Environmental Engineering Reference
In-Depth Information
Animals as Reservoirs
A number of animal species serve as reservoirs for diseases that may affect
humans, including the following 13 diseases:
1. Brucellosis (undulant fever)
2. Clonorchiasis
3. Fascioliasis (intestinal fluke) and fasciolopsiasis
4. Leptospirosis
5. Paragonimiasis (lung fluke)
6. Salmonella infection (salmonellosis)
7. Schistosomiasis
8. Taeniasis (pork or beef tapeworm) and cysticercosis
9. Toxoplasmosis
10. Trichinosis (trichiniasis)
11. Trichuriasis (whipworm)
12. Tularemia
13. Yersiniosis
In 1948, the prevalence of trichinosis in grain-fed hogs was 0.95 percent and
in garbage-fed hogs 5.7 percent.
15
Surveys in New England and the Mid-Atlantic
States in 1985 found infection rates of 0.73 and 0.58 percent, respectively, in pigs,
compared to an estimated national rate of 0.1 percent
16
Wild animals, including
bears, boars, martens, wolverines, bobcats, and coyotes, are also carriers. Horse-
meat has also been implicated as a source of infection.
17
The incidence of adult
Trichinella
infection in the United States has been declining, with only 129 cases
reported in 1990
18
and 16 cases reported in 2005.
19
Processed meats may be considered acceptable when stamped “U.S. inspected
for wholesomeness,” but this is no guarantee that the product is absolutely safe;
it signifies the product was processed in accordance with U.S. Department of
Agriculture (USDA) specifications. This is also true of raw meat and poul-
try, which frequently contain
Salmonella
and other pathogenic organisms, even
though stamped “inspected.” Raw meat products require hygienic handling and
adequate cooking. Uncooked summer sausage (fresh ground pork, beef, and sea-
soning plus light smoking) and raw or partially cooked pork products should be
avoided.
20
Some organisms are excreted in the urine of mice and rats, including the
following:
Lymphocytic choriomeningitis virus
•
Escherichia coli
•
Leptospira
•
Salmonella
•
