No evidence of transmission from an acute case of hepatitis A in a foodhandler: follow-up of almost 1,000 potentially exposed individuals, London, United Kingdom, April 2012.

Identification of acute hepatitis A virus (HAV) infection in a foodhandler in a London hotel led to a large incident response. We identified three potentially exposed groups: hotel staff who had regularly consumed food prepared by the case and shared toilet facilities with the case, patients who shared the same hospital ward as the case and hotel guests who consumed food prepared by the case. We arranged post-exposure HAV vaccination for all 83 potentially exposed hotel staff and all 17 patients. We emailed 887 guests advising them to seek medical care if symptomatic, but did not advise vaccination as it was too late to be effective for most guests. Through the International Health Regulations national focal points and the European Union Early warning and response system (EWRS), we communicated the details of the incident to public health agencies and potential risk of HAV transmission to international guests. Potentially exposed hotel staff and guests were asked to complete an online or telephone-administered questionnaire 50 days following possible exposure, to identify any secondary cases. Survey response was low, with 155 responses from guests and 33 from hotel staff. We identified no secondary cases of HAV infection through follow-up.

Estimating unreported malaria cases in England: a capture-recapture study.

A capture-recapture study was undertaken to estimate the incidence and likely total burden of malaria cases in England. Cases diagnosed by the national Malaria Reference Laboratory (MRL) between July 2003 and December 2004 were matched with cases reported to Hospital Episode Statistics using demographic, geographical, parasitological, and temporal information. A total of 3861 cases were recorded in one or both datasets; the 'unknown population' was estimated as 746 cases (95% CI 677-822) giving a total of 4607 cases (95% CI 4446-4767) over 18 months. Eighty-four percent (95% CI 83-85) of cases were recorded in one or both datasets. Fifty-six percent (95% CI 54-58) of cases were captured by the MRL surveillance system; ascertainment for Plasmodium falciparum and London cases was higher at 66% and 62%, respectively. Improving case ascertainment will facilitate effective measures to reduce the burden of this preventable disease in the UK.

Central mechanisms of stress-induced headache.

Stress is the most commonly reported trigger of an episode of chronic tension-type headache (CTTH); however, the causal significance has not been experimentally demonstrated to date. Stress may trigger CTTH through hyperalgesic effects on already sensitized pain pathways in CTTH sufferers. This hypothesis could be partially tested by examining pain sensitivity in an experimental model of stress-induced headache in CTTH sufferers. Such examinations have not been reported to date. We measured pericranial muscle tenderness and pain thresholds at the finger, head and shoulder in 23 CTTH sufferers (CTH-S) and 25 healthy control subjects (CNT) exposed to an hour-long stressful mental task, and in 23 CTTH sufferers exposed to an hour-long neutral condition (CTH-N). Headache developed in 91% of CTH-S, 4% of CNT, and 17% of CTH-N subjects. Headache sufferers had increased muscle tenderness and reduced pain thresholds compared with healthy controls. During the task, muscle tenderness increased and pain thresholds decreased in the CTH-S group compared with CTH-N and CNT groups. Pre-task muscle tenderness and reduction in pain threshold during task were predictive of the development and intensity of headache following task. The main findings are that stress induced a headache in CTTH sufferers, and this was associated with pre-task muscle tenderness and stress-induced reduction in pain thresholds. The results support the hypothesis that stress triggers CTTH through hyperalgesic effects on already increased pain sensitivity in CTTH sufferers, reducing the threshold to noxious input from pericranial structures.

Reliability of temporal summation and diffuse noxious inhibitory control.

BACKGROUND: The test-retest reliability of temporal summation (TS) and diffuse noxious inhibitory control (DNIC) has not been reported to date. Establishing such reliability would support the possibility of future experimental studies examining factors affecting TS and DNIC. Similarly, the use of manual algometry to induce TS, or an occlusion cuff to induce DNIC of TS to mechanical stimuli, has not been reported to date. Such devices may offer a simpler method than current techniques for inducing TS and DNIC, affording assessment at more anatomical locations and in more varied research settings. METHOD: The present study assessed the test-retest reliability of TS and DNIC using the above techniques. Sex differences on these measures were also investigated. RESULTS: Repeated measures ANOVA indicated successful induction of TS and DNIC, with no significant differences across test-retest occasions. Sex effects were not significant for any measure or interaction. Intraclass correlations indicated high test-retest reliability for all measures; however, there was large interindividual variation between test and retest measurements. CONCLUSION: The present results indicate acceptable within-session test-retest reliability of TS and DNIC. The results support the possibility of future experimental studies examining factors affecting TS and DNIC.

Large outbreak of salmonella phage type 1 infection with high infection rate and severe illness associated with fast food premises.

OBJECTIVES: To describe the epidemiology of an outbreak of Salmonella enteritidis phage type 1 (PT1) infection associated with a fast food premises, and to identify the causative factors leading to an acute outbreak with high attack rate and severe illness including hospital admission. STUDY DESIGN: Integrated descriptive study of epidemiology, food and environmental microbiology, and professional environmental health assessment, supplemented by a case-case analytical study. METHODS: Cases were identified through multiple sources and were interviewed to identify food items consumed. Descriptive epidemiology of all cases and a case-case analytical study of risk factors for severe illness were undertaken. Microbiological investigation included analysis and typing of pathogens from stools, blood and environmental surfaces. Professional environmental heath assessment of the premises was undertaken. RESULTS: S. enteritidis PT1 was recovered from two-thirds of faecal samples. Three cases had dual infection with enterotoxin-producing Clostridium perfringens. S. enteritidis PT1 was isolated from 14 of 40 food samples examined and C. perfringens was isolated from eight food samples. Environmental health inspection of the premises revealed multiple deficiencies, including deficits in food preparation and hygiene consistent with multiple cross-contamination, and time-temperature abuse of sauces widely used across menu items. Severe cases were associated with consumption of chips and salad. CONCLUSIONS: Outbreaks from fast food premises have been infrequently described. This outbreak demonstrates the potential for fast food premises, with multiple deficiencies in food preparation and hygiene, to produce large, intense community outbreaks with high attack rates and severe illness, highly confined in space and time.

Onychomycosis and diabetes.

OBJECTIVE: This study aims to discuss factors specific to diabetics in the diagnosis and treatment of onychomycosis. DISCUSSION: Onychomycosis has the potential to cause severe complications in diabetics and should be treated promptly. The existence of comorbid conditions and potential for drug-drug interactions complicates the selection of an appropriate treatment regimen. The role of Candida in onychomycosis is controversial but may be of increased significance in the diabetic population due to an underlying vulnerability to this organism. CONCLUSIONS: Terbinafine is an excellent choice in diabetics due to its low risk of drug-drug interaction and proven efficacy against the typical pathogens that cause onychomycosis. Itraconazole, while an effective treatment for onychomycosis, is not a first-choice therapy due to its black-box cardiac warning and numerous drug interactions. Larger studies are needed in diabetics to determine the frequency of candidal nail infections.

A fatal case of Lassa fever in London, January 2009.

In January 2009, the eleventh [corrected] case of Lassa fever imported to the United Kingdom was diagnosed in London. Risk assessment of 328 healthcare contacts with potential direct exposure to Lassa virus - through contact with the case or exposure to bodily fluids - was undertaken. No contacts were assessed to be at high risk of infection and no secondary clinical cases identified.

Effects of induced stress on experimental pain sensitivity in chronic tension-type headache sufferers.

BACKGROUND AND PURPOSE: It has been proposed that stress may contribute to chronic tension-type headache (CTH) through hyperalgesic effects on already sensitized pain pathways in CTH sufferers. This hypothesis could be partially tested by examining effects of stress on mechanical and thermal pain sensitivity in CTH sufferers. Such examinations have not been reported to date. MATERIALS AND METHODS: In the present study, we measured cephalic and extra-cephalic pressure [pressure-pain threshold (PPT)] and cold-pain thresholds (CPT) in CTH sufferers (n = 8 females, n = 8 males) and healthy control subjects (n = 8 males, n = 7 females) recruited from the general population before and after exposure to a 15-min stressful mental task. RESULTS: Results indicated that PPT's at head and hand were lower in the CTH compared with control group both before and after task exposure. PPT's and CPT's decreased from pre- to post-task in both groups, with a significantly greater pre- to post-task reduction in cephalic PPT in the CTH compared with control group. Subjective stress increased from pre- to post-task in both groups and did not differ between groups. In the CTH group, stress reactivity was negatively correlated with PPT's, whilst absolute stress levels were positively correlated with pre- to post-task decrease in PPT's. CONCLUSIONS: The main finding is an enhanced hyperalgesic effect of stress on cephalic pressure-pain sensitivity in the CTH sufferers compared with the healthy controls. The results support the hypothesis that stress may contribute to CTH through hyperalgesic effects on already sensitized pain pathways in CTH sufferers.

Pre-travel preparation and outcome of HIV-infected travellers from a UK clinic.

Objectives. To review the pre-travel preparations and travel health outcomes of HIV-infected individuals. Methods. A prospective questionnaire-based study among English speaking adults with HIV infection attending an outpatient clinic from July to November 2000. Results. Baseline and follow-up questionnaire data were available for 34 individuals whose median CD4 count was 451 cells/mm(3). Eleven of these (32%) had sought travel advice before departure. Eight (23.5%) had been vaccinated or were planning vaccination against at least one condition and 17 (50%) listed travel-specific medications they planned to take with them. Those who were travelling to Africa were more likely to be vaccinated than those who were not travelling to Africa (3/4 vs 5/30, respectively, P=0.03). Those travelling to Europe were less likely to be vaccinated than those who were not (1/16 vs 7/18, P=0.04). The median duration of travel was 14 days (1-180). Fifteen subjects (44%) became ill while abroad. Those who became ill abroad were more likely to have visited Asia (P=0.003) and less likely to have visited the Americas (P=0.02) than those who did not become ill abroad. In addition, they tended to have stayed abroad for longer periods (P=0.07) and had visited more countries (P=0.04) than those who did not become ill abroad. Sixteen individuals (47%) reported illness on their return to the UK. Conclusions. HIV-infected travellers have an increased susceptibility to opportunistic and other travel-related infections and the need for appropriate advice, vaccination and prophylactic therapy is important. Health care provision in this field is in need of uniform guidelines to coordinate travel health management for this particular high risk group.

Schizophrenia-like psychosis following traumatic brain injury: a chart-based descriptive and case-control study.

BACKGROUND: Head injury has been reported to increase the likelihood of the development of schizophrenia-like psychosis (SLP), but its features and risk factors have been insufficiently investigated. METHOD: Between 1987 and 1997, we examined 45 referred patients with SLP following brain trauma. These subjects were matched with 45 head-injured subjects without SLP on age (current and at injury) and gender, and their case records reviewed systematically. The groups were compared and logistic regression analyses performed. RESULTS: The psychoses had a mean age of onset of 26.3 years, a mean latency of 54.7 months after head injury, usually a gradual onset and a subacute or chronic course. Prodromal symptoms were common and depression often present at onset. Paranoid delusions and auditory hallucinations were the predominant features, with formal thought disorder, catatonic features and negative symptoms being uncommon. The SLP group had more widespread brain damage on neuroimaging, especially in the left temporal and right parietal regions, and were more impaired cognitively. Fewer (non-significantly) SLP subjects had epilepsy which was more likely to be well-controlled in this group. On regression analysis, a positive family history of psychosis and duration of loss of consciousness were the best predictors of SLP. CONCLUSIONS: Head injury-related psychosis is usually paranoid-hallucinatory and subacute or chronic in its presentation. A genetic predisposition to schizophrenia and severity of injury with significant brain damage and cognitive impairment may be vulnerability factors.

Anger, depression, and coping interactions in headache activity and adjustment: a controlled study.

OBJECTIVE: To determine if individuals in the general community with chronic headache or migraine differ in terms of anger, depression, and coping strategies and from headache-free individuals in terms of anger and depression. METHOD: A community sample comprising 16 chronic tension-type headache (CTH), 28 migraine headache (MH), and 38 headache-free control subjects (CNT) were compared on measures of anger, depression, and use of various coping strategies. Affective and coping measures, recorded during a headache-free period, were regressed on headache activity measured in a daily diary over the following 2 weeks. Relationships between anger, depression, and coping were also examined in each of the headache groups. RESULTS: The MH subjects were found to use less effective coping strategies than controls and CTH, while the CTH group had higher levels on depression and various anger scales compared to controls and MH. Direct positive relationships were observed between suppressed anger and depression in the MH group, and between trait anger and depression in the CTH group. Anger and coping were predictive of headache activity in the following 2 weeks for both MH and CTH groups, while depression and coping, compared to coping only, were predictive of lifestyle interference from head pain in MH and CTH, respectively. CONCLUSION: The results support a relationship between affective and coping factors in headache activity and adjustment.

Hippocampus and amygdala volumes in elderly schizophrenic patients as assessed by magnetic resonance imaging.

Reduced size of the hippocampus and amygdala has been one of the more consistent morphological findings in schizophrenia, but the question of medial temporal abnormalities in elderly schizophrenia patients has been inadequately addressed. We examined 20 elderly subjects with a DSM-III-R diagnosis of schizophrenia, five of whom had a late-onset schizophrenia (LOS), and compared them with 20 healthy volunteers on magnetic resonance imaging (MRI) and neuropsychological parameters. Hippocampus and amygdala volumes were obtained by manual tracing on T1-weighted 1.5 mm thick contiguous coronal slices perpendicular to the long axis of the hippocampus. Patients had smaller left hippocampal and right amygdala volumes than comparison subjects, the mean differences being 9.7 and 11.1%, respectively, but the right amygdala volumes were not significantly different after Bonferroni correction. The hippocampus-amygdala volumes together were smaller in the schizophrenia group bilaterally. In a pilot analysis, the LOS subjects had non-significantly smaller hippocampus-amygdala volumes than did the early-onset schizophrenia (EOS) subjects. For the schizophrenia group, there were significant correlations between amygdala and hippocampus volumes and some neuropsychological performance indices. The findings are consistent with those reported in younger schizophrenics, and are of the same order of magnitude, suggesting that they are not likely to be progressive. This pilot analysis in LOS subjects argues against the condition being secondary to Alzheimer's disease.

The preventative role of antioxidants (selegiline and vitamin E) in a rat model of tardive dyskinesia.

BACKGROUND: We examined the potential protective effects of two potent antioxidants, selegiline and vitamin E, in a rodent model of tardive dyskinesia (TD), viz. neuroleptic-induced spontaneous orofacial movements. METHODS: Rats were treated with fortnightly injections of fluphenazine decanoate for 12 weeks, and examined at baseline and at fortnightly intervals for vacuous chewing movements, mouth tremors and tongue protrusions. RESULTS: The administration of fluphenazine led to a progressive increase of all three types of orofacial movements. In the first study, the impact of the concomitant administration of selegiline on orofacial movements was examined. Selegiline led to a reduction in orofacial movements in neuroleptic-treated rats to the level of control rats not being administered a neuroleptic drug. In the second study, rats were fed diets either high or low in their vitamin E content. High and low vitamin E diets did not significantly affect neuroleptic-induced orofacial movements. CONCLUSIONS: Our studies provide some support for the hypothesis that oxidative injury may play a role in the genesis of neuroleptic-induced movement disorder, and prompt further examination of this hypothesis in both animals and humans.

Schizophrenia with onset after age 50 years. 2: Neurological, neuropsychological and MRI investigation.

BACKGROUND: Late-onset schizophrenia (LOS) may have a basis in age-related coarse brain disease, but empirical support for this is conflicting. AIMS: Is LOS characterised by more neurological disease than early-onset schizophrenia (EOS)? METHODS: DSM-III-R-defined LOS subjects (n = 27) were compared with 30 EOS and 34 volunteer control subjects on neurological status, neuropsychological test performance and brain magnetic resonance imaging (MRI). RESULTS: LOS and EOS groups had more 'soft' neurological signs and drug-induced movement abnormalities, and performed more poorly on tests assessing speed of information processing, memory and frontal executive functioning. On MRI, the LOS and EOS groups had greater lateral ventricular size than the control group. The LOS subjects also had more signal hyperintensities in periventricular white matter and subcortical nuclei than controls. CONCLUSIONS: LOS and EOS subjects were very similar on neuropsychological, neurological and structural neuroimaging parameters, except that there were more MRI periventricular hyperintensities in LOS subjects.

Reliability and validity of ratings of signal hyperintensities on MRI by visual inspection and computerised measurement.

Brain magnetic resonance imaging (MRI) scans on 98 elderly subjects, 62 with a diagnosis of schizophrenia and 36 healthy controls, were independently and blindly rated by two investigators using the visual rating methods of Fazekas et al. (Fazekas, F., Chawluk, J.B., Alavi, A., Hurtig, H.I., Zimmerman, R.A., 1987. MR signal abnormalities at 1.5 T in Alzheimer's dementia and normal aging. American Journal of Neuroradiology 8, 421-426) and Victoroff et al. (Victoroff, J., Mack, W.J., Grafton, S.T., Schreiber, S.S., Chui, H.C., 1994. A method to improve interrater reliability of visual inspection of brain MRI scans in dementia. Neurology 44, 2267-2276) for periventricular, deep white matter and subcortical gray matter signal hyperintensities (SHs) on T2-weighted images. The hyperintense signal volumes were measured by manual delineation of the signals on a workstation using Analyze software (computerised method). The subjects also underwent a detailed neuropsychological assessment. There was a high correlation between two experienced raters for both visual ratings, and the correspondence between the two methods was high. The inter-rater reliability for the computerised method was modest but significant, and the association between the visual and computerised methods was good except for ratings for SHs in subcortical nuclei. The Fazekas and computerised methods, and to a lesser degree the Victoroff method, had modest but significant correlations with some neuropsychological test measures. In conclusion, we did not demonstrate a clear superiority in reliability or validity for one demanding computerised method of rating SHs. Visual ratings should therefore be considered adequate for most clinical and research purposes, but such ratings should be accompanied by adequate training and the provision of standard reference images.

Time-series analyses of general arousal and headache activity in the natural environment.

A naturalistic longitudinal study was conducted to examine temporal relationships between subjective dimensions of general arousal and headache activity. The "tense arousal" dimension of Thayer's biopsychological model of mood and arousal (The Biopsychology of Mood and Arousal. New York: Oxford University Press; 1989) was recorded using the Activation-Deactivation Adjective Check List (ADACL). Recordings were made eight times daily, every 2 hours from awakening, in conjunction with a clinical diary recording head pain intensity and duration. Three time series of daily, half-daily, and bihourly headache and tension scores were modeled and cross-correlated. Results indicated moderate positive same-time correlations, but revealed large interindividual and intraindividual variation in temporal relationships.

Headache interference as a function of affect and coping: an artificial neural network analysis.

Artificial neural networks present a technique for modeling relationships between variables in complex systems. The negative effects of headache are determined by many "biopsychosocial" elements that represent a complex system. Artificial neural networks may therefore be useful for examining psychological factors in headache. To test this hypothesis, we trained an artificial neural network to predict life-style interference attributed to headache from psychological measures of anger, depression, and coping appraisal and strategies. The artificial neural network demonstrated a better fit of the data than that obtained by multiple regression, and predicted interference levels to within 10% error for 80% of novel cases. Artificial neural networks may be a useful technique for examining psychological correlates of headache.

Factors in human serum interfere with the measurement of advanced glycation endproducts.

Advanced glycation endproducts (AGEs) have been implicated in the pathophysiology of coronary heart disease in ageing, diabetes and renal disease. Competitive enzyme-linked immunosorbent assays (ELISAs) have been developed to measure these compounds in serum, but as recognition of AGEs is both carrier protein- and antibody-dependent standardisation is problematic. We report here on another barrier to standardization, as yet unrecognised. During the development of an AGE ELISA, we found that serum samples did not dilute in parallel to AGE standards or each other. This finding was confirmed by recovery studies that showed over-recovery of AGEs at high serum concentrations, but under-recovery at high dilutions of serum in assay buffer. We developed an inhibition assay to detect factors in serum capable of interacting directly with AGEs immobilised on microtitre plates. Binding of these factors prevented recognition of AGEs by a CML monoclonal antibody and a polyclonal anti-AGE antibody, and was neither sugar- nor carrier protein-dependent. We detected the presence of this factor in all human sera tested and also in foetal calf serum. Pre-incubation of sera with AGEs or heat-treatment at 56 degrees C for 30 min. significantly reduced this binding. We are currently investigating the nature of this factor and the possibility that it may be complement. The effect of this factor on immunoassays for AGEs can only be detected by performing parallelism and recovery studies and we suggest the use of the method referred to in this paper to aid interpretation of parallelism data.

Relationships between arousal-related moods and episodic tension-type headache: a biopsychological study.

An exploratory study was conducted examining arousal-related moods and episodic tension-type headache. Twelve subjects meeting International Headache Society criteria for episodic tension-type headache and 12 headache-free controls recorded headache activity and mood eight times daily for 14 consecutive days. Moods were measured using the Activation-Deactivation Adjective Check List, a self-report list that subjectively represents general arousal along two dimensions of Tension and Energy. Headache subjects had higher Tension levels than controls even in the absence of pain, and greater variation in this dimension as well. Within the headache group, Tension during pain-free periods was significantly lower than when experiencing headache, and was correlated with headache activity. The results were taken to support Thayer's (1989) biopsychological model of mood and arousal, and are discussed in terms of the model's heuristic value for general arousal and headache research.