W. David Colby IV MSc MD FRCPC


Ehrlichiosis

Ehrlichiosis is an infectious disease that can be passed to humans by ticks. It causes fever, chills, headache (often severe), general ill feeling (malaise), nausea and vomiting, and a purple or red rash. Symptoms usually start from 1 to 21 days (average of 7 days) after the tick bite. Ehrlichiosis is usually treated…

South African Tick-Bite Fever

South African tick-bite fever is a disease passed to humans by ticks that are infected with an organism called Rickettsia africae. These ticks, known as buffalo ticks, usually live on cattle in southern Africa. Symptoms usually begin within 8 days after the tick bite and may last for 1 to 15 days. Symptoms may include…

Measurement of a Tuberculin Skin Test Reaction

Two to three days after getting a tuberculin skin test, the size of any bump at the site is measured. Your risk of having TB is used along with the size of the bump to determine whether the test is: Positive, meaning you have been infected with TB bacteria. Negative, meaning you have not been infected with TB bacteria…

Food Poisoning

Food poisoning is an illness caused by eating foods that have harmful germs in them, like bacteria, parasites, and viruses. These germs are mostly found in raw meat, chicken, fish, and eggs, but they can spread to any type of food. They can also grow on food that is left out on counters or outdoors or is stored too long…

Tuberculosis (TB)

What is tuberculosis? Tuberculosis (TB) is an infection caused by slow-growing bacteria that grow best in areas of the body that have lots of blood and oxygen. That’s why it is most often found in the lungs. This is called pulmonary TB. But TB can also spread to other parts of the body, which is called extrapulmonary…