Hantavirus pulmonary syndrome is a rare infectious disease that starts with flu-like symptoms and quickly progresses to a more serious illness. It can cause life-threatening heart and lung problems. The disease is also called hantavirus cardiopulmonary syndrome. Every spring and fall, rural areas in the western United States are at high risk for hantavirus pulmonary syndrome.
▸Hantavirus is a virus that can cause serious illness and death in people worldwide.
▸Infected rodents spread the virus in their urine, feces, and saliva.
▸Some hantaviruses cause hantavirus pulmonary syndrome (HPS).
▸The early symptoms of HPS in people are similar to many other respiratory illnesses, so HPS can be difficult to diagnose when it occurs.
▸Healthcare providers should test patients for hantavirus if they have symptoms consistent with hantavirus syndrome (HPS) and have had contact with rodents.
Overview
Hantaviruses are spread through rodent body fluids and excreta. People are infected with hantaviruses primarily by inhaling the virus. Most hantaviruses found in North, Central, and South America can cause Hantavirus Pulmonary Syndrome (HPS). Andes viruses found in South America have been reported to have spread from person to person.
Different hantaviruses are found in the United States. Most of them cause HPS, which primarily affects the lungs. Non-HPS hantavirus infections can also occur, in which patients experience nonspecific viral symptoms but no cardiopulmonary symptoms. Hantaviruses found throughout the United States are not spread from person to person.
HPS initially causes flu-like symptoms, which then gradually become more severe and patients have difficulty breathing. People with HPS should start treatment early to increase their chances of recovery. Nearly 40% of people infected with HPS die. (https://tinyurl.com/y348872s)
How it's spread
Each hantavirus has a primary rodent that carries the disease. In the United States, the most common hantavirus that causes HPS is spread by deer mice.
People can get hantavirus if they come into contact with urine, feces, or saliva from rodents that carry the virus. This can happen when people:
▸Breathe in air contaminated with hantavirus while cleaning up rodent waste.
▸Touch a contaminated object and then touch their nose or mouth.
▸Be bitten or scratched by an infected rodent.
▸Eat food contaminated with hantavirus.
Cases often occur in rural areas where forests, fields, and farms provide habitat for rodents. Rodents can get into houses and barns, where they leave urine or feces.
No cases of dogs and cats being infected with hantavirus have been found in the United States. Pets may bring infected rodents to people or into homes.
Testing and Diagnosis
Evaluating patients for hantavirus infection can be difficult in the early stages of infection because symptoms are nonspecific and similar to many other viral infections, such as influenza, Legionnaires’ disease, leptospirosis, mycoplasma, and Q fever. Because hantavirus resembles these infections, blood testing is often the only way to formally diagnose.
To diagnose hantavirus or HPS, clinicians should know:
▸Illness symptoms and rodent exposure history
▸Virus identification testing guidelines
▸How to request testing support from CDC, if needed, and
▸How to report a case to CDC
If a patient has symptoms consistent with HPS and may have been exposed to rodents, clinicians should contact their state, tribal, local, or territorial health department.
CDC can provide counseling or diagnostic testing. Clinicians can call the CDC Emergency Operations Center at 770-488-7100 and ask for the hantavirus epidemiologist on duty.
Testing
CDC uses an enzyme-linked immunosorbent assay (ELISA) to detect IgM antibodies and diagnose acute hantavirus infection. This diagnostic test is used to diagnose HPS and HFRS. Diagnostic testing is available at the following locations:
▸CDC
▸State laboratories running CDC-developed tests
▸State public health laboratories using other diagnostic tests
▸Commercial laboratories
The reporting criteria for positive hantavirus cases are based on the national case definition, which includes clinical symptoms (HPS or non-HPS) and acute laboratory diagnostic results, such as:
▸IgM positive
▸IgG positive with elevated titers
▸Immunohistochemistry positive, or
▸PCR positive
Treatment and recovery
There is no specific treatment for hantavirus infection. If hantavirus syndrome is suspected, the patient needs to receive emergency medical care immediately, preferably in an intensive care unit, even before a diagnosis is made.
Early intensive care is essential because patients with sudden acute illness can quickly become seriously ill and die. If the patient is extremely distressed, treatment may be less effective.
Patient management should include:
▸ Monitoring and regulation of cardiac function
▸ Careful fluid administration
▸ Provision of supplemental oxygen
▸ Intubation and ventilation, if needed
Patients with suspected HPS should receive appropriate broad-spectrum antibiotics, even if you are still awaiting a diagnosis. Care should also include antipyretics and analgesics.
Although HPS can be quite severe, critical illness is brief. The cardiopulmonary dysfunction seen in HPS is likely due to circulating inflammatory mediators. Autopsies performed on fatal cases have not revealed significant tissue damage.
Extracorporeal membrane oxygenation (ECMO) therapy initiated at the earliest signs of decompensation has resulted in an 80% survival rate despite cardiopulmonary failure.
Within 24 hours of initial evaluation, most patients with HPS develop some degree of hypotension. They also develop progressive signs of pulmonary edema and hypoxia, often requiring mechanical ventilation.
Patients with life-threatening infections often develop severe myocardial depression and develop sinus bradycardia followed by electromechanical dissociation, ventricular tachycardia, or fibrillation.
For HPS patients, poor prognostic indicators include plasma lactate greater than 4.0 mmol/L or cardiac index less than 2.2 L/min/m2.
Pulmonary edema and pleural effusion are common, and multiple organ dysfunction syndrome is less common, but HPS patients sometimes have mild renal impairment, and survivors have polyuria during the recovery period and their condition improves rapidly.
