Information on Smallpox-Topics
Description of Smallpox-Small pox is a disease caused by the variola virus.
It had many natural presentations associated with the various strains of the virus.
The difference in the presentations, however, were primarily in the severity of
the disease they caused, as well as the mortality rates associated. Two
common presentations were variola minor, also called alastrim and variola
major.
Variola minor’s presentation was more benign, giving rise to less pox lesions,
a less severe disease in general, with a mortality rate of 1% or less. Variola major
gave rise to more severe disease with mortality rates as high as 40%.
Their presentations were otherwise similar and can be broken down into three
phases: an incubation period, the prodrome, and the pox/rash phase.
Smallpox Information-Quick Links....
History
Small pox is an infectious disease that has plagued man for thousands of years,
causing more deaths than perhaps any other illness. And in the last century, alone,
it has touted to have caused the death of some 500 million people—more than
warfare had. It was, however, certified eradicated by man in 1980, no longer able
to cause natural epidemics after 1977. During its reign as the scourge of mankind, it
has probably had a significant impact on the history of man. It is thought that Ramsey
V died of this infection in 1155 B.C.
A small pox epidemic struck Athens 430 B.C., killing approximately one-third of
the population. This may have played a factor in the defeat by Sparta of the Greeks
in the Peloponnesian War. It also caused the death of Marcus Aureilus in 165 A.D.
Again, affecting the history of man. During the Elephant Wars, 570 A.D., the
Abyssinians were decimated by an outbreak of small pox while they laid siege to
Mecca. This preempted a successful conquest of Mecca, again, playing a role in
the history of man. In the 1500s, the Conquistadors brought the infection to
the Americas, and over the ensuing 300 years, played a role in the decimation of
the Native American population. However, the advent of its demise came with
the introduction of vaccinations by the British doctor Edward Jenner with cow pox in
the late 1700s. These vaccines, using vaccinia, were used in the ’60s and ’70s by
D.A. Henderson and the World Health Organization to contain epidemics, and since
there were no other hosts for the virus to ultimately eradicate the virus. After 1980,
the virus only existed reportedly in two repositories—one in the former USSR
(Moscow) and in a repository in Atlanta, Georgia (at the CDC).
The ultimate eradication of the virus was scheduled for December of 1983. However,
a debate ensued, and at the conclusion of that debate, the virus lived on in those
two repositories where they were reportedly well protected. However, now we’re
told that the virus may be in the hands of North Korea, Iraq and perhaps
other adversaries. And we’re also faced with the reality, post-9/11, that there
are zealots or individuals with the ruthlessness and willingness to use such a virus
to harm the United States. Thus the need to know about small pox.
Incubation Phase
The incubation period has a range of 4 to 17 days, on the average, of about 12
days. During this phase, there are no symptoms. The virus is replicating within the
host cell after the virus has been inhaled. During this phase, the individual is
not infectious, however, the virus is in stealth, undetectable. The advantage of
the longer incubation period is that it gives physicians a longer period of time to
find individuals who are exposed, quarantine them, and vaccinate those who
require vaccination.
It is touted that if an individual who has been exposed is
vaccinated within 4 days of the exposure, it may protect them against the infection
or lessen the disease that will develop as a result of the infection. Conversely,
the shorter the incubation period, the less time there is to do all this.
Prodrome
Prodrome is the phase when the patient becomes symptomatic. At this point, there is
no rash. However, the patient begins to develop fevers, which could be as high as 104
or 105 degrees, body aches, headaches, nausea, vomiting, and abdominal pain. This
is associated with a decrease in appetite, sensitivity to light, and, in many
cases, dehydration. This phase coincides with the release of the virus from the
initially infected cells.
It is not uncommon to misdiagnose the patient during this
phase with something other than small pox. Since there is no classic rash to
distinguish these patients from other illness that gave rise to abdominal pain and
fevers. The symptomatology is so severe that in most cases, the patients are
bedridden and are unable to get about. With variola major, many patients succumb
to the disease in this phase. Individuals with concurrent illnesses or who are
immune-deficient are more likely to succumb to the disease than those
otherwise healthy. The prodrome lasts 2 to 5 days on the average.
Rash Phase
The rash phase begins after the prodrome. It is in this phase, or a day before this,
that the patient is most infectious. That is, he is able to transmit the disease to
other individuals. However, the patient can be infectious perhaps to a lesser
extent during the prodrome. This we know because the virus can be isolated in the
oral cavity during the prodrome. What heralds the rash phase is the appearance of
a rash which is characterized by small red spots which eventually transforms
into papules (small pimples) then into a vesicle (small blister) and finally into a
pustule which is akin to a pus-filled blister. The rash initially presents over the face
and upper extremities, and subsequently over the lower extremities. To a lesser
extent, over the torso. However, as the disease develops, the rash covers the
entire body. At any one time, the rash is in the same stage of development with
little variation. That is, they are either spots (macules), pimples (papules),
blisters (vesicles) or pustules, all in the same stage. This distinguishes it from
chicken pox, which can be found on various parts of the body in different stages,
that is, some macules, some vesicles, some pustules. When the rash initially presents
as a red spot, it can be mistaken for the measles, allergies, and other viruses. If
the individual succumbs during this stage, he may be misdiagnosed and the
real diagnoses eluding the physician.
As the rash matures, it begins to scab, forming umbilicated lesions (that is, a
rash characterized by pimples that appear like a mouth of a volcano). In severe
cases, the rash covers the entire body. That is, each individual pus lesion is side by
side, covering most of the body. This is referred to as confluent small pox. This
is particularly painful since any movement results in the cracking of the scabs.
The hands and feet become covered which makes it impossible to walk or to use
one’s hands. At times, the scabs fall from the hands and feet, leaving the hands and
feet raw. This phase of the disease lasts two to four weeks. It is not unusual though,
at the beginning of this phase of the disease, for the individual’s fever to dissipate,
only to rise again with complications from the infection.
Complications
Complications of the disease include pneumonitis, that is, the infection of the
lung; meningitis, that is, the infection of the lining of the brain; encephalitis, infection
of the brain, meningoencephalitis, the infection of the lining around the brain as well
as the brain; dehydration; secondary bacterial infection of the pox rash;
hemorrhaging and weakening of the immune system, predisposing the individual
to other types of infections. For those who survive the small pox disease,
chronic complications include scarring of the cornea (which is the clear part of the eye), resulting in blindness and disfiguring scarring of the skin. Many patients die of
these complications, and these complications are more common in two forms of
small pox—hemorrhagic small pox and malignant small pox which will be discussed later.
Diagnosis
The diagnosis of small pox is not difficult if the classic skin lesion
(that is, the pox lesion) is present. Most physicians would probably be able to make
the diagnosis when they are presented such a rash. However, many patients will
present in the prodrome with an atypical rash, or with the initial rash which may
appear more macular, that is more like a red-spotted rash. The diagnosis of these
cases is much more difficult, and unless there is a high suspicion for the disease,
the diagnosis may be missed. Common mis-diagnoses (when the patient presents
with less than a classic rash) include: chicken pox, hand, foot and mouth
disease, folliculitis, impetigo, staphylococcal and streptococcal, skin infections,
allergies, and other blood disorders. There are specific studies that can be performed
to make the definitive diagnosis.
However, unless one has the suspicion of the disease being present, these studies
are not ordered. Also, the threshold for ordering these studies is quite high since
no physician wants to unduly alarm his patients or a community about the presence
of small pox. There is an adage in medicine, and that adage is when you hear
hooves you think of horses, not zebras. In an era where small pox has not been seen
in several decades, small pox is the zebra not the horse. Also, certain studies such
as variola viral cultures or electromicroscopy to identify the variola virus or small
pox serologies, that is, the study to identify antibodies to the variola virus
require approval by a public health official. This could be an infectious
diseases consultant, but he may not want to approve such a study unless there
are classic lesions of the disease. So, it may be a Catch-22 set of circumstances
which will ultimately give rise to a delay in the diagnosis of the disease or the
recognition of an epidemic brewing.
Treatment
There is no specific treatment for small pox, however, there is treatment for many of
the complications from small pox, including dehydration and the treatment of
secondary bacterial infections with antibiotics. There are no specific antiviral agents
for small pox. However, there is some research using agents such as
cidofovir. However, these have not been released for use in the treatment of small
pox by the FDA. There are, however, several antiviral agents used for patients
suffering from AIDS, herpes simplex, herpes zostor (also known as shingles), and
the influenza virus.
These agents either abort the infection or lessen it. However, these agents are
not approved for the treatment of small pox, nor do we know whether they would
be effective. However, if there were an epidemic of small pox, my feeling is
the physicians, out of desperation, would attempt to use some of these agents
in consultation, having no other form of therapy for small pox. In essence, the
only effective therapy would be prevention and that would be vaccinating the
individual before he acquires the infection.
Mortality
The mortality rate of small pox varies. An epidemic of variola minor gives rise
to mortality rates in the 1% range. However, in variola major, depending on
the epidemic (the strain), the mortality rate may range from 10% to 40%.
Mortality rates being higher for hemorrhagic small pox and malignant small pox. This
will be discussed later. The true mortality rate of small pox is not well known. This
is because mortality rates quoted of epidemics occurring in the last century
were epidemics occurring in populations where vaccinations were used, that is to
say, some individual who acquired the infection had some immunity depending on
when the vaccine was given to them in relation to the infection. Thus, they faired
better than those individuals with no immunity. This is because immunity to small
pox lessens years after the vaccine is given.
So, unless the individual has been recently vaccinated, the immunity to small pox
may be at a level where an infection can take hold, however, not to the degree that
it would cause the death of the individual.
No one knows what the actual mortality would be in a population where there is little
or no immunity to the variola virus. We do, however, know that in certain
individual groups, the mortality rate is higher, such as in the pediatric population,
less than one year of age. Their mortality rate is higher than the general
population. Also, pregnant females are more likely to get hemorrhagic small
pox perhaps as high as 50% which has a higher mortality rate, ranging as high as
100%. And also, patients with concurrent illnesses
(such as diabetes, heart disease, etc.) or more specifically immune deficiencies,
will succumb to the disease more readily. We know nutrition plays a role in how
an individual will weather the small pox infection as it plays a role in many
other diseases. Then, of course, the mortality rate would probably be negatively
affected if the emergency medical services in a community were inundated by
an overwhelming number of small pox cases. It is safe to say, the more immunity
there is in the population, the less the mortality.
Dr. Reyes is available for media interviews, radio interviews, etc. by contacting
Publisher Diana Ennen at Diana@pauloreyes.com or 954.971.4025 |
5 Star Medical Fiction Thriller by Paulo J. Reyes -- 
