Direct Real-Time PCR for the Detection and Serotyping of Haemophilus influenzae without DNA Extraction.

To monitor the burden and changes in Haemophilus influenzae (Hi) disease, direct real-time PCR (drt-PCR) assays have been developed for Hi detection in monoplex form and its six serotypes in triplex form, directly from cerebrospinal fluid (CSF) specimens. These assays target the gene for the species detection (Hi-) and serotype-specific genes in region II of the capsule biosynthesis locus (Hi-abf and Hi-cde), identified through comparative analysis of Hi and non-Hi whole-genome sequences. The lower limit of detection (LLD) is 293 CFU/mL for the Hi- assay and ranged from 11 to 130 CFU/mL for the triplex serotyping assays.

Genomic Insights on Variation Underlying Capsule Expression in Meningococcal Carriage Isolates From University Students, United States, 2015-2016.

In January and February 2015, serogroup B (NmB) outbreaks occurred at two universities in the United States, and mass vaccination campaigns using MenB vaccines were initiated as part of a public health response. Meningococcal carriage evaluations were conducted concurrently with vaccination campaigns at these two universities and at a third university, where no NmB outbreak occurred. Meningococcal isolates ( = 1,514) obtained from these evaluations were characterized for capsule biosynthesis by whole-genome sequencing (WGS).

Genetic Diversity of Meningococcal Serogroup B Vaccine Antigens among Carriage Isolates Collected from Students at Three Universities in the United States, 2015-2016.

Carriage evaluations were conducted during 2015 to 2016 at two U.S. universities in conjunction with the response to disease outbreaks caused by serogroup B and at a university where outbreak and response activities had not occurred.

Genomic characterization of Haemophilus influenzae: a focus on the capsule locus.

Background: Haemophilus influenzae (Hi) can cause invasive diseases such as meningitis, pneumonia, or sepsis. Typeable Hi includes six serotypes (a through f), each expressing a unique capsular polysaccharide. The capsule, encoded by the genes within the capsule locus, is a major virulence factor of typeable Hi.

Meningococcal Carriage Following a Vaccination Campaign With MenB-4C and MenB-FHbp in Response to a University Serogroup B Meningococcal Disease Outbreak-Oregon, 2015-2016.

Background: Limited data exist on the impact of the serogroup B meningococcal (MenB) vaccines MenB-FHbp and MenB-4C on meningococcal carriage and herd protection. We therefore assessed meningococcal carriage following a MenB vaccination campaign in response to a university serogroup B meningococcal disease outbreak in 2015.

Methods: A convenience sample of students recommended for vaccination provided oropharyngeal swab specimens and completed questionnaires during 4 carriage surveys over 11 months.

Changes in the Population Structure of Invasive Neisseria meningitidis in the United States After Quadrivalent Meningococcal Conjugate Vaccine Licensure.

Background: Meningococcal conjugate vaccines against serogroups A, C, W, and Y (MenACWY) are recommended for routine use in adolescents aged 11-18 years. The impact of these vaccines on the meningococcal population structure in the United States have yet to be evaluated.

Methods: Meningococcal isolates recovered during 2006-2010 (ie, after introduction of MenACWY) collected through Active Bacterial Core surveillance (ABCs) were characterized; serogroup distribution and molecular features of these isolates were compared to previously published data on ABCs isolates recovered from 2000 to 2005 (ie, before introduction of MenACWY).

Meningococcal carriage among Georgia and Maryland high school students.

Background: Meningococcal disease incidence in the United States is at an all-time low. In a previous study of Georgia high school students, meningococcal carriage prevalence was 7%. The purpose of this study was to measure the impact of a meningococcal conjugate vaccine on serogroup Y meningococcal carriage and to define the dynamics of carriage in high school students.

Prolonged university outbreak of meningococcal disease associated with a serogroup B strain rarely seen in the United States.

Background: College students living in residential halls are at increased risk of meningococcal disease. Unlike that for serogroups prevented by quadrivalent meningococcal vaccines, public health response to outbreaks of serogroup B meningococcal disease is limited by lack of a US licensed vaccine.

Methods: In March 2010, we investigated a prolonged outbreak of serogroup B disease associated with a university.

sodC-based real-time PCR for detection of Neisseria meningitidis.

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.

Prevalence and genetic diversity of candidate vaccine antigens among invasive Neisseria meningitidis isolates in the United States.

Neisseria meningitidis (Nm) serogroups B, C and Y are the major causes of meningococcal diseases in the United States. NmB accounts for ∼1/3 of the disease but no licensed vaccine is yet available. Two candidate vaccines are being developed specifically to target NmB, but may also provide protection against other serogroups.

Early estimate of the effectiveness of quadrivalent meningococcal conjugate vaccine.

Background: In January 2005, a quadrivalent meningococcal conjugate vaccine (MenACWYD) was licensed for use in the United States. The Advisory Committee on Immunization Practices recommends MenACWYD for all adolescents 11 to 18 years of age and others at increased risk for meningococcal disease.

Methods: Reports of breakthrough meningococcal disease after vaccination with MenACWYD were collected.

Population structure and capsular switching of invasive Neisseria meningitidis isolates in the pre-meningococcal conjugate vaccine era--United States, 2000-2005.

Background: A quadrivalent meningococcal conjugate vaccine (MCV4) was licensed in the United States in 2005; no serogroup B vaccine is available. Neisseria meningitidis changes its capsular phenotype through capsular switching, which has implications for vaccines that do not protect against all serogroups.

Methods: Meningococcal isolates from 10 Active Bacterial Core surveillance sites from 2000 through 2005 were analyzed to identify changes occurring after MCV4 licensure.

Meningococcus genome informatics platform: a system for analyzing multilocus sequence typing data.

The Meningococcus Genome Informatics Platform (MGIP) is a suite of computational tools for the analysis of multilocus sequence typing (MLST) data, at http://mgip.biology.gatech.

Emergence of ciprofloxacin-resistant Neisseria meningitidis in North America.

We report on three cases of meningococcal disease caused by ciprofloxacin-resistant Neisseria meningitidis, one in North Dakota and two in Minnesota. The cases were caused by the same serogroup B strain. To assess local carriage of resistant N.

Epidemiologic investigation and targeted vaccination initiative in response to an outbreak of meningococcal disease among illicit drug users in Brooklyn, New York.

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.

Molecular epidemiology of Neisseria meningitidis isolates from an outbreak of meningococcal disease among men who have sex with men, Chicago, Illinois, 2003.

We characterized five Neisseria meningitidis serogroup C isolates from a Chicago outbreak of meningococcal disease that occurred in 2003 among a community of men who have sex with men. Isolates from this outbreak were identical to each other but distinct from the clone that caused a similar outbreak in Canada in 2001.

Predictors of immunity after a major serogroup W-135 meningococcal disease epidemic, Burkina Faso, 2002.

Background: The African meningitis belt undergoes recurrent epidemics caused by Neisseria meningitidis serogroup A. During 2002, Burkina Faso documented the first large serogroup W-135 (NmW-135) meningococcal disease epidemic. To understand the emergence of NmW-135, we investigated meningococcal carriage and immunity.

Neisseria meningitidis serogroup W-135 carriage among US travelers to the 2001 Hajj.

In 2000, a large international outbreak of meningococcal disease caused by Neisseria meningitidis serogroup W-135 was identified among pilgrims returning from the Hajj in Saudi Arabia. To assess ongoing risk, we evaluated N. meningitidis carriage among US travelers to the 2001 Hajj.

Use of real-time PCR to resolve slide agglutination discrepancies in serogroup identification of Neisseria meningitidis.

Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia in children and young adults in the United States. Rapid and reliable identification of N. meningitidis serogroups is crucial for judicious and expedient response to cases of meningococcal disease, including decisions about vaccination campaigns.