15.21C: Hantavirus
- Paraphrase the causes of hantavirus and the phases of symptoms: febrile, hypotensive, oliguric, diuretic and convalescent
Hantaviruses are negative sense RNA viruses and are a relatively newly discovered genus in the Bunyaviridae family. The name hantavirus comes from the Hantaan River area in South Korea, where the first known strain – Hantaan virus (HTNV) – was isolated in 1978. Although some hantaviruses lead to potentially fatal diseases, such as hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS), not all are associated with human disease.
Human infections of hantaviruses have almost entirely been linked to human contact with rodent excrement, thus, rodent control is the primary strategy for preventing hantavirus infection. Human-to-human transmission (via urine, saliva, etc. ) may also occur, and has been recently reported with the Andes virus in South America.
HTNV is one of several hantaviruses that cause hemorrhagic fever with renal syndrome (HFRS), formerly known as Korean hemorrhagic fever. HFRS has an incubation time of two to four weeks in humans before symptoms of infection occur. The symptoms of HFRS can be split into five phases: febrile, hypotensive, oliguric, diuretic, and convalescent. The febrile phase begins two to three weeks after exposure, and normally lasts from three to seven days. Symptoms include fever, chills, diarrhea, malaise, headaches, nausea, abdominal and back pain, and respiratory and gastro-intestinal problems. These symptoms can resemble that of the flu. The hypotensive phase occurs when the blood platelet levels drop, and can lead to tachycardia and hypoxemia. This phase can last for 2 days. The oliguric phase begins with renal failure and proteinuria, and lasts from three to seven days. The diuretic phase is characterized by excessive urination (diuresis) of up to six liters per day, and can last for a couple of days up to a week. Although there is no known antiviral treatment for hantavirus, natural recovery is possible. The phase where symptoms begin to improve is the convalescent phase.
Hantavirus pulmonary syndrome (HPS) is another potentially fatal disease caused by hantavirus infection. Although rare, HPS is fatal in up to 60% of cases. HPS has been identified throughout the United States, and was first recognized in 1993 in the southwest where it was originally referred to as the “Four Corners disease. ” The symptoms are very similar to those of HFRS. Additionally, patients will develop difficulty breathing, coughing and shortness of breath, and may lead to cardiovascular shock.
Key Points
- The name hantavirus comes from the Hantaan River area in South Korea, where the first known strain – Hantaan virus (HTNV) – was isolated in 1978.
- Human infections of hantaviruses have almost entirely been linked to human contact with rodent excrement, thus, rodent control is the primary strategy for preventing hantavirus infection.
- There is no known antiviral treatment, but natural recovery from the virus is possible.
Key Terms
- hypoxemia : an abnormal deficiency in the concentration of oxygen in the blood, be it the partial pressure of oxygen (mm Hg), the content of oxygen (ml oxygen per dl of blood) or the percent saturation of the blood’s hemoglobin, singly or in combination.
- tachycardia : a rapid resting heart rate, especially one above 100 beats per minute.
- proteinuria : excessive protein in the urine.