Abstract

During December 12-29, 1998, seven patients ages 2-18 years were diagnosed with serogroup C meningococcal disease in two neighboring Florida towns with 33,000 residents. We evaluated a mass vaccination campaign implemented to control the outbreak. We maintained vaccination logs and recorded the resources used in the campaign that targeted 2- to 22-year-old residents of the two towns. A total of 13,148 persons received the vaccinations in 3 days. Vaccination coverage in the target population was estimated to be 86% to 99%. Five additional cases of serogroup C meningococcal disease occurred in the community during the year after the campaign began, four in patients who had not received the vaccine. The cost of control efforts was approximately $370,000. Although cases continued to occur, the vaccination campaign appeared to control the outbreak. Rapid implementation, a targeted approach, and high coverage were important to the campaign's success.

Introduction

Neisseria meningitidis is a leading cause of bacterial meningitis and sepsis in children and young adults in the United States^[1,2]. An estimated 2,600 cases occur each year, most of them sporadic^[2]. Between 10 and 15 outbreaks of meningococcal disease are reported in the country annually^[1,3]. Outbreaks can occur in institutions as well as in communities. Communitywide outbreaks can persist for several months, and controlling them remains a major challenge in public health^[4-6].

The primary method for preventing sporadic meningococcal disease is chemoprophylaxis of close contacts after a case is identified^[1,7,8]. However, the protective effect of chemoprophylaxis is of limited duration^[6,9,10].

A quadrivalent polysaccharide meningococcal vaccine effective against N. meningitidis serogroup A, C, W135, and Y is available in the United States^[7,11]. Serogroup C N. meningitidis accounts for most U.S. outbreaks^[3]. The Advisory Committee on Immunization Practices (ACIP) has released recommendations for the use of meningococcal vaccine to control outbreaks of serogroup C meningococcal disease^[11].

Identifying the need for a vaccination campaign, defining the target population, implementing the campaign rapidly, and achieving high vaccination coverage are difficult^[5]. Mass vaccination campaigns require major logistic efforts and often take place in an atmosphere of public anxiety^[5,6,12,13]. Few local and state health departments have much experience in responding to such outbreaks. Mass vaccination campaigns in response to meningococcal disease outbreaks have been reported before, but only limited information is available on the operational aspects of such efforts^[4,5,9,14].

In December 1998, two neighboring towns with a combined population of 33,000 persons in Putnam County, Florida, had a community outbreak of meningococcal disease^[1,3]. The health department administered chemoprophylaxis to close contacts of the case-patients and investigated links between patients. Detailed results of the investigation have been described elsewhere^[15]. On December 29, 1998, the decision was made to implement a mass vaccination campaign to control the outbreak in the community, based on ACIP recommendations^[7]. We describe the epidemiology of the outbreak and the methods used for providing chemoprophylaxis and implementing the vaccination campaign. We also evaluate the results and the cost of the control efforts.