Expansion of Neisseria meningitidis Serogroup C Clonal Complex 10217 during Meningitis Outbreak, Burkina Faso, 2019.

During January 28-May 5, 2019, a meningitis outbreak caused by Neisseria meningitidis serogroup C (NmC) occurred in Burkina Faso. Demographic and laboratory data for meningitis cases were collected through national case-based surveillance. Cerebrospinal fluid was collected and tested by culture and real-time PCR. Among 301 suspected cases reported in 6 districts, N. meningitidis was the primary pathogen detected; 103 cases were serogroup C and 13 were serogroup X. Whole-genome sequencing revealed that 18 cerebrospinal fluid specimens tested positive for NmC sequence type (ST) 10217 within clonal complex 10217, an ST responsible for large epidemics in Niger and Nigeria. Expansion of NmC ST10217 into Burkina Faso, continued NmC outbreaks in the meningitis belt of Africa since 2019, and ongoing circulation of N. meningitidis serogroup X in the region underscore the urgent need to use multivalent conjugate vaccines in regional mass vaccination campaigns to reduce further spread of those serogroups.

Early Detection and Surveillance of the SARS-CoV-2 Variant BA.2.86 - Worldwide, July-October 2023.

Early detection of emerging SARS-CoV-2 variants is critical to guiding rapid risk assessments, providing clear and timely communication messages, and coordinating public health action. CDC identifies and monitors novel SARS-CoV-2 variants through diverse surveillance approaches, including genomic, wastewater, traveler-based, and digital public health surveillance (e.g., global data repositories, news, and social media). The SARS-CoV-2 variant BA.2.86 was first sequenced in Israel and reported on August 13, 2023. The first U.S. COVID-19 case caused by this variant was reported on August 17, 2023, after a patient received testing for SARS-CoV-2 at a health care facility on August 3. In the following month, eight additional U.S. states detected BA.2.86 across various surveillance systems, including specimens from health care settings, wastewater surveillance, and traveler-based genomic surveillance. As of October 23, 2023, sequences have been reported from at least 32 countries. Continued variant tracking and further evidence are needed to evaluate the full public health impact of BA.2.86. Timely genomic sequence submissions to global public databases aided early detection of BA.2.86 despite the decline in the number of specimens being sequenced during the past year. This report describes how multicomponent surveillance and genomic sequencing were used in real time to track the emergence and transmission of the BA.2.86 variant. This surveillance approach provides valuable information regarding implementing and sustaining comprehensive surveillance not only for novel SARS-CoV-2 variants but also for future pathogen threats.

COVID-19 Mortality and Progress Toward Vaccinating Older Adults - World Health Organization, Worldwide, 2020-2022.

After the emergence of SARS-CoV-2 in late 2019, transmission expanded globally, and on January 30, 2020, COVID-19 was declared a public health emergency of international concern.* Analysis of the early Wuhan, China outbreak (1), subsequently confirmed by multiple other studies (2,3), found that 80% of deaths occurred among persons aged ≥60 years. In anticipation of the time needed for the global vaccine supply to meet all needs, the World Health Organization (WHO) published the Strategic Advisory Group of Experts on Immunization (SAGE) Values Framework and a roadmap for prioritizing use of COVID-19 vaccines in late 2020 (4,5), followed by a strategy brief to outline urgent actions in October 2021.† WHO described the general principles, objectives, and priorities needed to support country planning of vaccine rollout to minimize severe disease and death. A July 2022 update to the strategy brief§ prioritized vaccination of populations at increased risk, including older adults,¶ with the goal of 100% coverage with a complete COVID-19 vaccination series** for at-risk populations. Using available public data on COVID-19 mortality (reported deaths and model estimates) for 2020 and 2021 and the most recent reported COVID-19 vaccination coverage data from WHO, investigators performed descriptive analyses to examine age-specific mortality and global vaccination rollout among older adults (as defined by each country), stratified by country World Bank income status. Data quality and COVID-19 death reporting frequency varied by data source; however, persons aged ≥60 years accounted for >80% of the overall COVID-19 mortality across all income groups, with upper- and lower-middle-income countries accounting for 80% of the overall estimated excess mortality. Effective COVID-19 vaccines were authorized for use in December 2020, with global supply scaled up sufficiently to meet country needs by late 2021 (6). COVID-19 vaccines are safe and highly effective in reducing severe COVID-19, hospitalizations, and mortality (7,8); nevertheless, country-reported median completed primary series coverage among adults aged ≥60 years only reached 76% by the end of 2022, substantially below the WHO goal, especially in middle- and low-income countries. Increased efforts are needed to increase primary series and booster dose coverage among all older adults as recommended by WHO and national health authorities.

Cruise Ship Travel in the Era of Coronavirus Disease 2019 (COVID-19): A Summary of Outbreaks and a Model of Public Health Interventions.

BACKGROUND: Cruise travel contributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission when there were relatively few cases in the United States. By 14 March 2020, the Centers for Disease Control and Prevention (CDC) issued a No Sail Order suspending US cruise operations; the last US passenger ship docked on 16 April. METHODS: We analyzed SARS-CoV-2 outbreaks on cruises in US waters or carrying US citizens and used regression models to compare voyage characteristics. We used compartmental models to simulate the potential impact of 4 interventions (screening for coronavirus disease 2019 (COVID-19) symptoms; viral testing on 2 days and isolation of positive persons; reduction of passengers by 40%, crew by 20%, and reducing port visits to 1) for 7-day and 14-day voyages. RESULTS: During 19 January to 16 April 2020, 89 voyages on 70 ships had known SARS-CoV-2 outbreaks; 16 ships had recurrent outbreaks. There were 1669 reverse transcription polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infections and 29 confirmed deaths. Longer voyages were associated with more cases (adjusted incidence rate ratio, 1.10, 95% confidence interval [CI]: 1.03-1.17, P < .003). Mathematical models showed that 7-day voyages had about 70% fewer cases than 14-day voyages. On 7-day voyages, the most effective interventions were reducing the number of individuals onboard (43.3% reduction in total infections) and testing passengers and crew (42% reduction in total infections). All four interventions reduced transmission by 80.1%, but no single intervention or combination eliminated transmission. Results were similar for 14-day voyages. CONCLUSIONS: SARS-CoV-2 outbreaks on cruises were common during January-April 2020. Despite all interventions modeled, cruise travel still poses a significant SARS-CoV-2 transmission risk.

COVID-19 Mortality and Vaccine Coverage - Hong Kong Special Administrative Region, China, January 6, 2022-March 21, 2022.

On January 6, 2022, a cluster of COVID-19 cases* caused by the Omicron variant of SARS-CoV-2, the virus that causes COVID-19, was detected in Hong Kong Special Administrative Region, China (Hong Kong), resulting in the territory's fifth wave of COVID-19 cases (1). This wave peaked on March 4, 2022, with 8,764 COVID-19 cases per million population (2), resulting in a total of 1,049,959 cases and 5,906 COVID-19-associated deaths reported to the Hong Kong Department of Health during January 6-March 21, 2022.† Throughout this period, the COVID-19 mortality rate in Hong Kong (37.7 per million population) was among the highest reported worldwide since the COVID-19 pandemic began (3). Publicly available data on age-specific vaccination coverage in Hong Kong with a 2-dose primary vaccination series (with either Sinovac-CoronaVac [Sinovac], an inactivated COVID-19 viral vaccine, recommended for persons aged ≥3 years or BNT162b2 [Pfizer-BioNTech], an mRNA vaccine, for persons aged ≥5 years), as of December 23, 2021,§,¶ and COVID-19 mortality during January 6-March 21, 2022, were analyzed. By December 23, 2021, 67% of vaccine-eligible persons in Hong Kong had received ≥1 dose of a COVID-19 vaccine, 64% had received ≥2 doses, and 5% had received a booster dose. Among persons aged ≥60 years, these proportions were 52%, 49%, and 7%, respectively. Among those aged ≥60 years, vaccination coverage declined with age: 48% of persons aged 70-79 years had received ≥1 dose, 45% received ≥2 doses, and 7% had received a booster, and among those aged ≥80 years, 20%, 18%, and 2% had received ≥1 dose, ≥2 doses, and a booster dose, respectively. Among 5,906 COVID-19 deaths reported, 5,655 (96%) occurred in persons aged ≥60 years**; among these decedents, 3,970 (70%) were unvaccinated, 18% (1,023) had received 1 vaccine dose, and 12% (662) had received ≥2 doses. The overall rates of COVID-19-associated mortality among persons aged ≥60 years who were unvaccinated, who had received 1 COVID-19 vaccine dose, and who had received ≥2 vaccine doses were 10,076, 1,099, and 473 per million population, respectively; the risk for COVID-19-associated death among unvaccinated persons was 21.3 times that among recipients of 2-3 doses in this age group. The high overall mortality rate during the ongoing 2022 Hong Kong Omicron COVID-19 outbreak is being driven by deaths among unvaccinated persons aged ≥60 years. Efforts to identify and address gaps in age-specific vaccination coverage can help prevent high mortality from COVID-19, especially among persons aged ≥60 years.

Public Health Responses to COVID-19 Outbreaks on Cruise Ships - Worldwide, February-March 2020.

An estimated 30 million passengers are transported on 272 cruise ships worldwide each year* (1). Cruise ships bring diverse populations into proximity for many days, facilitating transmission of respiratory illness (2). SARS-CoV-2, the virus that causes coronavirus disease (COVID-19) was first identified in Wuhan, China, in December 2019 and has since spread worldwide to at least 187 countries and territories. Widespread COVID-19 transmission on cruise ships has been reported as well (3). Passengers on certain cruise ship voyages might be aged ≥65 years, which places them at greater risk for severe consequences of SARS-CoV-2 infection (4). During February-March 2020, COVID-19 outbreaks associated with three cruise ship voyages have caused more than 800 laboratory-confirmed cases among passengers and crew, including 10 deaths. Transmission occurred across multiple voyages of several ships. This report describes public health responses to COVID-19 outbreaks on these ships. COVID-19 on cruise ships poses a risk for rapid spread of disease, causing outbreaks in a vulnerable population, and aggressive efforts are required to contain spread. All persons should defer all cruise travel worldwide during the COVID-19 pandemic.

Health workers' perceptions and challenges in implementing meningococcal serogroup a conjugate vaccine in the routine childhood immunization schedule in Burkina Faso.

BACKGROUND: Meningococcal serogroup A conjugate vaccine (MACV) was introduced in 2017 into the routine childhood immunization schedule (at 15-18 months of age) in Burkina Faso to help reduce meningococcal meningitis burden. MACV was scheduled to be co-administered with the second dose of measles-containing vaccine (MCV2), a vaccine already in the national schedule. One year following the introduction of MACV, an assessment was conducted to qualitatively examine health workers' perceptions of MACV introduction, identify barriers to uptake, and explore opportunities to improve coverage. METHODS: Twelve in-depth interviews were conducted with different cadres of health workers in four purposively selected districts in Burkina Faso. Districts were selected to include urban and rural areas as well as high and low MCV2 coverage areas. Respondents included health workers at the following levels: regional health managers (n = 4), district health managers (n = 4), and frontline healthcare providers (n = 4). All interviews were recorded, transcribed, and thematically analyzed using qualitative content analysis. RESULTS: Four themes emerged around supply and health systems barriers, demand-related barriers, specific challenges related to MACV and MCV2 co-administration, and motivations and efforts to improve vaccination coverage. Supply and health systems barriers included aging cold chain equipment, staff shortages, overworked and poorly trained staff, insufficient supplies and financial resources, and challenges with implementing community outreach activities. Health workers largely viewed MACV introduction as a source of motivation for caregivers to bring their children for the 15- to 18-month visit. However, they also pointed to demand barriers, including cultural practices that sometimes discourage vaccination, misconceptions about vaccines, and religious beliefs. Challenges in co-administering MACV and MCV2 were mainly related to reluctance among health workers to open multi-dose vials unless enough children were present to avoid wastage. CONCLUSIONS: To improve effective administration of vaccines in the second-year of life, adequate operational and programmatic planning, training, communication, and monitoring are necessary. Moreover, clear policy communication is needed to help ensure that health workers do not refrain from opening multi-dose vials for small numbers of children.

Invasive Meningococcal Disease in Africa's Meningitis Belt: More Than Just Meningitis?

Since the progressive introduction of the meningococcal serogroup A conjugate vaccine within Africa's meningitis belt beginning in 2010, the burden of meningitis due to Neisseria meningitidis serogroup A (NmA) has substantially decreased. Non-A serogroups C/W/X are now the most prevalent. Surveillance within the belt has historically focused on the clinical syndrome of meningitis, the classic presentation for NmA, and may not adequately capture other presentations of invasive meningococcal disease (IMD). The clinical presentation of infection due to serogroups C/W/X includes nonmeningeal IMD, and there is a higher case-fatality ratio associated with these non-A serogroups; however, data on the nonmeningeal IMD burden within the belt are scarce. Expanding surveillance to capture all cases of IMD, in accordance with the World Health Organization's updated vaccine-preventable disease surveillance standards and in preparation for the anticipated introduction of a multivalent meningococcal conjugate vaccine within Africa's meningitis belt, will enhance meningococcal disease prevention across the belt.

Development and Implementation of a Cloud-Based Meningitis Surveillance and Specimen Tracking System in Burkina Faso, 2018.

Nationwide case-based meningitis surveillance was established in Burkina Faso following the introduction of meningococcal serogroup A conjugate vaccine in 2010. However, timely tracking and arrival of cerebrospinal fluid specimens for confirmation at national reference laboratories remained suboptimal. To better understand this gap and identify bottlenecks, the Burkina Faso Ministry of Health, along with key partners, developed and implemented a cloud-based System for Tracking Epidemiological Data and Laboratory Specimens (STELAB), allowing for timely nationwide data reporting and specimen tracking using barcodes. STELAB was adapted to Burkina Faso's infrastructure to ensure suitability, functionality, flexibility, and sustainability. We describe the design, development, and implementation of STELAB. In addition, we discuss strategies used to promote sustainability, lessons learned during the first year of implementation, and future directions. STELAB's novel design and country-driven approach has the potential to achieve sustainable real-time data reporting and specimen tracking for the first time in sub-Saharan Africa.

Future Directions for Meningitis Surveillance and Vaccine Evaluation in the Meningitis Belt of Sub-Saharan Africa.

In sub-Saharan Africa, bacterial meningitis remains a significant public health problem, especially in the countries of the meningitis belt, where Neisseria meningitidis serogroup A historically caused large-scale epidemics. In 2014, MenAfriNet was established as a consortium of partners supporting strategic implementation of case-based meningitis surveillance to monitor meningitis epidemiology and impact of meningococcal serogroup A conjugate vaccine (MACV). MenAfriNet improved data quality through use of standardized tools, procedures, and laboratory diagnostics. MenAfriNet surveillance and study data provided evidence of ongoing MACV impact, characterized the burden of non-serogroup A meningococcal disease (including the emergence of a new epidemic clone of serogroup C), and documented the impact of pneumococcal conjugate vaccine. New vaccines and schedules have been proposed for future implementation to address the remaining burden of meningitis. To support the goals of "Defeating Meningitis by 2030," MenAfriNet will continue to strengthen surveillance and support research and modeling to monitor the impact of these programs on meningitis burden in sub-Saharan Africa.

A New Sequence Type of Neisseria meningitidis Serogroup C Associated With a 2016 Meningitis Outbreak in Mali.

In 2016, Mali reported a bacterial meningitis outbreak consisting of 39 suspected cases between epidemiologic weeks 9 and 17 with 15% case fatality ratio in the health district of Ouéléssebougou, 80 kilometers from the capital Bamako. Cerebrospinal fluid specimens from 29 cases were tested by culture and real-time polymerase chain reaction; 22 (76%) were positive for bacterial meningitis pathogens, 16 (73%) of which were Neisseria meningitidis (Nm). Of the Nm-positive specimens, 14 (88%) were N meningitidis serogroup C (NmC), 1 was NmW, and 1 was nongroupable. Eight NmC isolates recovered by culture from the outbreak were characterized using whole genome sequencing. Genomics analysis revealed that all 8 isolates belonged to a new sequence type (ST) 12446 of clonal complex 10217 that formed a distinct clade genetically similar to ST-10217, a NmC strain that recently caused large epidemics of meningitis in Niger and Nigeria. The emergence of a new ST of NmC associated with an outbreak in the African meningitis belt further highlights the need for continued molecular surveillance in the region.

Impact of 13-Valent Pneumococcal Conjugate Vaccine on Pneumococcal Meningitis, Burkina Faso, 2016-2017.

BACKGROUND: In 2013, Burkina Faso introduced 13-valent pneumococcal conjugate vaccine (PCV13) into the routine childhood immunization program, to be administered to children at 8, 12, and 16 weeks of age. We evaluated the impact of PCV13 on pneumococcal meningitis. METHODS: Using nationwide surveillance, we gathered demographic/clinical information and cerebrospinal fluid (CSF) results for meningitis cases. Pneumococcal cases were confirmed by culture, polymerase chain reaction (PCR), or latex agglutination; strains were serotyped using PCR. We compared annual incidence (cases per 100 000) 4 years after PCV13's introduction (2017) to average pre-PCV13 incidence (2011-2013). We adjusted incidence for age and proportion of cases with CSF tested at national laboratories. RESULTS: In 2017, pneumococcal meningitis incidence was 2.7 overall and 10.5 (<1 year), 3.8 (1-4 years), 3.5 (5-14 years), and 1.4 (≥15 years) by age group. Compared to 2011-2013, PCV13-serotype incidence was significantly lower among all age groups, with the greatest decline among children aged <1 year (77%; 95% confidence interval [CI], 65%-84%). Among all ages, the drop in incidence was larger for PCV13 serotypes excluding serotype 1 (79%; 95% CI, 72%-84%) than for serotype 1 (52%; 95% CI, 44%-59%); incidence of non-PCV13 serotypes also declined (53%; 95% CI, 37%-65%). In 2017, 45% of serotyped cases among all ages were serotype 1 and 12% were other PCV13 serotypes. CONCLUSIONS: In Burkina Faso, meningitis caused by PCV13 serotypes continues to decrease, especially among young children. However, the concurrent decline in non-PCV13 serotypes and short pre-PCV13 observation period complicate evaluation of PCV13's impact. Efforts to improve control of serotype 1, such as switching from a 3 + 0 schedule to a 2 + 1 schedule, may improve overall control of pneumococcal meningitis in this setting.

Bacterial Meningitis Epidemiology in Five Countries in the Meningitis Belt of Sub-Saharan Africa, 2015-2017.

BACKGROUND: The MenAfriNet Consortium supports strategic implementation of case-based meningitis surveillance in key high-risk countries of the African meningitis belt: Burkina Faso, Chad, Mali, Niger, and Togo. We describe bacterial meningitis epidemiology in these 5 countries in 2015-2017. METHODS: Case-based meningitis surveillance collects case-level demographic and clinical information and cerebrospinal fluid (CSF) laboratory results. Neisseria meningitidis, Streptococcus pneumoniae, or Haemophilus influenzae cases were confirmed and N. meningitidis/H. influenzae were serogrouped/serotyped by real-time polymerase chain reaction, culture, or latex agglutination. We calculated annual incidence in participating districts in each country in cases/100 000 population. RESULTS: From 2015-2017, 18 262 suspected meningitis cases were reported; 92% had a CSF specimen available, of which 26% were confirmed as N. meningitidis (n = 2433; 56%), S. pneumoniae (n = 1758; 40%), or H. influenzae (n = 180; 4%). Average annual incidences for N. meningitidis, S. pneumoniae, and H. influenzae, respectively, were 7.5, 2.5, and 0.3. N. meningitidis incidence was 1.5 in Burkina Faso, 2.7 in Chad, 0.4 in Mali, 14.7 in Niger, and 12.5 in Togo. Several outbreaks occurred: NmC in Niger in 2015-2017, NmC in Mali in 2016, and NmW in Togo in 2016-2017. Of N. meningitidis cases, 53% were NmC, 30% NmW, and 13% NmX. Five NmA cases were reported (Burkina Faso, 2015). NmX increased from 0.6% of N. meningitidis cases in 2015 to 27% in 2017. CONCLUSIONS: Although bacterial meningitis epidemiology varied widely by country, NmC and NmW caused several outbreaks, NmX increased although was not associated with outbreaks, and overall NmA incidence remained low. An effective low-cost multivalent meningococcal conjugate vaccine could help further control meningococcal meningitis in the region.

Evaluation of the Impact of Meningococcal Serogroup A Conjugate Vaccine Introduction on Second-Year-of-Life Vaccination Coverage in Burkina Faso.

BACKGROUND: After successful meningococcal serogroup A conjugate vaccine (MACV) campaigns since 2010, Burkina Faso introduced MACV in March 2017 into the routine Expanded Programme for Immunization schedule at age 15-18 months, concomitantly with second-dose measles-containing vaccine (MCV2). We examined MCV2 coverage in pre- and post-MACV introduction cohorts to describe observed changes regionally and nationally. METHODS: A nationwide household cluster survey of children 18-41 months of age was conducted 1 year after MACV introduction. Coverage was assessed by verification of vaccination cards or recall. Two age groups were included to compare MCV2 coverage pre-MACV introduction (30-41 months) versus post-MACV introduction (18-26 months). RESULTS: In total, 15 925 households were surveyed; 7796 children were enrolled, including 3684 30-41 months of age and 3091 18-26 months of age. Vaccination documentation was observed for 86% of children. The MACV routine coverage was 58% (95% confidence interval [CI], 56%-61%) with variation by region (41%-76%). The MCV2 coverage was 62% (95% CI, 59%-65%) pre-MACV introduction and 67% (95% CI, 64%-69%) post-MACV introduction, an increase of 4.5% (95% CI, 1.3%-7.7%). Among children who received routine MACV and MCV2, 93% (95% CI, 91%-94%) received both at the same visit. Lack of caregiver awareness about the 15- to 18-month visit and vaccine unavailability were common reported barriers to vaccination. CONCLUSIONS: A small yet significant increase in national MCV2 coverage was observed 1 year post-MACV introduction. The MACV/MCV2 coadministration was common. Findings will help inform strategies to strengthen second-year-of-life immunization coverage, including to address the communication and vaccine availability barriers identified.

MenAfriNet: A Network Supporting Case-Based Meningitis Surveillance and Vaccine Evaluation in the Meningitis Belt of Africa.

Meningococcal meningitis remains a significant public health threat, especially in the African meningitis belt where Neisseria meningitidis serogroup A historically caused large-scale epidemics. With the rollout of a novel meningococcal serogroup A conjugate vaccine (MACV) in the belt, the World Health Organization recommended case-based meningitis surveillance to monitor MACV impact and meningitis epidemiology. In 2014, the MenAfriNet consortium was established to support strategic implementation of case-based meningitis surveillance in 5 key countries: Burkina Faso, Chad, Mali, Niger, and Togo. MenAfriNet aimed to develop a high-quality surveillance network using standardized laboratory and data collection protocols, develop sustainable systems for data management and analysis to monitor MACV impact, and leverage the surveillance platform to perform special studies. We describe the MenAfriNet consortium, its history, strategy, implementation, accomplishments, and challenges.

Whole-Genome Characterization of Epidemic Neisseria meningitidis Serogroup C and Resurgence of Serogroup W, Niger, 2015.

In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013-2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa.

Introduction and Rollout of a New Group A Meningococcal Conjugate Vaccine (PsA-TT) in African Meningitis Belt Countries, 2010-2014.

BACKGROUND: A group A meningococcal conjugate vaccine (PsA-TT) was developed specifically for the African "meningitis belt" and was prequalified by the World Health Organization (WHO) in June 2010. The vaccine was first used widely in Burkina Faso, Mali, and Niger in December 2010 with great success. The remaining 23 meningitis belt countries wished to use this new vaccine. METHODS: With the help of African countries, WHO developed a prioritization scheme and used or adapted existing immunization guidelines to mount PsA-TT vaccination campaigns. Vaccine requirements were harmonized with the Serum Institute of India, Ltd. RESULTS: Burkina Faso was the first country to fully immunize its 1- to 29-year-old population in December 2010. Over the next 4 years, vaccine coverage was extended to 217 million Africans living in 15 meningitis belt countries. CONCLUSIONS: The new group A meningococcal conjugate vaccine was well received, with country coverage rates ranging from 85% to 95%. The rollout proceeded smoothly because countries at highest risk were immunized first while attention was paid to geographic contiguity to maximize herd protection. Community participation was exemplary.

Public Health Impact After the Introduction of PsA-TT: The First 4 Years.

BACKGROUND: During the first introduction of a group A meningococcal vaccine (PsA-TT) in 2010-2011 and its rollout from 2011 to 2013, >150 million eligible people, representing 12 hyperendemic meningitis countries, have been vaccinated. METHODS: The new vaccine effectiveness evaluation framework was established by the World Health Organization and partners. Meningitis case-based surveillance was strengthened in PsA-TT first-introducer countries, and several evaluation studies were conducted to estimate the vaccination coverage and to measure the impact of vaccine introduction on meningococcal carriage and disease incidence. RESULTS: PsA-TT implementation achieved high vaccination coverage, and results from studies conducted showed significant decrease of disease incidence as well as significant reduction of oropharyngeal carriage of group A meningococci in vaccinated and unvaccinated individuals, demonstrating the vaccine's ability to generate herd protection and prevent group A epidemics. CONCLUSIONS: Lessons learned from this experience provide useful insights in how to guide and better prepare for future new vaccine introductions in resource-limited settings.

Population-based surveillance for bacterial meningitis in China, September 2006-December 2009.

During September 2006-December 2009, we conducted active population and sentinel laboratory-based surveillance for bacterial meningitis pathogens, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b, in 4 China prefectures. We identified 7,876 acute meningitis and encephalitis syndrome cases, including 6,388 among prefecture residents. A total of 833 resident cases from sentinel hospitals met the World Health Organization case definition for probable bacterial meningitis; 339 of these cases were among children <5 years of age. Laboratory testing confirmed bacterial meningitis in 74 of 3,391 tested cases. The estimated annual incidence (per 100,000 population) of probable bacterial meningitis ranged from 1.84 to 2.93 for the entire population and from 6.95 to 22.30 for children <5 years old. Active surveillance with laboratory confirmation has provided a population-based estimate of the number of probable bacterial meningitis cases in China, but more complete laboratory testing is needed to better define the epidemiology of the disease in this country.