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Kamis, 05 Desember 2013


Meningitis is an infection that affects the membranes covering the brain and spinal cord and can be very serious. The meningococcal vaccines protect against meningococcal meningitis. Some people should not receive these vaccines, including those with Guillain-Barre syndrome and those who have had a reaction to the vaccine. Serious side effects are rare but possible. Follow the links below to find WebMD's comprehensive coverage about how the meningococcal meningitis vaccine works, who should get it, side effects, and much more.
Here is what else parents and students need to know to stay healthy and minimize risk.
Q: What is meningitis, also known as meningococcal meningitis?
''Meningococcal meningitis is several diseases caused by different strains" of bacteria, says William Schaffner, MD, an infectious disease specialist at Vanderbilt University. Bacteria infect the protective covering of the brain and spinal cord, called the meninges. The bacteria can also infect the bloodstream.
A strain labeled B caused both campus outbreaks, Schaffner says. He reports consultant work for Sanofi Pasteur and Merck.
Q: Are the outbreaks related?
No, says Amanda Cohn, MD, an epidemiologist at the Meningitis and Vaccine Preventable Diseases Branch of the CDC.
While both are strain B, they are different types of B, she says.
Q: How is the disease spread?
The disease is spread when people exchange saliva during close contact, such as kissing and living in close quarters. That’s why the risk is high for university students.
Q: What does the current U.S. meningitis vaccine protect against? 
It protects against several different strains, including A, C, Y, and W-135, says Schaffner. This vaccine, known as meningococcal vaccine or MCV4, is given at age 11 or 12 with a booster dose at age 16.
Q: How is this B strain different, and why does the U.S. have no vaccine for it?
The bacteria in the B strain include a protein that resembles some proteins that we have in our bodies, Schaffner says. That’s why it's been difficult to create a vaccine that fights it.
The vaccine Bexsero, approved in Europe and Australia, can attack B strains. Under a special arrangement, the FDA agreed to import supplies of Bexsero to offer to Princeton students.
Immunizations are set to start at Princeton Monday, Dec. 9, according to the university web site.
Q: How common are B strains?
They account for about a third of the 500 cases of meningitis typically seen in the U.S. in the last few years, Cohn says.
Meningitis involving the other strains has decreased, she says, as more and more students have become protected with the vaccine.
Q: What can the healthy students do to stay that way?
''Students should be vigilant," Cohn says, by paying attention to possible symptoms.
A fever along with a bad headache or a rash, typically on the arms and legs, are reasons to seek medical help right away, she says. Stiff neck, confusion, and nausea and vomiting are other possible symptoms, according to the CDC.
Practice good hygiene, Cohn says. Cough into your arm instead of your hands. "There is data that suggests that healthy habits do protect kids from getting meningococcal disease," Cohn says.
Q: Will the CDC ask the FDA to approve Bexsero for universal use?
"That is really the role of the FDA and pharmaceutical companies," Cohn says.
Meningococcal disease is an infection caused by a strain of bacteria calledNeisseria meningitidis. This nasty bug is one of the leading causes of bacterialmeningitis in children aged 2 to 18 in the U.S.
Meningococcal disease can include meningitis -- a serious, potentially life-threatening inflammation of the membranes covering the brain and spinal cord -- and a life-threatening blood infection. Meningococcal disease can cause limb loss through amputation, hearing loss, problems with the nervous system, mental retardation, seizures, and strokes.

Did You Know?

Under the Affordable Care Act, many health insurance plans will provide free children’s preventive care services, including checkups, vaccinations and screening tests. Learn more.
Fortunately, meningococcal disease is preventable, and the key to prevention is the meningococcal vaccine. Here is information about the vaccine that you can use to help protect yourself and your family from meningococcal disease.

How Is Meningococcal Disease Spread and Who Is Most at Risk?

Meningococcal disease is not as contagious as other illnesses, such as a cold or the flu. But it is spread by contact with infected respiratory and throat secretions. That can happen with coughing, kissing, or sneezing.
Because the risk increases with close or prolonged contact with an infected person, family members in the same household and caregivers are at an increased risk. For the same reason, so are college students who live in dormitories.

Can the Meningococcal Vaccine Cause Meningococcal Disease?

The short answer is no. There are actually two meningococcal vaccines licensed in the U.S. Neither of the vaccines contains live bacteria.
The vaccines contain antigens -- substances that trigger the body's immune system and cause it to make antibodies. These antibodies then protect the body by attacking and killing the bacteria if it should invade.
The first vaccine -- meningococcal polysaccharide vaccine or MPSV4 -- was approved in 1978. It's made with the antigens contained in the outer polysaccharide or sugar capsule that surrounds the bacterium.
The newer vaccine, approved in 2005, is the meningococcal conjugate vaccine or MCV4. It uses antigens taken from the polysaccharide capsule and then bound to a separate protein that targets the body's immune cells. This makes it easier for the body's immune system to see and recognize the antigens.
One type of MCV4, Menveo, is licensed for use in people aged 2 to 55. Another version, Menactra, is approved for those 9 months to 55 years old. MPSV4 is the only vaccine licensed for use in people over 55 as well as people 2 to 55. Both vaccines protect against four types of meningococcal disease.

Are Both Meningococcal Vaccines Equally Effective?

Both MCV4 and MPSV4 are about 90% effective in preventing meningococcal disease. There are actually several types of N meningitidis -- the bacterium that causes meningococcal disease. Both vaccines protect against four of those types, including two types that are the most common in the U.S.
MCV4 has not been available long enough to compare the long-term effectiveness of the two vaccines. But most experts think that MCV4 provides better, longer-lasting protection. 

Is It Possible to Get the Vaccine and Still Get Meningitis?

Because the vaccines do not protect against all causes of meningitis, it is still possible that someone could receive the vaccine and still get meningitis. But the risk of contracting meningococcal meningitis is significantly lower after the vaccine.
Vaccines like the Hib vaccine and the pneumococcal vaccine are very effective at protecting against other causes of meningitis and should be included as part of a routine childhood vaccination schedule. Check with your doctor and your children's doctor to make sure that you and your family are protected against meningitis, as well as other serious illnesses.

Who Should Get Which Meningococcal Vaccine and When?

Although MCV4 is the preferred vaccine for most people, if it is not available when it's time for the vaccination, MPSV4 can be used.
Routine immunization with the meningococcal vaccine MCV4 is recommended for children aged 11 or 12, with a booster to be given between ages 16 and 18. It is also recommended for the following groups:
  • College freshmen living in a dorm
  • Military recruits
  • Someone who has a damaged spleen
  • Someone whose spleen has been removed
  • Someone with terminal complement component deficiency (an immune system problem)
  • Microbiologists who are routinely exposed to meningococcal bacteria
  • Someone traveling to or residing in a country where the disease is common
  • Someone who has been exposed to meningitis
Preteens who are 11 and 12 usually have the shot at their 11- or 12-year-old checkup. An appointment should be made to get the shot for teenagers who did not have it when they were 11 or 12.
The vaccine may be given to pregnant women. However, since MCV4 is a newer vaccine, there is limited data about its effect on pregnant women. It should only be used if clearly needed.
Anyone who is allergic to any component used in the vaccine should not get the vaccine. It's important to tell your doctor about all your allergies.
People with mild illness can usually get the vaccine. But people who are moderately or severely ill when it's time for the vaccine should wait until they recover.
Anyone with a history of Guillain-Barre syndrome should discuss it with their doctor before getting a vaccination.

What Are the Side Effects From the Meningococcal Vaccines?

With any vaccine, there is the potential of a severe allergic reaction within a few minutes to a few hours after the shot. But the likelihood that the meningococcal vaccines would cause a severe reaction is extremely slight.
About one out of every two people who get the shot experience mild reactions such as redness or a mild pain where the shot was given. Those usually go away in one to two days. A small percentage of people develop a mild fever.
There have been reports that a few people have been diagnosed with Guillain-Barre syndrome (GBS) after receiving MCV4. But experts say it occurs so rarely that it's not possible to tell if it's related to the vaccine.

What Are the Risks of GBS With the MCV4 Vaccine?

Since 2005, more than 15 million doses of MCV4 have been distributed. It's uncertain how many of those have actually been given. In that same time period, there have been 26 confirmed cases of GBS, a serious nervous system disorder, reported within six weeks of the vaccine being taken. There is not enough data at this time to tell whether or not the vaccine was a factor. But analysis of the data suggests that the incidence of GBS is no higher for people receiving the vaccine than the incidence of GBS in the general population.
Still, the timing of the onset of symptoms has raised concern. The CDC is continuing to study the issue and has recommended that people be told about the study when they are considering the vaccine. The current opinion is that even if there is a slight increase in the risk of GBS, it's significantly outweighed by the risk of meningococcal disease without the vaccine.

What is meningitis?

Meningitis camera is inflammation of the coverings around the brain and spinal cord. It is usually caused by an infection.
The infection occurs most often in children, teens, and young adults. Also at risk are older adults and people who have long-term health problems, such as a weakened immune system.
There are two main kinds of meningitis:
  • Viral meningitis is fairly common. It usually does not cause serious illness. In severe cases, it can cause prolonged fever and seizures.
  • Bacterial meningitis is not as common but is very serious. It needs to be treated right away to prevent brain damage and death.
The two kinds of meningitis share the same symptoms. It’s very important to see a doctor if you have symptoms, so that he or she can find out which type you have.

What causes meningitis?

Viral meningitis is caused by viruses. Bacterial meningitis is caused by bacteria.
Meningitis can also be caused by other organisms and some medicines, but this is rare.
Meningitis is contagious. The germs that cause it can be passed from one person to another through coughing and sneezing and through close contact.

What are the symptoms?

The most common symptoms among teens and young adults are:
  • A stiff and painful neck, especially when you try to touch your chin to your chest.
  • Fever.
  • Headache.
  • Vomiting.
  • Trouble staying awake.
  • Seizures.
Children, older adults, and people with other medical problems may have different symptoms:
  • Babies may be cranky and refuse to eat. They may have a rash. They may cry when held.
  • Young children may act like they have the flu. They may cough or have trouble breathing.
  • Older adults and people with other medical problems may have only a slight headache and fever.
It is very important to see a doctor right away if you or your child has these symptoms. Only a doctor can tell whether they are caused by viral or bacterial meningitis. And bacterial meningitis can be deadly if not treated right away.

How is meningitis diagnosed?

Your doctor will ask questions about your health, do an exam, and use one or more tests.
Lumbar puncture is the most important lab test for meningitis. It is also called a spinal tap. A sample of fluid is removed from the spine and tested to see if it contains organisms that cause the illness.
Your doctor may also order other tests, such as blood tests, a CT scan, or an MRI.

How is it treated?

Treatment depends on the cause. See your doctor right away if you or your child has symptoms, because bacterial meningitis can be deadly if not treated right away.
Bacterial meningitis is treated with antibiotics in a hospital. You may also get dexamethasone. And you will be watched carefully to prevent serious problems such as hearing loss, seizures, or brain damage.

Source : MD

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