Hantavirus Infection

Hantavirus Infection overview and Definition

Hantavirus pulmonary syndrome is an infectious disease characterized by flu-like symptoms that can progress rapidly to potentially life-threatening breathing problems.

Several types of hantaviruses can cause hantavirus pulmonary syndrome. They are carried by several types of rodents, particularly the deer mouse. You become infected primarily by breathing air infected with hantaviruses that are shed in rodent urine and droppings

Routes of Transmission

People who become infected with the North American strain of hantavirus pulmonary syndrome aren't contagious to other people. However, certain outbreaks in South America have shown evidence of being transmitted from person to person, which illustrates variation across strains in different regions.

Clinical signs & symptoms

  • Phase 1: Incubation:The virus is inhaled into the lungs. Immune cells ingest the virus, which is then transported through the bloodstream to other organs. This phase lasts 2 to 3 weeks, but there are no symptoms, yet.
  • Phase 2: Fever, dry cough, body aches, headaches, diarrhea, and abdominal pain appear. Heart and lung failure can develop during this phase, as well. Blood vessels become leaky, and fluid builds up in the lungs. Bleeding and heart failure follow. This phase lasts 2 to 8 days, and all these changes lead to shock and often death.
  • Phase 3: Changes in urination:Patients may alternate between making a lot of urine and making very little urine.
  • Phase 4: Recovery: Patients who survive the first 3 phases begin to improve, and their organs start to function properly again. It may take several weeks before patients feel completely well again. The symptoms of HPS seem to disappear as quickly and dramatically as they first appeared.

Early Symptoms

Early symptoms include fatigue, fever and muscle aches, especially in the large muscle groups—thighs, hips, back, and sometimes shoulders. These symptoms are universal.

There may also be headaches, dizziness, chills, and abdominal problems, such as nausea, vomiting, diarrhea, and abdominal pain. About half of all HPS patients experience these symptoms.

Late Symptoms

Four to 10 days after the initial phase of illness, the late symptoms of HPS appear. These include coughing and shortness of breath and feeling of tightdness in the chest.

Differential Diagnosis

Chest Xray:

The chest x ray predicts any abnormal area in the lungs

Computed tomography:

It reveals the slice of the lung. It uses both the combination of x ray and computer aided device.

It helps to analyse the size, shape and position of any lung tumour and also it helps in the detection of enlarged lymph nodes.

It also looks for any masses in the adrenal gland, liver, brain and other organs.

 CT guided needle Biopsy:

CT scan might be used to guide a biopsy needle into this  area to get the tissue for lung and further investigations are made.

MRI scan:

It uses the soft tissue image of the organ. It uses the both the magnet and radiowaves and aids in the view of soft tissues of the internal organs.

Immunosorbent assay- detect the virus specific IgM or IgG antibodies.

Greater than fourfold rise in titer between acute and convalescent sera  and  cerebo spinal fluid containing virus specific IgG or IgM or both are the diagnostic features.

Real time polymerase chain reaction (RT-PCR)- is valuable in the early confirmation of arbovirus infections, particularly chikungunya. However, the value of RT-PCR is limited to diagnosis in the viraemic phase, with later infection requiring serology.

Direct immunofluorescence assay -to detect chikungunya IgM has a high sensitivity and specificity and is used in the latter stages.However, the use of these tests in the tropics may be limited by financial constraints.

A normal erythrocyte sedimentation rate-  it is defined as the rate of red blood cell which are termed as erythrocytes and their deposition or sedimentation rate. The normal erythrocyte sedimentation rate is 0-22mm/hr.



The prognosis of 80% can be achieved if the treatment can be started earlier.


The best treatment for HPS is to prevent infection in the first place. To do that, minimize your exposure to rodents:

  • Seal up (using cement or other patching material) holes or cracks through which rodents can enter your home or work environment. Remember, they can get through much smaller openings than you may think!
  • Identify potential nesting sites, and clean up debris, clear bushes, and trap rodents to remove them.
  • Open and air out any rodent-infested spaces that have been shut up for a long time before you enter them.
  • If you know of an area heavily infested with rodents, contact state or federal health officials about cleaning the area up.