Grosse Île: The Quarantine Island

Discover the quarantine station that was the gateway for millions of immigrants to Canada, and a front line in the fight against infectious disease in the 19th and 20th centuries

Grosse Île - Québec area map (2023) by Google EarthParks Canada

An Island Like No Other

Grosse Île and the Irish Memorial National Historic Site lies less than 50 kilometres down the St. Lawrence River from Québec City. Over its 105 years of operation, it was the gateway for more than 4 million immigrants on their way to new lives in North America.

Grosse Île - Regional map (2023) by Google EarthParks Canada

Evidence of Indigenous use on the island, like arrowheads, fragments of ceramic tools and traces of fires, date back to at least the 1200s. This region is part of the traditional territories of several first nations who fished and hunted here on their river travels.

Painting originally titled "A View of the Quarantine Station at Grosse Île," (1850) by Henri DelattreParks Canada

At the Beginning

The nineteenth century was an intense period of immigration to what is now Canada. Québec City became Canada's main immigration hub, and Grosse Île served as a quarantine station for the Port of Québec.

"A young woman of Vienna who died of cholera, depicted when healthy and four hours before death" (1831?) by unknownParks Canada


The quarantine station at Grosse Île was established in 1832 to prevent cholera from gaining a foothold in North America. This illness, already a global pandemic, was a serious threat to public health... and anticipated on ships arriving from Europe.

Cholera is a bacterial infection spread by contaminated food and water that causes severe dehydration through vomiting and diarrhea. If left untreated, it can lead to death in just a few hours. 

Unfortunately, the quarantine process failed to prevent the spread of cholera in North America and by the end of 1832, more than 3,000 people had died in Québec City.

Interior view of the Lazaretto (2012) by Parks CanadaParks Canada

The Tragedy of 1847

From 1845 to 1849, Ireland experienced a devastating famine. In 1847 alone, 100,000 immigrants  arrived at Grosse Île, nearly four times the average annual number. The vast majority were Irish.

Originally designed to house healthy immigrants, the Lazaretto, the wooden building pictured here, was converted into a hospital. It is one of the oldest buildings still standing on the island.

Originally titled "Emigrants Arrival at Cork - The Scene on the Quay," Cork, Ireland (1851) by "Illustrated London News", 10 mai, 1851, p.386Parks Canada


Many of the Irish immigrants had weakened immune systems due to starvation. Of the many diseases aboard the coffin ships (named for the vast number of sick and dying passengers aboard) typhus, a bacterial infection spread by lice, was the most common… and the most deadly.

Dr. Frederic Montizambert (1869) by William James TopleyParks Canada


In 1866, a new doctor named Frederick Montizambert arrived at Grosse Île, initially as an inspecting physician. He was promoted to medical superintendent in 1869 - a position he held for 30 years, overseeing a major modernization drive.

Germ Theory

Dr. Montizambert was an early adopter of Germ Theory - one of the most important medical developments of the nineteenth century. The idea that microorganisms like bacteria, invisible to the naked eye, can cause illness was revolutionary at the time.

The south side of the disinfection building right after its construction (1893) by S. ou D.A. McLaughlinParks Canada

Dr. Montizambert was able to build modern, effective quarantine facilities based upon advances in science and technology. He introduced medical labs, disinfection procedures, and ensured that the ill were isolated to avoid infecting the healthy.

Dr. Frederick Montizambert is recognized as a Person of National Historic Significance for his many contributions to medicine and science. Many of the buildings and machines constructed under his leadership can be viewed at Grosse Île today. 

A view of the entrance to the disinfection chambers (1893) by S. ou D.A. McLaughlinParks Canada

Disinfection Station

The disinfection building opened in 1892. On the lower floor were dry-steam chambers, pictured here. Luggage was packed into wire-mesh boxes and pushed on tracks into these chambers. Dry steam - superheated water vapour - was used to kill pathogens, similar to pasteurization.

Disinfection building with showers at Grosse Île and the Irish Memorial National Historic Site (1997) by Parks CanadaParks Canada

Disinfecting Shower

The passengers themselves were disinfected in the shower room. For privacy, each of the 44 steel stalls had a door and chicken wire around the top. A showerhead and three curved horizontal bars sprayed diluted mercury bichloride from above and from the side.

Mercury bichloride was the primary disinfectant used at Grosse Île. It's great for killing microorganisms, but highly toxic to humans in anything but tiny amounts. It’s not widely used today when safer alternatives like bleach are available.

Two waiters in the first class hotel dining room (circa 1912) by unknownParks Canada

Quarantine Accommodation

Once the newly-arrived immigrants and their belongings were disinfected, they were sent to a hotel to complete a mandatory quarantine. There were hotels for first, second and third class passengers. The first-class hotel, pictured here, had a dining room with full table service.

Three views of the Admission and Discharge Book from the Marine Hospital (c.1878) by unknownParks Canada

Reading Between the Lines

Thanks to some large leather-bound books in the Parks Canada collection, we know about the immigrants who were hospitalized after 1878. These Admission and Discharge Books record their names, ages, places of origin, and diseases.

These registry books even tell us what ship the patient arrived on and whether or not they were discharged or died onsite. Most came from England, Scotland, and Ireland, but there were patients from Norway, Sweden, Portugal, Germany and Italy as well. 

The Marine Hospital (1893) by S. ou D.A. McLaughlinParks Canada

New Facilities for a New Era

The Marine Hospital was built in 1881 in the eastern sector, away from the accommodation for the healthy in the western sector, as part of the strategy to prevent the spread of disease.

The ambulance sitting next to the barn near the village bakery (1893) by unknownParks Canada

Ambulance on the Move

Pictured here is a horse-drawn ambulance that brought sick individuals to the hospital. It was a black, horse-drawn carriage with a pedal-operated bell to alert the medical staff. The ambulance is on display at Grosse Île today.

View inside the red room of the Lazaretto (2022) by Parks CanadaParks Canada


Some immigrants were infected with smallpox. In 1904, part of the Lazaretto was converted to a ‘red room.’ Sunlight was considered harmful to smallpox sufferers with pustules on their eyelids and bodies, so the walls, blankets, and even windows were red to make it darker.

Smallpox is an infectious virus spread from person to person, with high fevers, body aches and a painful rash of open sores in the mouth and body. It became the first contagious disease to be prevented by a vaccine and was eradicated globally in 1980.

Immigrants on the ship "Numidian" leaving Liverpool, England (1902) by unknownParks Canada

Closing of the Station

During the First World War (1914-18), there was a sharp drop in immigration. In the years that followed, an increase in medical inspections and vaccinations abroad meant immigrants were generally healthier when leaving their home countries.

In 1937, after 105 years of operation, the quarantine station closed, and the medical screening of immigrants was moved to Québec City.

A visitor looks at the Irish National Memorial (2012) by Parks CanadaParks Canada

In Memory

Today, there are two memorials and three cemeteries on the island to commemorate the thousands of people who died at the Grosse Île quarantine station. The island is a powerful symbol of the hope and tragedy that mark the experiences of many immigrants.

A Parks Canada interpreter meets visitors at the First Class Hotel (2012) by Parks CanadaParks Canada

Visiting Today

Grosse Île and the Irish Memorial National Historic Site is open from May to October. You can access the island by boat from Berthier-sur-Mer, located 45 minutes from Québec City, or by plane from nearby Montmagny.

Dive into History

To learn more about the history of Grosse Île and the Irish Memorial National Historic Site, please listen to the ReCollections podcast episode Grosse Île: The Quarantine Island

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