CDC Rats Out First U.S. Transmission of Seoul Hantavirus

— Case report documents two locally transmitted cases of this infection in D.C.

MedicalToday
A photo of a rat running on a wet city street.

Two service workers in Washington, D.C. contracted Seoul hantavirus in what is believed to be the first locally transmitted cases of the virus on U.S. soil.

Both patients presented with several days of chills, high fever, headache, diarrhea, and vomiting. Both had acute kidney injury and responded to supportive treatment, and were later discharged.

Rats seem to be the culprit in both cases, as Washington, D.C. has experienced increased calls to rodent control centers due to overpopulation, and Seoul hantavirus can be transmitted through aerosol exposure from rodent feces, saliva, or urine, noted Nivedita Ravi-Caldwell, DVM, of the CDC, and colleagues in the .

They said that the first patient developed the first case of hemophagocytic lymphohistiocytosis, "a potentially fatal systemic inflammatory syndrome," related to hantavirus infection in the U.S., and only the second worldwide. The first was .

"Although extremely rare, the two ... cases ... highlight the importance of physicians including hantavirus infection in their differential diagnoses in patients with compatible symptoms and history of animal exposure or travel and underscore the importance of reporting notifiable infectious disease cases to health departments for investigation and response," the researchers wrote.

The first patient, a 30-year-old man who worked in maintenance, presented in May 2018 to a Washington, D.C. healthcare facility with a 4-day history of symptoms, despite taking antipyretic medication. In addition to acute kidney injury over several days, he experienced hemoconcentration and thrombocytopenia. A week later, he had "signs consistent with hemophagocytic lymphohistiocytosis," including elevated levels of ferritin, triglycerides, and interleukin-2, as well as hemophagocytosis cells on a bone marrow biopsy.

The second patient, a 37-year-old man who worked as a dishwasher and plumber's assistant, presented in November 2018 to a Washington, D.C. emergency department with a 3-day history of symptoms, including myalgia and productive cough. Laboratory results showed elevated levels of hepatic transaminases.

Both patients had serology testing sent to CDC, showing hantavirus IgG and IgM titers that confirmed recent infection. Interestingly, Ravi-Caldwell's group noted that while the first patient had "frequent rodent sightings" at his workplace, the second was "unaware of exposure to rodents at work, at home, or during his commute."

The researchers explained that Norway rats can serve as reservoirs for Seoul hantavirus in the U.S., and "previous cases of hantavirus infection have been linked to wild or pet rodents."

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    Molly Walker is deputy managing editor and covers infectious diseases for . She is a 2020 J2 Achievement Award winner for her COVID-19 coverage.

Disclosures

The authors disclosed no conflicts of interest.

Primary Source

Morbidity and Mortality Weekly Report

Ravi-Caldwell N, et al "First reports of locally transmitted Seoul hantavirus infection -- District of Columbia, May 2018-December 2018" MMWR 2022; DOI: 10.15585/mmwr.mm7109a3.