Zoonoses 4th year 16-4-2017 Dr.Osamah Muwaffag
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Anthrax
AGENT: Bacillus anthracis
RECOGNITION
Human:
1. Cutaneous: most common, cutaneous pruritic made, becomes
edematous, vesiculates, then necrotic with black central scar;
2. Pulmonary: febrile respiratory tract disease, mild onset, then
sudden onset of second stage with dyspnea, sweating,
cyanosis, and death with 24 hours
3. Intestinal: febrile gastrointestinal disease.
Animal: Affects domestic and wild ruminants (cattle, goats,
sheep), horses, and swine.
Incubation period: Cutaneous, 1-7 days; pulmonary, 1-5 days;
intestinal, 12 hours-5 days.
Case fatality rate: If untreated, cutaneous 5%-20%, pulmonary
l00%,and intestinal 50%.
Confirmatory tests:
1) Gram or Giemsa stain,
2) Ascoli precipitin test, culture blood or tissue.
3) Radiographic evidence of mediastinal widening in pulmonary
cases.
Occurrence:
1. Worldwide, particularly in areas of alkaline soil subject to
flooding.
2. Occurs in dry, warm periods after heavy rains,
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3. frequently recurring on same pasture.
4. Seen in occupations handling livestock or wool.
Transmission:
1. direct contact with infected animal.
2. ingestion of undercooked meat
3. inhalation of spores in wool from infected ruminants.
4. Spores are found in bone meal, soil, water, and on vegetation.
5. Some arthropods, such as horseflies, may be involved in
animal-to-animal spread.
6. Spores form readily when vegetative form is exposed to air,
are long-lived, and are very resistant to environmental
extremes and disinfectants.
Control and Prevention
Individual/herd
1. Treat with penicillin; tetracyclines or erythromycin effective
if treated early.
2. Vaccinate livestock in endemic areas.
3. Vaccination may be considered for high-risk occupations.
4. Avoid necropsy of (suspected) infected carcasses beyond
collection of blood specimen.
5. Dispose of carcass by deep burial or burning.
Local/community:
1. Control dust in industries handling wool or hides.
2. Wash and disinfect wool hair from endemic areas (10%
formalin, 5% lye).
3. Prevent livestock movement from affected premises during
outbreak.
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National/international:
1. Require sterilization of imported bone meal.
Botulism
AGENT:
Clostridium botulinum
Toxin types A, B, E, F, and G affect people; A-D affect horses; C,
D affect cattle; C affects sheep; A, C, and E affect birds; C and E
affect mink.
RECOGNITION
Human:
1. Nausea, vomiting, sometimes constipation
2. followed by toxic effects on the central nervous system
(ptosis, blurred or double vision, dizziness, dysphagia,
blurred speech, muscle weakness, respiratory paralysis).
Animal:
1. Deaths occur in wild waterfowl, cattle, chickens, horses,
mink, pheasants, and sheep.
Incubation period: 4 hours-4 days.
Case fatality rate: Incubation, severity, and prognosis related to
toxin dose. If incubation is short, prognosis is very poor.
Confirmatory tests: Test suspect food or patient serum for
specific toxin by mouse protection, hemagglutination inhibition, or
indirect fluorescent antibody.
Zoonoses 4th year 16-4-2017 Dr.Osamah Muwaffag
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Occurrence:
1. Worldwide.
2. Principal reservoirs are soil and intestinal flora of herbivores
and fish.
3. Type E toxin associated with fish and marine mammals.
Infant botulism, associated with use of contaminated honey
in formula, results from multiplication and toxin formation in
the intestine.
Transmission: Ingestion of toxin.
CONTROL AND PREVENTION
Individual/herd:
1. Treat patients immediately with polyvalent antitoxin.
2. Provide respiratory support.
3. Properly preserve food contaminated by soil or intestinal
flora to prevent anaerobic replication and toxin production.
4. Heat ( 3 minutes) preserved foods likely to contain toxins
(fruits and vegetables with pH >4.5, certain fish, and meat
products) to destroy heat-labile toxin before eating.
5. To prevent disease in animals:
a. prevent herbivores from eating carrion (rodent
carcasses in forage, bovine pica);
b. do not feed spoiled meat to mink;
c. prevent birds and mink from eating sarcophagous
insect larvae in which toxin concentrates.
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Local/community:
1. Educate community regarding proper home food
preservation, especially canning to destroy spores, and the
use of home-preserved foods.
Brucellosis
AGENT
Brucella spp. (B. abortus, B. canis, B. melitensis & B. suis),
multiple biotypes.
Humans resistant to infection with B. neotomae and B. ovis .
RECOGNITION
Human:
1. Gradual onset,
2. febrile systemic disease without rash,
3. undulating fever, chills, sweating, headache, myalgia,
fatigue, backache, weakness, malaise,
4. weight loss; long convalescence;
5. often chronic with relapses following stress; arthritic, cardiac,
and emotional complications.
6. Human disease most often severe when infected with B.
rnelitensis
7. less frequently severe in decreasing order when infected with
B. suk, B. abortus, and B. canis.
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Animal:
1. Syndromes include abortion, weak newborn, reduced milk
yield, retained placenta, orchitis, spondylitis, salpingitis,
testicular atrophy.
2. Most susceptible bovine is pregnant female.
3. Many inapparent infections in all susceptible species.
4. Also occurs in some regions among sheep, reindeer, camels,
elk, and bison.
5. Fistulous withers or poll evil seen in horses in contact with
infected cattle.
Incubation period: 1 week-several months. Varies inversely with
stage of gestation in cattle.
Case fatality rate: <1%.
Confirmatory tests:
1. Test paired sera by agglutination or complement fixation.
Cultural examination of acute blood or lesions (include
placenta, fetus, milk, or semen).
2. Biotyping is aid in epidemiologic studies.
Occurrence:
1. Worldwide.
2. Occupational in livestock farmers, veterinarians, diagnostic
laboratory workers.
3. Major reservoirs are cattle (B. abortus), dogs (B. canis),
goats (B. melitensis), and swine (B. suis). Infection persists
for lifetime in animals.
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Transmission:
1. Contact with infected tissues or fluids, usually placental.
2. Ingestion of raw milk or dairy products (e.g., soft cheeses).
3. Airborne under abattoir or laboratory conditions.
4. Can penetrate intact skin or mucous membranes.
5. Venereal in swine and dogs.
6. Strain 19 vaccine pathogenic for humans.
CONTROL AND PREVENTION
Individual/herd:
1) Treat human patients with tetracyclines (also
dihydrostreptomycin in severe cases) for 3-4 weeks.
2) Add animals to herd or breed to animals from known
uninfected premises only.
3) Segregate parturient females.
4) Shorten breeding season to limit time when susceptible
animals are available.
5) Use serologic surveillance, remove infected animals.
6) Use strain 19 or 45/20 vaccine in heifer calves, Rev 1 in
goats and sheep.
7) Cook meat.
8) Wear protective clothing.
Local/community:
1) Pasteurize milk and dairy products.
2) Eradicate infection in domestic animal reservoir.
3) Control airflow in abattoirs and laboratories.
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Campylobacteriosis
AGENT
Campylobacter spp. (C. fetus ssp. intestinalis, C. jejuni), multiple
serotypes
RECOGNITION
Human:
1) Systemic form (C. fetus):
a) variable onset, chills, sweats,
b) fever (repeated episodes, 1-2 days in adults, up to 12
days in children),
c) cough, headache, meningitic signs (usually premature
neonatal infants),
d) weight loss, inappetence, vomiting, diarrhea in infants
and children,
e) abortion in latter half of pregnancy.
2) Enteric form (C. jejwi):
1) acute diarrhea-some with visible blood,
2) fever, abdominal pain, vomiting;
3) may have headache, malaise,
4) myalgia course 7-10 days;
5) meningitis unusual complication.
Animal:
1. C. feu:
1. Abortion, as well as embryonic death and resorption
in sheep, cattle, other ruminants, dogs.
2. C. jejuni:
2. Diarrhea in calves and puppies, abortion in sheep.
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Incubation period:
C. jejuni: 1-10 days, usually 2-5 days; C. fetus:unknown.
Case fatality rate:
C. jejuni: typically benign enteritis, risk with unusual systemic
complications (<1%);
C. fetus: up to 50% in premature infants, prognosis good in older
persons unless complicated by underlying disease (e.g., AIDS).
Confirmatory tests:
1. Culture feces (enteric), blood (febrile), cerebrospinal
fluid, aborted fetus, or bile (C. jejwu').
2. Test paired sera by agglutination or indirect
hemagglutination.
3. Lack of detectable response not uncommon.
Occurrence:
1. Worldwide.
2. C. fetus: Unusual in people; stress (pregnancy), debilitation,
impaired immune response predispose.
3. C. jejuni: Very common, is leading cause of human diarrheal
illness in many areas.
4. Large outbreaks associated with contaminated milk,
municipal water
Transmission:
1. Ingestion of food, raw milk, or water contaminated by
intestinal or biliary (C. jejuni) carriers.
2. Contact with household pets (especially immature).
3. Transplacental to fetus if bacteremia.
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4. Several ruminant species, dogs, swine, domestic and wild
birds are reservoirs of C. jejuni,
5. whereas C. fetus found principally in sheep and cattle.
People may be carriers of either species.
CONTROL AND PREVENTION
Individual/herd
1. Treat patients with systemic infection with ampicillin or
dihydrostreptomycin for 4 weeks;
2. if severe enteric illness, treat 10 days with gentamicin or
erythromycin.
3. Dispose of aborted fetuses and placentas promptly.
4. Use proper hygiene and cooking of meat and poultry.
5. Keep pets with diarrhea away from children.
6. Immunize cattle and sheep to prevent abortion (does not
prevent carrier).
Local/community: Pasteurize milk.
NationaUinternstiona1: None.
leprosy
AGENT
Mycobacterium leprae
RECOGNITION
Human:
1. In endemic areas, many subclinical infections exist.
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2. Range of clinical response from tuberculoid (paucibacillary)
to lepromatous (multi-bacillary active).
3. Clinically, begins as indeterminate form with small, flat,
hypopigmented patches which may be anesthetic.
4. These may regress or develop into tuberculoid form with one
or several roughly circular lesions with raised edges or
lepromatous form with numerous, diffuse skin lesions,
thickening of the ears and lips, and madarosis.
5. A third form, borderline, is intermediate between the
tuberculoid and lepromatous forms and may progress into
either of the "polar" forms.
6. Because of nerve damage a dropped foot or clawed hand
may be present.
7. Wounds resulting from loss of heat or touch sensation are
common.
Animal: Naturally acquired infections have been found in
armadillos in the southern United States as well as in a few
primates from West Africa.
Incubation period: Indeterminate: 6 months-> 10 years, usually
3-4 years; tuberculoid: 4 years; lepromatous: 8 years.
Case fatality rate:
1. 1%-2%.
2. Fatalities are usually the result of secondary complications
Confirmatory tests:
1. Microscopic examination of lesion material, although in
tuberculoid may be difficult to find organisms.
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2. In lepromatous form, organisms are easily isolated from
lymphoid organs, respiratory tract, and the skin.
3. A very sensitive ELISA test has been developed recently.
Occurrence:
1. In the tropics.
Transmission:
1. Human-to-human only route of major significance.
2. Prolonged close contact, such as with infected member of
household, important.
3. Inhalation and through broken skin most likely.
4. Childhood exposure greatest risk.
5. Significance of interspecies transmission uncertain.
CONTROL AND PREVENTION
Individual/herd:
1) Treat patients with dapsone, rifampicin, clofazimine, often in
combination, for 6 weeks and monitor for 2 years.
2) Surgically correct deformities and treat ulcers locally.
Local/community:
1) Active case detection and health education in endemic
areas.
2) BCG vaccination possibly protective in affected
households.