Acquired by inhalation of contaminated rodent urine or feces, and possibly by bites
In North America, it is carried by the deer mouse (most common in NA, transmits Sin Nombre), meadow vole (also present, transmits Prospect Hill), and white-footed mouse (also present, transmits New York); also cotton rat, rice rat, shrew, and mole
Essentially worldwide, though New World viruses tend to cause hantavirus pulmonary syndrome and Old World viruses tend to cause hemorrhagic fever with renal syndrome
In Canada, no cases have been described east of Manitoba
No cases of HPS have been described in Ontario since it became reportable in 2001
About 4 or 5 new cases annually from southern rural parts of BC, Alberta, Saskatchewan, and Manitoba
Incidence of HPS peaks in summer months (in North America)
Clinical Manifestations
Incubation period of 14 days (range 5 to 42 days)
Hemorrhagic Fever With Renal Syndrome (HFRS)
Caused by Old World hantaviruses, such as Hantaan, Dobrava, Seoul, Puumala, and other Old World hantaviruses
Also headache, abdominal pain, low back pain, dizziness, and blurred vision
Can have conjunctival injection and petechiae on upper trunk and soft palate
Febrile phase lasts 4 to 7 days of acute, severe illness, followed by hypotensive, oliguric, and polyuric phases
Leukocytosis and thrombocytopenia seen on CBC
Mortality up to 5%
Hantavirus Pulmonary Syndrome (HPS)
Caused by New World hantaviruses such as Sin Nombre, Bayou, and Black Creek Canal
Incubation for 2 to 3 weeks
Prodromal phase
Lasts 2 to 8 days
Nonspecific syndrome of fevers, chills, myalgias (including severe myalgias)
Continues to develop, with headache, vomiting, weakness, abdominal pain (can be severe), and sometimes diarrhea
Typically does not include upper respiratory symptoms, except cough and, in children, pharyngitis
Some strains can cause conjunctivitis, facial flushing, and a petechial rash
Thrombocytopenia is common, and can see elevated LDH
Cardiopulmonary phase
Characterized by capillary leak
Usually characterized by non-productive cough, with rapid onset of shock, coagulopathy, pulmonary edema (including ARDS), bronchorrhea, and arrhythmias
Chest x-ray almost always shows bilateral infiltrates suggestive of ARDS
Elevated hematocrit (from third-spacing), leukocytosis, atypical lymphocytes, thrombocytopenia (with severity predicting mortality), prolonged PTT, and mild elevations in AST and LDH
Triad of a left shift, lymphoid blasts >10%, and thrombocytopenia, is a helpful diagnostic triad
Oliguric and diuretic phases
Oliguria can last 3 to 7 days, followed by diuresis of variable duration
Creatinine may be elevated, but not as severe as HFRS
Convalescent phase
Initial recovery can be dramatically fast (over days), but complete recovery can be slow
