccinia, false cowpox
AGENT
DNA virus, genus Parapox virus, family Poxviridae, known as
paravaccinia virus or milkers’ nodule virus (MNV).
It is endemic in cattle worldwide.
The virus is closely related to orf and bovine papular stomatitis
virus, both of which are capable of causing zoonotic infection
RECOGNITION
Syndrome:
Human:
Small, erythematous papules appear, usually on the hands, and
over 4-6 weeks develop into firm nodules before resolving. There
is no systemic involvement.
Animal:
Papular lesions that umbilicate and pustulate appear on the udders
and teats of dairy cows.
Dark red scabs remain for about 2 weeks.
In some cases lesions may persist longer, and often recur.
Nursing calves may develop oral lesions.
Incubation period: Human, 5-7 days.
Case fatality rate: None.
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Confirmatory tests:
Electron microscopy of lesion fluid.
Virus isolation from lesions.
Occurrence:
Worldwide, but the prevalence is not well known.
Many subclinical infections.
Human infection mainly where milking is done by hand.
Transmission:
Dairy cattle are the reservoir.
Infection spreads within a herd by contamination of milking
machines or the hands of milkers.
Humans are infected by contact through skin abrasions.
CONTROL AND PREVENTION
Individual\herd:
Good hygienic standards should be maintained in dairies,
and infected cows milked last.
Only treatment is topical ointment applied to teats.
Acquired immunity is of short duration, and there is no vaccine.
Local\community: None.
National\international: None.
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Contagious Ecthyma
AGENT
DNA virus, genus Parapoxvirus, family Poxviridae; closely related
to bovine papular stomatitis
It is endemic in sheep and goats and occurs globally; some herds
are completely free of the organism
RECOGNITION
Syndrome:
Human:
Characterized by a (usually) single maculopapular or pustular
lesion at the site of virus entry, most often on the hands, arms, or
face.
The papule is painful and gradually becomes a firm,
Disease in animals
In sheep or goats, crusty lesions on or around the muzzle, eyelids,
mouth, feet or external genitalia may be laden with virus.
Necrosis of the skin of the gastrointestinal and urogenital tract can
occur.
The virus is shed by infected animals in secretions from lesions
and also in faeces and urine.
The virus is persistent in the environment and may survive for
many years.
The disease is under-reported because most farmers and veterinary
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surgeons recognise the condition and do not need to submit
samples to confirm the diagnosis.
Transmission:
Orf is an uncommon disease in humans;
however, it is easily transmitted by contact with lesions on animals
or infected wool.
Accidental infection with live vaccine during vaccination of sheep
also poses a risk.
Disease in humans
After infection, ulcerative suppurating lesions on face, hands and
arms appear.
Shepherds, sheep shearers and others who handle live sheep, warm
carcasses or unprocessed fleeces or wool are at risk.
The low number of cases reported by laboratories is likely to
represent a small proportion of the total number of cases seen by
GPs in rural areas as diagnosis of human orf infection is often
made on the basis of clinical
Treatment:
Treatment is purely supportive, because no therapy is
recommended.
Lesions usually regress within 6–8 weeks with minimal scarring.
Secondary
infection of sores may occur and management using antiseptics or
antibiotics
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may be required.
Prevention:
Good hygiene practices and wearing rubber gloves when handling
infected sheep helps to prevent infection in individuals at risk due
to their occupation.
Fomite contact may also be responsible for spread, and prevention
strategies centre around good disinfection procedures.
Care when using the live attenuated vaccine to vaccinate flocks is
essential.
COW POX
AGENT
Cowpox virus is a member of the genus Orthipoxvirus in the
family poxviridae
RECOGNITION
Syndrome:
Human:
Characterized by lesions at the site of inoculation (usually the
hands),
and progress from macular, through papular and vesicular stages,
to pustule formation.
Fever,
lymphadenitis,
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edema near the lesions may also occur.
Animal:
Affects cattle, and has been reported in domestic cats and in felines
in zoos.
In cattle,
onset is characterized by a mild febrile period during which
papules appear on the teats.
These progress to vesicles, then pustules
when the pustules rupture they leave raw, ulcerated areas that take
about a month to heal.
CP is similar in domestic cats, with dermal lesions that vary from
red, hairless, well circumscribed areas to ulcerated or purulent
spots.
Occasionally ulcers may appear on the tongue or lips, and
respiratory signs,
nasal discharge and dyspnea, may develop.
Cheetahs have severe respiratory disease.
Incubation period
3-7 days in humans and cattle.
Case fatality rate:
None in humans and cattle
may be high in cats, especially zoo species, if the respiratory tract
is affected.
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Confirmatory tests:
Because CP indistinguishable from vaccinia virus serologically,
virus isolation is essential to confirm.
Lesion material examined by electron microscopy to detect virus.
Occurrence:
Rare, only reported from Great Britain and western Europe.
Transmission:
The reservoir is unknown
source of cattle infection is unknown, possibly rodents
humans are infected from the same source or from exposure to
affected cattle.
In domestic cats, lesions usually develop near a bite wound,
possibly sustained while hunting.
Infections in zoo felines have been traced to white rats used as
feed.
CONTROL AND PREVENTION
Individual\herd
Wear gloves and practice good hygiene when handling infected
animals.
Local\community: None.
National\international: None.
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Foot and mouth disease FMD
It is questionable whether foot-and-mouth disease (FMD) is a
zoonosis, although as a disease it has a huge economic impact for
livestock farmers.
It does have a zoonotic potential, as a single case in the 1967 UK
outbreak and one confirmed case in the 2001 UK outbreak
demonstrated. However, the circumstances leading to human
infection are usually extreme.
The disease is found worldwide and all cloven-hoofed animals are
affected.
ACENT
aphthovirus, there are several different serotypes, of which the
most virulent is serotype O (pan-Asiatic), which was responsible
for the last UK epidemic.
Transmission
Contact with already infected animals,
infected aerosols (which can carry long distances downwind),
fomites
uncooked or insufficiently cooked meat that is contaminated,
especially where this is incorporated into animal feed.
Disease in animals
The first symptom of infection in animals is a high fever;
blisters and ulceration develop on the mouth and the feet, leading
to lameness and poor feeding ability.
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The disease spreads rapidly within herds, as infected animals are
actively infectious and large amounts of live virus are produced
before
and after clinical symptoms start.
Piglets are the worst affected, and the disease can cause high
mortality.
Spread to other sites is believed to occur on the wind or by
physical means, including vehicular, livestock or human
movement.
The virus can also infect wild deer which can then become a
reservoir for infection.
Disease in humans
The WHO has recorded only about 40 confirmed cases of FMD in
humans worldwide in the twentieth century, of which most were
related to the O serotype.
Transmission was first documented following deliberate ingestion
of unpasteurised milk from infected cows by three German
veterinary surgeons in 1834.
In brief, very close contact with infected cattle or their products
seems to be necessary for infection to occur.
Following an incubation period of between 2 and 6 days,
clinical signs of infection commence.
Blisters appear on the hands and sometimes on the feet and in the
mouth and/or the tongue.
Symptoms normally resolve spontaneously, usually within a week
of the last appearance of blistering.
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Media misconceptions have much to do with the publicity that this
condition has received.
There is another, non-zoonotic, virus of the Coxsackie family that
produces similar symptoms in children, called hand, foot and
mouth disease, which leads to confusion, as may infection with
other viral pathogens.
Diagnosis
Confirmation of the diagnosis is made by serology testing on
clinical samples.
Treatment
There is no treatment except symptomatic support.
Prevention of disease in humans
protective clothing for personnel handling
culling infected animals,
pasteurisation of dairy products.
A vaccine is available for animal use;
there is no provision or clinical need for its use in humans.
Prevention
Prevention of FMD in animals relies upon a host of organisations.
Importation of infected foodstuffs, which then entered the animal
food chain after inadequate heat treatment of swill, was probably
the source of the latest UK outbreak.
Customs services have the task of controlling this trade, but
individual travellers may illegally import meat, meat products or
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contaminated dairy products into the UK in their luggage, making
the task of control impossible.
Importation of contaminated livestock has also been suggested
as
a means of spread, and outbreaks in continental Europe have been
linked to infected livestock exported from the UK.
Locally, disinfectant in foot and vehicular baths helps prevent
physical transfer.
In the UK, DEFRA provides a list of disinfectants that are
approved under the Diseases of Animals (Approved Disinfectants)
1978 as amended for use against FMD and/or in respect of General
Orders (25 April 2001).