- Dr. Weeks served with the U.S. Air Force Medical Corps
and was hospital commander at Bitburg Air Force Base. He is a lecturer
on infectious diseases and biological warfare. ---
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- A significant problem in dealing with biological attacks
is that we may not be aware that we have been subjected to a biological
attack until several days or weeks later.
-
- There would be no warning until the first deaths had
taken place and the medical community had properly ascertained the cause
of death.
-
- One such biological agent physicians may not recognize
and correctly diagnose the first victims as having is Ebola or a related
viral hemorrhagic fever (VHF) until the laboratory data begins to accumulate.
-
- Ebola breakouts in Africa have been widely reported.
But Ebola's use as a bio weapon has not.
-
- A small amount of Ebola (variety Marburg) released into
the subways of New York, Boston or Washington, D.C., could result in hundreds
of thousands of deaths within days.
-
- Within the last 25 years, scientists in Russia, Iraq
and several other countries have created genetically modified organisms,
including plague, anthrax, tularemia and glanders, that are resistant to
most antibiotics.
-
- The Russian strains of weaponized anthrax are resistant
to penicillin and tetracycline, and probably other antibiotics also.
-
- Bacteria, viruses and toxins have been modified to enhance
virulence and infectivity, paving the way for development of pathogens
with resistance to vaccines.
-
- Viruses such as Ebola have no known effective treatment
at this time, and a vaccine has not been developed.
-
- Wearing a chemical or fireman's mask, or even a surgical
mask may possibly offer some protection to prevent contracting the disease,
which is caught by inhaling the virus or contact with a patient's blood
or body fluids.
-
- However, it is highly contagious with a very small number
of viruses inhaled, and the chances of contracting the disease with close
and prolonged contact with acutely ill patient shedding viruses is high.
-
- Caregivers are in serious jeopardy without the Level
4 biohazard suits.
-
- In 1994, President Clinton declared a state of emergency
relating to weapons of mass destruction, which has been renewed every year.
-
- The FBI, DOD, USAMRIID and the CDC in Atlanta, along
with State Health agencies have been equipped to investigate and identify
biological and chemical agents that could be used in an attack.
-
- However, delays of several days may be inevitable, and
many deaths could occur before the alarm is sounded.
-
- Ebola is a hemorrhagic filovirus shaped like a hockey
stick, and belongs to one of four groups of the category, family Filoviridae:
Ebola hemorrhagic fever was first recognized in the western equatorial
province of the Sudan and the nearby region of Zaire in 1976.
-
- A second outbreak occurred in Sudan in 1979, and in 1995
a large outbreak (316 cases) developed in Kikwit, Zaire, from a single
index case.
-
- Subsequent epidemics have occurred in Gabon and the Ivory
Coast. The African strains cause severe disease and death. It is not known
why this disease appears infrequently.
-
- A related virus (Ebola Reston) was isolated from monkeys
imported into the United States from the Philippines in 1989, and and they
subsequently developed hemorrhagic fever. While subclinical infections
occurred among exposed animal handlers, Ebola Reston has not been identified
as a human pathogen.
-
- Ebola Marburg epidemics have occurred on six occasions:
five times in Africa, and once in Europe.
-
- The first recognized outbreak occurred in Marburg, Germany,
and Yugoslavia, among people exposed to African green monkeys, and resulted
in 31 cases and 7 deaths.
-
- Filoviruses can be spread from human to human by direct
contact with infected blood, secretions, organs, or semen.
-
- Dr. Ken Alibek believes that Russia may have developed
a strain that is transmissible via the respiratory route. The natural reservoirs
of the filoviruses are unknown, although some suspect a species of bat
in Africa with exposure to bat droppings.
-
- Clinical Features
-
- The clinical syndrome that these viruses may cause is
generally referred to as viral hemorrhagic fever, or VHF.
-
- The target organ in the VHF syndrome mainly small capillary
vessels. Attachment of the virus to the lining cells results in leakage
of blood and serum into the surrounding tissue.
-
- Antibody directed against the virus enhances uptake by
white corpuscles (WBC), and then the cell is dissolved releasing body defense
mechanisms called cytokines. The dissolved WBC results in the release of
pro-inflammatory cytokines, pro-coagulants, and anticoagulants, which in
turn result in vascular injury to the capillary lining cells and marked
permeability (leakage), with complement activation, and a systemic coagulation
defect (DIC).
-
- The body actually begins to dissolve before your eyes,
rapidly becoming a skin sack of bloody fluid and bone.
-
- Common symptoms beginning 2-3 days after exposure are
fever, headache, confusion, muscle pain, and prostration. Physical examination
may reveal only conjunctival redness, mild hypotension, flushing, and small
skin hemorrhages (petichiae).
-
- Full-blown VHF typically evolves to shock and generalized
mucous membrane hemorrhage, and often is accompanied by evidence of lung,
bone marrow, kidney, and neurologic involvement. Kidney failure is proportional
to general capillary damage.
-
- Most varieties of hemorrhagic fever are notable for pulmonary
(lung) involvement, and a biphasic illness with subsequent brain damage.
With involvement of lung capillaries, there is rapidly progressive and
severe pulmonary capillary leak, which presents as ARDS or Adult Respiratory
Distress Syndrome, similar to what is seen with Hantavirus.
-
- Subclinical or clinical pulmonary edema occurs very commonly
in Ebola.
-
- Mortality may be substantial, ranging from 50 to 90 percent
among Ebola victims.
-
- Diagnosis
-
- Congo-Crimean Fever is a hemorrhagic fever resembling
Ebola seen in Afghanistan, but it is caused by either tick bites or person
to person exposure.
-
- Large numbers of military personnel presenting with VHF
manifestations in the same geographic area over a short time period should
lead treating medical care providers to suspect either a natural outbreak
in an endemic setting, or possibly a biowarfare attack, particularly if
this type of disease does not occur naturally in the local area.
-
- VHF should be suspected in any patient presenting with
a severe febrile illness and evidence of vascular involvement (postural
hypotension--low BP, small skin hemorrhages, easy bleeding, flushing of
face and chest, non-dependent edema) who has traveled to an area where
the virus is known to occur, or where intelligence information suggests
a biological warfare threat.
-
- Symptoms and signs suggesting additional organ system
involvement are common (headache, photophobia, pharyngitis, cough, nausea
or vomiting, diarrhea, constipation, abdominal pain, tingling , dizziness,
confusion, tremor), but usually do not dominate the picture with the exceptions
listed above under "Clinical Features."
-
- The clinical laboratory can be very helpful. Definitive
diagnosis in an individual case rests on specific virologic diagnosis.
Diagnosis by virus cultivation and identification will require 3 to 10
days or longer.
-
- Specialized microbiologic containment is required for
safe handling of these viruses. Appropriate precautions should be observed
in collection, handling, shipping, and processing of diagnostic samples.
Both the Centers for Disease Control and Prevention (CDC, Atlanta, Georgia)
and the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID,
Frederick, Maryland) have diagnostic laboratories functioning at the highest
(BL-4 or P-4) containment level.
-
- Medical Management
-
- General principles of supportive care apply to pulse,
blood pressure , blood counts, and pulmonary, and neurologic manifestations
of VHF, regardless of the specific causative agent. Only intensive care
will save the most severely ill patients.
-
- Health care providers employing vigorous IV fluid resuscitation
of hypotensive patients must be mindful of the propensity of some VHFs
for pulmonary capillary leak. Pressor agents are frequently required to
support blood pressure. Antiviral agents such as ribavirin and fresh or
frozen plasma may be of some benefit to replace some of the consumed clotting
factors.
-
- Isolation and Containment
-
- These viruses pose special challenges for hospital infection
control. VHF patients generally have significant quantities of virus in
blood and often other secretions. Special caution must be exercised in
handling sharps, needles, and other potential sources of parenteral exposure
from contact with the patient's blood.
-
- Strict adherence to standard precautions will prevent
nosocomial (in hospital) transmission of most VHFs. Lassa Fever, Congo-Crimean
Fever, Ebola, and Marburg viruses may be particularly prone to aerosol
spread. Secondary infections among contacts and medical personnel who were
not parenterally exposed are well documented, and evidently have inhaled
viruses suspended in the air.
-
- With Ebola, the incubation period is so short and death
is so rapid, that by the time health authorities know what hit us, everyone
would be dead who was exposed. Inhalation of only 5 viruses (or virions)
are usually sufficient to be infectious.
-
- Thus, even the chemical mask gives uncertain protection.
Any exposure would require a Level 4 biohazard protection suite and self
contained breathing apparatus for assured protection. The only real way
to avoid Ebola is to flee the urban areas as soon as the situation is known.
Short of that, the people should avoid football games, concerts, subways,
convention halls, hospitals and schools, wherever large crowds make an
inviting target.
-
- In a village setting, the disease tends to burn out quickly
because of rapid incapacity and death of the victims. The picture may be
different in large cities with numerous cases and more people exposed.
-
- Our health authorities have been remiss in getting us
prepared for NBC warfare. There is a biocensor that can do air analysis
for rapid identification of plague, anthrax, tularemia, and Botulism toxin,
but not for any of the viral diseases. But where are the units available?
None are, except for some research by the army.
-
- It is difficult to know how much information to disseminate
to a panicky, and generally unsophisticated public. Then, of course, we
don't dare announce anything that might hurt the economy -- such is the
common wisdom.
-
- Posted by permission of NewsMax.com http://www.newsmax.com/archives/articles/2001/10/12/82239.shtml
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