Investigation of an outbreak of vomiting in nurseries in South East England, May 2012.

On 30 May 2012, Surrey and Sussex Health Protection Unit was called by five nurseries reporting children and staff with sudden onset vomiting approximately an hour after finishing their lunch that day. Over the following 24 h 50 further nurseries supplied by the same company reported cases of vomiting (182 children, 18 staff affected). Epidemiological investigations were undertaken in order to identify the cause of the outbreak and prevent further cases. Investigations demonstrated a nursery-level attack rate of 55 out of 87 nurseries (63·2%, 95% confidence interval 52·2-73·3). Microbiological tests confirmed the presence of Bacillus cereus in food and environmental samples from the catering company and one nursery. This was considered microbiologically and epidemiologically consistent with toxin from this bacterium causing the outbreak. Laboratory investigations showed that the conditions used by the caterer for soaking of pearl haricot beans (known as navy bean in the USA) used in one of the foods supplied to the nurseries prior to cooking, was likely to have provided sufficient growth and toxin production of B. cereus to cause illness. This large outbreak demonstrates the need for careful temperature control in food preparation.

Pathology of inhalational Francisella tularensis spp. tularensis SCHU S4 infection in African green monkeys (Chlorocebus aethiops).

Tularemia, caused by Francisella tularensis, is a sporadic zoonotic disease with the potential to be an agent of biowarfare or bioterrorism. We describe here the gross, histologic, immunohistochemical, and ultrastructural findings in a group of 5 African green monkeys (AGMs) that received an average inhaled dose of 729 colony-forming units of F. tularensis and died or were euthanatized between days 7 and 11 post infection. Clinical changes were evident by 48 hours post infection, and key physiologic abnormalities included increases in body temperature, heart rate, peak cardiac pressure, and mean blood pressure. Prominent gross changes in all cases included numerous pinpoint to 1-cm, well-demarcated, necrotic foci present consistently in the lungs, mediastinal lymph nodes, and spleen but also seen in the heart, mediastinum, diaphragm, liver, urinary bladder, urethra, and mesentery. The lungs, mediastinal lymph nodes, and spleen were most severely affected, with as much as 50% of the tissue replaced by necrotic foci. Histologic changes in all tissues consisted of well-delineated foci of necrosis and neutrophilic and histiocytic inflammation, with varying amounts of hemorrhage, edema, fibrin, and vasculitis. Some lesions were immature pyogranulomas. Strong immunoreactivity was identified primarily within macrophages. Ultrastructurally, bacteria were present within cytoplasmic vacuoles of alveolar macrophages, many of which were degenerate. In summary, AGMs infected with F. tularensis by aerosol develop lethal multisystemic disease that particularly targets the lungs and lymphoid tissues. Thus, AGMs should serve as a suitable and reliable animal model for further studies of tularemia.

Endocrine and ingestive behavioral responses to fluid deprivation in sheep chronically exposed to ethanol.

Endocrine responses to fluid deprivation/restoration and preference for ethanol solution vs. water were assessed in sheep maintained for 5 months on a 10% ethanol solution as their sole source of fluid. Blood pressure, body weight, plasma composition and hormone levels of the alcohol maintained sheep were all within a normal range, except for high plasma concentrations of ANG II and ALDO. During fluid deprivation, AVP concentration increased and fluid-deprived sheep displayed a natriuresis and then a rehydration anti-natriuresis. Sheep did not drink the 10% ethanol solution avidly upon fluid restoration, preferring to drink steadily over the following 24 h; there was an associated increase in blood alcohol concentration (BAC). PRC, ANG II and ALDO all increased throughout the fluid restoration period, whereas plasma AVP and ANP gradually fell. In a separate experiment when water was also supplied to the sheep, they preferred water to 10% ethanol; however, alcohol intake was not eliminated. Overall, this degree of chronic consumption of 10% ethanol solution did not appear to adversely affect physiological mechanisms concerned with body fluid homeostasis after fluid deprivation conditions.

Avian influenza viruses detected by surveillance of waterfowl in Ireland during 2003-2007.

Specimens for the detection of avian influenza virus (AIV) were collected from 1937 waterfowl on the Wexford Sloblands, a major wetland reserve in southeast Ireland, between January 2003 and September 2007. During the same period, 1404 waterfowl were sampled at other locations in Ireland. Specimens were tested either by virus isolation or real-time reverse transcriptase polymerase chain reaction (rtRT-PCR). A total of 32 isolates of AIV, comprising nine subtypes, was obtained from specimens from the Sloblands compared with just one isolate from elsewhere in Ireland. Samples from nine other waterfowl, five of which were from the Sloblands, tested positive for AIV by rtRT-PCR. Ecological factors are likely to have contributed to the higher detection rate of AIV at the Sloblands compared with the rest of Ireland. It was concluded that targeted surveillance at such sites is a cost-effective means of monitoring the circulation of new AIVs in waterfowl, whereas widespread opportunistic sampling is unproductive and wasteful of resources.

Association of Bacillus anthracis capsule with lethal toxin during experimental infection.

Bacillus anthracis lethal toxin (LT) was characterized in plasma from infected African Green monkeys, rabbits, and guinea pigs. In all cases, during the terminal phase of infection only the protease-activated 63-kDa form of protective antigen (PA(63)) and the residual 20-kDa fragment (PA(20)) were detected in the plasma. No uncut PA with a molecular mass of 83 kDa was detected in plasma from toxemic animals during the terminal stage of infection. PA(63) was largely associated with lethal factor (LF), forming LT. Characterization of LT by Western blotting, capture enzyme-linked immunosorbent assay, and size exclusion chromatography revealed that the antiphagocytic poly-gamma-d-glutamic acid (gamma-DPGA) capsule released from B. anthracis bacilli was associated with LT in animal blood in variable amounts. While the nature of this in vivo association is not understood, we were able to determine that a portion of these LT/gamma-DPGA complexes retained LF protease activity. Our findings suggest that the in vivo LT complexes differ from in vitro-produced LT and that including gamma-DPGA when examining the effects of LT on specific immune cells in vitro may reveal novel and important roles for gamma-DPGA in anthrax pathogenesis.

Cardiovascular effects of long-term central and peripheral administration of urocortin, corticotropin-releasing factor, and adrenocorticotropin in sheep.

The neuroendocrine hormones ACTH and corticotropin- releasing factor (CRF), which are involved in the stress response, have acute effects on arterial pressure. New evidence indicates that urocortin (UCN), the putative agonist for the CRF type 2 receptor, has selective cardiovascular actions. The responses to long-term infusions of these hormones, both peripherally and centrally, in conscious animals have not been studied. Knowledge of the long-term effects is important because they may differ considerably from their acute actions, and stress is frequently a chronic stimulus. The present experiments investigated the cardiovascular effects of CRF, UCN, and ACTH in conscious sheep. Infusions were made either into the lateral cerebral ventricles (i.c.v.) or i.v. over 4 d at 5 microg/h. UCN infused i.c.v. or i.v. caused a prolonged increase in heart rate (HR) (P < 0.01) and a small increase in mean arterial pressure (MAP) (P < 0.05). CRF infused i.c.v. or i.v. progressively increased MAP (P < 0.05) but had no effect on HR. Central administration of ACTH had no effect, whereas systemic infusion increased MAP and HR (P < 0.001). In conclusion, long-term administration of these three peptides associated with the stress response had prolonged, selective cardiovascular actions. The striking finding was the large and sustained increase in HR with i.c.v. and i.v. infusions of UCN. These responses are probably mediated by CRF type 2 receptors because they were not reproduced by infusions of CRF.

Vaccines or Latrines? Debating spending on health.

The final session of the 1st year Environmental Health module took the form of a class debate. "This class believes that the recent trend of increasing investment in health care in low income countries at the expense of environmental health measures will be detrimental to health outcomes overall." A few days prior to the debate, each student was asked to prepare a short paper arguing either for or against the motion. Students could not choose which side of the debate to argue for, but voting was free choice. We took a vote at the start on the motion. Three people from each side of the debate presented their case before the debate was opened up to the floor. A spokes-person from each side summed up, then there was a second vote on the motion. Interestingly, most of the class agreed with the title of the debate at the outset. But those arguing for the relative merits of health care spending, particularly in relation to reducing mortality in under-five's, had managed to convince more skeptics by the end of the morning. Two of the best papers are given here.

Differences in the use of health services among people with and without epilepsy in the United Kingdom: socio-economic and disease-specific determinants.

We aim to examine the socio-economic, demographic and disease-specific determinants in the use of health services by patients with epilepsy, compared to people without epilepsy. We used data from the fourth national survey of morbidity in general practice, carried out in 1991-1992. Overall mean annual number of consultations with general practitioners, home visits and referrals to secondary care per person were calculated for people with epilepsy, stratified by age, sex and socio-economic status. The proportion of patients consulting for certain diseases or disease groups were also calculated for patients with epilepsy. Results were compared to these in people without epilepsy, and rate ratios were calculated. Patients with epilepsy consulted twice as often, required three to four times more home visits, and were referred to secondary care three times more often than people without epilepsy, irrespective of age, sex and social class. Among patients with epilepsy, consultation rates and home visits were higher in females, older people and people from the manual social classes. A higher proportion of patients with epilepsy consulted for neoplasms, haematological and mental health disorders, dementia, stroke and gastrointestinal bleeding. Older age and low social class were less strongly associated with health service utilisation than in people without epilepsy, indicating that people with epilepsy lose much of the protective effect of young age and high social class on health. Factors contributing to the higher utilisation of health services in people with epilepsy need to be studied further and their effects taken into account in the organisation of health services for people with epilepsy.

Cerebral Na concentration, Na appetite and thirst of sheep: influence of somatostatin and losartan.

Na and water intakes of Na-depleted sheep are influenced by changes in cerebral Na concentration. The effect of intracerebroventricular infusion of somatostatin or losartan, the ANG II type 1 receptor antagonist, on the Na appetite and thirst of Na-depleted sheep during infusions that decrease (intracerebroventricular hypertonic mannitol) or increase (intracerebroventricular or systemic hypertonic NaCl) cerebral Na concentration was investigated. Na intake was increased but water intake was unchanged during intracerebroventricular infusion of hypertonic mannitol. The increased Na appetite caused by intracerebroventricular infusion of hypertonic mannitol was decreased by concurrent intracerebroventricular infusion of either somatostatin or losartan, with somatostatin being most effective. Water intake was increased during intracerebroventricular infusion of hypertonic mannitol and somatostatin. Na intake was decreased and water intake was increased during systemic or intracerebroventricular infusion of hypertonic NaCl. Intracerebroventricular infusion of losartan blocked both (Na and water intake), whereas somatostatin did not influence either of these changes in intake. The results further consolidate a role for somatostatin and ANG II in the central mechanisms controlling Na appetite and thirst of sheep.

The inhibitory effect of hormones associated with stress on Na appetite of sheep.

Stress is a large stimulus of Na appetite in rabbits, rats, and mice. This study investigated the influence of some peptides implicated in stress, i.e., adrenocorticotropin (ACTH), corticotropin-releasing factor (CRF), and the recently discovered member of the CRF family, urocortin, on the ingestive behavior of sheep. Intracerebroventricular infusion of these peptides over 4 days decreased the need-free Na intake of Na-repleted sheep. Intracerebroventricular infusion of urocortin, however, did not alter Na intake of Na-depleted sheep. Systemic infusion of ACTH increased, whereas systemic infusion of either urocortin or CRF decreased, Na intake of Na-repleted sheep. The increase in Na intake caused by the peripheral infusion of ACTH was blocked by concurrent i.v. infusion of urocortin, substantiating the inhibitory role of this peptide on Na appetite. Central administration of all peptides and i.v. administration of urocortin or urocortin and ACTH combined decreased food intake. Water intake was not directly influenced by the peptides. Rather, decreased water intake, when observed, was secondary to decreased food intake, as determined by pair-feeding experiments. Whereas systemic infusion of ACTH mimics the increase in Na intake observed in several different stressful situations, CRF and urocortin actually inhibit Na intake, indicating a direct central action overriding any effect of these peptides on ACTH release. Indeed, the inhibition of Na intake by urocortin occurred despite its stimulation of ACTH release and the subsequent increase in peripheral level of cortisol. Thus it would appear that hormones associated with stress have both excitatory and inhibitory influences on Na intake. Presumably, other physiological processes entrained by stress also will be important in determining the quantitative outcome on Na appetite.

Spiritual terrorism.

Spiritual abuse is the act of making people believe--whether by stating or merely implying--that they are going to be punished in this life and/or tormented in hell-fire forever for failure to live a good enough life to earn admission to heaven. Spiritual terrorism is the most extreme form of spiritual abuse, which in itself is a serious mental health problem. The 12 steps of Alcoholics Anonymous can be a useful therapeutic modality for countering this problem, provided step two and three are reworded to facilitate cognitive restructuring, therefore enabling victims to develop a positive conception of God. Biblical symbolism can be cognitively helpful if interpreted metaphorically rather than literally. Thus, victims will be able to trust God to restore them to sanity and empower them to be survivors who experience peace of mind, joy of living and freedom from fear.

Spiritual abuse.

Spiritual abuse is the act of making people believe--whether by stating or merely implying--that they are going to be punished in this life and/or tormented in hell-fire forever for failure to live life good enough to please God and thus earn admission to heaven. Spiritual terrorism is the most extreme form of spiritual abuse and may cause serious mental health problems. Those people who have not been spiritually terrorized have not necessarily been spared from spiritual abuse and therefore may still be in need of competent, spiritual counseling. Spiritual abuse, which may be active or passive, can best be conceptualized on a continuum from terroristic to zero abuse. Severity is determined by intensity, age of onset, duration, and individual reaction. The underlying issue in all forms of abuse is control.

Induction of protective immunity to Haemophilus ducreyi in the temperature-dependent rabbit model of experimental chancroid.

The temperature-dependent rabbit model for chancroid, a sexually transmitted disease caused by the fastidious Gram-negative bacterium Haemophilus ducreyi, was used to investigate the abilities of previous infection and immunization with an acellular preparation of H. ducreyi to induce protective immunity. In the first set of experiments, animals were infected intradermally with either the 35000 or Cha-1 strains of H. ducreyi and then rechallenged 30 days later with both the homologous and heterologous strains. In animals infected with the 35000 strain, statistically significant protective immunity occurred only against the homologous strain, whereas protection against both homologous and heterologous challenge was obtained in rabbits previously infected with strain Cha-1. In a separate series of experiments, rabbits were immunized with cell envelopes from either strain 35000 or strain Cha-1 and then challenged with both the homologous and heterologous strains. In rabbits immunized with strain 35000 cell envelopes, significant protective immunity was observed only against challenge with the homologous strain. In animals immunized with strain Cha-1 cell envelopes, protection was obtained against both homologous and heterologous challenge. Histopathologic analysis of sites inoculated with strain 35000 (10(5) CFU) demonstrated that the inflammatory response in control animals was predominantly suppurative (i.e., heterophilic), whereas that of immunized animals was predominantly mononuclear and, at later time points, largely histiocytic. ELISA and Western blot analyses revealed that immunization produced a better humoral immune response than did infection and provided evidence for antigenic cross-reactivity between these two strains. These results provide the experimental basis for continued efforts to identify potential H. ducreyi vaccinogens.

Lipid modification of the 17-kilodalton membrane immunogen of Treponema pallidum determines macrophage activation as well as amphiphilicity.

A murine monoclonal antibody specific for a 17-kDa major membrane immunogen of Treponema pallidum was used to select recombinant Escherichia coli clones expressing the molecule from a T. pallidum genomic library. Sequence analysis of the structural gene for the immunogen (designated tpp17) revealed a 468-bp open reading frame encoding a polypeptide of 156 amino acids with a calculated molecular mass of 16,441 Da. The deduced amino acid sequence included a putative leader peptide terminated by a consensus tetrapeptide for the modification and processing of prokaryotic lipoproteins. Immunoprecipitation of the cloned immunogen radiolabeled with [3H]palmitate confirmed that it was a lipoprotein. The amino acid sequence also predicted that the mature protein contains four cysteine residues in addition to the lipid-modified cysteine of the N terminus. The existence of disulfide-bonded multimeric forms of the native immunogen was demonstrated by immunoblotting T. pallidum solubilized in the presence and absence of 2-mercaptoethanol. Triton X-114 phase partitioning of a nonlipidated form of the 17-kDa immunogen cleaved from a glutathione S-transferase fusion protein demonstrated that lipid modification is responsible for the immunogen's hydrophobic character. The same nonlipidated form of the immunogen also was used to demonstrate that lipid modification is essential for the molecule's ability to stimulate production of tumor necrosis factor alpha by murine macrophages. We conclude that covalently attached fatty acids not only anchor T. pallidum lipoproteins to spirochetal membranes but also confer upon these molecules the ability to activate immune effector cells.

A temperature-dependent rabbit model for production of dermal lesions by Haemophilus ducreyi.

The fact that optimal in vitro growth of Haemophilus ducreyi occurs at 33 degrees C prompted evaluation of the effect of temperature on the ability of this organism to produce skin lesions in rabbits after intradermal inoculation. Animals housed at a reduced ambient temperature (15-17 degrees C) consistently developed necrotic lesions when injected intradermally with 10(5) cfu of H. ducreyi; this inoculum did not produce necrotic lesions in animals housed at normal room temperature (23-25 degrees C). Lesion production in this new model was dependent on both viability of the H. ducreyi inoculum and replication of these organisms after intradermal injection. Histopathologic examination of the lesions revealed that H. ducreyi infection of the rabbit dermis evolves from an acute inflammatory reaction to abscess formation. Evaluation of three additional strains of H. ducreyi in this model confirmed that lesion formation was not bacterial strain-dependent. This new temperature-dependent rabbit model for productive H. ducreyi infection will facilitate investigation of the molecular pathogenesis of chancroid.

Lipid modification of the 15 kiloDalton major membrane immunogen of Treponema pallidum.

The 15 kiloDalton major membrane immunogen was included among the Treponema pallidum polypeptides selectively labelled with [3H]-palmitate. The cloned gene for this immunogen, tpp15, encoded a signal peptide of 17 amino acids, a consensus signal peptidase II cleavage site, and a mature protein of 124 amino acids (13,967 Daltons). As predicted by the DNA sequence, the recombinant 15 kiloDalton immunogen labelled selectively with [3H]-palmitate, and globomycin inhibited processing of the precursor to the mature polypeptide. While the native and recombinant immunogens are amphiphilic, the 15 kiloDalton immunogen synthesized in a cell-free system was hydrophilic. The covalent attachment of fatty acids appears to be responsible for the amphiphilicity of the immunogen and its membrane attachment.