Bacterial Meningococcal Disease Alert: The Case for Vaccination

From the Centers for Disease Control and PreventionThose with Nonactive Disease Still Contagious

ATLANTA, Ga—At a recent meeting on meningococcal disease, experts from the Centers for Disease Control and Prevention (CDC) discussed who should be vaccinated and when, stressing the severity of bacterial meningococcal disease.

Viruses, primarily enteroviruses, are responsible for most cases of meningococcal disease in the United States. Viral disease is usually mild and resolves without treatment. The rarer bacterial form of meningococcal disease is a severe and often deadly illness that can present serious challenges to physicians. It is often difficult to diagnose in its earliest stages, and it can progress rapidly, killing an otherwise-healthy person in “just a day or two,” said Thomas Clark, MD, of the CDC National Center for Immunization and Respiratory Diseases.

Approximately 1400 to 2800 Americans are diagnosed with bacterial meningococcal disease every year, according to Dr Clark. Of these, college students who live in dormitories are at greatest risk. The number of cases varies from year to year, as do the age-groups and geographic regions affected.

“Even with rapid and appropriate medical treatment, including antibiotics, about 10% to 14% of those who get meningococcal disease will die from it,” Dr Clark said.

Those who survive often have serious long-term effects. Up to 19% are left with hearing loss, brain damage, kidney failure, limb amputations, or other potentially permanent disabilities, making the case for prevention so crucial.

Transmission

Neisseria meningitidis

N meningitidis

Bacterial meningococcal disease is caused by , which can enter the body through contact with oral secretions or large respiratory droplets. The disease is not spread by casual contact. Five types of bacteria cause most disease worldwide—A, B, C, Y, and W135.

About 10% or more of the population have the bacteria, but they will never get sick from it. “The large number of people who carry the bacteria in their nose or throat will develop immunity because of that carriage. However, they can still pass it on to others,” Dr Clark stressed.

In a minority of people, the bacteria can penetrate the lining of the nose and throat and enter the bloodstream. From there it can penetrate the lining of the brain and spinal cord or enter into other parts of the body.

Symptoms and Signs, Rapid Test

The type of illness and clinical features depend largely on where the bacteria travel within the body, Dr Clark explained. Most often the resulting meningococcal disease presents as meningitis (swelling around the lining of the brain and spinal cord) and/or meningococcemia (a severe blood infection). “Blood infection is actually the more severe but less common presentation,” he said.

Bacterial meningococcal infection is usually associated with a sudden onset of fever, malaise, muscle aches, and headache. Half of all patients develop a spotty purple or brown-purple rash that looks like bruising and can change or spread quickly. Bacterial meningitis may start in a much less obvious way.

Early features that can be easily mistaken for other less-serious illnesses include sudden-onset fever, headache, stiff neck, or mental status changes. However, specific signs and symptoms vary widely by age, and they can progress rapidly and change quickly, Dr Clark noted.

The FDA recently approved a new test that uses molecular biology to quickly detect the presence of viral meningitis. When used in combination with other laboratory tests, the Xpert EV test will allow physicians to exclude the possibility of the less-common, but more severe, bacterial meningitis.

Vaccination Recommendations

The increased risk for bacterial meningococcal disease in adolescents and young adults is related to behaviors that bring them in close contact with their peers, such as living in dormitories. The introduction of the new conjugated vaccine (Menactra, Menomune-A/C/Y/W-135) in 2005 has made vaccination, which offers widespread protection, much more appealing.

N meningitidis

The new vaccine protects against 4 of the 5 strains that cause the disease worldwide— A, C, Y, and W135. In the United States most cases are caused by types B, C, and Y. No vaccine is currently available in this country for type B infection.

A one-time vaccination is recommended for all adolescents between ages 11 and 12. For those who were not vaccinated at this age, the CDC recommends catch-up vaccination at high school entry or when entering college.

Other groups at increased risk for meningococcal disease include military recruits, patients who have had their spleen removed, certain international travelers, and scientists and physicians who work with the bacteria. The conjugate vaccine may be administered to anyone aged 11 to 55 years.

The older polysaccharide vaccine (Menomune) remains available for use in children aged 2 to 10 years and adults older than 55. It also protects against types A, C, Y, and W135, but it does not offer some of the benefits of the conjugate vaccine, such as a longer-lasting immune response and a reduction in asymptomatic bacterial carriage. But the polysaccharide vaccine is a good option when the conjugate vaccine is contraindicated, Dr Clark suggested.

“We’ve had some recent vaccination challenges…which led to supply disruptions. The CDC altered its recommendations for a time, but the vaccine supplies recovered, and all adolescents should be vaccinated at 11 to 12 years of age before high school or college entry,” he said.

“I also want to stress that the vaccine can and should be given at any time of the year. There is no reason to wait until school-entry time for vaccination,” he said, adding that meningococcal disease is most prevalent during the winter and early spring.

The Guillain-Barré Syndrome Controversy

The CDC received some reports about a possible link between the conjugate vaccine and an increased risk for Guillain-Barré syndrome (GBS), a disorder characterized by loss of the protective covering of the peripheral nerves. The CDC has investigated all such reports, but it is unclear whether there is any connection between the vaccine and this condition, Dr Clark said.

“We don’t always know the cause of GBS, or why this disease affects some and not others. If a link between the vaccine and GBS does exist, the risk appears to be very low. Because the risk of meningococcal disease is ongoing, the CDC recommends meningococcal vaccination at the ages I have outlined,” he said.

“As physicians we have a very important role to counsel parents when they come to us with questions,” said Nancy L. Snyderman, MD, of the Otolaryngology—Head and Neck Surgery Department, University of Pennsylvania, and chief medical editor of NBC news. “When we put anyone in high-stress, sleep-deprived, overworked, close quarters we increase the risks for infectious diseases, and meningococcus is no exception.”

“this case is an important cautionary tale that drug-resistant HIV truly can be transmitted to a chronically HIV-infected partner. Prior reports of HIV superinfection have documented transmission of drug-resistant HIV and potential rapid disease progression in early HIV infection.”

This case illustrates the risk of transmitting multidrug-resistant HIV infection among HIV-infected patients who are seroconcordant. It also highlights a potential new risk of serosorting, so far considered a safe way to reduce HIV transmission. How superinfection occurs remains unclear, the investigators note.

These HBV and HIV transmission cases illustrate the need for continued dedication to preventive measures for infectious diseases, including strict adherence to standard precautions and counseling all HIV-infected patients that they are not immune from progression to AIDS, and that safer sex techniques are still essential.