The name "Legionnaires' disease" was coined in 1976 after a respiratory disease affected many delegates attending a convention in Philadelphia held by the American Legion of Pennsylvania. Eventually, the bacteria that was responsible for the disease was isolated and named as Legionella pneumophila. Two distinct illnesses, Legionnaires' disease and Pontiac fever, have been associated with the Legionella species. Legionnaires' disease is a severe pneumonia. Pontiac fever is a mild, non-pneumonia influenza-like illness. It is not clear why the same causal agent can produce two distinct illnesses.

What is the cause of Legionnaires' disease?

The bacterium responsible for Legionnaires' disease belongs to the genus Legionella. There are approximately 35 Legionella species known to produce the disease. Legionella species are commonly found in any aquatic environment. They can survive for several months in a wet environment and multiply in the presence of algae and organic matter.

Disease transmission may happen by inhaling or drinking water contaminated with the Legionella bacteria. Transmission of the disease other than through direct inhalation of aerosols may occur, but the mechanisms are not clearly understood.

What are the symptoms?

Legionnaires' disease has an incubation period (the time from exposure to the onset of symptoms) of 2 to 10 days. Severity ranges from a mild cough and low fever to rapidly progressive pneumonia, coma, and death. The "attack rate" (the fraction of exposed persons who become infected) of the average population is approximately 5 percent of less. Not all individuals with Legionnaires' disease experience the same symptoms. Headache may be an early symptom of Legionnaires' disease. 

Early symptoms include slight fever, headache, aching joints and muscles, lack of energy or tiredness, and loss of appetite. 

Later symptom include: 

• High fever (102° to 105° F, or 39° to 41° C)

• Cough (dry at first, later producing phlegm) 

• Difficulty in breathing or shortness of breath 

• Chills 

• Chest pain 

• Common gastrointestinal symptoms include vomiting, diarrhea, nausea, and abdominal pain.

What occupations are at risk for Legionnaires' disease? 

It is not easy to identify all of the occupations posing the risk of Legionnaires' disease. In fact, the frequency of this disease occurring in workplaces cannot be evaluated or estimated because statistics are lacking. Workers most at risk are those with occupations that require them to work in sealed buildings including those workers who maintain water cooling towers in air conditioning systems. Some outdoor occupations should be considered at risk as well. Soil disturbed by bulldozing and areas where surface or aerosolized water discharge occurs can cause the exposure to the microorganism responsible for Legionnaires' disease.

West Nile Virus is spread by the bite of an infected mosquito. The virus can infect people, horses, many types of birds, and some other animals.

Most people who become infected with West Nile virus will have either no symptoms or only mild ones. However, on rare occasions, West Nile virus infection can result in severe and sometimes fatal illnesses.

FACT - In 1999, the West Nile Virus was first detected in the U.S.A., in New York City. FACT - August 2001, it was confirmed in two dead birds found in southern Ontario. 

FACT - 2002, the West Nile Virus spread to 34 states. In the state of Louisiana, 112 residents were infected, killing five and putting dozens in the hospital. Governor declares a state of emergency as the mosquito born virus has been found in virtually every corner of the state.

FACT - 2003, Provincial Governments have committed millions of dollars to programs that will monitor the West Nile Virus and will be putting into place more aggressive insect control campaigns during the spring and summer.