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Hantavirus
From WikEM
Contents
Background
- Infection by the Sin Nombre virus can range from a nonspecific viral syndrome to the Hanta Pulmonary Syndrome (HPS), which is a severe respiratory manifestation with a high mortality rate
- Virus is transmitted by rodent urine, droppings, and saliva
- North American resevoir includes deer mouse, white footed mouse, and cotton rat
- Most cases of exposure US have occurred in southwest states
Clinical Features
- Incubation of 1-8 weeks after exposure to source
- Early symptoms are nonspecific and includes fever, fatigue, myalgia, and headache
- May also exhibit abdominal pain, nausea, vomiting, and diarrhea
Hantavirus Pulmonary Syndrome (HPS)
- Develops several days later, including shortness of breath and cough which rapidly progresses to noncardiogenic pulmonary edema and respiratory failure over 24-48 hours
- Hemodynamical instability may ensue in the late phase
- Symptoms that make HPS less likely includes conjunctival injection, petechiae, or rashes
Differential Diagnosis
- Wegener's granulomatosis
- Goodpasture's syndrome
Lower Respiratory Zoonotic Infections
- Psittacosis
- Anthrax (Bacillus anthracis)
- Brucellosis (Brucella species)
- Q fever (C. burnetti)
- Pasteurellosis (Pasteurella multocida)
- Melioidosis (Burkholderia pseudomallei)
- Rocky Mountain Spotted Fever (R. rickettsii)
- Pulmonic Plague (Yersinia pestis)
- Influenza A
- Hantavirus
Evaluation
- Serologic test using ELISA assays are the gold standard used by the CDC
- Most patients have antiviral IgM when symptoms are present, IgG may also be positive later on
Labs and Imaging
- Earliest lab abnormalities includes a decline in platelet count
- May also see an elevation in LDH, LFTs, and lactate later
- In HPS, the chest x-ray shows diffuse bilateral interstitial edema that may resemble ARDS
- Decrease in albumin along with increases in H/H marks is a markeer of capillary leak in HPS
- The diagnostic triad in HPS includes thrombocytopenia, left shifted granulocytes, and immunoblast >10% of total lympoid series
LA County Guidelines (for Yosemite outbreak)
Physicians with Patients Presenting with Concerns or Symptoms of Hantavirus Pulmonary Syndrome (HPS) after Visit to Yosemite National Park, June through August 2012.
- If a patient presents with concerns or non-specific symptoms well after 6 weeks from their stay in Yosemite, the patient most likely does not have hantavirus infection and testing for hantavirus infection is not indicated.
- If a patient presents with non-specific symptoms within 6 weeks of their stay in Yosemite and hantavirus infection is not suspected, the patient should be followed as clinically indicated, but testing for hantavirus infection is not indicated.
- If a patient presents with fever and mild symptoms suspicious for early hantavirus infection within 6 weeks of their stay in Yosemite, then a complete blood count (CBC) and chemistry panel should be done at baseline and hantavirus serology should be requested.
- If a patient presents with fever, shortness of breath, and other symptoms suggestive of HPS within 6 weeks of their stay in Yosemite, or if the patient in #3 above progresses to having symptoms and laboratory results suggestive of HPS, the patient should be transferred to a hospital emergency department for full evaluation.
- In California, hantavirus infections are reportable. Suspect cases in LA County should be reported to Acute Communicable Disease Control immediately so that we may assist with diagnostic testing.
Call 213-240-7941 (business hours) or 213-974-1234 (after hours) to speak to the duty physician.
Treatment
- Supportive care is the main form of treatment
- Aggressive respiratory support including early intubation and mechanical ventilation for HPS
- Hemodynamic support with early vasopressor administration
- Consider ECMO for refractory cases
Disposition
See Also
References
These are abbreviated public health recommendations. Please see the full state guidance document at [1]
- https://www.cdc.gov/hantavirus/index.html
- Hjelle B, et al. Hanta cardiopulmonary syndrome. UpToDate. Waltham, Mass.: UpToDate; 2017. www.uptodate.com. Accessed April 9, 2017.