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"Hatcher, Cynthia"
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sodC-Based Real-Time PCR for Detection of Neisseria meningitidis
2011
Real-time PCR (rt-PCR) is a widely used molecular method for detection of Neisseria meningitidis (Nm). Several rt-PCR assays for Nm target the capsule transport gene, ctrA. However, over 16% of meningococcal carriage isolates lack ctrA, rendering this target gene ineffective at identification of this sub-population of meningococcal isolates. The Cu-Zn superoxide dismutase gene, sodC, is found in Nm but not in other Neisseria species. To better identify Nm, regardless of capsule genotype or expression status, a sodC-based TaqMan rt-PCR assay was developed and validated. Standard curves revealed an average lower limit of detection of 73 genomes per reaction at cycle threshold (C(t)) value of 35, with 100% average reaction efficiency and an average R(2) of 0.9925. 99.7% (624/626) of Nm isolates tested were sodC-positive, with a range of average C(t) values from 13.0 to 29.5. The mean sodC C(t) value of these Nm isolates was 17.6±2.2 (±SD). Of the 626 Nm tested, 178 were nongroupable (NG) ctrA-negative Nm isolates, and 98.9% (176/178) of these were detected by sodC rt-PCR. The assay was 100% specific, with all 244 non-Nm isolates testing negative. Of 157 clinical specimens tested, sodC detected 25/157 Nm or 4 additional specimens compared to ctrA and 24 more than culture. Among 582 carriage specimens, sodC detected Nm in 1 more than ctrA and in 4 more than culture. This sodC rt-PCR assay is a highly sensitive and specific method for detection of Nm, especially in carriage studies where many meningococcal isolates lack capsule genes.
Journal Article
Serogroup A meningococcal conjugate vaccination in Burkina Faso: analysis of national surveillance data
by
Djingarey, Mamoudou H
,
Kambou, Jean Ludovic
,
Ouédraogo-Traoré, Rasmata
in
Adolescent
,
Adult
,
Bacterial diseases
2012
An affordable, highly immunogenic Neisseria meningitidis serogroup A meningococcal conjugate vaccine (PsA–TT) was licensed for use in sub-Saharan Africa in 2009. In 2010, Burkina Faso became the first country to implement a national prevention campaign, vaccinating 11·4 million people aged 1–29 years. We analysed national surveillance data around PsA–TT introduction to investigate the early effect of the vaccine on meningitis incidence and epidemics.
We examined national population-based meningitis surveillance data from Burkina Faso using two sources, one with cases and deaths aggregated at the district level from 1997 to 2011, and the other enhanced with results of cerebrospinal fluid examination and laboratory testing from 2007 to 2011. We compared mortality rates and incidence of suspected meningitis, probable meningococcal meningitis by age, and serogroup-specific meningococcal disease before and during the first year after PsA–TT implementation. We assessed the risk of meningitis disease and death between years.
During the 14 year period before PsA–TT introduction, Burkina Faso had 148 603 cases of suspected meningitis with 17 965 deaths, and 174 district-level epidemics. After vaccine introduction, there was a 71% decline in risk of meningitis (hazard ratio 0·29, 95% CI 0·28–0·30, p<0·0001) and a 64% decline in risk of fatal meningitis (0·36, 0·33–0·40, p<0·0001). We identified a statistically significant decline in risk of probable meningococcal meningitis across the age group targeted for vaccination (62%, cumulative incidence ratio [CIR] 0·38, 95% CI 0·31–0·45, p<0·0001), and among children aged less than 1 year (54%, 0·46, 0·24–0·86, p=0·02) and people aged 30 years and older (55%, 0·45, 0·22–0·91, p=0·003) who were ineligible for vaccination. No cases of serogroup A meningococcal meningitis occurred among vaccinated individuals, and epidemics were eliminated. The incidence of laboratory-confirmed serogroup A N meningitidis dropped significantly to 0·01 per 100 000 individuals per year, representing a 99·8% reduction in the risk of meningococcal A meningitis (CIR 0·002, 95% CI 0·0004–0·02, p<0·0001).
Early evidence suggests the conjugate vaccine has substantially reduced the rate of meningitis in people in the target age group, and in the general population because of high coverage and herd immunity. These data suggest that fully implementing the PsA–TT vaccine could end epidemic meningitis of serogroup A in sub-Saharan Africa.
None.
Journal Article
Progress with the Second Dose Measles Vaccine Introduction and Coverage in the WHO African Region
by
Shibeshi, Messeret E.
,
Wiysonge, Charles S.
,
Masresha, Balcha G.
in
Africa
,
Antigens
,
COVID-19 vaccines
2024
Introduction: To achieve global and regional measles elimination objectives, the World Health Organization (WHO) recommends coverage of 95% or higher with two doses of measles-containing vaccine. A second dose of measles-containing vaccine (MCV) is typically administered in the second year of life after 12 months of age. Methods: We reviewed WHO-UNICEF estimates of national coverage (WUENIC) for the first and second doses of MCV (MCV1 and MCV2, respectively) and calculated drop-out rates between MCV1 and MCV2 for countries in the WHO African Region. Results: From 2013 to 2023, estimated regional MCV2 coverage increased from 7% to 49%, and at the end of 2023, 43 (91%) countries had introduced MCV2 into their routine immunization programs. Countries with more antigens provided in the second year of life had higher mean and median MCV2 coverage levels, and lower drop-out rates between MCV1 and MCV2, as compared to countries providing only MCV2. Discussion: Despite substantial progress, MCV2 coverage remains below the required levels to achieve and sustain elimination, and many countries have high drop-out rates between MCV1 and MCV2 coverage, indicating challenges in reaching children over 12 months of age. Increasing coverage of MCV2 and other vaccines in the second year of life is essential to achieving higher and equitable routine immunization coverage. This will require continued efforts to understand and mitigate barriers to reaching children after 12 months of age and accelerated implementation of available tools.
Journal Article
Progress Toward Regional Measles Elimination — Worldwide, 2000–2020
by
Portnoy, Allison
,
Gacic-Dobo, Marta
,
Dixon, Meredith G.
in
Child
,
Coronaviruses
,
COVID-19 vaccines
2021
In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan,* with the objective of eliminating measles
in five of the six World Health Organization (WHO) regions by 2020 (1). The Immunization Agenda 2021-2030 (IA2030)
uses measles incidence as an indicator of the strength of immunization systems. The Measles-Rubella Strategic Framework 2021-2030
and the Measles Outbreaks Strategic Response Plan 2021-2023** are aligned with the IA2030 and highlight robust measles surveillance systems to document immunity gaps, identify root causes of undervaccination, and develop locally tailored solutions to ensure administration of 2 doses of measles-containing vaccine (MCV) to all children. This report describes progress toward World Health Assembly milestones and measles elimination objectives during 2000-2020 and updates a previous report (2). During 2000-2010, estimated MCV first dose (MCV1) coverage increased globally from 72% to 84%, peaked at 86% in 2019, but declined to 84% in 2020 during the COVID-19 pandemic. All countries conducted measles surveillance, although fewer than one third achieved the sensitivity indicator target of ≥2 discarded
cases per 100,000 population in 2020. Annual reported measles incidence decreased 88% during 2000-2016, from 145 to 18 cases per 1 million population, rebounded to 120 in 2019, before falling to 22 in 2020. During 2000-2020, the annual number of estimated measles deaths decreased 94%, from 1,072,800 to 60,700, averting an estimated 31.7 million measles deaths. To achieve regional measles elimination targets, enhanced efforts are needed to reach all children with 2 MCV doses, implement robust surveillance, and identify and close immunity gaps.
Journal Article
Progress Toward Regional Measles Elimination — Worldwide, 2000–2021
2022
All six World Health Organization (WHO) regions have committed to eliminating measles.* The Immunization Agenda 2021-2030 (IA2030)
aims to achieve the regional targets as a core indicator of impact and positions measles as the tracer of a health system's ability to deliver essential childhood vaccines. IA2030 highlights the importance of ensuring rigorous measles surveillance systems to document immunity gaps and achieve 95% coverage with 2 timely doses of measles-containing vaccine (MCV) among children. This report describes progress toward measles elimination during 2000-2021 and updates a previous report (1). During 2000-2021, estimated global coverage with a first MCV dose (MCV1) increased from 72% to a peak of 86% in 2019, but decreased during the COVID-19 pandemic to 83% in 2020 and to 81% in 2021, the lowest MCV1 coverage recorded since 2008. All countries conducted measles surveillance, but only 47 (35%) of 135 countries reporting discarded cases
achieved the sensitivity indicator target of two or more discarded cases per 100,000 population in 2021, indicating surveillance system underperformance in certain countries. Annual reported measles incidence decreased 88% during 2000-2016, from 145 to 18 cases per 1 million population, then rebounded to 120 in 2019 during a global resurgence (2), before declining to 21 in 2020 and to 17 in 2021. Large and disruptive outbreaks were reported in 22 countries. During 2000-2021, the annual number of estimated measles deaths decreased 83%, from 761,000 to 128,000; an estimated 56 million measles deaths were averted by vaccination. To regain progress and achieve regional measles elimination targets during and after the COVID-19 pandemic, accelerating targeted efforts is necessary to reach all children with 2 MCV doses while implementing robust surveillance and identifying and closing immunity gaps to prevent cases and outbreaks.
Journal Article
Health workers’ perceptions and challenges in implementing meningococcal serogroup a conjugate vaccine in the routine childhood immunization schedule in Burkina Faso
by
Walldorf, Jenny A.
,
Tarbangdo, Felix
,
Kambou, Ludovic
in
Aging
,
Aging (natural)
,
Attitude of Health Personnel
2020
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.
Journal Article
Emergence of Ciprofloxacin-Resistant Neisseria meningitidis in North America
2009
Meningococcal disease is associated with significant morbidity. Three cases of ciprofloxacin-resistant
Neisseria meningitidis
disease caused by the same serogroup B strain were detected in North Dakota and Minnesota. Recommendations for the antimicrobial agents to be used as secondary chemoprophylaxis have been modified in these areas.
Three cases of ciprofloxacin-resistant
Neisseria meningitidis
disease caused by the same serogroup B strain were detected in North Dakota and Minnesota. Recommendations for the antimicrobial agents to be used as secondary chemoprophylaxis have been modified in these areas.
Increasing antimicrobial resistance among bacterial pathogens is a public health threat.
1
N. meningitidis,
the cause of meningococcal disease, has been an exception, rarely showing resistance to commonly used antibiotics in the United States.
2
Nasopharyngeal carriage of
N. meningitidis
precedes meningococcal disease. Approximately 8 to 20% of the general population are asymptomatic carriers,
3
and the vast majority remain well. Close contacts of case patients are at increased risk for disease, and chemoprophylaxis is an urgent intervention for prevention of disease.
4
The currently recommended chemoprophylactic antibiotics are rifampin, ciprofloxacin, and ceftriaxone.
4
The fluoroquinolone ciprofloxacin is frequently prescribed, and ciprofloxacin-resistant
N. meningitidis
is . . .
Journal Article
Lessons learnt from the applying the Centers for Disease Control and Prevention (CDC) evaluation framework to the measles incident management system response, USA, 2020–2021
by
Hatcher, Cynthia
,
Blough, Sara
,
Grant, Gavin
in
Centers for Disease Control and Prevention, U.S
,
COVID-19
,
COVID-19 - epidemiology
2023
The functionality and performance of public health programmes at all levels of government play a critical role in preventing, detecting, mitigating and responding to public health threats, including infectious disease outbreaks. Multiple and concurrent outbreaks in recent years, such as COVID-19, Ebola and Zika, have highlighted the importance of documenting lessons learnt from public health responses of national and global agencies. In February 2020, the US Centers for Disease Control and Prevention (CDC) Center for Global Health (CGH) activated the Measles Incident Management System (MIMS) to accelerate the ability to detect, mitigate and respond to measles outbreaks globally and advance progress towards regional measles elimination goals. The activation was triggered by a global resurgence in reported measles cases during 2018–2019 and supported emergency response activities conducted by partner organisations and countries. MIMS leadership decided early in the response to form an evaluation team to design and implement an evaluation approach for producing real-time data to document progress of response activities and inform timely decision-making. In this manuscript, we describe how establishing an evaluation unit within MIMS, and engaging MIMS leadership and subject matter experts in the evaluation activities, was critical to monitor progress and document lessons learnt to inform decision making. We also explain the CDC’s Framework for Evaluation in Public Health Practice applied to evaluate the dynamic events throughout the MIMS response. Evaluators supporting emergency response should use a flexible framework that can be adaptable in dynamic contexts and document response activities in real-time.
Journal Article
Epidemiologic Investigation and Targeted Vaccination Initiative in Response to an Outbreak of Meningococcal Disease among Illicit Drug Users in Brooklyn, New York
by
Mayer, Leonard W.
,
Weiss, Don
,
Zimmerman, Christopher
in
Addictive behaviors
,
Adolescent
,
Adult
2009
Background. An outbreak of serogroup C meningococcal disease that involved illicit drug users and their contacts occurred in Brooklyn, New York, during 2005 and 2006. Methods. The objectives of this study were to identify the population at risk for meningococcal disease, describe efforts to interrupt disease transmission, and assess the impact of a vaccine initiative. Descriptive and molecular epidemiological analysis was used to define the extent of the outbreak and the common risk factors among outbreak-related cases. A vaccine initiative that used community-based service providers was targeted to illicit drug users and their close contacts. The vaccine initiative was assessed through cessation of outbreak-related cases and the reduction in carriage rate. Results. The investigation identified 23 outbreak-related cases of serogroup C meningococcal disease; 17 isolates were indistinguishable and 4 isolates were closely related according to pulsed-field gel electrophoresis. Two additional culture-negative cases had epidemiological links to laboratory-confirmed cases. The median age of patients with outbreak-related cases was 41 years, and 19 (83%) of 23 patients reported an association with illicit drug use. There were 7 outbreak-related deaths. Vaccination was administered to 2763 persons at 29 community locations, including methadone treatment centers, syringe-exchange programs, and soup kitchens. Three additional cases of meningococcal disease due to strains with the same pulsed-field gel electrophoresis pattern were identified after the vaccination initiative. Conclusions. Community-based outbreaks of meningococcal disease are difficult to control, and the decision to vaccinate is not straightforward. Current national guidelines for implementing a vaccination campaign are not strict criteria and cannot be expected to accommodate the myriad of factors that occur in community-based invasive meningococcal disease outbreaks, such as the inability to enumerate the population at risk.
Journal Article
Progress Toward Measles Elimination — Worldwide, 2000–2022
by
Portnoy, Allison
,
O’Connor, Patrick
,
Caro, William Perea
in
Children
,
Comparative studies
,
COVID-19
2023
Measles is a highly contagious, vaccine-preventable disease that requires high population immunity for transmission to be interrupted. All six World Health Organization regions have committed to eliminating measles; however, no region has achieved and sustained measles elimination. This report describes measles elimination progress during 2000-2022. During 2000-2019, estimated coverage worldwide with the first dose of measles-containing vaccine (MCV) increased from 72% to 86%, then declined to 81% in 2021 during the COVID-19 pandemic, representing the lowest coverage since 2008. In 2022, first-dose MCV coverage increased to 83%. Only one half (72) of 144 countries reporting measles cases achieved the measles surveillance indicator target of two or more discarded cases per 100,000 population in 2022. During 2021-2022, estimated measles cases increased 18%, from 7,802,000 to 9,232,300, and the number of countries experiencing large or disruptive outbreaks increased from 22 to 37. Estimated measles deaths increased 43% during 2021-2022, from 95,000 to 136,200. Nonetheless, an estimated 57 million measles deaths were averted by vaccination during 2000-2022. In 2022, measles vaccination coverage and global surveillance showed some recovery from the COVID-19 pandemic setbacks; however, coverage declined in low-income countries, and globally, years of suboptimal immunization coverage left millions of children unprotected. Urgent reversal of coverage setbacks experienced during the COVID-19 pandemic can be accomplished by renewing efforts to vaccinate all children with 2 MCV doses and strengthening surveillance, thereby preventing outbreaks and accelerating progress toward measles elimination.Measles is a highly contagious, vaccine-preventable disease that requires high population immunity for transmission to be interrupted. All six World Health Organization regions have committed to eliminating measles; however, no region has achieved and sustained measles elimination. This report describes measles elimination progress during 2000-2022. During 2000-2019, estimated coverage worldwide with the first dose of measles-containing vaccine (MCV) increased from 72% to 86%, then declined to 81% in 2021 during the COVID-19 pandemic, representing the lowest coverage since 2008. In 2022, first-dose MCV coverage increased to 83%. Only one half (72) of 144 countries reporting measles cases achieved the measles surveillance indicator target of two or more discarded cases per 100,000 population in 2022. During 2021-2022, estimated measles cases increased 18%, from 7,802,000 to 9,232,300, and the number of countries experiencing large or disruptive outbreaks increased from 22 to 37. Estimated measles deaths increased 43% during 2021-2022, from 95,000 to 136,200. Nonetheless, an estimated 57 million measles deaths were averted by vaccination during 2000-2022. In 2022, measles vaccination coverage and global surveillance showed some recovery from the COVID-19 pandemic setbacks; however, coverage declined in low-income countries, and globally, years of suboptimal immunization coverage left millions of children unprotected. Urgent reversal of coverage setbacks experienced during the COVID-19 pandemic can be accomplished by renewing efforts to vaccinate all children with 2 MCV doses and strengthening surveillance, thereby preventing outbreaks and accelerating progress toward measles elimination.
Journal Article