Withington Community Hospital

BACKGROUND: Scales to measure the severity of different dimensions of auditory hallucinations and delusions are few. Biochemical and psychological treatments target dimensions of symptoms and valid and reliable measures are necessary to measure these. METHOD: The inter-rater reliability and validity of the Psychotic Symptom Rating Scales (PSYRATS: auditory hallucination subscale and delusions subscale), which measure several dimensions of auditory hallucinations and delusions were examined in this study. RESULTS: The two scales were found to have excellent inter-rater reliability. Their validity as compared with the KGV scale (Krawiecka et al. 1977) was explored. CONCLUSIONS: It is concluded that the PSYRATS are useful assessment instruments and can complement existing measures.

BACKGROUND: An instrument was required to quantify and thus potentially measure progress towards a Health of the Nation target, set by the Department of Health, "to improve significantly the health and social functioning of mentally ill people". METHOD: A first draft was created in consultation with experts and on the basis of literature review. This version was improved during four stages of testing: two preliminary stages, a large field trial involving 2706 patients (rated by 492 clinicians) and tests of the final Health of the Nation Outcome Scales (HoNOS), which included an independent study (n = 197) of reliability and relationship to other instruments. RESULTS: The resulting 12-item instrument is simple to use, covers clinical problems and social functioning with reasonable adequacy, has been generally acceptable to clinicians who have used it, is sensitive to change or the lack of it, showed good reliability in independent trials and compared reasonably well with equivalent items in the Brief Psychiatric Rating Scales and Role Functioning Scales. CONCLUSIONS: The key test for HoNOS is that clinicians should want to use it for their own purposes. In general, it has passed that test. A further possibility, that HoNOS data collected routinely as part of a minimum data set, for example for the Care Programme Approach, could also be useful in anonymized and aggregated form for public health purposes, is therefore testable but has not yet been tested.

AIMS: To determine the incidence of, and clinically relevant risk factors for, new foot ulceration in a large cohort of diabetic patients in the community healthcare setting. METHODS: Diabetic patients (n = 9710) underwent foot screening in six districts of North-west England in various healthcare settings. All were assessed at baseline for demographic information, medical and social history, neuropathy symptom score, neuropathy disability score, cutaneous pressure perception (insensitivity to the 10 g monofilament), foot deformities, and peripheral pulses. Two years later, patients were followed up via postal questionnaire to determine the incidence of new foot ulcers. Cox's proportional hazards regression analysis was used to determine the independent, relative risk of baseline variables for new foot ulceration. RESULTS: New foot ulcers occurred in 291/6613 patients who completed and returned their 2-year follow-up questionnaire (2.2% average annual incidence). The following factors were independently related to new foot ulcer risk: ulcer present at baseline (relative risk (95% confidence interval)) 5.32 (3.71-7.64), past history of ulcer 3.05 (2.16-4.31), abnormal neuropathy disability score (> or = 6/10) 2.32 (1.61-3.35), any previous podiatry attendance 2.19 (1.50-3.20), insensitivity to the 10 g monofilament 1.80 (1.36-2.39), reduced pulses 1.80 (1.40-2.32), foot deformities 1.57 (1.22-2.02), abnormal ankle reflexes 1.55 (1.01-2.36) and age 0.99 (0.98-1.00). CONCLUSIONS: More than 2% of community-based diabetic patients develop new foot ulcers each year. The neuropathy disability score, 10 g monofilament and palpation of foot pulses are recommended as screening tools in general practice.

OBJECTIVE: To assess, in the general diabetic population, 1) the prevalence of painful neuropathic symptoms; 2) the relationship between symptoms and clinical severity of neuropathy; and 3) the role of diabetes type, sex, and ethnicity in painful neuropathy. RESEARCH DESIGN AND METHODS: Observational study of a large cohort of diabetic patients receiving community-based health care in northwest England (n = 15,692). Painful diabetic neuropathy (PDN) was assessed using neuropathy symptom score (NSS) and neuropathy disability score (NDS). RESULTS: Prevalence of painful symptoms (NSS ≥5) and PDN (NSS ≥5 and NDS ≥3) was 34 and 21%, respectively. Painful symptoms occurred in 26% of patients without neuropathy (NDS ≤2) and 60% of patients with severe neuropathy (NDS >8). Adjusted risk of painful neuropathic symptoms in type 2 diabetes was double that of type 1 diabetes (odds ratio [OR] = 2.1 [95% CI 1.7-2.4], P < 0.001) and not affected by severity of neuropathy, insulin use, foot deformities, smoking, or alcohol. Women had 50% increased adjusted risk of painful symptoms compared with men (OR = 1.5 [1.4-1.6], P < 0.0001). Despite less neuropathy in South Asians (14%) than Europeans (22%) and African Caribbeans (21%) (P < 0.0001), painful symptoms were greater in South Asians (38 vs. 34 vs. 32%, P < 0.0001). South Asians without neuropathy maintained a 50% increased risk of painful neuropathy symptoms compared with other ethnic groups (P < 0.0001). CONCLUSIONS: One-third of all community-based diabetic patients have painful neuropathy symptoms, regardless of their neuropathic deficit. PDN was more prevalent in patients with type 2 diabetes, women, and people of South Asian origin. This highlights a significant morbidity due to painful neuropathy and identifies key groups who warrant screening for PDN.

The gram-negative bacterium Campylobacter jejuni has extensive reservoirs in livestock and the environment and is a frequent cause of gastroenteritis in humans. To date, the lack of (i) methods suitable for population genetic analysis and (ii) a universally accepted nomenclature has hindered studies of the epidemiology and population biology of this organism. Here, a multilocus sequence typing (MLST) system for this organism is described, which exploits the genetic variation present in seven housekeeping loci to determine the genetic relationships among isolates. The MLST system was established using 194 C. jejuni isolates of diverse origins, from humans, animals, and the environment. The allelic profiles, or sequence types (STs), of these isolates were deposited on the Internet (http://mlst.zoo.ox.ac.uk), forming a virtual isolate collection which could be continually expanded. These data indicated that C. jejuni is genetically diverse, with a weakly clonal population structure, and that intra- and interspecies horizontal genetic exchange was common. Of the 155 STs observed, 51 (26% of the isolate collection) were unique, with the remainder of the collection being categorized into 11 lineages or clonal complexes of related STs with between 2 and 56 members. In some cases membership in a given lineage or ST correlated with the possession of a particular Penner HS serotype. Application of this approach to further isolate collections will enable an integrated global picture of C. jejuni epidemiology to be established and will permit more detailed studies of the population genetics of this organism.

AIM: To determine the prevalence, symptom pattern and impact of the irritable bowel syndrome, across eight European countries, using a standardized methodology. METHODS: A community survey of 41 984 individuals was performed using quota sampling and random digit telephone dialing to identify those with diagnosed irritable bowel syndrome or those meeting diagnostic criteria, followed by in-depth interviews. RESULTS: The overall prevalence was 11.5% (6.2-12%); 9.6% had current symptoms, 4.8% had been formally diagnosed and a further 2.9%, 4.2% and 6.5% met the Rome II, Rome I or Manning criteria, respectively. Bowel habit classification varied by criteria: 63% had an 'alternating' bowel habit by Rome II vs. 21% by self-report. On average, 69% reported symptoms lasting for 1 h, twice daily, for 7 days a month. Irritable bowel syndrome sufferers reported more peptic ulcer (13% vs. 6%), reflux (21% vs. 7%) and appendectomy (17% vs. 11%), but not hysterectomy, cholecystectomy or bladder procedures. Ninety per cent had consulted in primary care and 17% in hospital; 69% had used medication. Irritable bowel syndrome substantially interfered with lifestyle and caused absenteeism. CONCLUSIONS: Irritable bowel syndrome is common with major effects on lifestyle and health care. The majority of cases are undiagnosed and the prevalence varies strikingly between countries. Diagnostic criteria are associated with varying prevalences and bowel habit sub-types. This limits their utility in clinical practice and the transferability of research findings using them.

Gardner and Alunan explained the rationale for using estimation and confidence intervals in making inferences from analytical studies and described their calculation for means or proportions and their differences.1 In this paper we present methods for calculating confidence intervals for other common statistics obtained from medical investigations. The techniques for obtaining confidence intervals for estimates of relative risk are described. These can come either from an incidence study, where, for example, the frequency of a congenital malformation at birth is compared in two defined groups of mothers, or from a case-control study, where a group of patients with the disease of interest (the cases) is compared with another group of people without the disease (the controls). The methods of obtaining confidence intervals for standardised disease ratios and rates in studies of incidence, prevalence, and mortality are described. Such rates and ratios are commonly calculated to enable appropriate comparisons to be made between study groups after adjustment for confounding factors like age and sex. The most frequently used standardised indices are the standardised incidence ratio (SIR) and the standardised mortality ratio (SMR). A worked example is included for each method. The calculations have been carried out to full arithmetical precision, as is recom? mended practice,2 although intermediate steps are shown as rounded results. Some of the methods given in this paper are large sample approximations and are not reliable for studies with fewer than about 20 cases. Appropriate design principles for these types of study have to be adhered to since confidence intervals convey only the effects of sampling variation on the precision of the estimated statistics and cannot control for other errors such as biases due to the selection of inappropriate controls or in the methods of collecting the data.

A single-tube 5' nuclease multiplex PCR assay was developed on the ABI 7700 Sequence Detection System (TaqMan) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae from clinical samples of cerebrospinal fluid (CSF), plasma, serum, and whole blood. Capsular transport (ctrA), capsulation (bexA), and pneumolysin (ply) gene targets specific for N. meningitidis, H. influenzae, and S. pneumoniae, respectively, were selected. Using sequence-specific fluorescent-dye-labeled probes and continuous real-time monitoring, accumulation of amplified product was measured. Sensitivity was assessed using clinical samples (CSF, serum, plasma, and whole blood) from culture-confirmed cases for the three organisms. The respective sensitivities (as percentages) for N. meningitidis, H. influenzae, and S. pneumoniae were 88.4, 100, and 91.8. The primer sets were 100% specific for the selected culture isolates. The ctrA primers amplified meningococcal serogroups A, B, C, 29E, W135, X, Y, and Z; the ply primers amplified pneumococcal serotypes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10A, 11A, 12, 14, 15B, 17F, 18C, 19, 20, 22, 23, 24, 31, and 33; and the bexA primers amplified H. influenzae types b and c. Coamplification of two target genes without a loss of sensitivity was demonstrated. The multiplex assay was then used to test a large number (n = 4,113) of culture-negative samples for the three pathogens. Cases of meningococcal, H. influenzae, and pneumococcal disease that had not previously been confirmed by culture were identified with this assay. The ctrA primer set used in the multiplex PCR was found to be more sensitive (P < 0.0001) than the ctrA primers that had been used for meningococcal PCR testing at that time.

OBJECTIVE: To determine the efficacy of teaching patients with bipolar disorder (manic-depressive psychosis) to identify early symptoms of relapse and seek prompt treatment from health services. DESIGN: Single blind randomised controlled trial with matching on four baseline variables using a minimisation algorithm. SETTING: Mental health services in four NHS trusts (one teaching, three non-teaching). SUBJECTS: 69 patients with bipolar disorder who had had a relapse in the previous 12 months. INTERVENTIONS: Seven to 12 individual treatment sessions from a research psychologist plus routine care or routine care alone. MAIN OUTCOME MEASURES: Time to first manic or depressive relapse, number of manic or depressive relapses, and social functioning examined by standardised interviews every six months for 18 months. RESULTS: 25th centile time to first manic relapse in experimental group was 65 weeks compared with 17 weeks in the control group. Event curves of time to first manic relapse significantly differed between experimental and control groups (log rank 7.04, df=1, P=0.008), with significant reductions in the number of manic relapses over 18 months (median difference 30% (95% confidence interval 8% to 52%), P=0.013). The experimental treatment had no effect on time to first relapse or number of relapses with depression, but it significantly improved overall social functioning (mean difference 2.0 (0.7 to 3.2), P=0.003) and employment (mean difference 0.7 (0.1 to 1.3), P=0.030) by 18 months. CONCLUSION: Teaching patients to recognise early symptoms of manic relapse and seek early treatment is associated with important clinical improvements in time to first manic relapse, social functioning, and employment.

Donepezil has been shown to be well tolerated and to improve cognition and global function in patients with mild to moderately severe Alzheimer's disease (AD). The current trial was undertaken to investigate further the efficacy and safety of donepezil, in a multinational setting, in patients with mild to moderately severe AD. This 30-week, placebo-controlled, parallel-group study consisted of a 24-week, double-blind treatment phase followed by a 6-week, single-blind, placebo washout. Eight hundred and eighteen patients with mild to moderately severe AD were randomly allocated to treatment with single, daily doses of 5 or 10 mg donepezil, or placebo. The two primary efficacy measures were: a cognitive performance test, the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and a global evaluation, the Clinician's Interview-Based Impression of Change with caregiver input (CIBIC plus). Secondary outcome measures included the Sum of the Boxes of the Clinical Dementia Rating Scale (CDR-SB), a modified Interview for Deterioration in Daily living activities in Dementia (IDDD) and a patient rated quality of life assessment. Statistically significant improvements in cognitive and global function were observed, as evaluated by ADAS-cog and CIBIC plus, respectively, in both the 5 and 10 mg/day donepezil groups, compared with placebo. Treatment-associated changes were also observed in functional skills, as shown by improved scores on the CDR-SB and the complex-tasks component of the IDDD. A dose-response effect was evident, with the 10 mg/day donepezil group demonstrating greater benefits in all outcome measures than the 5 mg/day group. Donepezil was well tolerated by this patient population and did not produce any clinically significant laboratory test abnormalities. The results of this study confirm that donepezil is effective and well tolerated in treating the symptoms of mild to moderately severe AD.

Abstract Objective: To study the effectiveness of fluoxetine and cognitive-behavioural counselling in depressive illness in postnatal women: to compare fluoxetine and placebo, six sessions and one session of counselling, and combinations of drugs and counselling. Design: Randomised, controlled treatment trial, double blind in relation to drug treatment, with four treatment cells: fluoxetine or placebo plus one or six sessions of counselling. Subjects: 87 women satisfying criteria for depressive illness 6-8 weeks after childbirth, 61 (70%) of whom completed 12 weeks of treatment. Setting: Community based study in south Manchester. Main outcome measures: Psychiatric morbidity after 1, 4, and 12 weeks, measured as mean scores and 95% confidence limits on the revised clinical interview schedule, the Edinburgh postnatal depression scale and the Hamilton depression scale. Results: Highly significant improvement was seen in all four treatment groups. The improvement in subjects receiving fluoxetine was significantly greater than in those receiving placebo. The improvement after six sessions of counselling was significantly greater than after a single session. Interaction between counselling and fluoxetine was not statistically significant. These differences were evident after one week, and improvement in all groups was complete after four weeks. Conclusions: Both fluoxetine and cognitive-behavioural counselling given as a course of therapy are effective treatments for non-psychotic depression in postnatal women. After an initial session of counselling, additional benefit results from either fluoxetine or further counselling but there seems to be no advantage in receiving both. The choice of treatment may therefore be made by the women themselves. Key messages Fluoxetine, an anxiolytic antidepressant, is an effective treatment for postnatal depression A course of six sessions of a simple form of counselling derived from cognitive-behavioural therapy is more effective than a single session The drug and counselling treatments do not interact significantly, and there seems to be no advantage in receiving both In primary care, the simplest treatment after a single session of cognitive-behavioural counselling may be fluoxetine as it removes the need for additional counselling Many women with postnatal depression are reluctant to take medication, and for them a course of cognitive-behavioural counselling is as effective as an antidepressant drug

Concern over those individuals who drink alcohol to excess goes back many centuries, this concern being directed at the effect alcohol has on the individual and on society. Levine (1978) pointed out that the idea of alcoholism as a progressive disease with the key symptom of ‘loss of control’ did not simply start with the foundation of Alcoholics Anonymous or the publication of Jellinek's monograph. Such a concept is, in fact, at least 200 years old.

BACKGROUND: Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies. AIMS: To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food. PATIENTS: A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies. METHODS: Primary outcome measures were change in IBS symptom severity and global rating scores. Non-colonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model. RESULTS: After 12 weeks, the true diet resulted in a 10% greater reduction in symptom score than the sham diet (mean difference 39 (95% confidence intervals (CI) 5-72); p = 0.024) with this value increasing to 26% in fully compliant patients (difference 98 (95% CI 52-144); p<0.001). Global rating also significantly improved in the true diet group as a whole (p = 0.048, NNT = 9) and even more in compliant patients (p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24% greater deterioration in symptoms in those on the true diet (difference 52 (95% CI 18-88); p = 0.003). CONCLUSION: Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the combined occurrence of parathyroid, pancreatic islet and anterior pituitary tumours. To facilitate a screening programme for MEN1, we investigated 709 people (364 males and 345 females, age range 1-84 years) from 62 MEN1 families, and 36 non-familial MEN1 patients. Of those investigated, 220 (95 males and 125 females, age range 8-79 years) suffered from MEN1. Parathyroid, pancreatic and pituitary tumours occurred in 95%, 41% and 30% of the patients, respectively. Parathyroid tumours were the first manifestation of MEN1 in 87% of patients, and amongst the pituitary and pancreatic tumours, somatotrophinomas and gastrinomas were more common in patients above the age of 40 years, whilst insulinomas occurred more frequently in patients below the age of 40 years. Biochemical screening indicated that the penetrance of MEN1 by the ages of 20, 35 and 50 years was 43%, 85% and 94%, respectively, and that the development of MEN1 was confined to first-degree relatives in 91% of patients and to second-degree relatives in 9% of patients. These findings have helped to define a proposed screening programme for MEN1.

OBJECTIVES: To investigate whether intensive cognitive behaviour therapy results in significant improvement in positive psychotic symptoms in patients with chronic schizophrenia. DESIGN: Patients with chronic schizophrenia were randomly allocated, stratified according to severity of symptoms and sex, to intensive cognitive behaviour therapy and routine care, supportive counselling and routine care, and routine care alone. SETTING: Adjunct treatments were carried out in outpatient clinics or in the patient's home. SUBJECTS: 87 patients with persistent positive symptoms who complied with medication; 72 completed treatment. OUTCOME MEASURES: Assessments of positive psychotic symptoms before treatment and 3 months after treatment. Number of patients who showed a 50% or more improvement in symptoms. Exacerbation of symptoms and rates of readmission to hospital. RESULTS: Significant improvements were found in the severity (F=5.42, df =2,86; P=0.006) and number (F=4.99, df=2,86; P=0.009) of positive symptoms in those treated with cognitive behaviour therapy. The supportive counselling group showed a non-significant improvement. Significantly more patients treated with cognitive behaviour therapy showed an improvement of 50% or more in their symptoms (chi2=5.18, df=1; P=0.02). Logistic regression indicated that receipt of cognitive behaviour therapy results in almost eight times greater odds (odds ratio 7.88) of showing this improvement. The group receiving routine care alone also experienced more exacerbations and days spent in hospital. CONCLUSIONS: Cognitive behaviour therapy is a potentially useful adjunct treatment in the management of patients with chronic schizophrenia.

A randomized trial was performed in which imaginal exposure (IE) and cognitive therapy (CT) were compared in the treatment of chronic posttraumatic stress disorder (PTSD). Patients who continued to meet PTSD caseness at the end of a 4-week symptom-monitoring baseline period (n = 72) were randomly allocated to either IE or CT. There was a significant improvement in all measures over treatment and at follow-up, although there were no significant differences between the 2 treatments at any assessment. A significantly greater number of patients who showed worsening over treatment received IE, although this effect was not found at follow-up. Patients who worsened showed a greater tendency to miss treatment sessions, rated therapy as less credible, and were rated as less motivated by the therapist. It was concluded that either exposure or a challenge to cognition can result in symptom reduction, although neither resulted in complete improvement.

Despite neuroleptic medication, many schizophrenic patients continue to experience residual positive psychotic symptoms. These residual symptoms cause distress and disability. We report a controlled trial of two cognitive-behavioural treatments to alleviate residual hallucinations and delusions. Forty-nine patients were recruited into the trial, of whom 27 entered the trial and completed post-treatment assessment, and 23 were reassessed at six-month follow-up. Patients were randomly allocated to either coping strategy enhancement (CSE) or problem solving (PS). Half the patients were allocated to a high-expectancy positive demand condition and half to a counter-demand condition to evaluate expectation of improvement. Patients receiving either cognitive-behavioural treatment showed significant reductions in psychotic symptoms compared with those in the waiting period, who showed no improvement. There was some evidence, although equivocal, that patients receiving CSE improved more than those receiving PS. There was no evidence that improvements generalised to negative symptoms or social functioning, nor was there evidence that expectancy of treatment benefit contributed to the treatment effect.

A set of universal oligonucleotide primers specific for the conserved regions of the eubacterial 16S rRNA gene was designed for use with the real-time PCR Applied Biosystems 7700 (TaqMan) system. During the development of this PCR, problems were noted with the use of this gene as an amplification target. Contamination of reagents with bacterial DNA was a major problem exacerbated by the highly sensitive nature of the real-time PCR chemistry. This was compounded by the use of a small amplicon of approximately 100 bases, as is necessary with TaqMan chemistry. In an attempt to overcome this problem, several methodologies were applied. Certain treatments were more effective than others in eliminating the contaminating DNA; however, to achieve this there was a decrease in sensitivity. With UV irradiation there was a 4-log reduction in PCR sensitivity, with 8-methoxypsoralen activity facilitated by UV there was between a 5- and a 7-log reduction, and with DNase alone and in combination with restriction digestion there was a 1.66-log reduction. Restriction endonuclease treatment singly and together did not reduce the level of contaminating DNA. Without the development of ultrapure Taq DNA polymerase, ultrapure reagents, and plasticware guaranteed to be free of DNA, the implementation of a PCR for detection of eubacterial 16S rRNA with the TaqMan system will continue to be problematical.

Wound healing in adult human skin results in varying degrees of scar formation, ranging clinically from fine asymptomatic scars to problematic hypertrophic and keloid scars, which may limit function and restrict further growth. At present, no good objective method of clinically assessing scars exists, which is problematic for the evaluation of scar prevention or treatment regimens. Similarly lacking are histologic correlates of what we consider good and bad clinical scars. The objective of this study was to quantitatively assess human scarring (1) clinically, by developing a comprehensive rating scale, (2) photographically, using an image capture system and a scar assessment panel, and (3) by histologic analysis following scar excision. We assessed 69 scars, with a wide clinical range of severity, in patients who were undergoing surgery, for whatever reason, that involved removal of an old scar. Preoperatively, patients had their scars assessed, clinically using our newly developed scale and photographically using a computerized image capture system. These photographs were then sent to a panel for assessment using similar criteria to those used clinically. Assessment of scars from photographs correlated well with the clinical scar evaluation, indicating its potential utility in multicenter scar prevention/treatment trials. Following excision, scars were processed and analyzed for histology. We also found a strong correlation between the macroscopic and microscopic appearance of scars, particularly between the clinical appearance and histologic scores of features in the epidermis and papillary dermis. This suggests that our clinical scale is a sensitive instrument in scar assessment, allowing validated quantification of the severity of a wide range of scars.

SUMMARY A total of 6234 nasopharyngeal swabs was collected during a survey of the population of Stonehouse, Gloucestershire in November 1986 as part of an investigation into an outbreak of meningococcal disease. The overall meningococcal carriage rate was 10·9%. The carriage rate rose with age from 2·1% in the 0- to 4-year-olds to a peak of 24·5% in the 15- to 19-year-olds, and thereafter declined steadily with age. Male carriers outnumbered female carriers of meningococci by 3:2. Group B (or non-groupable) type 15 sulphonamide-resistant strains which had caused the outbreak were isolated from 1·4% of subjects. The age distribution of carriers of these strains was similar to that of other meningococci apart from an additional peak in the 5–9-year age group and a more rapid decline in carriage with increasing age. Variations in the carriage rates of the outbreak strain were seen in children attending different schools and in the residents of different areas of the town. The low carriage rate of these strains in a community during a prolonged outbreak supports the hypothesis that these organisms are less transmissible but more virulent than other strains of pathogenic meningococci. Carriage of Neisseria lactamica , which is thought to be important in the development of meningococcal immunity, was most frequent in children under the age of 5 years and was six times commoner in this age group than carriage of Neisseria meningitidis . In older children and adults female carriers of N. lactamica increasingly outnumbered males in contrast to the male preponderance observed with meningococcal carriage.