Jonathan L. Temte, MD, PhD
WMJ. 2026;125(2):233. Published June 2, 2026.
To the Editor:
Recent attention has been directed to a cluster of hantavirus cases linked to a cruise ship, and the aftermath of global concern and response.1 This cluster has been identified as resulting from the South American virus species (Orthohantavirus andesense). Whereas hantavirus infection has been, and likely will be a rare event in the United States – with 890 cases reported between 1993 and 20232 – rare events are worthy of careful consideration.
The openness of the Wisconsin Medical Journal (WMJ) to the publication of case reports, even if uncommon in clinical practice, underscores the essential role of a statewide medical journal. In 1997, the WMJ published a case report of hantavirus pulmonary syndrome (HPS) occurring in Wisconsin in May 1996.3 Complete clinical information was provided though a succinct review of the symptoms, examination, laboratory and radiographic findings, and the clinical course of this fatal case.
This case is illustrative of rare events encountered by clinicians. On presentation, the patient reported common, nonspecific symptoms of fever, myalgias, and cough. A broad-spectrum antibiotic was prescribed; the patient returned with worsening cough and shortness of breath and was admitted to an outlying hospital, then transferred to a tertiary care hospital. Diagnosis was made through reverse transcriptase polymerase chain reaction performed on necropsy tissues at the Centers for Disease Control and Prevention.3
During 2002, I worked with a medical student identifying the primary care differential diagnosis of inhalational anthrax, another extremely rare infection.4 We surveyed a random, national sample of practicing family physicians and documented 35 distinct diagnostic categories for inhalational anthrax. Seven diagnostic categories – pneumonia, influenza, viral syndrome, septicemia, bronchitis, central nervous system (CNS) infection, and gastroenteritis – accounted for 86.1% of all diagnoses.
The take-home lesson is thus: rare things usually present in common ways. Four-legged equines in the US are almost entirely horses and not zebras. As the authors of the first Wisconsin HPS case noted: “Differentiating HPS from other respiratory infections can be difficult, given the nonspecific symptoms associated with the prodromal stage.”3 In addition, they concluded, “Recognition of the clinical pattern, a history of rodent exposure, and a high index of suspicion are the keys to making the diagnosis.”3
Rare events are detected by astute frontline physicians and laboratorians providing usual medical care to their patients as shown by Wisconsin’s first HPS case. Accordingly, clinicians need to consider, with higher acuity, those troubling cases that are out of season, out of range, and out of context.
REFERENCES
- World Health Organization. Disease Outbreak News. Hantavirus cluster linked to cruise ship travel, Multi-country. May 4, 2026. Accessed May 13, 2026. https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON599
- Centers for Disease Control and Prevention. Reported cases of hantavirus disease. April 23, 2026. Accessed May 13, 2026. https://www.cdc.gov/hantavirus/data-research/cases/index.html
- Kahl BS, Kumar A, Hale SJ, Hart MN, Badr S. Hantavirus pulmonary syndrome in Wisconsin. WMJ. 1997;96(2):33-36. PMID 9046232.
- Temte JL, Zinkel AR. The primary care differential diagnosis of inhalational anthrax. Ann Fam Med. 2004;2(5):438-444. doi:10.1370/afm.125