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Infectious Diseases

Infectious diseases are caused when germs like viruses, bacteria, parasites or fungi, enter our body. 

Bacteria live almost everywhere in our environment. Of the billions of types of bacteria, only 50 are known to cause infection in humans. Viruses cause far more infection than bacteria and spread more easily. If more than one person in your family has an illness, chances are it’s a viral infection.

Germs can live on surfaces such as desks, door handles and phones. Most people get sick when they touch something with germs on it and then touch their eyes, nose or mouth. The best way to lower your risk of getting sick is to clean your hands often.

On this page

child with measles rash on their torso

Information about Measles

Here, you will find information related to measles infection risks, vaccination, and how to access your or your child’s immunization history.

Reportable Diseases


  • Phone: 519-426-6170 or fax: 519-426-4767 (Monday to Friday 8:30 AM – 4:30 PM only)
  • For after-hours and holidays, phone: 1-877-298-5888 Public Health Inspector on-call

Disease-Specific Information

Infectious Diseases – Guidelines for Schools

Sexually Transmitted Infections

Sexual Health Services for Haldimand and Norfolk Residents