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It has long been known that tissue non-specific alkaline phosphatase (TNAP) is essential for the correct formation of bone, as altered expression or function of this enzyme results in hypophosphatasia, a disease characterised by compromised bone structure, density and strength. However, recent evidence strongly suggests that the enzyme also has a role in lipid accrual and adipogenesis, a function that seems far removed from bone formation. Given that mesenchymal stromal cells (MSCs) are progenitors of both osteoblasts and adipocytes, the question arises of how TNAP is regulated to potentially have a different function when MSCs undergo either osteogenesis or adipogenesis. As the primary protein sequence is unchanged for the enzyme during both types of differentiation, any differences in function must be attributed to post-translational modification and/or localisation. We therefore examined the location of TNAP in bone- or adipose-derived MSCs differentiated into an adipocytic phenotype and compared the glycosylation state of the enzyme in MSCs differentiated into either osteoblasts or adipocytes. TNAP was found to co-locate with perilipin around lipid droplets in MSCs from bone, subcutaneous- and visceral adipose tissue during adipocytic differentiation. Treatment of TNAP with wheat germ lectin followed by electrophoresis showed minor differences in glycosylation between the phosphatase isolated from cells from these tissues, whereas electrophoresis after neuraminidase digestion highlighted differential glycosylation between cell types and during adipogenesis and osteoblastogenesis. This infers that post-translational modification of TNAP is altered during differentiation and is dependent on the eventual phenotype of the cells., Competing Interests: Conflicts of interest There are no conflicts of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Tissue-nonspecific alkaline phosphatase (TNAP) is one of four isozymes, which include germ cell, placental and intestinal alkaline phosphatases. The TNAP isozyme has 3 isoforms (liver, bone and kidney) which differ by tissue expression and glycosylation pattern. Despite a long history of investigation, the exact function of TNAP in many tissues is largely unknown. Only the bone isoform has been well characterised during mineralization where the enzyme hydrolyses pyrophosphate to inorganic phosphate, which combines with calcium to form hydroxyapatite crystals deposited as new bone. The inorganic phosphate also increases gene expression of proteins that support tissue mineralization. Recent studies have shown that TNAP is expressed in preadipocytes from several species, and that inhibition of TNAP activity causes attenuation of intracellular lipid accumulation in these and other lipid-storing cells. The mechanism by which TNAP stimulates lipid accumulation is not known; however, proteins that are important for controlling phosphate levels in bone are also expressed in adipocytes. This review examines the evidence that inorganic phosphate generated by TNAP promotes transcription that enhances the expression of the regulators of lipid storage and consequently, that TNAP has a major function of lipid metabolism., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Phosphate is an essential nutrient for life on Earth, present in adenosine triphosphate (ATP), deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and phospholipid membranes. Phosphorus does not have a significant volatile phase, and its release from minerals is therefore critical to its bioavailability. Organic ligands can enhance phosphate release from minerals relative to release in inorganic solutions, and phosphorus depletion in paleosols has consequently been used as a signature of the presence of ligands secreted by terrestrial organisms on early Earth. We performed batch dissolution experiments of the Mars-relevant phosphate minerals merrillite, whitlockite, chlorapatite, and fluorapatite in solutions containing organic compounds relevant to Mars. We also analyzed these phosphate minerals using the ChemCam laboratory instrument at Los Alamos, providing spectra of end-member phosphate phases that are likely present on the surface of Mars. Phosphate release rates from chlorapatite, whitlockite, and merrillite were enhanced by mellitic, oxalic, succinic, and acetic acids relative to inorganic controls by as much as >35 × . The effects of the organic compounds could be explained by the denticity of the ligand, the strength of the complex formed with calcium, and the solution saturation state. Merrillite, whitlockite, and chlorapatite dissolution rates were more strongly enhanced by acetic and succinic acids relative to inorganic controls (as much as >10 ×) than were fluorapatite dissolution rates (≲2 ×). These results suggest that depletion of phosphate in soils, rocks or sediments on Mars could be a sensitive indicator of the presence of organic compounds.

Clay mineral-bearing locations have been targeted for martian exploration as potentially habitable environments and as possible repositories for the preservation of organic matter. Although organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected from meteoritic and indigenous igneous and hydrothermal reduced carbon. We conducted synthesis experiments motivated by the hypothesis that some clay mineral formation may have occurred under oxidized conditions conducive to the destruction of organics. Previous work has suggested that anoxic and/or reducing conditions are needed to synthesize the Fe-rich clay mineral nontronite at low temperatures. In contrast, our experiments demonstrated the rapid formation of Fe-rich clay minerals of variable crystallinity from aqueous Fe 3+ with small amounts of aqueous Mg 2+ . Our results suggest that Fe-rich clay minerals such as nontronite can form rapidly under oxidized conditions, which could help explain low concentrations of organics within some smectite-containing rocks or sediments on Mars.

Background: A 2010 CDC-sponsored consultation of psoriasis, psoriatic arthritis, and public health experts developed a public health agenda for psoriasis and psoriatic arthritis indicating that additional population-based research is needed to better characterize psoriasis in the population., Purpose: To better characterize the burden of psoriasis in the U.S. using recent population-based, cross-sectional data in this 2012 analysis., Methods: A subset of 10,676 adults aged 20-59 years from the 2003-2006 and 2009-2010 National Health and Nutrition Examination Surveys was used to examine psoriasis prevalence, severity, disparities, health-related quality of life, and selected comorbidities., Results: The overall prevalence of psoriasis was 3.1% (95% CI=2.6, 3.6); extrapolating to older adults suggests that 6.7 million adults aged ≥20 years are affected. Psoriasis was significantly more prevalent among non-Hispanic whites than other race/ethnicity subgroups, as well as among those with arthritis. Approximately 82% reported no/little or mild disease; the impact of psoriasis on daily life increased with disease severity (p=0.0001 for trend). Those with psoriasis reported significantly more frequent mental distress or mild to severe depression than those without psoriasis. Psoriasis was also significantly associated with obesity and former smoking status., Conclusions: Psoriasis is a large public health problem. Further characterizing psoriasis from a public health perspective will require better survey questions and inclusion of these questions in national surveys., (Published by Elsevier Inc.)

Background: Legionella spp. and other waterborne pathogens have been isolated from various water systems on land based premises as well as on ships and cases of Legionnaires' disease have been associated with both sites. Peculiarities of cruise ships water systems make the risk management a challenging process. The World Health Organization suggests a Water Safety Plan (WSP) as the best approach to mitigate risks and hazards such as Legionella spp. and others., Objectives: To develop WSP on a cruise ship and discuss challenges, perspectives and key issues to success., Methods: Hazards and hazardous events were identified and risk assessment was conducted of the ship water system. Ship company management, policies and procedures were reviewed, site visits were conducted, findings and observations were recorded and discussed with engineers and key crew members were interviewed., Results: A total of 53 hazards and hazardous events were taken into consideration for the risk assessment and additional essential barriers were established when needed. Most of them concerned control measures for biofilm development and Legionella spp. contamination. A total of 29 operational limits were defined. Supplementary verification and supportive programs were established., Conclusions: Application of the WSP to ship water systems, including potable water, recreational water facilities and decorative water features and fountains, is expected to improve water management on ships. The success of a WSP depends on support from senior management, commitment of the Captain and crew members, correct execution of all steps of a risk assessment and practicality and applicability in routine operation. The WSP provides to shipping industry a new approach and a move toward evidence based water safety policy., (Copyright © 2012 Elsevier B.V. All rights reserved.)

This study was conducted within the European SHIPSAN (ship sanitation) project and aims at exploring the legislative framework and current practices related to surveillance of communicable diseases and response aboard passenger ships in Europe. A detailed questionnaire was disseminated and completed by 59 competent authorities in 27 European countries. The majority of competent authorities used national legislation without special provisions for passenger ships. Only 20% had specific provisions for ships regarding quarantine, while a smaller proportion of new Member States (MS) have specific legislation in comparison with old MS (p = 0.01). The Maritime Declaration of Health (MDH) was the main reporting tool used. About 30.5% of the competent authorities declared that they require submission of MDH by all arriving ships, but 28.8% only from affected areas, and 11.9% never require MDH. A total of 45 outbreaks or incidents (36 gastrointestinal, 1 incident of legionellosis, 3 respiratory, and 1 influenza-like illness outbreak, occupational tuberculosis, varicella, scabies, and meningitis) were reported to EU competent authorities during 2006. About 75% of the responders stated that there are gaps in the surveillance and control of communicable diseases. A diversity of approaches in EU countries, and gaps regarding surveillance and response and training needs of personnel were identified.

Background: Hygiene inspections on passenger ships are important for the prevention of communicable diseases. The European Union (EU) countries conduct hygiene inspections on passenger ships in order to ensure that appropriate measures have been taken to eliminate potential sources of contamination which could lead to the spread of communicable diseases. This study was implemented within the framework of the EU SHIPSAN project and it investigates the legislation applied and practices of hygiene inspections of passenger ships in the EU Member States (MS) and European Free Trade Association countries., Methods: Two questionnaires were composed and disseminated to 28 countries. A total of 92 questionnaires were completed by competent authorities responsible for hygiene inspections (n = 48) and the creation of legislation (n = 44); response rates were 96%, and 75.9%, respectively., Results: Out of the 48 responding authorities responsible for hygiene inspections, a routine programme was used by 19 (39.6%) of these to conduct inspections of ships on national voyages and by 26 (54.2%) for ships on international voyages. Standardised inspection forms are used by 59.1% of the authorities. A scoring inspection system is applied by five (11.6%) of the 43 responding authorities. Environmental sampling is conducted by 84.1% of the authorities (37 out of 44). The inspection results are collected and analysed by 54.5% (24 out of 44) of the authorities, while 9 authorities (20.5%) declared that they publish the results. Inspections are conducted during outbreak investigations by 75% and 70.8% of the authorities, on ships on national and international voyages, respectively. A total of 31 (64.6%) and 39 (81.3%) authorities conducted inspections during complaint investigations on ships on international and on national voyages, respectively. Port-to-port communication between the national port authorities was reported by 35.4% (17 out of 48) of the responding authorities and 20.8% (10 out of 48) of the port authorities of other countries., Conclusion: This study revealed a diversity of approaches and practices in the conduct of inspections, differences in the qualifications/knowledge/experience of inspectors, the legislation applied during inspections, and the lack of communication and training among many EU countries. An integrated European inspection programme involving competent expert inspectors in each EU Member States and special training for ship hygiene delivered to crew members and inspectors would help to minimize the risk of communicable diseases. Common inspection tools at a European level for hygiene inspection practices and port-to-port communication are needed.

Background: Seafarers play an important role in the transmission of communicable diseases. The aim of the present study is to draw information and identify possible gaps on occupational health practices related to seafarers sailing on ships within the European Union Member States (EU MS) with focus on communicable diseases., Methods: A structured questionnaire was sent to competent authorities from 21 EU MS. The questionnaire included questions about occupational health policies, medical certification of seafarers, communicable diseases reporting and relevant legislation. Descriptive analysis of the data was conducted by the use of Epi Info software: EU MS were categorized in four priority groups (A, B, C, D) based on: number of passenger ships visits, volume of passengers, and number of ports in each country. Moreover, EU MS were categorized to old and new, based on the date of entry in the EU., Results: All 21 countries with relevant competent authorities responded to the questionnaire. The existence of specific national legislation/regulation/guidelines related to vaccination of seafarers was reported by three out of the 21 (14%) responding authorities. Surveillance data of communicable diseases related to seafarers are collected and analyzed by 4 (19%) authorities. Five out of 21 of the responding countries (24%) reported that tuberculin test result is required for the issuance of seafarer's medical certificate while a great variety of medical examination is required for the issuance of this certificate among countries.Gaps on occupational health services focused on communicable diseases related to maritime occupation have been reported by 33% of the responding countries.Responding authorities from Group A and B had the highest percentage of reported gaps followed by groups C and D. Old MS reported a higher frequency regarding gaps on occupational health services in comparison to new MS., Conclusion: Our results revealed heterogeneity regarding occupational health of maritime employees in EU MS. This work provides some evidence that further work at international and European level could be considered, in order to explore the potential for harmonized initiatives regarding occupational health of seafarers.

Background: Public health measures at sea ports have posed a challenge for public health competent authorities, especially in the context of the influenza pandemic of 2009. This paper discusses the response of authorities to notifications of infectious diseases on passenger ships and the importance of assessing the risks related to cases of influenza. It further provides options for health measures and considerations for decision making during a pandemic such as the influenza pandemic of 2009., Discussion: Prevention and control of influenza have included action taken by both competent port authorities and ships' crews. Assessing the public health risk of each event reported from ships to competent authorities at ports is important before advice is given on implementation of control measures. Public health risk assessment involves appraisal of threats to passengers and crew on board the ship as well as to the population in the community., Summary: Any public health measures taken should be necessary and proportional to the threat. Measures at ports cannot alone be effective in the prevention of the spread of a disease to the community since other means of transport play a major role. Measures taken on board ships can be effective in containing the disease. Consistent policy based on common protocols and carried out by competent authorities at local, national, European, or international levels are essential.

The Communicable Disease Surveillance Centre (CDSC) is now firmly established within the new Health Protection Agency (HPA), which was inaugurated on 1st April 2003. In 2002, CDSC celebrated its 25th anniversary. Its achievements over those 25 years, a period when it evolved from a small unit with three staff to an international centre of excellence with over 250 staff, are recalled in this paper. The development of the Centre is reviewed, as are the ways in which it identified and responded to changing patterns of communicable disease over the quarter century. The considerable benefits of placing CDSC within the Public Health Laboratory Service are demonstrated through several examples. The fact that the expansion of CDSC took place during an era when public expenditure was constrained indicates that government valued the service it provided. The elements required and put in place for effective control and prevention of communicable diseases are highlighted and several themes emerge including the close working relationship needed between the various agencies and disciplines, particularly those between epidemiologists, microbiologists and clinicians. Another theme is the commitment to training, (which is necessary to ensure that work is practiCed to the highest standards), as well as to innovation through research and development. A rigorous approach to field investigation is essential, not just to enable the most appropriate control measures to be applied but to increase the knowledge base on infections and the means of prevention. Good surveillance and reference microbiology stand out as the vital components needed to produce the timely and precise information required to influence practice and policy.

A case-control study of risk factors for community-acquired pneumonia in adults admitted to hospital is reported. Cases were surviving patients (n = 178) admitted to 14 hospitals in England. Controls were individuals (n = 385) randomly selected from the electoral registers of the areas served by the hospitals. The two groups were compared with regard to risk factors for pneumonia using a standardized postal questionnaire. Independent risk factors associated with cases in log-linear regression analysis were age, heart disease (as indicated by congestive heart failure and/or digitalis treatment), lifetime smoking history, chronic airway disease (chronic bronchitis and/or asthma), occupational dust exposure, pneumonia as a child, single marital status and unemployment. Corticosteroid and bronchodilator therapy were also independent risk factors in the log-linear regression analysis, but may reflect the severity of underlying lung disease for which these drugs were prescribed. These data suggest that cigarette smoking is the major avoidable risk factor for acute pneumonia in adults.

The purpose of this study was to identify risk factors for pneumonia diagnosed in the community by general practitioners, using a case control study in 29 general practices in Nottingham, U.K. Patients with radiographically confirmed pneumonia were compared with adults randomly selected from electoral registers corresponding to the catchment areas of the general practices taking part in the study. Sixty-six cases and 489 controls participated. Significant risk factors in univariate analysis included age, chronic obstructive pulmonary disease, congestive heart failure and lifetime consumption of cigarettes. Multiple logistic regression analysis of these four variables showed that age [adjusted odds ratio = 2.69 (for 30 year increment), 95%CI = 1.66-4.35] and chronic obstructive pulmonary disease (adjusted odds ratio= 1.99, 95%CI = 1.15-3.45) were independent risk factors. Only age and chronic obstructive pulmonary disease were independent risk factors for pneumonia in this study. Since cigarette smoking is the major cause of chronic obstructive pulmonary disease, these data suggest that cigarette smoking is the main avoidable risk factor for community-acquired pneumonia in adults.

Two hundred and twenty-six cases of legionnaires' disease who acquired infection in 1998 have been reported to the PHLS Communicable Disease Surveillance Centre. Twenty-five cases (11%) were reported to have died. One hundred and fifteen cases were associated with travel, either abroad or in the United Kingdom, three cases acquired infection in hospital, and the remaining 108 were presumed to have acquired infection in the community. Thirty-five cases were linked to industrial or community associated outbreaks in England and Wales, 22 cases to outbreaks or clusters abroad, and the remaining 169 cases (75%) were reported as single cases. The proportion of cases diagnosed by detection of urinary antigen has continued to increase; in 1998 it contributed to the diagnosis of 117 cases.

The European Surveillance Scheme for Travel Associated Legionnaires Disease was set up by the European Working Group on Legionella Infections (EWGLI) in 1987 to identify cases of legionella infection in returning travellers and to detect outbreaks and cl

Two hundred and twenty-six residents of England and Wales who developed legionnaires' disease with onset of infection in 1997 were reported to the PHLS Communicable Disease Surveillance Centre. Twenty-eight cases (12%) were reported to have died. Half of the reported cases (114) were associated with travel, either abroad or in the United Kingdom. Six cases acquired infection in hospital and the remaining 106 were presumed to have acquired infection in the community. Nineteen cases were linked to industrial or community associated outbreaks or clusters in England, two cases to a hospital outbreak, and 25 cases to outbreaks or clusters abroad. The remaining 180 cases (80%) were reported as single cases. The proportion of cases diagnosed by detection of urinary antigen has continued to increase. In 1997 this method of diagnosis was included for 60% of confirmed cases and in 46% of all cases.

The European Surveillance Scheme for Travel Associated Legionnaires' Disease was established in 1987 to identify clusters and outbreaks of cases of the disease. Twenty-nine collaborating centres in 25 countries contribute case reports in a standard format

We quantify the effects of disk tilt and objective lens tilt on the push-pull tracking error signal of an optical disk data storage system. For a grooved disk, such as a recordable compact disk that operates at a laser wavelength of lambda, it is found that disk tilt produces a tracking offset of 0.05lambda per degree of tilt, whereas objective lens tilt produces an offset of 0.012lambda per degree of tilt. The amplitude of the tracking error signal decreases by 2.5% at the disk tilt angle of 0.3 degrees and by 5% at the objective lens tilt of 0.3 degrees . We achieved these simulations with the computer program Diffract, which performs a combination of diffraction and ray-tracing calculations through the entire optical path, from the light source to the detectors.

Two hundred and one cases of legionnaires' disease were reported to the PHLS Communicable Disease Surveillance Centre in 1996. Twenty-four cases (12%) were known to have died. One hundred and one cases were associated with travel, either abroad or in the United Kingdom. Two cases acquired infection in hospital, the smallest number ever reported, and the remaining 98 were presumed to have acquired infection in the community. Fifty-five (27%) of the 201 cases were linked to outbreaks or clusters and the remaining 146 (73%) were reported as single cases. Six outbreaks were associated with industrial premises. Twenty-two of the travel associated cases were part of three travel outbreaks and six clusters. The proportion of cases diagnosed by detection of urinary antigen has continued to increase and in 1996 this method of diagnosis was used for 43% of the cases.

We discuss the optomechanical design and fabrication of a novel wideband (440-690-nm), leaky polarizing beam splitter with an adjustable leak ratio. This beam splitter is an important component of a multiwavelength dynamic testbed that we have constructed for testing optical disks. The multilayer thin-film structure of the beam splitter is essentially a stacked pair of narrow-band dielectric reflectors that have been fine tuned for optimal performance. The characteristics of the fabricated device are in good agreement with our theoretical calculations.

Objectives: To identify the source of an international outbreak of food poisoning due to Salmonella agona phage type 15 and to measure how long the underlying cause persisted., Design: Case-control study of 16 primary household cases and 32 controls of similar age and dietary habit. Packets of the implicated foodstuff manufactured on a range of days were examined for salmonella. All isolates of the epidemic phage type were further characterised by pulsed field gel electrophoresis., Results: 27 cases were identified, of which 26 were in children. The case-control study showed a strong association between infection with S agona phage type 15 and consumption of a peanut flavoured ready to eat kosher savoury snack imported from Israel. S agona phage type 15 was isolated from samples of this snack. The combined food sampling results from the United Kingdom, Canada, the United States, and Israel showed that contaminated snacks were manufactured on at least seven separate dates during a four month period between October 1994 and February 1995. Voluntary recalls of the product successfully interrupted transmission., Conclusions: Rapid international exchanges of information led to the identification of the source of a major outbreak of S agona in Israel and of associated cases in North America. The outbreak showed the value of the Salm-Net surveillance system and its links outside Europe, both for increasing case ascertainment and for improving the information on the duration of the fault at the manufacturing plant.

One hundred and sixty cases of legionnaires' disease were reported to the PHLS Communicable Disease Surveillance Centre in 1995. Twenty cases (13%) were known to have died. Ninety cases (56%) were associated with travel (in the United Kingdom or abroad), four were associated with a stay in hospital, and the remaining 66 were presumed to have acquired infection in the community. One hundred and twenty-three cases (77%) occurred sporadically. Three community outbreaks and one outbreak at an industrial site were detected in England and Wales. One outbreak and five clusters were detected among visitors to Turkey, Spain, and Italy. Seven cases and one outbreak of nonpneumonic legionellosis were also reported. Cases of travel associated legionnaires' disease continue to account for the largest proportion of the total reported in 1995 and the number of hospital acquired cases continues to decline. A cause for concern in 1995 was a fall in the proportion of cases diagnosed by culture of the organism (from 16% in 1994 to only 9% in 1995). This corresponded with a small increase in the proportion of cases diagnosed solely by detection of antigen to L. pneumophila serogroup 1 in urine.

The European Working Group for Legionella Infections (EWGLI) was set up in 1986 and introduced the European Surveillance Scheme for Travel Associated Legionnaires Disease in 1987. The microbiologists working in reference laborat-ories and the epidemiolog

One hundred and sixty cases of legionnaires' disease in England and Wales were reported to the PHLS Communicable Disease Surveillance Centre in 1994, a rate of 3.1 cases per million population. Twenty-seven cases died. Eighty-nine cases (56%) were associated with travel, either in the United Kingdom (UK) or abroad, and six with a stay in hospital; the remaining cases were presumed to have acquired infection in the community. Seven outbreaks were detected in England and Wales: one was associated with a holiday centre, one with a hotel in London, two with industrial sites, and three occurred in the community. A further four clusters were associated with travel abroad: Spain, Ibiza, the Channel Islands, and a Mediterranean cruise. One hundred and twenty-eight of the 160 cases (79%) were sporadic--that is, not known to be associated with outbreaks--43 of which (34%) were not associated with travel nor acquired in hospital.

Mueller-matrix polarimetry performed in the visible and near IR indicates that an integrating sphere acts as an ideal depolarizer to the 0.5% accuracy of the polarimeter. The integrating sphere emits unpolarized light regardless of the incident polarization state.

One hundred and twenty-nine cases of legionnaires' disease were reported in England and Wales in 1993. Twenty-two of the cases died. Sixty-six cases (51%) were associated with travel (in the United Kingdom or abroad), six were associated with a stay in hospital, and the remaining 57 were thought to have acquired infection in the community. Two community and two hospital outbreaks were recognised in England and Wales and four outbreaks were detected in travellers from the United Kingdom to Spain, Greece, and the United States. One hundred and six cases (82%) were not known to have been associated with outbreaks, and 51 (40%) of these were not associated with travel or hospitals.

Two hundred and eighteen nosocomial cases of Legionnaires' disease with 68 deaths were reported to the National Surveillance Scheme for Legionnaires Disease between 1980 and 1992, representing 15% of the reported infections acquired in England and Wales. Twenty-two nosocomial outbreaks accounted for 135 (62%) of these cases, the remainder occurring as single cases either in hospitals where other single cases or outbreaks had been reported in different years or as 'sporadic' cases in hospitals from which no other cases were reported. A clinical history prior to onset of Legionnaires' disease was available for 124 patients, 61 of whom had undergone recent transplant therapy or were immunosuppressed for other reasons. Sixty cases (27%) were diagnosed by culture of the organism and isolates from 56 patients were typed; 25 (42%) were non L. pneumophila serogroup 1 infections. Methods for prevention and control of nosocomial outbreaks are discussed, in particular the susceptibility to Legionnaires' disease of certain groups of hospital patients.

A previous study demonstrated that laboratory based ward liaison surveillance (LBWLS) of hospital infection was an effective and efficient method. The method involved the follow-up of positive microbiology reports by the review of patient records and liaison with ward nursing staff to consider whether any patients had infection. Here we report the introduction of LBWLS into six district general hospitals to determine whether it is feasible to use this method on an everyday basis. The time required for data collection was assessed and the method was compared with a reference method in one hospital to check its ability to detect infections. To assess reproducibility two infection control nurses (ICNs) performed LBWLS independently, but concurrently, for 5 weeks. The method could be used in all hospitals studied; however, the time for data collection ranged from 3.0 to 6.8 h/100 beds per week. In comparison with the reference method, LBWLS detected 15/41 (37%) of community acquired infections and 30/43 (70%) of hospital acquired infections. In the reproducibility assessment 72 patients were identified by both ICNs. There was agreement about the infected/non-infected status of 65 of these patients. The mean pair agreement and Kappa statistic were 0.88 and 0.72. Laboratory based ward liaison was readily used in all hospitals and was reproducible.

Eight selective surveillance methods were compared with a reference method for their ability to detect hospital infections in patients was also assessed. In the reference method, case records were reviewed three times a week, and during the 11-month period of study, 668 infections were identified amongst 3326 patients. Three hundred and thirty-eight were community acquired infections (CAI) and 330 were hospital acquired infections (HAI). The time for data collection was 18.1 h per 100 beds per week. Of the selective surveillance methods, those based on the review of treatment and temperature charts detected the highest proportion (70%) of CAI; and the review of microbiology reports with regular ward liaison identified the highest proportion (71%) of HAI. The time for data collection in the eight methods ranged from 1.2 h per 100 beds per week to 6.5 h per 100 beds per week. After considering the sensitivity for identifying patients with HAI and time for data collection, the review of microbiology reports with regular ward liaison was judged to be an effective and efficient method of surveillance.

Between March 1988 and January 1989, an incidence study of infections in patients occupying 122 beds in a district general hospital was undertaken. Nursing notes, medical notes, temperature charts, drug prescription charts and laboratory information were reviewed three times a week to determine if patients had infection which met strict case definitions. In addition, the surveyor consulted with ward nursing and medical staff for clarification of symptoms and signs indicative of infection. During the study, 668 infections were identified amongst 3326 patients. Three hundred and thirty-eight (51%) were community-acquired infections (CAI) and 330 hospital-acquired infections (HAI). Excluding 24 HAI acquired in other hospitals, the incidence rates were 9.2 HAI per 100 discharges, and 1.1 HAI per 100 patient days. The common types of CAI were pneumonia, abdominal infection and urinary tract infection. The main types of HAI were urinary tract infection, surgical wound infection and pneumonia. The microorganisms most frequently associated with CAI and HAI were Gram-negative bacilli.

Fourteen people living in or near the city of Gloucester fell ill with Legionnaires' disease caused by Legionella pneumophila serogroup (SG) 1 between 27 August and 27 October 1986. Another patient had fallen ill on 30 May. Nine of the 15 were diagnosed retrospectively during a case finding exercise. There were three deaths. Three cases of Pontiac fever were also diagnosed. The source was probably one or more wet cooling towers. Nineteen premises in the city with such towers were identified, and three just outside Gluocester. Samples from 11 of the 22 premises grew Legionella spp.; from nine of these L. pneumophila SG 1 (Pontiac) was isolated. The efficacy of regular addition of biocide in addition to hypochlorite added at the time of disinfection in inhibiting the growth of Legionella spp. was demonstrated. A survey of patients' movements during their likely incubation period showed that there was no single building that all patients had visited, but there were two areas of the city which nearly all had visited or passed through by car. A case-control study demonstrated an association with one of these areas. Cooling towers near both areas may have been sources but the evidence is insufficient to incriminate any single one. The unexpected finding of L. pneumophila SG 1 (Pontiac) in nine towers supports the hypothesis that there may have been multiple sources. Cooling towers may have been contaminated by mains water or by drift from other towers.

Fourteen recirculating cooling water systems were surveyed during the summer, 1981, to see what factors might influence the prevalence of Legionella pneumophila. The effect on the organism of three anti-microbials was studied, each in two systems, by intermittent treatment at two week intervals. L. pneumophila was isolated from six of the 14 cooling systems at the beginning of the trial but by the end was present in ten. An association was found between the presence of the organism and the concentration of dissolved solids, and chlorides and the pH. There also appeared to be associations with exclusion of light and higher water temperatures. Repeated tests on eight untreated systems showed that two were consistently infected, three became and remained infected, one was infected on a single occasion and two were never infected with L. pneumophila. Treatment of a contaminated system, either with a 10 p.p.m mixture of a quaternary ammonium compound and tributyltinoxide or slow release chlorine briquettes (maximum recorded free chlorine level 1.2 p.p.m.), did not eliminated legionellae. Treatment of two infected towers with a chlorinated phenol (100 p.p.m.) eliminated legionellae for at least three days, but after 14 days the organism was again found.

A preliminary survey of water systems in hospitals and hotels showed that Legionella pneumophila may be found in water storage and distribution systems as well as in the recirculating cooling water of air-conditioning plants. Altogether 42 isolates of L pneumophila were made from 31 establishments, six of which were associated with cases of legionnaires' disease but in 25 of which there was no known association with disease. In the six establishments implicated epidemiologically as the source of legionnaires' disease, these organisms were found in each of their water-distribution systems and also in the cooling water from each of the three with cooling towers. In establishments not associated with cases, water from three out of nine cooling towers, four out of 24 taps or showers, and one out of 15 storage tanks was found to contain legionellae. The organisms were isolated by guinea-pig inoculation and subsequent culture of their peritoneal fluid, liver, and spleen. Finding L pneumophila in water systems in the absence of cases of legionnaires' disease should not at present be an indication for attempts at eradication.

National surveillance of legionnaires' disease in England and Wales identified 588 cases during the years 1979--1982. The majority of cases appeared to be sporadic but 32 clusters of two or more cases were recognised, 24 in association with hotels, seven with hospitals and one with a construction site. Reports (3 published and 3 unpublished) on the investigation and control of six outbreaks are reviewed. All six were found to be common source outbreaks; four hotel associated, one was nosocomial and one was associated with a construction site. Domestic water systems were implicated as sources in the four hotels and the hospital. The most effective control measure was found to be continuous chlorination of the water supply combined with raising the hot water temperature to 60 degrees C or more in the calorifier and at least 55 degrees C to a maximum of 60 degrees C at outlets. Raising hot water temperatures alone was not always completely successful as a control measure. Only in the construction site outbreak was a cooling water system shown to be the principal source of infection.

In two outbreaks of diarrhoea and vomiting that were caused by a small round structured virus (SRSV) that affected over 275 people, epidemiological and laboratory evidence showed that certain foods were the vehicles of infection and suggest that one of the chefs who prepared them may have been excreting this virus for a long time.

In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.

Between December, 1979, and July, 1980, 12 cases of legionnaires' disease were recognised in a district general hospital. 11 of the patients probably acquired their infection within the hospital. Epidemiological and environmental studies indicated that the plumbing system and possibly also the air-conditioning cooling-tower exhaust in the new building of the hospital were the sources of infection. Chlorination of the cold-water supply and raising the hot-water temperature appeared to terminate the outbreak.

An outbreak of Salmonella napoli infection in England and Wales in 1982 was detected by the surveillance of routine reports of salmonella infections from hospital and public-health laboratories. Epidemiological investigation quickly identified two types of small chocolate-covered bars, imported from Italy, as the vehicles of infection, and subsequently both were found to be contaminated with the organism. The prompt recognition of this outbreak and rapid identification of the vehicle of infection enabled four-fifths of the consignment of contaminated chocolate to be withdrawn from the market. The 245 reported cases resulted from the sale of 600 000 bars; as these were presumably only a small fraction of the total number of cases, it is likely that many thousands of infections were prevented.