D6-Lancaster Farming, Saturday, July 27, 1996
VERY FEW
POULTRY DISEASES
ARE TRANSMISSIBLE
TO MAN
Patty Dunn, DVM
Animal Diagnostic Lab
The term “zoonosis” is defined
as “an infection or infestation
shared in nature by man and lower
vertebrate animals.”
Even though it is much more
likely that we will acquire conta
gious diseases from our fellow
humans rather than from other spe
cies, many people are very con
cerned about zoonotic diseases
that they might “catch” due to
association with the animal
kingdom.
Man shares a number of infec
tious diseases with other mam
mals. One of these, rabies, is one of
the deadliest viral diseases ever
discovered. Most, however, are
much milder conditions that
should be recognized but not
feared.
Fortunately, very few infectious
diseases of avian species are
directly transmissible to man.
Most successful disease-causing
organisms are highly adapted to
particular biological conditions in
specific hosts. As avian anatomy
and physiology are in many
respects quite different form those
of mammals, very few avian
pathogens can cross the gap and
flourish in mammalian hosts to
which they are not adapted. Bio
logically, man has even less in
common with other groups such as
fish, reptiles, amphibians and
invertebrates, so even fewer dis
eases are shared between these
groups.
It should be noted, however, that
insects do play a very important
role in “vectoring” disease organ
isms between warm-blooded ani
mals. In fact, some microbes
require an insect host to complete
stages in their life cycle necessary
to become infective to humans.
Malaria is a prime example of a
serious protozoal infection depen
dent upon certain types of mosqui
toes for propagation and transmis
sion. In a slightly different fashion,
the Lyme disease bacterium is gen
erally introduced into huipans by
the deer tick. Equine encephalitis
and St Louis encephalitis are viral
diseases that may be carried from
birds to man by mosquitoes.
Poultry infectious diseases that
can directly infect humans are
chlamydiosis, Newcastle disease,
erysipelas, and avian tuberculosis.
Of these, chlamydiosis (also called
psittacosis or parrot fever) is the
most serious. It is caused by the
bacteria Chlamydia Psittaci. Pet
bird species (psittacines) are much
more likely to be infected with-the
organism and pass it on to their
owners and handlers than are most
other avian species. These com
prise the bulk of human exposure
cases of chlamydiosis.
Wild bird reservoirs of C. Psit
taci include sea gulls, ducks,
herons, egrets and pigeons. Of
domestic poultry, turkeys are the
most common species known to be
productively infected. Very few
confirmed chicken cases have ever
been cited. Minor species such as
ducks,'phcasants and pigeons have
been reported to have disease
problems related to infection with'
C. Psittaci.
Clinical signs in turkeys
infected by a mild strain of C. Psit
taci may include loss of appetite,
loose greenish droppings, and
mortality rates of 1-4 percent.
More virulent strains cause exacer
bation of the above signs with sig
nificant weight loss and mortality
rates from 10-30 percent. Egg pro
duction of breeders drops rapidly.
Post-mortem lesions look similar
to those of colibacillosis and
include fibrin and pus coating the
heart (pericarditis) and, less fre
quently, air sacculitis. Enlarged,
congested spleens and livers may
also be noted. Chlortetracycline is
used to treat diagnosed flocks.
In humans infected with
chlamydiosis, flu-like symptoms
occur. Signs include fever, chills,
headache, weakness, and coughing
associated with atypical pneumo
nia. Joint pain, stomach cramps,
and diarrhea are reported less fre
quently. The incubation period is
4-15 days, and the mean duration
of illness is 9-10 days. The infec
tion may be serious enough to
require hospitalization, and deaths
have occurred. Tetracycline-class
antibiotics are generally used in
treatment of human cases.
The most common scenario for
human infection from turkeys
occurs at the turkey processing
plant when workers handling
infected turkey carcasses are
exposed to aerosolized infectious
particles. During the last SO years
in the U.S., several human out
breaks of chlamydiosis have been
reported in turkey processing plant
workers in Texas, Missouri,
Nebraska, Ohio, and Minnesota.
Most of the infections in these
cases occurred in employees in the
kill-pick and evisceration depart
ments, but cases also occurred in
other areas including further pro
cessing. Workers in infected turk
ey flocks have also been infected.
Newcastle Disease Virus
(NDV) infects chickens, turkeys,
and pigeons as well as other types
of birds. In commercial poultry in
the U.S., only mild strains of NDV
are generally present Cases of
Newcastle disease in growing
chickens and turkeys result in mild
respiratory symptoms and are
often followed by secondary E.
Coli infections. ND in breeders or
layers can cause mild egg produc
tion drops and shell quality prob
lems. Most commercial chickens
are vaccinated against ND using
attenuated live virus strains which
may be followed in breeders and
layers by killed virus vaccines.
If people contact live ND virus,
including the vaccine strains, in
the tissues of the eye, conjunctivi
tis results. The thin covering of the
white of the eyeball and the lining
of the eyelids become inflamed,
reddened, and irritated. The condi
tion generally lasts for 5-10 days
and resolves completely. No sys
temic invasion of the virus into
other parts of the body occurs. No
treatment other than topical eye
drops or ointments to reduce
inflammation, discomfort, and
secondary bacterial infections is
generally necessary. The infection
is uncomfortable and cosmetically
undesirable, but not serious. Peo
ple most at risk are those handling
and administering live NDV vac
cines, those doing post-mortem
exams on actively infected birds,
and laboratory workers handling
concentrated virus. Wearing
gloves and lab goggles, avoiding
touching hands to eyes, and wash-
ing hands after handling virus or
vaccine are effective preventive
measures,
Erysipelas is a disease condition
of poultry caused by the bacteria,
Erysipelothrix Rhusiopathiae
(ER). Turkeys, pheasants, ducks,
geese, and rarely chickens are
affected. Most species of birds are
potentially susceptible. The dis
ease in poultry is most common in
middle to late growout of market
10m turkeys as well as turkey
breeders. Range flocks are more
often affected than housed birds.
The bacteria is picked up from
infected soil and enters the bird
through skin scratches and wound
s. Flocks that are picking and fight
ing excessively are more likely to
become infected with erysipelas.
Artificial insemination procedures
used in turkey breeders can also
spread the infection.
Infected birds often die quickly
with unnoticed clinical signs.
More chronic cases can show
depression and lameness due to
arthritis. Signs of general sep
ticemia such as carcass conges
tion, enlarged livers and spleens,
and hemorrhages on the heart and
other organs are present. Red
dened wounds may be present on
heads or vents. Penicillin is the
drug of choice for treatment, and
bacterins have been used for pre
vention and control in at-risk
flocks. Beak trimming, desnood
ing, and careful artificial insemi
nation techniques should be prac
ticed. Flocks should be moved
from infected ranges.
Large numbers of ER bacteria
are present in infected carcasses.
People handling these carcasses
and performing post-mortem
exams on dead birds contract can
the bacteria tissues through small
scratches and cuts on unprotected
hands and arms. A painful, hot
swelling with a dark center called
an “erysipeloid” results at the site
of infection.
It usually remains localized, but
in rare instances the bacteria can
spread through the bloodstream to
other parts of. the body causing
arthritis and other more serious
conditions.-Treatment with peni
cillin or other effective antibiotics
should be instituted at once. Local
ized erysiploid lesions should
resolve completely in a few weeks
with treatment. Latex/vinyl dis
posable gloves should always be
worn when posting dead birds. If
erysipelas is suspected, double sets
of gloves should be worn for added
protection.
BUY.SELL.TRADE OR RENT THAI llKill III!
PHONE; 717-626-1164 or 717-394-3047
FAX 717-733-6058
Mon., Tues., Wed., Fri. 8 AM to 5 PM; Thurs. 7 AM to 5 PM
FARM
EQUIPMENT
JD 4010 diesel, dual re
mote, rollamatic, weak en
gine, $2,800.
(717)532-8926.
1025ga1. Norwesco Hori
zontal Poly Tank, 2 bands
and valve included, like
new, $650. 814/793-4077.
10' header for K Gleaner,
very good, $1,575. Larry
Stalter ‘The Combine Man'
1-800-248-2151
1982 FKS Gleaner, 13',
4-30', very good, $6,950.
plus Freight. Financing
Available. Larry Stalter
"The Combine Man'
- 1-800-248-2151 --
Avian tuberculosis (T. 8.),
caused by the bacteria Mycobac
terium Avium, is no longer present
in commercial poultry in the U.S.
Today, it is seen only sporadically
in smaller, “backyard” flocks of
chickens greater than two or three
years of age. Older ducks, geese,
game birds, pet birds and zoologi
cal species can also have avian
T.B. It is very rare in turkeys.
Avian T.B. causes progressive
general debilitation with weight
loss, decreased egg production,
and death. Liver, spleen, intestine,
and bone are target organs of the
infection in birds. Granulomatous
lesions are seen in these organs.
There is no effective treatment for
birds. Mammals such as swine,
rabbits, and mink can succumb to
progressive disease and M. Avium
can cause sensitivity in cattle to the
tuberculin test. Although humans
are considered relatively resistant
to infection by the organism, more
cases of avian T.B. have been seen
in recent years, particularly in
immunosuppressed people (peo
ple on immunosuppressive drugs
or those with acquired immunode
ficiencies). Therefore, avian T.B.
is considered potentially zoonotic
by most medical professionals.
It should be noted, however, that
most M. Avium strains isolated
from people are different from the
common chicken isolates. M.
Avium is relatively resistant to the
commonly used antituberculosis
drugs, so effective treatment is dif
ficult to achieve.
Internal parasites (intestinal
worms, coccidia, etc.) of poultry
are very host specific. Most won’t
cross over into other avian species,
let alone into mammals. For exam
ple, chicken coccidial species will
not infect turkeys and vice versa.
Most external parasites (lice,
mites, etc.) arc also specifically
adapted to avian hosts and will not
willingly colonize human hosts for
any extended length of time. How
ever, some lice, mites, ticks or bed
bugs in infested poultry houses can
board humans working in the
1993 New Holland 1915
forage harvester, 400 hrs.,
4-30' head, hayiage pickup
head, automatic knife shar
pening, shear bar adjust
ment, 4x4, excellent condi
tion, $llO,OOO 080.
(717)865-4534.
13' Brillion cultimuleher,
Brillion 10-tooth chisel.
800/919-3322.
1948 Farmall Cub w/5‘
belly mower, $2300 OBO;
19 5 1
JO B w/hydraulics, $2500
080.
717-624-1686.
1977 JD 4630 PS. SGB,
w/heat and air, 20.8x38
tires, repowered w/rebuilt
466 engine, excellent con
dition (717)597-5623.
1982 Deere 6620, low hrs.,
Indiana machine, emma
culate, 90% tires, $26,650.
Call Sam. 717-630-2736
house. They bite and irritate the
skin causing temporary physical
(and emotional) discomfort
The category of foodbomc
zoonotic disease which includes
such bacterial pathogens as Sal
monella SPP, Campylobacter
SPP., E. Coli, etc. is a large topic in
itself and will not be addressed in
any detail in this article. By defini
tion, it is a human disease caused
by ingestion of meat or other ani
mal products (egg, milk) that 1$
"contaminated with an offending
organism or microbial toxin.
Salmonella Enteritidis in poul
try meat or eggs is the most com
monly cited poultry food-borne
human pathogen. Usually, these
organisms are not causing clinical
disease in the animals themselves.
However, they may reside in the
animal’s intestinal tract or conta
minate the carcass or product from
a completely different source dur
ing handling, processing, trans
port, or final preparation. Proper
food handling, storing, and prepa
ration are the best defenses against
foodbome zoonotic disease.
Some human disease conditions
of a noninfectious nature can arise
from man’s association with poul
try. Some individuals develop
allergies to bird dander; feathers,
bedding materials, etc., that result
in typical allergic respiratory
symptoms. Ammonia gases in
confinement poultry houses are
just as irritating to human eyes,
noses, and throats as they are to the
birds’.
Optimizing ventilation and
using litter treatments help birds
and humans alike. Wearing high
quality masks or respirators help
decrease people’s exposure to
dust, dander, and irritating gases.
Good hygienic practices should
always be followed after handling
any animal including birds and
their secretions and excrements.
Remember, however, that rarely
will normal, healthy animals trans
mit diseases to humans. People
should not fear close association
with poultry as a significant human
health risk.
* POPE IN
SOME EXTRA M
CASH!
Advertise With A \j 5£S u
Lancaster Farming v / i
CLASSIFIED AD... JU^-'
Phone; 717-394-3047 !|l ‘
or 717-626-1164
1946 JD A ready for field or
to restore, $1,500. Even
ings. (614)766-2703.
1600 Case tractor, 4,700
hrs., Powershift, 540+
1000 PTO, rubber 75%. ex.
cond, $9,000.
(717)380-1130.
1088 7720 Titan 11, 2,016
engine hrs., about 1,400
sep. hrs., big rubber, chop
per, heavy adjustable axle,,
sharp, $39,500. Trade &
Finance. Larry'Stater The
Combine Man'
1-800-248-2151
1991 Deutz 8F6L913 six
cyl 178 hp with mod.
DIIB3L clutch and 10'
drive pulley 2152 hours.
Adams Co,
(717)526-4134.
1910 Studebaker wagon,
wheels and axles solid
$BOO. Delta, PA,
(717)456-7414 -
1995 Deere 6810 cutter,
759 hrs., $123,500. Trade
A Finance. Larry Stater
‘The Chopper Man'
1-800-248-2151
1995 JD 6710 forage
harvester, 4-30' head, 252
hrs., $134,900. Trade &
Finance. Larry Stater The
Chopper Man’
1-600-248-2151
1R pull-type FMC sweet
corn harvester. V46OD
Wisconsin engine pow
ered, good condition
$3,500 080. After 7:30
pm, (610)258-9818.
273 NH baler w/engine,
late model, real nice, motor
not very old, can sell w/
PTO. 717/442-7497.
2RN corn head and pickup
for Papac 180 harvester,
$225. (717)786-2839.
(2) Wayne gas station
pumps, excellent condi
tion, $275/each or
$6OO/pair. 717/858-3432.