Decades ago, a just-graduated medical student had an unsettling experience.
As he walked a dark, deserted street overlooking the sparkling lights of Florence, Italy, a dog appeared. Suddenly, the young doctor felt pain on his wrist the sharp teeth of a young dog. Black and middling in size, its Italian name was cane lupo, wolf-like dog. The bite drew blood through a jacket and sweater. The dog disappeared: big problem.
One of the greatest scientific names is French chemist Louis Pasteur (1822-1895), whose research answered questions that had plagued humanity for centuries. He began with the problem of spoiled brews and wines, fermentations gone wrong. Some yeasts in the presence of air (aerobic) produce vinegar (acetic acid). In an anaerobic (no air) medium, others make ethanol. After Pasteur, brewers and vintners no longer wasted malt, hops or grapes.
Then Pasteur solved the problem of failed silk crops (diseased silk worms), cholera in chickens, anthrax in cattle and sheep, and, in the mid-1880s, rabies. He recognized that nerve tissue from a rabid dog injected into healthy dogs produced rabies. He then developed a weakened virus (although viruses were then unknown), now termed an attenuated virus, which prevented rabies in vaccinated animals. He found his vaccine was effective even after rabid bites had occurred.
Most rabies in humans comes from animal reservoirs and bites carrying infected saliva. Raccoons are the most common reservoir, especially along the eastern seaboard inland to the Appalachians. Similarly, skunks claim the middle third of the country from Canada to the Gulf of Mexico. Foxes and coyotes predominate in Texas, Arizona and Alaska. Rabid bats have been found in every state but Hawaii. Except along the Mexican border, dogs present lesser threats because of generally high-vaccination rates. In recent years, more cats than dogs have tested positive for rabies. Find more at http://cdc.gov/rabies.
In the post-bite scenario, Pasteur was lucky. Rabies usually takes 10 days to a year (average is one to two months) to develop in its victim. This latency period provides a window for the vaccine to actively generate natural antibodies. Untreated rabies in humans is almost always fatal. Since Pasteurs time, we also have passive immunization. Immunoglobulin (extracted from human plasma) is injected into highly at-risk bite victims and simultaneously vaccination is begun as the latency period ticks away. The combined treatment costs thousands of dollars.
The new doctor was lucky. Accompanied by his fluent-in-Italian wife, he went to a Florentine emergency room. He had a high-risk bite: An unprovoked attack by an unknown, unlocated animal. If the dog (or other animal) can be observed for 10 days and remains healthy, then no worries. If sick, the brain must be examined; if rabies-positive, passive and active immunization are started.
The victim was started on rabies duck embryo vaccine the old stuff, meaning daily injections in the lower abdomen. The shots were not painful, but the itchy, swollen and red welts were. Our hero attended the Clinico Anti-rabico, carefully the other line was for STDs. On day 12, the dog was found healthy, so no more shots. The Italian police, the Questura, were very helpful; we recovered enough lira (for the jacket and sweater) for a fine dinner.
www.alanfraserhouston.com. Dr. Fraser Houston is a retired emergency room physician who worked at area hospitals after moving to Southwest Colorado from New Hampshire in 1990.