DOCTOR'S VIEW ARCHIVE
ATLANTA-In the Four Corners area of Arizona, Utah,
Colorado, and New Mexico in the summer of 1993, there were reported
a cluster of patients that were afflicted by a deadly virus infection
involving the lungs which later was identified as a hantavirus.
The disease that affected these individuals has come to be known
as the hantavirus pulmonary syndrome (HPS).
Hantaviruses are a family of viruses that can lead
to bleeding in the lungs (hemorrhagic fever) and kidney damage.
Prior to the outbreak in the southwestern United States, they
were best known to cause disease from western Europe to eastern
A recent update of hantavirus infection by authors
from the Centers for Disease Control and Prevention (CDC) was
published in the medical journal HOSPITAL PRACTICE
Anne K. Pflieger, former coordinator of HPS U.S.
national surveillance, and Dr. Ali S. Khan, an epidemiologist
with the CDC, authored the article which outlined new features
of hantavirus disease as well as current thoughts on both treatment
The virus originally responsible for the outbreak
in the U.S. has now been named the Sin Nombre (SNV) virus. ("Sin
Nombre" means "without name" in Spanish!) This
virus is transmitted by deer mice which are most common in the
HPS cases totaled 160 as of May, 1997.
Symptoms of HPS include an early phase of fever for
3 to 5 days, with muscle aches, headaches, dizziness, rapid heart
rate, chills, nausea and vomiting. Patients can develop abdominal
pain. Next, shortness of breath rapidly becomes severe as the
lungs fill up with bloody fluid. Blood pressure drops and soon
patients require mechanical (artificial) breathing machines. Some
patients develop serious kidney disease. Death occurs by an average
of 5 days as a result of heart and lung failure.
The diagnosis of hantavirus infection is suspected
on finding the typical early phase symptoms without signs of other
infections (such as rashes, redness of the eyes or throat, and
swelling of the limbs or eyes) as well as the rapid lung disease
phase. Patients frequently have elevated white blood cell counts
with a particular type of unusual white cell in the blood called
an immunoblast. Chest x-rays, which may be normal initially, rapidly
demonstrate fluid build-up in the lungs.
The diagnosis is confirmed by specialized testing
of the blood for antibodies against the virus.
The treatment of HPS involves supporting the heart
and lungs as necessary while the body's immune system (own infection-
system) fights off the virus. Intravenous fluids are given to
correct abnormally low blood pressure.
Patients who survive recover completely without ongoing
There are now rare reports of patients with documented
acute hantavirus infection and minimal or mild symptoms.
The authors of the report emphasize that hantavirus
is spread to humans by inhaling virus particles or through direct
contact with rodent urine or excrement. The average incubation
period is 2 to 3 weeks (though periods as short as 6 days and
as long as 5 weeks have been reported).
The authors further emphasize that prevention of hantavirus disease is focused on avoiding exposure to rodents. Hantaviruses can be inactivated by bleach and household disinfectants. In cleaning out rodent-infested areas, it is recommended that the area first be wetted with disinfectant to minimize the risk of inhaling active virus particles. For big clean-out jobs, wearing mobile respirators with filters is recommended.