Hantavirus: A Deadly Threat from Rodents to Humans

Hantavirus is a virus that can cause severe infections in humans. It is a zoonotic disease primarily carried by mice and other rodents. When transmitted to humans, it can lead to fatal respiratory issues, blood system complications, and kidney failure.

The World Health Organization (WHO) is currently monitoring a Hantavirus outbreak linked to cruise ship passengers traveling between Argentina and Antarctica, where three fatalities have been reported. Of particular concern is the Andes strain, which is rare but has been reported to spread from person to person.

How is Hantavirus Transmitted?

The natural reservoir for Hantavirus is mice and rodents. Infected rodents do not show symptoms but can shed the virus in their urine, feces, and saliva for several weeks or months. Humans can be infected through:

• Inhalation of aerosolized droplets or dust contaminated with rodent urine, feces, or saliva (the most common route).
• Consuming food or water contaminated by rodent excretions.
• Direct contact of the virus with broken skin, scratches, or mucous membranes (such as the eyes).
• Being bitten or scratched by an infected rodent.

What are the Symptoms of Hantavirus Infection?

Once inhaled, the virus travels to the lower bronchioles of the lungs, then spreads into the bloodstream and lymphatic system. This causes inflammation and vascular leakage throughout the body, leading to fluid accumulation in the lungs and kidney damage. The incubation period is typically 1-8 weeks. Symptoms generally fall into two main categories depending on the viral strain:

1. Hantavirus Pulmonary Syndrome (HPS)

Commonly found in the Americas, with a high mortality rate of approximately 38-40%.

• Early Stage: High fever, chills, muscle aches (especially in the back and thighs), headache, nausea, vomiting, and diarrhea.
• Critical Stage: After 4-10 days, severe coughing and shortness of breath occur due to pulmonary edema (fluid in the lungs), followed by low blood pressure, heart arrhythmias, and potential shock.

2. Hemorrhagic Fever with Renal Syndrome (HFRS)

Commonly found in Asia (including Thailand) and Europe, with a mortality rate of about 1-15%.

• Early Stage: Sudden high fever, headache, back pain, nausea, vomiting, and facial/eye flushing or petechiae (tiny red spots on the skin).
• Critical Stage: Abnormal bleeding, vomiting blood, black stools, acute kidney failure, inability to urinate, edema, and potential shock from blood loss.

How is Hantavirus Diagnosed?

Diagnosis is performed through blood tests to detect antibodies against the virus or by identifying the virus’s genetic material using the RT-PCR method.

Treatment for Hantavirus

Currently, there is no specific treatment for Hantavirus infection. Treatment focuses on supportive care based on symptoms:

• Oxygen therapy and mechanical ventilation for patients with respiratory failure. In severe cases, ECMO (extracorporeal membrane oxygenation) may be required.
• Management of shock using intravenous fluids and vasopressors to maintain blood pressure.
• Maintaining fluid balance; temporary dialysis may be necessary if acute kidney failure occurs.
• Treatment of abnormal bleeding complications.

How to Prevent Hantavirus Infection?

There is currently no vaccine available. The best prevention is rodent control:

• Eliminate rodent habitats by keeping your home clean and sealing gaps where rodents might enter.
• If rodent droppings are found, spray them with disinfectant or a bleach solution before cleaning to prevent the virus from becoming airborne.
• Store food in tightly sealed containers and dispose of food scraps in bins with secure lids.
• Wear masks and gloves when cleaning areas that may be infested with rodents.
• Sleep on elevated beds and avoid sleeping directly on the floor.

Summary of Hantavirus Situation and Global Surveillance

In Thailand, Hantavirus has been detected in field mice and house rats, but human cases remain extremely rare. Generally, Hantavirus does not spread from person to person, except for the rare Andes strain found in South America.