Hanta Virus Hantaviral Diseases

Hantaviral diseases are caused by a group of viruses called Hanta viruses. These viruses infect rodents all over the world and can be transmitted to humans. The infections vary in severity from relatively mild to severe illness.  These viruses may cause severe respiratory failure or attack the lining of the blood vessels, causing hypotensive shock (low blood pressure) and haemorrhaging. Hantaviral diseases include Haemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS).

For HFRS, the incubation period is generally 2 to 4 weeks with a range of a few days to 2 months. For HPS, the incubation period is approximately 2 weeks, with a range of a few days to 6 weeks.

Persons who have never been infected appear to be uniformly susceptible. Second attacks of Hantaviral diseases have not been documented.

For HFRS, symptoms include sudden onset of fever, lower back pain, kidney failure and bleeding. There are five stages of the disease: fever (fever), hypotensive (low blood pressure), oliguric (decreased or absent urine production), diuretic (increased urination) and convalescence (gradual recovery). The phase of fever lasts 3-7 days, accompanied by headache, malaise, and anorexia followed by severe abdominal and lower back pain, nausea and vomiting, facial redness and conjunctivitis pain. The hypotensive (low blood pressure) phase lasts from several hours to three days and involves sudden hypotension that can lead to hypotonic shock. The oliguric phase lasts 3 to 7 days with persistent nausea and vomiting. Severe bleeding can occur but the blood pressure returns to normal. Usually 5 to 15 percent of cases results in death, usually during the hypotensive and oliguric stage.

In HPS, symptoms include fever, muscle and gastrointestinal pains, followed by severe breathing problems and shock (loss of blood pressure). If left untreated, death occurs in 40 to 50 percent of cases.

HFRS infections may occur without developing symptoms. On the other hand, there have been no reports of HPS infection without symptoms, but the infection may be mild HPS.

There is no specific cure or treatment for HPS, other than intensive therapeutic care and treatment of the severe symptoms. Patients experiencing Hantaviral disease symptoms who may have come into contact with contaminated rodent saliva, droppings, or urine should seek medical care. Bed rest and early hospitalisation are crucial in both types of Hantaviral diseases.

Different types of hanta viruses are distributed in different parts of the world depending on the particular type and the rodent host. Different types of these viruses are found in China, the Korean peninsula, Russia, northern and western Europe, Argentina, Chile, Brasil, the United States, Canada, and Panama.