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[National action plan for the emergence of invasive meningococcal disease in Chile, 2012-2013]
M Teresa Valenzuela1, Jaime Mañalich2, Jorge Díaz3
1Ex Instituto de Salud Pública, Facultad de Medicina, Universidad de los Andes, Santiago, Chile.
Abstract:
Invasive meningococcal disease is challenging for public health, mainly when it manifests with sudden changes in incidence, serogroups and hypervirulent clones that spread in the population, causing great alarm due to its sequelae and often fatal course, a situation that occurred in Chile, starting at week 26 of the year 2012. To face this scenario, an organization of multidisciplinary teams was required, called W-135 Action Plan in Chile, which included sanitary alerts, education, reinforcement of the epidemiological surveillance of suspicious cases, immediate diagnosis through state-of-the-art techniques, blocking of contacts, communication plans, and, from the 42nd week, ON the vaccination campaign was started for children aged from 9-months-old to less than 5 years of age. The vaccination strategy had a great impact on the decrease in incidence (1.3 to 0.1/100,000) and case fatality rate in the vaccinated population (23% to 0%), with a high safety profile, leading to its subsequent inclusion in the national immunization program. The ability to develop molecular, clinical and epidemiological studies allowed us to better understand the situation, supporting public health policy decisions for its control. The W-135 Action Plan implemented by the Ministry of Health in Chile, to manage the outbreak of meningococcal disease by Neisseria meningitidis serogroup W, demonstrated that the coordination of these efforts, through an organized Action Plan, allows the implementation of campaigns at the national level achieving high coverage of risk populations in short periods of time, generating a positive impact on the health of the population.
Insights
Chile
Area of Science:
- Public Health
- Epidemiology
- Immunization
Background:
- Invasive meningococcal disease (IMD) poses public health challenges due to incidence shifts and hypervirulent strains.
- Chile experienced an alarming outbreak of IMD caused by Neisseria meningitidis serogroup W starting in 2012.
- The outbreak necessitated a coordinated multidisciplinary response to mitigate severe sequelae and fatalities.
Purpose of the Study:
- To evaluate the impact of the W-135 Action Plan on controlling a Neisseria meningitidis serogroup W outbreak in Chile.
- To assess the effectiveness of a targeted vaccination campaign in reducing IMD incidence and case fatality rates.
- To inform public health policy decisions for managing future IMD outbreaks.
Main Methods:
- Implementation of the W-135 Action Plan, including sanitary alerts, education, enhanced surveillance, rapid diagnostics, contact tracing, and communication.
- A national vaccination campaign targeting children aged 9 months to under 5 years.
- Molecular, clinical, and epidemiological studies to monitor the outbreak and intervention effectiveness.
Main Results:
- The vaccination strategy significantly decreased IMD incidence from 1.3 to 0.1 per 100,000 population.
- Case fatality rate in the vaccinated population dropped from 23% to 0%.
- The intervention demonstrated a high safety profile and led to the inclusion of the vaccine in the national immunization program.
Conclusions:
- The coordinated W-135 Action Plan effectively managed the IMD outbreak in Chile.
- National-level vaccination campaigns can achieve high coverage in at-risk populations rapidly, yielding significant public health benefits.
- Integrated public health strategies, supported by scientific studies, are crucial for controlling infectious disease outbreaks.
