While we tend to think that vaccines and antibiotics have eliminated the risks posed by most pesky bugs, more than 15,000 Canadians a year still die of infectious diseases and 21 million require medical treatment, new research shows
Virus transmitted by blood, most commonly through sharing needles and transfusions. Many develop chronic hepatitis, while about 10 per cent will get cirrhosis of the liver, and 3 per cent liver cancer. There are about 8,500 new cases and 900 deaths annually.
No vaccine. Prevention measures include needle exchange and safe-injection sites.
A bacterial infection that attacks the respiratory tract. The No. 1 cause of pneumonia and meningitis, especially among the elderly in institutions.
A vaccine that can protect against 23 types of the infection is recommended for older adults and people with chronic illnesses.
A sexually transmitted infection that can cause genital warts and cervical cancer, it causes about 600 deaths and 2,700 new cases of cancer annually.
The vaccine Gardasil protects against strains that cause most genital warts and cancers. Cervarix protects against most cancer-causing strains.
A virus transmitted by droplets in the breath. Outbreaks and epidemics occur each year, principally in winter, with an average of 1.5 million cases and about 700 deaths annually. (The number of deaths increases to 1,500-4,000 if related pneumonias are included.)
A vaccine that protects against commonly circulating strains is updated annually.
Hepatitis B virus
Transmitted by sexual contact, injection drug use, and during childbirth or breastfeeding. Can cause liver diseases, with an estimated 800 deaths and 500 new cases annually.
Virtually all Canadian children are immunized. Most cases are in immigrants from countries where it is endemic.
Common and largely harmless bacteria in the gastrointestinal tract that can produce deadly infections in the urinary tract and bloodstream. In elderly hospital patients, E. coli causes an estimated 1,500 deaths and 1.1 million cases requiring medical attention each year.
No vaccine. Better hygiene measures and using urinary catheters less are the best prevention methods.
Human immunodeficiency virus
Spread by the exchange of bodily fluids, usually during sex or sharing needles. Attacks the immune system and eventually causes AIDS. Canada has about 300 deaths and 4,000 new cases annually.
No vaccine. Safer sexual practices and treatment with antiretroviral drugs are the best prevention techniques. Also needle exchanges and safe injection sites.
A bacterium carried by up to 40 per cent of the population, but a danger to those with medical conditions. The main cause of hospital-acquired infection, causing about 670 deaths and 400,000 infections requiring medical care each year.
Some strains can be treated with antibiotics. Better infection control in hospitals, including hand-washing, is key.
A bacterium that causes intestinal infections in patients who have been treated with antibiotics. Causes severe and potentially fatal diarrhea. Almost all cases are acquired in health-care institutions. Responsible for about 420 deaths and 13,500 cases that require additional hospital treatment annually.
No vaccine. Good hygiene, infection-control measures and appropriate use of antibiotics would prevent most cases.
A group of viruses that cause the common cold. The single most common form of infection in humans, it is spread principally by droplets from infected persons (i.e. sneezing). Rarely fatal, but kills an estimated 12 people annually (all with underlying respiratory conditions) and leads to more than four million cases requiring medical attention.
No vaccine or effective pharmaceutical prevention or treatment. Hygiene measures such as covering sneezes and hand washing are the best methods of prevention.