Neisseria meningitidis Invasive Disease, 2004

Twenty-four cases of Neisseria meningitidis invasive disease (0.5 per 100,000 population) were reported in 2004, compared to 29 cases in 2003. The distribution of serogroups among case isolates from 2004 was similar to 2003, with 12 (50%) serogroup C cases, six (25%) serogroup B cases, four (17%) serogroup Y cases, one (4%) serogroup W-135 case, and one (4%) case whose isolate was not groupable.

Case-patients ranged in age from 2 months to 91 years, with a mean of 32 years. Seventy-one percent of the cases occurred in the Twin Cities metropolitan area. Twelve (50%) case-patients had meningitis, 10 (42%) had bacteremia without another focus of infection, and two (8%) had bacteremia with pneumonia. All cases were sporadic, with no definite epidemiologic links.

Three deaths occurred among cases reported in 2004. An 81-year-old female and a 91-year-old female died of bacteremia attributed to serogroup Y (one had bacteremia with pneumonia). An 83-year-old male died of bacteremia due to serogroup C.

Since the fall of 1998, MDH has collected additional information on college-aged students with N. meningitidis invasive disease as part of a nationwide effort to determine whether providing meningococcal vaccine to incoming college freshmen effectively prevents disease in this age group. In the fall of 1999, the Advisory Committee on Immunization Practices (ACIP) recommended that health care providers inform college students about meningococcal disease and the availability of vaccine. Serogroups A, C, Y, and W-135 are covered by the quadrivalent vaccine. No cases reported in Minnesota during 2004 were identified as college students.

In the spring of 2002, MDH in collaboration with CDC and other EIP sites nationwide, began a case-control study of risk factors for meningococcal disease among high school students in Minnesota. One culture-confirmed, serogroup undetermined case, and one confirmed serogroup C case occurred among high school students in 2004. Two culture-negative suspected cases of meningococcal disease, positive by polymerase chain reaction (PCR) in the Public Health Laboratory, occurred in high school students also were included in the study in 2004.

In January 2005, a meningococcal polysaccharide-protein conjugate vaccine for serogroups A,C,Y, and W135 was licensed for use in the United States for persons aged 11 to 55 years. The ACIP and American Academy of Pediatrics recommend immunization with the new vaccine at age 11-12 years or at high school entry as well as for college freshmen living in dormitories and other groups previously determined to be at high risk in the licensed age range. Complete recommendations are available in MMWR 2005; 54 (No. RR-7).

• For up to date information see>> Meningococcal Disease
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2004