 |
|
|
Meningococcal disease fact sheet
What is Meningococcal Disease? Meningococcal disease means illness caused by the bacterium Neisseria meningitidis, which is also called the "meningococcus." Meningococcal meningitis occurs when N. meningitidis causes inflamation of the tissue surrounding the brain and spinal cord (the meninges). Meningococcemia occurs when N. meningitidis enters the blood stream. Pneumonia occurs when meningococci infect the lungs.What is Neisseria meningitidis? Neisseria meningitidis is a bacterium that lives in the noses and throats of 5%-10% of the population but rarely causes serious disease. Serious "invasive" disease occurs when N. meningitidis spreads through the body via the blood stream after penetrating the mucous membranes of the nose and throat. Viral infections, household crowding, chronic illnesses and both active and passive smoking increase the chance of invasive disease occurring. College freshmen, particularly those living in residence halls, have a slightly higher chance of getting meningococcal disease than people the same age who do not attend college. There are thirteen types (serogroups) of Neisseria meningitidis, nine of which cause invasive disease (A, B, C, D, X, Y, Z, 29E and W-135). Serogroup B is by far the most common cause of meningococcal disease in Oregon, accounting for more than 60% of the cases. Unfortunately, meningococcal vaccine is only effective against serogroups A, C, Y and W-135—not against serogroup B.What are the signs and symptoms of invasive meningococcal disease? The hallmark symptoms of meningococcal meningitis are high fever, headache and stiff neck; fever and rash are symptoms of meningococcemia. Meningococcemic rash is non-blanching, develops rapidly and usually appears on the armpits, groin, and ankles, and in areas where elastic pressure is applied (like underwear and socks). Other signs and symptoms include nausea, vomiting, weakness, low blood pressure, discomfort looking into bright lights, confusion, sleepiness and, in the extreme, delirium, seizures, and coma.How is meningococcal disease diagnosed? Meningococcal disease is diagnosed by culturing N. meningitis from a normally sterile site like spinal fluid or blood (not a sputum specimen or throat swab).How does Neisseria meningitidis spread? Fortunately, meningococci aren't nearly as contagious as the common cold or influenza; they are not spread by simply breathing the same air where a person with meningococcal disease has been. Meningococci spread among people through the exchange of saliva and other respiratory secretions during activities like coughing, kissing, and chewing on toys. Close contacts of cases (like household members or day-care-center cohorts) have a higher chance of developing illness than casual contacts.How soon after exposure do symptoms appear? Usually 3 to 4 days, but may range from 2 to 10 days.How long are people with meningococcal disease contagious? People are contagious as long as bacteria are present in the nose or throat, especially during the three days before symptoms begin. Those exposed to people with meningococcal disease seven or more days before the infected person becomes ill are not likely to become ill themselves.How common is meningococcal disease? Ten year average incidence rates are 2 per 100,000 Oregonians (compared to 1 per 100,000 Americans). But, while meningococcal disease is more common in Oregon than it is in the United States as a whole, it is still a rare disease that has been getting rarer. Incidence rates have decreased 50% since 1994, based on a high of 136 cases (1994) and a low of 70 cases (2000).Disease incidence is highest in December, January and February. It occurs most frequently in children less than 5 years old, with a peak incidence in children aged 6-12 months. What happens when a case of meningococcal disease occurs? Local health departments are notified when a doctor suspects meningococcal disease and when laboratories culture N. meningitidis from blood or spinal fluid. Local health department staff then interview the case, the case's parents or any others who may have information about possible sources of infection and people who may have been exposed, including:
How are potentially exposed people protected from meningococcal disease? The antibiotic Rifampin should be prescribed for all household members and other exposed persons. Ceftriaxone and Ciprofloxacin are used when Rifampin cannot be. Antibiotic prophylaxis should be instituted as soon as possible after exposure. If more than fourteen days have passed since the last contact with the case, medication is likely to be of little benefit.Co-workers and K-12 classmates usually don't require antibiotic prophylaxis. Vaccination is not recommended to protect contacts of isolated cases, but vaccine is used to control outbreaks of meningococcal disease caused by serogroups A, C, Y, and W-135. For whom is meningococcal vaccine recommended?
How can individuals reduce their risk of contracting meningococcal disease?
Issued by: The Oregon Health Services Date: March 2001 Return to top |
|
