Transfer of bacteria between individuals is thought to occur through direct contact with respiratory and throat secretions and is more common among individuals living in crowded conditions (e.g., college dormitories or armed service barracks).1-3 Although meningococcal carriage is usually asymptomatic, in rare cases and for unfamiliar reasons, the bacteria can enter the bloodstream and cause a life-threatening invasive infection. to occur through direct contact with respiratory and throat secretions and is more common among individuals living in packed conditions (e.g., college dormitories or armed service barracks).1-3 Although meningococcal carriage is usually asymptomatic, in rare cases and for unfamiliar reasons, the bacteria can enter the bloodstream and cause a life-threatening invasive infection. Invasive meningococcal disease progresses rapidly and, despite the availability of sophisticated medical care, continues to be associated with a 5% to 15% case fatality rate as well as devastating sequelae including limb loss, epilepsy, mental retardation and deafness.4,5 The burden of invasive meningococcal disease is often underappreciated because of the low incidence: 0.28 cases per 100,000 individuals in the United States (US) and 0.89 cases per 100,000 persons in Europe.6,7 Twelve capsular serogroups of have been identified; however, five (A, B, C, W and Y) are responsible for most instances of invasive disease.8,9 Analyses of carriage and disease-causing strains in Greece, Norway and the Czech Republic have shown that prevalence of variation among serogroups and clonal complexes happens in geographically distinct areas, and that the serogroups Rabbit polyclonal to MDM4 and clonal complexes associated with hypervirulent strains responsible for most cases of invasive disease will also be common among carriage isolates.3,10,11 The prevalence of meningococcal carriage may vary among geographic regions, but generally is believed to increase through child years, from 4.5% in infants to a peak at 23.7% in adolescents (19 y of age).12 Vaccination with polysaccharide conjugate meningococcal serogroup C (MnC) vaccines is highly effective in avoiding invasive disease. All European countries with routine MnC vaccination programs Gabapentin Hydrochloride possess considerably reduced incidence of MnC disease, particularly those that implemented a program that included vaccination of an adolescent group.13 The MnC conjugate vaccination campaign in the United Kingdom (UK), which included vaccination of individuals between 2 mo and 18 y of age when it was initiated in 1999, resulted in a 66% reduction (p = 0.004) of MnC carriage in the group 15 to 17 y of age.14 Two to three years after the vaccination marketing campaign began, even unvaccinated individuals, 1 to 18 y of age, showed a decreased incidence of invasive disease suggesting the induction of herd safety as a result of vaccination.15,16 Herd protection extends to infants who have not received the Gabapentin Hydrochloride complete MnC vaccination course and to individuals 25 y of age who would not have been offered MnC vaccines.15 Following a introduction of polysaccharide conjugate vaccines that target serogroups A, C, W and Y, meningococcal serogroup B (MnB) remains a prominent cause of invasive meningococcal disease in the US and Europe.6,7,17 Infants and toddlers have the highest Gabapentin Hydrochloride incidence of invasive MnB disease (IMBD), with a second incidence maximum often noted for adolescents and young adults, resulting in significant disease burden in these age groups (Fig.?1A and C).6,18 Analyses of case numbers by age reveal that the total case numbers in the group 10 to 25 y of age are often greater than the total numbers seen in infants (Fig.?1B and D). This is evident in many European countries with the expeption of Greece and the UK where more instances in the infant age group are reported (Fig.?1D). Multiple studies across Gabapentin Hydrochloride Europe possess identified that MnB is definitely a common serogroup recognized among carriage isolates.19 In the US, MnB and meningococcal serogroup Y are the most common identifiable serogroups of carriage isolates.20 Available evidence from Latin America also suggests that meningococcal carriage is common, and serogroup.
Transfer of bacteria between individuals is thought to occur through direct contact with respiratory and throat secretions and is more common among individuals living in crowded conditions (e