Hantavirus Pulmonary Syndrome: Symptoms, Types, Causes and Treatment

Hantavirus Pulmonary Syndrome (HPS) is a rare but often deadly disease, known for its rapid progression and severe impact on the lungs and heart. First recognized in the United States in the early 1990s, HPS has since become a significant public health concern across the Americas. Understanding this disease—from its hallmark symptoms and different forms, to how it is contracted and the latest in treatment strategies—is crucial for anyone living in or visiting areas where hantaviruses are found. This article provides a comprehensive, evidence-based overview of HPS, using the latest research to guide you through each aspect of this dangerous syndrome.

Symptoms of Hantavirus Pulmonary Syndrome

Hantavirus Pulmonary Syndrome can begin innocuously, often resembling a standard flu. However, the illness can escalate swiftly, progressing to life-threatening respiratory distress. Early recognition of symptoms is essential for effective intervention and improved outcomes.

Early Signs	Progressive Symptoms	Severe Manifestations	Source(s)
Fever, myalgia	Non-productive cough, dyspnea	Acute pulmonary edema, shock	1 5 6 7
Headache	Gastrointestinal symptoms	Hypoxemia, cardiac dysfunction	1 4 5 6
Malaise	Tachypnea, tachycardia	Hypotension, respiratory failure	4 5 6 7

Table 1: Key Symptoms

The Course of HPS Symptoms

Prodromal Phase: The Early Signals

• Lasts 2–5 days
• Presents with non-specific, flu-like symptoms:
  • Fever and muscle aches (myalgia) are nearly universal
  • Headache, fatigue, and malaise are common
  • Many experience gastrointestinal complaints such as nausea, vomiting, or abdominal pain
• These early symptoms can easily be mistaken for other, less severe viral illnesses 1 5 6 7.

Cardiopulmonary Phase: The Danger Escalates

• Usually begins with a cough—initially dry, then possibly productive
• Rapid progression to:
  • Severe shortness of breath (dyspnea)
  • Tachypnea (rapid breathing) and tachycardia (fast heart rate)
  • Hypotension (low blood pressure) as the capillaries in the lungs leak fluid
• Pulmonary edema (fluid in the lungs) is the hallmark, leading to hypoxemia (low blood oxygen) and, often, shock 4 5 6 7.

Laboratory and Imaging Findings

• Blood tests may reveal:
  • Leukocytosis (elevated white blood cells) with a left shift (more immature cells)
  • Thrombocytopenia (low platelets)
  • Elevated hematocrit (concentrated red blood cells due to plasma leakage)
  • Abnormal liver enzymes (e.g., raised LDH, AST)
• Imaging (such as high-resolution CT scans) shows diffuse, bilateral ground-glass opacities and possible pleural effusions 5.

Severity and Fatality

• The disease can progress from mild symptoms to severe respiratory failure within hours or days.
• Many fatalities are due to refractory shock and multi-organ failure 4 6 7.

Types of Hantavirus Pulmonary Syndrome

While HPS is a specific syndrome, it is caused by several related viruses and can be distinguished from a related group of diseases found in other regions.

Syndrome Type	Geographic Distribution	Key Features	Source(s)
HPS (New World)	Americas	Pulmonary edema, high mortality	2 5 7
HFRS (Old World)	Europe, Asia	Renal failure, hemorrhage	2 5
Andes Virus HPS	South America	Person-to-person possible	5 11 14

Table 2: Hantavirus Syndromes

Hantavirus Disease Spectrum

Hantavirus Pulmonary Syndrome (HPS)

• Region: Primarily North and South America
• Viruses: Sin Nombre virus (North America), Andes virus (South America), and others
• Features: Sudden onset pulmonary edema, severe respiratory distress, and high fatality rates (30–50%) 2 5 7 11
• Transmission: Inhalation of aerosolized rodent excreta; Andes virus can occasionally spread from person to person 5 11 14

Hemorrhagic Fever with Renal Syndrome (HFRS)

• Region: Europe and Asia ("Old World" hantaviruses)
• Viruses: Hantaan, Seoul, Dobrava, Puumala viruses, etc.
• Features: Prominent kidney involvement, hemorrhages, and hypotension
• Distinct from HPS: Rarely involves the lungs; renal failure is the main threat 2 5

Notable HPS Variants

• Andes Virus HPS:
  • Found in South America, especially Argentina and Chile
  • Unique: Only hantavirus with documented person-to-person transmission 5 11 14
  • Tends to affect younger adults, often related to occupational or outdoor exposure

Causes of Hantavirus Pulmonary Syndrome

HPS is a zoonotic disease—meaning it is transmitted from animals to humans. Understanding its origins and transmission pathways is key to preventing infection.

Cause/Reservoir	Transmission Route	Risk Factors	Source(s)
Rodent hosts	Inhalation of aerosolized excreta	Rural/occupational exposure	5 8 9 10
Sin Nombre virus (USA)	Rodent urine, droppings, saliva	Cleaning, farming, camping	5 9 10
Andes virus (S. America)	Occasionally person-to-person	Close contact with patients	5 11 14

Table 3: Causes and Transmission

How HPS Develops

Rodents: The Natural Reservoirs

• Wild rodents, especially deer mice (Peromyscus maniculatus) in North America, are the main carriers of hantaviruses 8 9 10
• In South America, other rodents, such as those carrying the Andes virus, act as reservoirs

Transmission to Humans

• Primary Route: Inhalation of tiny, aerosolized particles from rodent urine, feces, or saliva 5 8 9
• Scenarios: Cleaning rodent-infested buildings, farming, camping, or other outdoor activities
• Person-to-Person Transmission: Very rare, but documented with Andes virus infections 5 11 14

Incubation Period

• The time from exposure to symptoms is typically 9 to 33 days, with a median of about two weeks 10

Pathogenesis: What Happens in the Body

• Hantaviruses infect the endothelial cells lining the capillaries, especially in the lungs 7 12
• This infection increases vascular permeability—capillaries leak fluid into the lung tissue, causing edema
• The immune response, particularly the release of cytokines such as VEGF, further disrupts the endothelial barrier 12
• The result: rapid accumulation of fluid in the lungs, leading to respiratory failure and, in severe cases, shock 4 7 12

Risk Factors

• Living or working in rural areas with high rodent populations
• Occupational exposure (e.g., farmers, construction workers, outdoor enthusiasts)
• Contact with rodent-infested buildings or materials

Treatment of Hantavirus Pulmonary Syndrome

There is no specific cure for HPS, but advances in supportive care and experimental therapies are improving survival rates. Early recognition and aggressive intervention are crucial.

Therapy Type	Approach/Description	Effectiveness / Notes	Source(s)
Supportive care	Oxygen, ventilation, fluids	Mainstay, improves outcomes	4 5 13
ECMO	Extracorporeal membrane oxygenation	For severe cardiopulmonary failure	15
Antivirals (Favipiravir)	Investigational, post-exposure	Promising in animal models	11
Immunotherapy	Convalescent plasma, duck IgY	Experimental, post-exposure	14

Table 4: Treatment Strategies

Current Management Strategies

Supportive and Intensive Care

• Mainstay of Treatment: There are no approved antivirals for HPS, so management focuses on:
  • Careful monitoring and support of breathing and blood pressure
  • Oxygen supplementation or mechanical ventilation if needed
  • Fluid management to avoid worsening pulmonary edema 4 5 13
• Early transfer to intensive care is associated with better survival

Extracorporeal Membrane Oxygenation (ECMO)

• For severe cases: ECMO can be life-saving in patients with refractory respiratory and cardiac failure 15
• How it works: Blood is circulated through an external machine that oxygenates it and removes carbon dioxide, allowing the lungs to rest
• Outcomes: Some patients with otherwise fatal HPS have survived after ECMO support 15

Experimental and Investigational Therapies

• Antivirals:
  • Favipiravir: Shown to inhibit hantaviruses in laboratory and animal models; shows promise for post-exposure prophylaxis and early treatment 11
• Immunotherapy:
  • Convalescent plasma: Antibodies from HPS survivors may provide benefit if given early 14
  • Duck IgY antibodies: Produced via DNA vaccine technology; effective in animal models and a scalable potential therapy 14

No Vaccine—Yet

• There is currently no approved vaccine for HPS, although research is ongoing 14

Prevention

• The best "treatment" is prevention:
  • Reduce exposure to rodents and their droppings
  • Seal homes and outbuildings, use protective equipment when cleaning
  • Public health education and rodent control are essential in endemic areas

Conclusion

Hantavirus Pulmonary Syndrome remains a serious, often fatal disease, but early awareness and medical advances are improving outcomes. Here’s what you need to remember:

• Early symptoms are non-specific and resemble flu, making vigilance crucial in at-risk areas.
• The disease can progress rapidly, with hallmark signs being pulmonary edema and shock.
• HPS is distinct from related hantavirus diseases, such as HFRS, which is more common in Europe and Asia.
• Rodents are the main source of infection, so prevention relies on minimizing contact with their excreta—especially in rural or outdoor settings.
• Treatment is primarily supportive, but advanced interventions like ECMO and experimental therapies are offering new hope.
• No vaccine exists yet, but research into antivirals and immunotherapies is ongoing.

Stay informed, take precautions in rodent-prone environments, and seek medical attention promptly if symptoms develop after potential exposure.

Key Points:

• HPS is a rapidly progressive, often fatal respiratory disease linked to rodent-borne hantaviruses 1 2 5 6 7.
• Key symptoms include fever, myalgia, cough, and sudden respiratory distress 1 4 5 6 7.
• The disease is most common in the Americas and is caused by inhalation of aerosolized rodent excreta 5 8 9 10.
• Supportive care and intensive interventions like ECMO are the mainstays of treatment 4 13 15.
• Prevention and early recognition remain the most effective strategies against HPS.