The Centers for Disease Control and Prevention (CDC) announced reports of two trichinellosis outbreaks in Alaska related to the consumption of walrus meat. These are the first multiple-case outbreaks of walrus-related trichinellosis in Alaska since 1992.
The First Outbreak
The CDC detailed the multiple cases of walrus-related trichinellosis (trichinosis) in their Morbidity and Mortality Weekly Report (MMWR). Between July 2016 and May 2017, the Alaska Division of Public Health (ADPH) conducted an investigation on the outbreaks that were associated with the consumption of raw or undercooked walrus meat.
The first patient in the first outbreak was an adolescent female who experienced myalgia, fever, rashes, severe lower extremity edema and pain, and difficulty walking that began on Aug. 15, 2016. Her adolescent brother and her father who accompanied her to the clinic were also evaluated for the symptoms of the illness and were found to have signs of a parasitic infection.
Blood tests reveal that the adolescent girl and her father were positive for trichinosis, while her brother was considered a probable patient. All three had consumed walrus meat of medium doneness on July 17 of the same year.
On Sept. 19, the adolescent girl's aunt and uncle were also confirmed to have trichinosis after consuming raw walrus meat.
The Second Outbreak
The second outbreak occurred in a coastal community just approximately 100 miles from where the first outbreak occurred. An adult male admitted to the Norton Sound Regional Hospital on May 12 was confirmed to be the first patient of the second outbreak. Soon, four other adults were suspected to have trichinosis as well.
The individuals involved in the second outbreak were members of two households who hunted and harvested walrus meat together and likely shared a meal of undercooked walrus meat. Although all of them exhibited symptoms of the infection, only two tested positive for trichinosis, while the other three were considered as probable cases.
What Is Trichinellosis?
Signs and symptoms such as nausea, neurologic complications, and cardiopulmonary impairment typically occur one or two weeks after ingesting the infected meat. Further, the weakness and muscle soreness may persist for months even after the other symptoms have subsided.
Forty-one percent of all trichinosis cases in Alaska since 1975 have been linked to the consumption of walrus meat, but that number has since seen a sharp decline in recent years due to unknown reasons.
Other reported sources of trichinosis are black bears, grizzly bears, polar bears, and seals.