52 Cases of Bacterial Illness From Shellfish Discovered in Washington Following Heat Wave

Washington health officials are warning of a spike in bacterial-related illnesses linked to shellfish following an intense heat wave across the Pacific Northwest last month.

The Washington Department of Health (DOH) has reported 52 cases of the intestinal illness vibriosis in July, a figure that surpasses the highest number of cases ever recorded for the month, the Seattle Post-Intelligencer reported.

Of those cases, 26 were contracted from commercial oysters and four were from oysters harvested recreationally.

According to the DOH, vibriosis is caused by small bacteria called vibrio. The bacteria is found in fish and shellfish in coastal waters, and can multiply rapidly in warmer conditions. While vibrio is typically more likely to contaminate fish in the summer months, last month's midday low tides and hot weather appeared to further accelerate their growth.

"Another effect of the recent heat wave is the perfect storm of conditions for Vibrio infections. It's important that when enjoying shellfish, we follow simple steps to stay healthy," Todd Phillips, director of the Office of Environmental Health and Safety, said in a statement.

Symptoms of vibriosis usually occur about 12 to 24 hours after consumption and include diarrhea, abdominal cramps, nausea, vomiting, headache, fever and chills. The illness typically runs its course in two to three days, but in severe cases, hospitalization may be required.

The DOH did not report that there have been any hospitalizations or severe illnesses related to the recent spike in cases.

Mussels
The Washington Department of Health warned that there have been 52 cases of vibriosis, a bacterial-related illness linked to shellfish, due to last month's heat wave. LEX VAN LIESHOUT/ANP/AFP/Getty Images

The department advises Washington residents to follow three rules when consuming shellfish: Check the state's safety maps before harvesting, chill shellfish immediately and cook at 145 degrees Fahrenheit for 15 seconds to kill any bacteria.

The department also said shellfish should be gathered as the tide goes out, and any shellfish that has been exposed to the sun for more than an hour should not be harvested.

The heat wave that scorched the Pacific Northwest for several weeks last month sent temperatures to triple digits and had a devastating impact on marine life. Experts said that over 1 billion aquatic animals on the Pacific Coast—including snails, mussels and clams—may have been cooked to death in the heat.

After seeing scores of dead shellfish, Lissa Monberg, marketing director at Hama Hama, an oyster and tree farm in Lilliwaup, Washington, said, "They [the clams] look like they had just been cooked, like they were ready to eat," according to a Daily Mail report.

The heat wave was also responsible for over 100 human deaths in the region. Temperatures exceeded 100 degrees across several areas, with cities such as Portland, Oregon reaching a record-breaking 116.

Newsweek reached out to the Washington Department of Health for additional comment but did not hear back in time for publication.