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At least 19 recordsLinked to original sources
PubMed1988

Meningococcal carriage, meningococcal disease and vaccination.

Group A meningococcal carriage rates were determined 6 months before and 6 and 18 months after a mass vaccination campaign with a combined group A and group C meningococcal polysaccharide vaccine in a rural area of The Gambia. During the first pre-vaccination survey, performed during an outbreak of meningococcal disease, the carriage rate was high (16%). The carriage rate remained high during a second survey made 6 months after a vaccination campaign that covered approximately 90% of the study population. A year later very few group A meningococcal carriers were found. Membrane protein patterns of isolates obtained before and after vaccination were similar. We conclude that vaccination had little influence on the carriage rate of group A meningococci but that this was influenced by changes in herd immunity or by other unidentified factors.

Bacterial Outer Membrane Proteins↗
PubMed1979

An epidemic of meningococcal infection at Zaria, Northern Nigeria. 3. Meningococcal carriage.

Meningococcal carriage was studied in household contacts of patients with group A meningococcal disease and in controls. The carriage rate of group A meningococci among 1,098 household contacts was low (3.8%) and only slightly higher than the carriage rate found among 416 controls (2.6%). However, higher carrier rates were found among those in close contact with a patient. Carriage was found most frequently among children and young adults and was commoner in adult females than in adult males. Sulphonamides had no effect on carriage and all 60 strains tested in vitro were resistant to sodium sulphadiazine at a concentration of 10 micrograms/ml.

Adolescent↗
PubMed2006

Social behavior and meningococcal carriage in British teenagers.

Understanding predisposing factors for meningococcal carriage may identify targets for public health interventions. Before mass vaccination with meningococcal group C conjugate vaccine began in autumn 1999, we took pharyngeal swabs from approximately 14,000 UK teenagers and collected information on potential risk factors. Neisseria meningitidis was cultured from 2,319 (16.7%) of 13,919 swabs. In multivariable analysis, attendance at pubs/clubs, intimate kissing, and cigarette smoking were each independently and strongly associated with increased risk for meningococcal carriage (p<0.001). Carriage in those with none of these risk factors was 7.8%, compared to 32.8% in those with all 3. Passive smoking was also linked to higher risk for carriage, but age, sex, social deprivation, home crowding, or school characteristics had little or no effect. Social behavior, rather than age or sex, can explain the higher frequency of meningococcal carriage among teenagers. A ban on smoking in public places may reduce risk for transmission.

Adolescent↗
PubMed1997

Meningococcal carriage: prevalence and sex-related risk factors.

A retrospective analysis was done to examine whether sexual behaviour was associated with meningococcal carriage. Over the 4 month period from January to April 1994, 136 (27.4%) of the 496 consecutive new/re-registered genito-urinary medicine clinic attenders showed meningococcal carriage. Two (15.4%) of 13 homosexual men compared with 134 (27.7%) of 484 heterosexual men and women had evidence of meningococcal carriage. Relative risk (RR) of meningococcal carriage was 1.8 with > 10 lifetime partners and 1.2 with 3-10 partners (P < 0.007). RR with age group of 16-25 was 4.2 and for 26-35 it was 3.5. There was no relationship with meningococcal carriage and pharyngeal symptoms, sexual orientation, intravenous drug use, number of partners per month and orogenital sex. Further longitudinal studies may be of value in order to determine whether a high number of sexual partners is a marker for meningococcal carriage. In addition, further study may show whether there is an increased risk of meningococcal carriage and disease in those who live with meningococcal carriers.

Adolescent↗
PubMed1989

Effect of smoking on meningococcal carriage.

A case-control study was done to examine whether certain environmental or medical factors were associated with meningococcal carriage. Questionnaires were posted to 138 meningococcal carriers and their controls, and to 52 carriers of Neisseria lactamica and their controls. Carriers were matched to controls by age, sex, and area of residence. The overall response rate was 89%. There were no differences in environmental or medical factors between N lactamica carriers and their controls, nor in household crowding, housing conditions, frequency of physical exercise, or upper respiratory disorders between meningococcal carriers and their controls. Active smoking and the presence of other smokers in the household were independently associated with meningococcal carriage; the risk of carriage increased significantly with heavier smoking.

Adolescent↗
PubMed2002

Detection of meningococcal carriage by culture and PCR of throat swabs and mouth gargles.

The standard method for detecting meningococcal carriage is culture of throat swabs on selective media, but the levels of carriage determined depend heavily on the skills of the individuals taking the swab and interpreting the cultures. This study aimed to determine the most sensitive detection method for meningococcal carriage. Throat swabs and saline mouth gargles, obtained from 89 university students, were processed in parallel by conventional culture and TaqMan ctrA PCR. Carriage of meningococci, as detected by the combined methods, was 20%. The sensitivities of throat swab culture, throat swab PCR, gargle culture, and gargle PCR were 72, 56, 56, and 50%, respectively, and the probabilities that these techniques would correctly identify the absence of carriage (negative predictive value [NPV]) were 93.4, 89.9, 89.9, and 88.8%. Culturing both throat swabs and gargles increased the NPV to 98.6%. The further addition of throat swab PCR increased this to 100%. Testing gargles by both culture and PCR was as sensitive as testing throat swabs by both methods, suggesting that gargles may be a suitable alternative for large-scale screening studies when throat swabs are difficult to obtain, although they required more lengthy laboratory processing. PCR was a useful adjunct to culture for detecting nasopharyngeal carriage, but it failed to detect some nongroupable strains. For maximum sensitivity, a combination of techniques was required. This study indicates the confidence with which health care professionals involved in meningococcal screening can regard laboratory results.

Adult↗
PubMed2000

Surveillance of cases of meningococcal disease associated with military recruits studied for meningococcal carriage.

Through a 14-months extended surveillance of meningococcal disease in Denmark, all 322 notified cases were investigated for possible connection with a military camp where 3 cohorts of recruits (n = 1069) were studied prospectively for meningococcal carriage. One case occurred in a recruit who was a constant non-carrier during the preceding 3 months. The invasive Neisseria meningitidis B:1:P1.1,7 strain was isolated from the pharynx only in 3 out of 17 room-mates (18%); the strains were identical as assessed by genotyping (PFGE and ribotyping). Two civilian cases outside the camp had direct contact with 2 recruits, but neither these 2 nor other recruits in the relevant divisions carried the invasive strains on any occasion. Six civilian cases had marginal relationship with the camp, but no contact with the recruits. In conclusion, pheno- and genotyping concordantly demonstrated a high carriage rate of the invasive strain among the room-mates to a recruit with meningococcal disease. Transmission to the patient most likely occurred shortly before onset of illness. The extended surveillance did, however, not identify any unexpected epidemiological links and restriction of antibiotic chemoprophylaxis to household/sleeping/kissing contacts in sporadic cases of meningococcal disease seems appropriate and relevant.

Adult↗
PubMed1999

Meningococcal carriage in relation to an outbreak of invasive disease due to Neisseria meningitidis serogroup C in the Netherlands.

BACKGROUND: a cross-sectional study on meningococcal carriage was performed in Putten, a small rural town in the Netherlands where an unusual high incidence of invasive meningococcal disease (IMD) due to Neisseria meningitidis C:2a:P1.5 occurred. The outbreak was controlled by mass vaccination of all inhabitants aged 2 to 20 years. METHODS: meningococcal carriage was studied in three groups: (1) a systematic age-specific sample of 2-20 year olds who visited the immunization clinic in Putten (January 1998: n=411); (2) children and adolescents in the same age range recruited through a kindergarten and schools in Venlo, a town where the causative strain of IMD had not been encountered (February 1998; n=374); (3) all initial carriers in Putten and a sample of non-carriers in that town (March 1998: n=145). Oropharyngeal swabs were taken for the purpose of isolating N. menigitidis. RESULTS: the prevalence of carriage was 12.4% in Putten and 18.2%, in Venlo, but the prevalence of group C meningococci was higher in Putten (1.7%) than Venlo (0.5%). N. meningitidis C:2a:P1.5 was isolated twice in Putten and not at all in Venlo. A second examination in Putten showed that 18 of the 22 repeatedly tested carriers were still carriers, and six new carriers were found among the 55 initial non-carriers. Of the two known carriers of C:2a:P1.5, one was still carrying the same strain, and the other did not participate in the second investigation. Carriage was associated with increasing family size, discotheque visits and visits to youth clubs and sports clubs. In contrast, visits to the swimming pool appeared to be related to a lower risk, as was recent antibiotic use. CONCLUSION: the prevalence of carriage with the invasive strain C:2a:P1.5 was low in the population that experienced a community-wide outbreak recently: the specific strain was not found in the reference population. This indicates a relatively high risk of developing the invasive disease for those who become infected with such strains.

Adolescent↗
PubMed1983

Longitudinal study of asymptomatic meningococcal carriage in two Belgian populations of schoolchildren.

In Brussels, a 15-month longitudinal survey was conducted in two primary schools, from March 1975 to May 1976, in order to analyse the dynamic of asymptomatic meningococcal carriage, during an epidemic mainly caused by serogroup B, serotype 2 Neisseria meningitidis. In the first school, which is situated in a suburban area with upper-middle socio-economic status of residents, a mean prevalence of carriers of 10 per cent, an acquisition rate of eight per 1000 months, and a mean duration of carriage of 12.4 months were observed among 158 schoolchildren aged six to 11 years old. In the second school, which is situated in a densely populated area with low socio-economic status of residents, a mean prevalence of carriers of 33 per cent, an acquisition rate of 28 per 1000 months, and a mean duration of carriage of 11.7 months were observed among 203 schoolchildren aged three to 14 years old. For both schools, the median duration of carriage was estimated at 9.4 months. The differences of prevalence and incidence of acquisition between the two schools cannot be explained by age, sex or ethnic factors and are probably related to socio familial variables. The theoretical relationship between prevalence, incidence and duration of meningococcal carriage was for the first time demonstrated in this study. The results also suggest that populations of low socio-economic status and living in densely populated areas constitute a target population for meningococcal disease prevention.

Adolescent↗
PubMed1995

Meningococcal carriage, alcohol consumption, and campus bar patronage in a serogroup C meningococcal disease outbreak.

Community outbreaks of serogroup C invasive meningococcal disease are increasing in North America (L. H. Harrison, JAMA 273:419-421, 1995; L. A. Jackson, A. Schuchat, M. W. Reeves, and J. D. Wenger, JAMA 273:382-389, 1995; C. M. Whalen, J. C. Hockin, A. Ryan, and F. Ashton, JAMA 273:390-394). In a recent 15-month university outbreak, disease was linked to patronage of a specific campus-area bar, suggesting that aspects of a campus bar environment might promote meningococcal transmission (P. B. Imrey, L. A. Jackson, P. H. Ludwinski, et al., Am. J. Epidemiol., in press). To investigate this hypothesis, oropharyngeal carriage results from samples taken from 867 university health service clients and 85 campus-area bar employees during the last 3 months of the outbreak were analyzed to determine factors correlated with carriage of any strain of Neisseria meningitidis. Results were validated with data from samples from 344 health center clients and 211 campus bar employees taken 8 months after the last outbreak case. Recent alcohol consumption (adjusted prevalence odds ratio = 3.8 for > 15 versus 0 drinks in last week [P = 0.0012]) and campus bar patronage (adjusted odds ratio = 1.9 for any versus no patronage in last 2 weeks [P = 0.0122]) showed separate effects in both univariate and multiple logistic regression analyses of data from the 1992 health center clients. Prevalence of meningococcal carriage among 1992 campus bar workers was 3.8 times that among health center clients; this prevalence ratio was roughly 2.5 after adjustment for alcohol consumption and bar patronage. Recent antibiotic usage was protective (prevalence odds ratio = 0.3) among health center clients and bar workers. These findings were generally supported by the validation samples. If alcohol consumption and other aspects of the campus bar environment facilitate transmission of and/or colonization by N. meningitidis, then the introduction of a highly pathogenic substrain into the campus bar environment may provide an unusual opportunity for invasive meningococcal disease within a campus community.

Adolescent↗
PubMed2026

Meningococcal carriage in adolescents and young adults in Kuwait.

BACKGROUND: Neisseria meningitidis is a major cause of invasive meningococcal disease (IMD), with asymptomatic carriage playing a crucial role in transmission. Adolescents (15-17&#x202f;years) and young adults (18-20&#x202f;years) have the highest carriage rates, yet data from Kuwait remain limited. This study aimed to estimate the prevalence of N. meningitidis carriage among adolescents and young adults in Kuwait. METHODS: A cross-sectional study was conducted from July 2023 to May 2024, enrolling 1,398 participants aged 15-20&#x202f;years. Randomly selected individuals provided oropharyngeal swabs, and demographic, behavioral, and vaccination data were collected via standardized questionnaires. Carriage prevalence was determined using selective culture-based methods. Whole genome sequencing was performed on culture-confirmed isolates. Descriptive statistics were used to summarize participant characteristics; carriage prevalence was reported as proportions, and associations were explored using Fisher's exact or chi-square tests and logistic regression where feasible. RESULTS: The overall meningococcal carriage rate was 0.21% (3/1,398). All isolates were non-groupable (NG), with one carrying the capsule null locus (CNL). Self-reported MenACWY vaccination coverage was 94.8%. No significant associations between demographic, geographic, or behavioral factors and carriage status were identified due to the small number of positive cases. CONCLUSION: This study provides a population-based estimate of meningococcal carriage among adolescents and young adults in Kuwait using a random sampling approach. The low carriage rate, alongside high vaccination coverage, suggests that existing immunization programs in Kuwait may be effective in reducing N. meningitidis transmission. However, the presence of NG strains stresses the need for continued surveillance. Further research is required to evaluate long-term vaccination impacts and potential gaps in disease protection.

Humans↗
PubMed1991

Meningococcal carriage in close contacts of cases.

Between 1 October 1986 and 31 March 1987, 55 cases of meningococcal disease were identified in the South-West of England, an attack rate of 1.54 per 100,000 during the study period. Antibiotics used in the treatment of the disease successfully eliminated nasopharyngeal carriage of meningococci in 13 out of 14 cases without use of rifampicin. The overall meningococcal carriage rate in 384 close contacts was 18.2% and the carriage rate of strains indistinguishable from the associated case strain was 11.1%. The carriage rate of indistinguishable strains in household contacts (16.0%) was higher than the carriage rate in contacts living at other addresses (7.0%, P less than 0.05). A 2-day course of rifampicin successfully eradicated meningococci from 46 (98%) of 47 colonized contacts. In one third of cases groupable meningococci were isolated from at least one household contact; 92% of these isolates were of the same serogroup as the associated case strain. When a meningococcus is not isolated from a deep site in a clinical case of meningococcal disease, culture of serogroup A or C strains from nasopharyngeal swabs of the case or of household contacts is an indication that the close contact group should be offered meningococcal A + C vaccine in addition to chemoprophylaxis. The failure in this and other studies to isolate meningococci from any household contact in the majority of cases may be due either to the relative insensitivity of nasopharyngeal swabbing in detecting meningococcal carriage or to the acquisition of meningococci by most index cases from sources outside the household.

Adolescent↗
PubMed2002

Characterization of humoral and cellular immune responses elicited by meningococcal carriage.

In order to study the immune response elicited by asymptomatic carriage of Neisseria meningitidis, samples of serum, peripheral blood mononuclear cells (PBMCs), and saliva were collected from a cohort of more than 200 undergraduate students in Nottingham, United Kingdom, who were subject to high rates of acquisition and carriage of meningococci. Serum immunoglobulin G levels were elevated following increases in the rate of carriage, and these responses were specific for the colonizing strains. In order to investigate T-cell responses, PBMCs from 15 individuals were stimulated with a whole-cell lysate of the H44/76 meningococcal strain (B:15:P1.7,16), stained to detect cell surface markers and intracellular cytokines, and examined by flow cytometry. The cells were analyzed for expression of CD69 (to indicate activation), gamma interferon (IFN-gamma) (a representative T-helper 1 subset [Th1]-associated cytokine), and interleukin-5 (IL-5) (a Th2-associated cytokine). Following a brief meningococcal stimulation, the numbers of CD69(+) IFN-gamma(+) CD56/16(+) NK cells were much higher than cytokine-positive CD4(+) events. Both IFN-gamma(+) and IL-5(+) events were detected among the CD69(+) CD4(+) population, leading to the conclusion that an unbiased T-helper subset response was elicited by meningococcal carriage.

Antibodies, Bacterial↗
PubMedDate not supplied

Meningococcal carriage in Umra pilgrims returning from Saudi Arabia.

BACKGROUND: Moslems from all over the world go to Mecca and Medina in Saudi Arabia for two types of pilgrimage: the major pilgrimage (hajj) and the minor (umra). An international outbreak of meningococcal disease with serogroup W-135 occurred in association with hajj pilgrimage in the years 2000 and 2001, and it has been shown that pharyngeal carriage of a single W-135 strain was high in returning hajj pilgrims. We investigated the meningococcal carriage in umra pilgrims to determine the extent of circulation of this strain, during the minor pilgrimage. METHOD: Tonsillopharyngeal swabs were taken from umra returnees. Serogrouping and pulsed field gel electrophoresis were performed on all meningococcal isolates. Subjects were questioned about the occurrence of symptoms of upper respiratory tract infection and use of antibiotics during the pilgrimage. RESULTS: were compared with those previously reported in hajj pilgrims. Results: We enrolled 160 pilgrims returning from the umra pilgrimage in 2001. The meningococcal carriage rate was 1.3%, which is significantly lower compared with the hajj pilgrimage (17%; p<0.001). None of the umra pilgrims carried serogroup W-135, whereas 90% of the isolates in returning hajj pilgrims were Neisseria meningitidis W-135. CONCLUSIONS: Meningococcal carriage during the umra pilgrimage was significantly lower compared with the hajj pilgrimage in the year 2001. No carriage of N. meningitidis W-135 was documented in umra pilgrims, whereas this was the predominant serogroup in hajj pilgrims. Public health measures to reduce the potential introduction of N. meningitidis W-135 into the countries of origin of returning pilgrims need to be prioritized for the hajj pilgrimage.

Adolescent↗
PubMed2003

Meningococcal carriage among local inhabitants during the pilgrimage 2000-2001.

The first international outbreak of Neisseria meningitidis serogroup W135 occurred in 2000, in direct association with the annual Hajj in Saudi Arabia. In anticipation of the following Hajj, we conducted a survey of oropharyngeal carriage rates of N. meningitidis both pre- and post-pilgrimage in the King Khalid National Guard Hospital (KKNGH) employees preparing to attend the Hajj. These KKNGH employees were native to the Mecca-Jeddah area. Pre-Hajj throat cultures were obtained 1 week prior to Hajj, and post-Hajj cultures within 10 days after completing the Hajj pilgrimage. A total of 327 throat culture samples were collected from 218 persons. Overall meningococcal carriage rate was found to be 4.7%. Serogroup W135 accounted for 40% of all recovered pre-Hajj strains of N. meningitidis. Only one post-Hajj sample was positive for N. meningitidis W135. This high rate of colonization with N. meningitidis serogroup W135 indicates this strain predominates amongst the population indigenous to the Mecca-Jeddah area. This 'nidus' of N. meningitidis W135 is a potential reservoir for future outbreaks. More worrying, there is real risk of future W135 endemicity in this vulnerable local population. These preliminary findings warrant larger surveillance studies examining both transmission and carrier rate acquisition of N. meningitidis in the Mecca-Jeddah area. These vital data are needed to curb further epidemic outbreaks during future Hajj pilgrimages.

Adolescent↗
PubMed2005

A novel porA-based real-time PCR for detection of meningococcal carriage.

Real-time PCR based on the capsule transfer gene (ctrA) is a significant aid in the diagnosis of meningococcal infection but fails to detect a high proportion (60 %) of non-groupable strains associated with nasopharyngeal carriage. This study aimed to design a novel real-time (TaqMan) PCR that would detect more strains of meningococci and be suitable for large-scale carriage studies. Primer and probe sequences were based on the meningococcal porA gene and designed specifically to exclude the highly related porA pseudogene in Neisseria gonorrhoeae. The specificity of the assay was confirmed by testing strains of N. gonorrhoeae known to contain the porA pseudogene together with commensal strains of Neisseria lactamica and Neisseria sicca. None of these was detected in the assay. Neisseria meningitidis strains representing a wide range of serogroups together with non-groupable strains isolated from the nasopharynx were tested by ctrA assay and the novel porA-based TaqMan PCR. All carriage strains were detected by the porA-based assay including four that gave weak or no reaction with the ctrA assay. Comparison of ctrA and porA assays on 71 throat swabs obtained from university students showed that the porA assay detected meningococcal DNA in all samples that were ctrA positive plus three that were ctrA negative but culture positive. This novel porA-based TaqMan assay provides a highly specific method for detecting meningococcal DNA that is more sensitive than the ctrA assay for detecting meningococcal carriage and is particularly suitable for carriage studies where non-groupable strains and other Neisseria are present.

Carrier State↗
PubMed2005

T-cell-stimulating protein A elicits immune responses during meningococcal carriage and human disease.

In recognition of the need for immunological memory-inducing components for future Neisseria meningitidis group B vaccines, we previously searched the proteome of N. meningitidis and identified T-cell-stimulating protein A (TspA). This study was designed to confirm the immunogencity of TspA and to examine the subset of T-helper cell responses to the protein in patients and nasopharyngeal carriers. The tspA gene was reconstructed, cloned, and expressed in Escherichia coli, and the recombinant TspA (rTspA) protein was affinity purified. T-cell proliferative responses to rTspA were detected in the peripheral blood mononuclear cells (PBMCs) of convalescent patients and carriers, confirming that TspA-specific T-cell responses were stimulated by invasive disease and nasopharyngeal colonization. Following stimulation of PBMCs with meningococcal lysate, increased frequencies of both Th1 and Th2 cells were observed, indicating that, as during carriage, invasive meningococcal disease induced an unbiased T-helper subset response. A similar unbiased T-helper response was also detected against rTspA in the PBMCs of convalescent patients. The response of PBMCs from the carriers to TspA stimulation, however, was very weak, and the frequencies of cytokine-positive CD4 cells were not significantly greater than the frequencies in unstimulated control cultures. All of the patients and carriers responded with serum antimeningococcal immunoglobulin G (IgG) antibodies, while four of six samples from patients and 5 of 14 samples from carriers contained detectable anti-rTspA IgG antibodies. Taken together, the results of this study confirmed the immunogenicity of TspA in humans during natural meningococcal infection, and therefore, TspA is worthy of further investigation as a possible T-cell stimulating component of future vaccines.

Antigens, Bacterial↗