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ZOONOSES
Continued from page 15
bor TB sets in motion an extensive epidemiologic investigation as fever outbreaks have resulted mainly from occupational exposure in-
the authorities attempt to determine the animal’s origin, how it came volving veterinarians, meat processing plant workers, sheep and dairy
to slaughter, and how many other cattle it had been in contact with. workers, livestock farmers, and researchers at facilities housing sheep.
Currently in the United States, bovine TB represents only about 2 Diagnosis depends on serologic testing.
percent of all TB in humans, and seems to be contracted largely by
people who ingest unpasteurized dairy products from infected ani- There has been a recent increase in funded research on zoonoses.
mals, which is the reason that unpasteurized cheeses, etc., from other Among others, Washington State and Kansas State universities have
countries are not permitted to be imported to this country. Bovine dedicated new facilities to these programs, and the University of
TB was the primary cause of bone involvement and its various de- Chicago, in conjunction with Field Museum of Chicago researchers,
formities such as “hunchback.” has started surveying 1,100 samples from small mammals and birds
brought back from an African collecting trip looking for pathogens
GIARDIASIS potentially transmissible to man.
Giardiasis, or “beaver fever,” is caused by a protozoan parasite, Gi-
Now for my only experience with “reverse zoonosis”: When I was
ardia lamblia, and has earned its colloquial name because it is har- in small animal veterinary practice, we would often have a family
bored by beavers (among others) and can infect people who drink bring in their new house-puppy because it became listless, wouldn’t
from crystal-clear mountain streams inhabited by beavers. There is eat, and felt hot. In the process of taking a history, we would often
also person-to-person transmission through fecal-oral contamination. discover that the pup was a gift for a child, who spent a lot of time
It occurs quite commonly among small children in daycare settings. playing “kissy-facey” with his or her new friend. Examination would
The disease is characterized by severe diarrhea and has the capability reveal a bright-red pharynx with perhaps a bit of pus on the surface,
of causing severe dehydration. The most common treatment is with conjunctivitis and temperature of 103º F or greater (normal is 101.5º
oral metranidozole (Flagyl). F). While we rarely did cultures, the almost miraculous response to
the administration of procaine penicillin G by injection, followed by
Q FEVER a few days of oral dosing, implied to us that the puppy had been in-
Q Fever, caused by the very durable and highly infectious bac- fected with a Streptococcus sp. by its new owner.
terium Coxiella burnetti, is one of those conditions that can be very Fred H. Olin, DVM, MD, spent six years in veteri-
difficult for the physician to figure out. The symptoms are those of nary practice with Thomas E. Vice, DVM, before enter-
nearly all generalized illnesses: fever, malaise, myalgia, sore throat, ing medical school. During that time, he and Dr. Vice
chills, cough, and so on. Researchers have postulated that as few as also were veterinarians for the San Antonio Zoo. Asking
a single organism inhaled into a susceptible host can cause the disease. him about his experiences in veterinary medicine is not suggested if you
The bug is harbored primarily by sheep, goats and cattle, and is shed have anything else to do that day. He is also a semi-retired orthopaedic
in large quantities in amniotic fluid and placental tissue. Transmission surgeon and chairman of the BCMS Communications/Publications
to humans seems to be mostly by inhalation of dust contaminated Committee.
by these fluids and tissues containing the organism. It has been noted
to have potential as a bioterrorism agent. In the United States, Q EDITOR’S NOTE: As this issue of San Antonio Medicine was heading
to the printer, a case of Lassa virus was confirmed in a patient who died
May 25 at a Newark, N.J., hospital. Lassa virus is a zoonotic disease
that kills an estimated 5,000 people in West Africa annually.
16 San Antonio Medicine • July 2015
