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1) Chickenpox
2) Cholera
3) Diabetes
4) Influenza
5) Hepatitis
Chickenpox
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Chickenpox is caused by varicella-zoster virus (VZV) and is
usually mild, but it may be severe in infants, adults, and persons
with impaired immune systems.
-
Almost everyone gets chickenpox by adulthood (more than 95% of
Americans). Chickenpox is highly contagious. Approximately 4
million cases occur in the United States each year.
-
The
virus spreads from person to person by direct contact, or through
the air. Approximately 90% of persons in a household who have not
had chickenpox will get it if exposed to an infected family
member.
-
The
greatest number of cases of chickenpox occurs in the late winter
and spring.
-
Chickenpox has a characteristic itchy rash, which then forms
blisters that dry and become scabs in 4-5 days. The rash may be
the first sign of illness, sometimes coupled with fever and
general malaise, which is usually more severe in adults. An
infected person may have anywhere from only a few lesions to more
than 500 lesions on his or her body during an attack (average
300-400).
-
Adults are more likely to have a more serious case of chickenpox
with a higher rate of complications and death.
-
Chickenpox is contagious 1-2 days before the rash appears and
until all blisters have formed scabs. Chickenpox develops within
10-21 days after contact with an infected person.
-
Every year there are approximately 5,000-9,000 hospitalizations
and 100 deaths from chickenpox in the United States.
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Varicella vaccine has been available since March 1995 and is
approved for use in healthy children 12 months of age or older,
and susceptible (i.e., no evidence of having had chickenpox in the
past) adolescents and adults.
-
Varicella vaccine is highly effective in protecting against severe
chickenpox. Cases of disease caused by the wild virus, which may
occur in a small proportion of vaccinees, are typically very mild,
with fewer than 50 skin lesions and no fever.
-
It
is recommended that all children be routinely vaccinated at 12-18
months of age and that all susceptible children receive the
vaccine before their 13th birthday (CDC Advisory Committee on
Immunization Practices, the American Academy of Pediatrics and the
American Academy of Family Physicians). The vaccine is also
approved for susceptible adolescents and adults, especially those
with close contact with persons at high risk for serious
complications (e.g., health-care workers, family contacts of
immunocompromised persons).
-
A
history of chickenpox is considered adequate evidence of immunity.
-
A
blood test is available to test immunity in persons who are
uncertain of their history or who have not had chickenpox. Many of
these persons will find that they are immune when tested and thus
will not need to be vaccinated.
-
Effective medications (e.g., acyclovir) are available to treat
chickenpox in healthy and immunocompromised persons (e.g, those
with cancer, human immunodeficiency virus/AIDS; those receiving
medications that depress the immune system).
-
Varicella zoster immune globulin (VZIG), an immune globulin made
from plasma of healthy volunteer blood donors with high levels of
antibody to VZV, is recommended after exposure for persons at high
risk for complications (e.g., immunocompromised persons, pregnant
women, premature infants <28 weeks gestation or <1000 grams at
birth and premature infants whose mothers are not immune).
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Cholera
What is
cholera?
Cholera is an acute, diarrheal
illness caused by infection of the intestine with the bacteria
Vibrio cholerae. The infection is often mild or without
symptoms, but sometimes it can be severe. Approximately one in 20
infected persons has severe disease characterized by profuse watery
diarrhea, vomiting, and leg cramps. In these persons, rapid loss of
body fluids leads to dehydration and shock. Without treatment, death
can occur within hours.
How does a person get cholera?
A person may get cholera by drinking
water or eating food contaminated with the cholera bacterium. In an
epidemic, the source of the contamination is usually the feces of an
infected person. The disease can spread rapidly in areas with
inadequate treatment of sewage and drinking water.
The cholera bacteria may also live in the environment in brackish
rivers and coastal waters. Shellfish eaten raw have been a source of
cholera, and a few persons in the United States have contracted
cholera after eating raw or undercooked shellfish from the Gulf of
Mexico. The disease is not likely to spread directly from one person
to another; therefore, casual contact with an infected person is not
a risk for becoming ill.
What is the risk for cholera in the United States?
In the United States, cholera was
prevalent in the 1800s but has been virtually eliminated by modern
sewage and water treatment systems. However, as a result of improved
transportation, more persons from the United States travel to parts
of Latin America, Africa, or Asia where epidemic cholera is
occurring. U.S. travelers to areas with epidemic cholera may be
exposed to the cholera bacterium. In addition, travelers may bring
contaminated seafood back to the United States; foodborne outbreaks
have been caused by contaminated seafood brought into this country
by travelers.
What should travelers do to avoid getting cholera?
The risk for cholera is very low for
U.S. travelers visiting areas with epidemic cholera. When simple
precautions are observed, contracting the disease is unlikely.
All travelers to areas where cholera has occured should observe the
following recomendations:
-
Drink
only water that you have boiled or treated with chlorine or
iodine. Other safe beverages include tea and coffee made with
boiled
water and carbonated, bottled beverages with no ice.
-
Eat
only foods that have been thoroughly cooked and are still hot, or
fruit that you have peeled yourself.
-
Avoid
undercooked or raw fish or shellfish, including ceviche.
-
Make
sure all vegetables are cooked and avoid salads.
-
Avoid
foods and beverages from street vendors.
-
Do
not bring perishable seafood back to the United States.
A simple rule of thumb is "Boil it, cook it, peel it, or forget
it. "
Is a
vaccine available to prevent cholera?
A vaccine for cholera is available;
however, it confers only brief and incomplete immunity and is not
recommended for travelers. There are no cholera vaccination
requirements for entry or exit in any Latin American country or the
United States.
Can cholera be treated?
Cholera can be simply and
successfully treated by immediate replacement of the fluid and salts
lost through diarrhea. Patients can be treated with oral rehydration
solution, a prepackaged mixture of sugar and salts to be mixed with
water and drunk in large amounts. This solution is used throughout
the world to treat diarrhea. Severe cases also require intravenous
fluid replacement. With prompt rehydration, fewer than 1% of cholera
patients die.
Antibiotics shorten the course and diminish the severity of the
illness, but they are not as important as rehydration. Persons who
develop severe diarrhea and vomiting in countries where cholera
occurs should seek medical attention promptly.
How long
will the current epidemic last?
Predicting how long the epidemic in
Latin America will last is difficult. The cholera epidemic in Africa
has lasted more than 20 years. In areas with inadequate sanitation,
a cholera epidemic cannot be stopped immediately, and there are no
signs that the epidemic in the Americas will end soon. Latin
American countries that have not yet reported cases are still at
risk for cholera in the coming months and years. Major improvements
in sewage and water treatment systems are needed in many of these
countries to prevent future epidemic cholera.
What is the U.S. government doing to
combat cholera?
U.S. and international public health
authorities are working to enhance surveillance for cholera,
investigate cholera outbreaks, and design and implement preventive
measures. The Centers for Disease Control is investigating epidemic
cholera wherever it occurs and is training laboratory workers in
proper techniques for identification of V.cholerae. In addition, the
Centers for Disease Control is providing information on diagnosis,
treatment, and prevention of cholera to public health officials and
is educating the public about effective preventive measures.
The U.S. Agency for International Development is sponsoring some of
the international government activities and is providing medical
supplies to affected countries.
The Environmental Protection Agency is working with water and sewage
treatment operators in the United States to prevent contamination of
water with the cholera bacteria.
The Food and Drug Administration is testing imported and domestic
shellfish for V. cholerae and monitoring the safety of U.S.
shellfish beds through the shellfish sanitation program.
With cooperation at the state and local, national, and international
levels, assistance will be provided to countries where cholera is
present, and the risk to U.S. residents will remain small.
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Diabetes
Most of the food we
eat is turned into glucose, or sugar, for our bodies to use for
energy. The pancreas, an organ that lies near the stomach, makes a
hormone called insulin to help glucose get into the cells of our
bodies. When you have diabetes, your body either doesn't make
enough insulin or can't use its own insulin as well as it should.
This causes sugars to build up in your blood.
Diabetes can cause
serious health complications including heart disease, blindness,
kidney failure, and lower-extremity amputations. Diabetes is the
seventh leading cause of death in the United States.
People who think they
might have diabetes must visit a physician for diagnosis. They
might have SOME or NONE of the following symptoms:
- Frequent urination
- Excessive thirst
- Unexplained weight
loss
- Extreme hunger
- Sudden vision
changes
- Tingling or
numbness in hands or feet
- Feeling very tired
much of the time
- Very dry skin
- Sores that are
slow to heal
- More infections
than usual.
Nausea, vomiting, or
stomach pains may accompany some of these symptoms in the abrupt
onset of insulin-dependent diabetes, now called type 1 diabetes.
The following types
of diabetes and some of their risk factors are quoted from the
National Diabetes Fact Sheet: National estimates and general
information on diabetes in the United States (Centers for
Disease Control and Prevention. Atlanta, GA: US Department of
Health and Human Services, 1997):
Type 1 diabetes
was previously called
insulin-dependent diabetes mellitus (IDDM) or juvenile-onset
diabetes. Type 1 diabetes may account for 5% to 10% of all
diagnosed cases of diabetes. Risk factors are less well defined
for type 1 diabetes than for type 2 diabetes, but autoimmune,
genetic, and environmental factors are involved in the development
of this type of diabetes.
Type 2
diabetes was previously called
non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset
diabetes. Type 2 diabetes may account for about 90% to 95% of all
diagnosed cases of diabetes. Risk factors for type 2 diabetes
include older age, obesity, family history of diabetes, prior
history of gestational diabetes, impaired glucose tolerance,
physical inactivity, and race/ethnicity. African Americans,
Hispanic/Latino Americans, American Indians, and some Asian
Americans and Pacific Islanders are at particularly high risk for
type 2 diabetes.
Gestational
diabetes develops in 2% to 5% of
all pregnancies but usually disappears when a pregnancy is over.
Gestational diabetes occurs more frequently in African Americans,
Hispanic/Latino Americans, American Indians, and people with a
family history of diabetes than in other groups. Obesity is also
associated with higher risk. Women who have had gestational
diabetes are at increased risk for later developing type 2
diabetes. In some studies, nearly 40% of women with a history of
gestational diabetes developed diabetes in the future.
Other
specific types of diabetes result
from specific genetic syndromes, surgery, drugs, malnutrition,
infections, and other illnesses. Such types of diabetes may
account for 1% to 2% of all diagnosed cases of diabetes.
Management
strategies should be planned along with a qualified health care
team.
The following
information on treatments for diabetes is from the National
Diabetes Fact Sheet: National estimates and general information on
diabetes in the United States (Centers for Disease Control and
Prevention. Atlanta, GA: US Department of Health and Human
Services, 1997):
Diabetes knowledge,
treatment, and prevention strategies advance daily. Treatment is
aimed at keeping blood glucose near normal levels at all times.
Training in self-management is integral to the treatment of
diabetes. Treatment must be individualized and must address
medical, psychosocial, and lifestyle issues.
Treatment of
type 1 diabetes: Lack of insulin
production by the pancreas makes type 1 diabetes particularly
difficult to control. Treatment requires a strict regimen that
typically includes a carefully calculated diet, planned physical
activity, home blood glucose testing several times a day, and
multiple daily insulin injections.
Treatment of
type 2 diabetes: Treatment
typically includes diet control, exercise, home blood glucose
testing, and in some cases, oral medication and/or insulin.
Approximately 40% of people with type 2 diabetes require insulin
injections.
The causes of type 1
diabetes appear to be much different than those for type 2
diabetes, though the exact mechanisms for development of both
diseases are unknown. The appearance of type 1 diabetes is
suspected to follow exposure to an "environmental trigger," such
as an unidentified virus, stimulating an immune attack against the
beta cells of the pancreas (that produce insulin) in some
genetically predisposed people.
A number of studies
have shown that regular physical activity can significantly reduce
the risk of developing type 2 diabetes. It also appears to be
associated with obesity. Researchers are making progress in
identifying the exact genetics and "triggers" that predispose some
individuals to develop type 1 diabetes, but prevention, as well as
a cure, remains elusive.
In response to the
growing health burden of diabetes mellitus (diabetes), the
diabetes community has three choices: prevent diabetes; cure
diabetes; and take better care of people with diabetes to prevent
devastating complications. All three approaches are actively being
pursued by the US Department of Health and Human Services.
Both the National
Institutes of Health (NIH) and the Centers for Disease Control and
Prevention (CDC) are involved in prevention activities. The NIH is
involved in research to cure both type 1 and type 2 diabetes,
especially type 1. CDC focuses most of its programs on being sure
that the proven science is put into daily practice for people with
diabetes. The basic idea is that if all the important research and
science are not made meaningful in the daily lives of people with
diabetes, then the research is, in essence, wasted.
Several approaches to
"cure" diabetes are being pursued:
- Pancreas
transplantation
- Islet cell
transplantation (islet cells produce insulin)
- Artificial
pancreas development
- Genetic
manipulation (fat or muscle cells that don’t normally make
insulin have a human insulin gene inserted — then these "pseudo"
islet cells are transplanted into people with type 1 diabetes).
Each of these
approaches still has a lot of challenges, such as preventing
immune system rejection; finding an adequate number of insulin
cells; keeping cells alive; and others. But progress is being made
in all areas.
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Influenza
Influenza, commonly
called "the flu," is caused by viruses that infect the respiratory
tract. Compared with most other viral respiratory infections, such
as the common cold, influenza infection often causes a more severe
illness. Typical clinical features of influenza include fever
(usually 100F to 103F in adults and often even higher in children)
and respiratory symptoms, such as cough, sore throat, runny or
stuffy nose, as well as headache, muscle aches, and often extreme
fatigue. Although nausea, vomiting, and diarrhea can sometimes
accompany influenza infection, especially in children,
gastrointestinal symptoms are rarely prominent. The term "stomach
flu" is a misnomer that is sometimes used to describe
gastrointestinal illnesses caused by other microorganisms.
Most people who get the flu recover completely in 1 to 2 weeks, but
some people develop serious and potentially life-threatening medical
complications, such as pneumonia. In an average year, influenza is
associated with about 20,000 deaths nationwide and many more
hospitalizations. Flu-related complications can occur at any age;
however, the elderly and people with chronic health problems are
much more likely to develop serious complications after influenza
infection than are younger, healthier people.
The Influenza Viruses
Influenza viruses are
divided into three types, designated A, B, and C. Influenza types A
and B are responsible for epidemics of respiratory illness that
occur almost every winter and are often associated with increased
rates for hospitalization and death. Influenza type C differs from
types A and B in some important ways. Type C infection usually
causes either a very mild respiratory illness or no symptoms at all;
it does not cause epidemics and does not have the severe public
health impact that influenza types A and B do. Efforts to control
the impact of influenza are aimed at types A and B, and the
remainder of this discussion will be devoted only to these two
types.
Influenza viruses continually change over time, usually by mutation.
This constant changing enables the virus to evade the immune system
of its host, so that people are susceptible to influenza virus
infection throughout life. This process works as follows: a person
infected with influenza virus develops antibody against that virus;
as the virus changes, the "older" antibody no longer recognizes the
"newer" virus, and reinfection can occur. The older antibody can,
however, provide partial protection against reinfection.
Currently, three
different influenza strains circulate worldwide: two type A viruses
and one type B. Type A viruses are divided into subtypes based on
differences in two viral proteins called the hemagglutinin (H) and
the neuraminidase (N). The current subtypes of influenza A are
designated A(H1N1) and A(H3N2).
Influenza type A viruses undergo two kinds of changes. One is a
series of mutations that occur over time and cause a gradual
evolution of the virus. This is called antigenic "drift." The other
kind of change is an abrupt change in the hemagglutinin and/or the
neuraminidase proteins. This is called antigenic "shift." In this
case, a new subtype of the virus suddenly emerges. Type A viruses
undergo both kinds of changes; influenza type B viruses change only
by the more gradual process of antigenic drift.
Influenza A and B
viruses continually undergo antigenic drift. This process accounts
for most of the changes that occur in the viruses from one influenza
season to another. Antigenic shift occurs only occasionally. When it
does occur, large numbers of people, and sometimes the entire
population, have no antibody protection against the virus. This may
result in a worldwide epidemic, called a pandemic. During this
century, pandemics occurred in 1918, 1957, and 1968, each of which
resulted in large numbers of deaths, as noted below.
Mortality associated
with pandemics:
- 1918-19 "Spanish
flu" A(H1N1) -- Caused the highest known influenza-related
mortality: approximately 500,000 deaths occurred in the United
States, 20 million worldwide.
- 1957-58 "Asian flu"
A(H2N2) -- 70,000 deaths in the United States.
- 1968-69 "Hong-Kong
flu" A(H3N2) -- 34,000 deaths in the United States.
The emergence of the
"Hong Kong flu" in 1968-69 marked the beginning of the type A(H3N2)
era. When this virus first emerged, it was associated with lower
mortality than that caused by the two previous pandemic viruses.
Several possible reasons for this lower mortality have been
hypothesized. First, only the hemagglutinin changed from the "Asian"
strain [type A(H2N2)]; the neuraminidase (N2) stayed the same, and
therefore existing antibody could be expected to offer some
protection. A second possibility is suggested by evidence that a
virus with a similar hemaglutinin may have circulated from the late
1890s to the early 1900s. If this were the case, people who were in
their sixties and older in 1968 may have had some protection from
antibody acquired in their youth.
There are still many things about influenza viruses that are not
understood. Although the newly emerged type A(H3N2) virus caused
only moderate mortality in 1968 compared with other pandemic
viruses, this virus has continued to cause substantial mortality as
it has continued to circulate and evolve. In the years since its
emergence, type A(H3N2) epidemics have caused more than 400,000
deaths in the United States alone, and more than 90% of these deaths
have occurred among elderly people. Of the influenza viruses
currently in worldwide circulation, A(H3N2) still has the most
severe overall impact.
The other influenza A subtype currently in circulation, type
A(H1N1), also has an interesting history. After the devastating
pandemic of 1918-19, this subtype continued to circulate and undergo
antigenic drift. It periodically caused large epidemics, but never
on the scale of the 1918-19 pandemic. When the "Asian" strain
[(A(H2N2)] emerged in 1957, the A(H1N1) viruses disappeared (as did
the A(H2N2) viruses when the "Hong Kong" virus emerged in 1968). In
1977, the A(H1N1) viruses reappeared and have cocirculated with
A(H3N2) viruses ever since. However, the impact of A(H1N1) has been
different during it's most recent appearance. The virus that
reappeared in 1977 was virtually identical to an A(H1N1) virus that
circulated in 1950. Therefore, most people born before 1950 were
immune, and epidemics caused by A(H1N1) viruses since 1977 have
primarily affected younger people. The fact that the elderly appear
to have natural protection against current A(H1N1) viruses probably
explains the low mortality associated with recent epidemics in which
this subtype was the predominant strain. However, as A(H1N1) viruses
continue to evolve, they could begin to have a more severe impact on
the elderly.
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Hepatitis
What is hepatitis A?
Hepatitis A is a liver disease caused by
hepatitis A virus.
What are the signs and symptoms of hepatitis A?
Persons with the hepatitis A
virus may not have any signs or symptoms of the disease. Older
persons are more likely to have symptoms than children. If symptoms
are present, they usually occur abruptly and may include fever,
tiredness, loss of appetite, nausea, abdominal discomfort, dark
urine, and jaundice (yellowing of the skin and eyes). Symptoms
usually last less than 2 months; some people are ill for as long as
6 months. The average incubation period for hepatitis A is 28 days
(range: 15–50 days).
How is
hepatitis A diagnosed?
A blood test (IgM
anti-HAV) is needed to diagnose hepatitis A. Talk to your doctor or
someone from your local health department if you suspect that you
have been exposed to hepatitis A or any type of viral hepatitis.
How is
hepatitis A transmitted?
The hepatitis A
virus is spread from person to person by putting something in the
mouth that has been contaminated with the stool of a person with
hepatitis A. This type of transmission is called "fecal-oral." For
this reason, the virus is more easily spread in areas where there
are poor sanitary conditions or where good personal hygiene is not
observed.
Most infections
result from contact with a household member or sex partner who has
hepatitis A. Casual contact, as in the office, factory, or a school
setting, does not spread the virus.
What products are
available to prevent hepatitis A virus infection?
Two products are used to
prevent hepatitis A virus infection: immune globulin and hepatitis
A vaccine.
- Immune globulin is
a preparation of antibodies that can be given before exposure for
short-term protection against hepatitis A and for persons who have
already been exposed to the hepatitis A virus. Immune globulin
must be given within 2 weeks after exposure to hepatitis A for
maximum protection.
- Hepatitis A
vaccine has been licensed in the United States for use in persons
2 years of age and older. The vaccine is recommended (before
exposure to hepatitis A virus) for persons who are more likely to
get a hepatitis A virus infection or are more likely to get
seriously ill if they do get hepatitis A. The vaccines that are
currently licensed in the United States are HAVRIX(®)
(manufactured by SmithKline Beecham Biologicals) and VAQTA(®)
(manufactured by Merck & Co., Inc).
Is
immune globulin safe?
Yes. No instance
of transmission of HIV (the virus that causes AIDS) or other viruses
has been observed with the use of immune globulin administered by
the intramuscular route. Immune globulin can be administered during
pregnancy and breast-feeding.
Is
immune globulin in short supply?
Yes. This
shortage is expected to continue necessitating a prioritization of
indications for the use of immune globulin.
Can
other vaccines be given at the same time that hepatitis A vaccine is
given?
Yes. Hepatitis
B, diphtheria, poliovirus (oral and inactivated), tetanus, oral
typhoid, cholera, Japanese encephalitis, rabies, yellow fever
vaccine or immune globulin can be given at the same time that
hepatitis A vaccine is given, but at a different injection site.
How
long does immunity last after hepatitis A vaccination?
Although data on
long-term protection are limited, estimates based on modeling
techniques suggest that protection will last for at least 20 years.
When
are persons protected after receiving hepatitis A vaccine?
Protection
against hepatitis A begins four weeks after the first dose of
hepatitis A vaccine. Check with your doctor for when the next dose
is due.
Can hepatitis A vaccine be given after exposure to hepatitis A
virus?
No, hepatitis A vaccine is not
licensed for use after exposure to hepatitis A virus. In this
situation, immune globulin should be used.
Should prevaccination testing be done?
Prevaccination
testing is done only in specific instances to control cost (e.g.,
persons who were likely to have had hepatitis A in the past). This
includes persons who were born in countries with high levels of
hepatitis A virus infection, elderly persons, and persons who have
clotting factor disorders and may have received factor concentrates
in the past.
Should
postvaccination testing be done?
No.
Can a
patient receive the first dose of hepatitis A vaccine from one
manufacturer and the second (last) dose from another manufacturer?
Yes. Although
studies have not been done to look at this issue, there is no
reason to believe that this would be a problem.
What should
be done if the second dose of hepatitis A vaccine is delayed?
The second dose
should be administered as soon as possible. There is no need to
repeat the first dose.
Can hepatitis A vaccine be given during pregnancy or lactation?
We don't know for sure, but
because vaccine is produced from inactivated hepatitis A virus, the
theoretical risk to the developing fetus is expected to be low.
The risk associated with vaccination, however, should be weighed
against the risk for hepatitis A in women who may be at high risk
for exposure to hepatitis A virus.
Can
hepatitis A vaccine be given to immunocompromised persons? (e.g.,
persons on hemodialysis or persons with AIDS)
Yes.
PERSONS WHO
SHOULD RECEIVE HEPATITIS A VACCINE
Hepatitis A
vaccination provides protection before one is exposed to hepatitis A
virus. Hepatitis A vaccination is recommended for the following
groups who are at increased risk for infection and for any person
wishing to obtain immunity.
Persons
traveling to or working in countries that have high or intermediate
rates of hepatitis A.
All susceptible
persons traveling to or working in countries that have high or
intermediate rates of hepatitis A should be vaccinated or receive
immune globulin before traveling. Persons from developed countries
who travel to developing countries are at high risk for hepatitis
A. Such persons include tourists, military personnel, missionaries,
and others who work or study abroad in countries that have high or
intermediate levels of of hepatitis A. The risk for hepatitis A
exists even for travelers to urban areas, those who stay in luxury
hotels, and those who report that they have good hygiene and that
they are careful about what they drink and eat.
Children in
communities that have high rates of hepatitis A and periodic
hepatitis A outbreaks.
Children living
in communities that have high rates of hepatitis A (e.g., American
Indian, Alaska Native) should be routinely vaccinated beginning at 2
years of age. High rates of hepatitis A are generally found in
these populations, both in urban and rural settings. In addition,
to effectively prevent epidemics of hepatitis A in these
communities, vaccination of previously unvaccinated older children
is recommended within 5 years of initiation of routine childhood
vaccination programs. Although rates differ among areas, available
data indicate that a reasonable cutoff age in many areas is 10-15
years of age because older persons have often already had hepatitis
A. Vaccination of children before they enter school should
receive highest priority, followed by vaccination of older children
who have not been vaccinated.
Men who have
sex with men
Sexually active
men (both adolescents and adults) who have sex with men should be
vaccinated.
Hepatitis A outbreaks
among men who have sex with men have been reported frequently.
Recent outbreaks have occurred in urban areas in the United States,
Canada, and Australia.
Illegal-drug
users
Vaccination is
recommended for injecting and noninjecting illegal-drug users if
local health authorities have noted current or past outbreaks among
such persons.
During the past
decade, outbreaks have been reported among injecting-drug users in
the United States and in Europe.
Persons who
have occupational risk for infection
Persons who work
with hepatitis A virus-infected primates or with hepatitis A virus
in a research laboratory setting should be vaccinated. No other
groups have been shown to be at increased risk for hepatitis A virus
infection because of occupational exposure.
Outbreaks of
hepatitis A have been reported among persons working with non-human
primates that are susceptible to hepatitis A virus infection,
including several Old World and New World species. Primates that
were infected were those that had been born in the wild, not those
that had been born and raised in captivity.
Persons who
have chronic liver disease
Persons with
chronic liver disease who have never had hepatitis A should be
vaccinated, as there is a higher rate of fulminant (rapid onset of
liver failure, often leading to death) hepatitis A among persons
with chronic liver disease. Persons who are either awaiting or have
received liver transplants also should be vaccinated.
Persons who
have clotting-factor disorders
Persons who have
never had hepatitis A and who are administered clotting-factor
concentrates, especially solvent detergent-treated preparations,
should be given hepatitis A vaccine.
All persons with
hemophilia (Factor VIII, Factor IX) who receive replacement therapy
should be vaccinated because there appears to be an increased risk
of transmission from clotting-factor concentrates that are not heat
inactivated.
Health-care workers
Health-care
workers are not at increased risk for hepatitis A. If a patient
with hepatitis A is admitted to the hospital, routine infection
control precautions will prevent transmission to hospital staff.
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