bluuebunny/crossref_metadata_2025 huggingface dataset:
Cattle as a possible source of verocytotoxin-producingEscherichia coliO157 infections in man
Authors: Chapman P. A. , Siddons C. A. , Wright D. J. , Norman P. , Fox J. , Crick E.
Published: May 2009

In May-June 1992 cases of infection with verocytotoxin-producing (VT+)Escherichia coliO157 in South Yorkshire could have been associated with prior consumption of beef from a local abattoir. During investigation of the abattoir, bovine rectal swabs and samples of meat and surface swabs from beef carcasses were examined forE. coliO157, isolates of which were tested for toxigenicity, plasmid content and phage type.E. coliO157 was isolated from 84 (4%) of 2103 bovine rectal swabs; of these 84, 78 (93%) were VT+, the most common phage types being 2 and 8, the types implicated in the cluster of human cases. Positive cattle were from diverse sources within England.E. coliO157 was isolated from 7 (30%) of 23 carcasses of rectal swab-positive cattle and from 2 (8%) of 25 carcasses of rectal swab-negative cattle. The study has shown that cattle may be a reservoir of VT+E. coliO157, and that contamination of carcasses during slaughter and processing may be how beef and beef products become contaminated and thereby transmit the organism to man.
An outbreak ofSalmonella mikawasimaassociated with doner kebabs
Authors: Synnott M. , Morse D. L. , Maguire H. , Majid F. , Plummer M. , Leicester M. , Threlfall E. J. , Cowden J.
Published: May 2009

During October 1992 an increase in the number of isolates ofSalmonella mikawasima, a rare serotype, was noted including a cluster of nine cases in the South West Thames region. A case control study was conducted and univariate analysis showed a statistical association between illness and eating at takeaway A for cases compared with household controls (P= O003) and with neighbourhood controls (P= 0.0245). Cases were also more likely to have eaten kebabs than were controls or average takeaway A customers, implicating doner kebabs as the most likely vehicle of infection. Plasmid profile analysis of the nine cases' isolates showed them to be indistinguishable and to be characterized by a single plasmid of approximately 60 MDa.

The original source of theSalmonella mikawasimacontamination was not determined, but food preparation practices for kebabs at takeaway A were insufficient to protect against illness if contaminated. This outbreak was only recognized because of the unusual serotype, but could be an indication of a more widespread problem with doner kebabs.
Malaria transmission rates estimated from serological data
Authors: Burattini M. N. , Massad E. , Coutinho F. A. B.
Published: May 2009

A mathematical model was used to estimate malaria transmission rates based on serological data. The model is minimally stochastic and assumes an age-dependent force of infection for malaria. The transmission rates estimated were applied to a simple compartmental model in order to mimic the malaria transmission.

The model has shown a good retrieving capacity for serological and parasite prevalence data.
Polymerase chain reaction for salmonella virulence–associated plasmid genes detection: a new tool in salmonella epidemiology
Authors: Rexach L. , Dilasser F. , Fach P.
Published: May 2009

The important role of plasmid genes in assessing virulence for BALB/c mice in salmonella, and the difficulty of using standard techniques to detect them, led us to develop a detection method by gene amplification.

One hundred and forty–three strains (71 serovars) of salmonella and 35 strains of other species were tested using specific oligonucleotide primers. The amplification products were identified by a specific oligonucleotide probe. Forty-nine salmonella strains from ten serovars (S. abortus ovis, S. choleraesuis, S. dublin, S. enteritidis, S. gallinarum / pullorum, S. hessarek, S. typhimurium, S. IIIa48:z4, z23,S. IV43: z4, z23:-,S. V28:a:-) produced a positive and specific response.

Because of various origins of the strains possessing the gene sought and the diversity of the responses, both from one serovar to another and in the same serovar, this search has its place among the epidemiological markers in general use. This method appears well suited to the research and detection of plasmid genes associated with mouse virulence in salmonella.
Prospective study of verocytotoxin–producing, enteroaggregative and diffusely adherentEscherichia coliin different diarrhoeal states
Authors: Brook M. G. , Smith H. R. , Bannister B. A. , McConnell M. , Chart H. , Scotland S. M. , Sawyer A. , Smith M. , Rowe B.
Published: May 2009

One hundred and eighty–one stool specimens from patients with various types of diarrhoea (135 patients) or from non-diarrhoeal controls (23 acute medical patients, 23 inflammatory bowel disease in remission) were investigated using a colony–blot DNA hybridization assay for the presence of Verocytotoxin–producing (VTEC), enteroaggregative (EAggEC) and diffusely adherent (DAEC)Escherichia coli. Twelve patients had probe–positive EAggEC in the stool and 8 of these had diarrhoea, 6 following recent travel. Eight patients had DAEC, 7 of whom had travellers diarrhoea. Six of 10 (60%) travellers with gastroenteritis, but without a recognized enteric pathogen, were positive for EAggEC (4) or DAEC (2). Five of 10 (50%) travellers with gastroenteritis related to a recognized enteric pathogen also had DAEC identified in their stool. Of the 23 acute medical control patients 11 had been abroad, 4 of these were immigrants and had EAggEC. VTEC were not found and, with one exception, immunoassays for antibodies toE. coliO 157 and O 2 lipopolysaccharides were negative.
A comparison of aerosol and intragastric routes of infection withListeriaspp
Authors: Bracegirdle P. , West A. A. , Lever M. S. , Fitzgeorge R. B. , Baskerville A.
Published: May 2009

Aerosol infection (AI) of Porton outbreak mice withListeriaspecies, exhibiting varying degrees of virulence, was compared with gastric intubation (GI) on the basis of numbers of deaths. 50% lethal dose (LD50) and pattern of listerial infection. The AI route appeared to be more sensitive, efficient and consistent than GI in that it required 105fewer micro-organisms to obtain infection and death then ensued within 4 days, with GI deaths usually occurring on day 7. All the virulent strains tested caused 100% mortality by AI, while virulent and avirulent strains were indistinguishable by GI. Bacterial counts in the livers and spleens of infected mice were consistent with the relative virulence of the infectious agent using AI but not in GI mice. There were higher numbers of micro-organisms and more widespread lesions in the organs of AI mice than in GI. Results indicate that AI is an accuratein vivoindicator of virulence in listeria and using AI, bacterial counts in the liver and spleen could replace LD50tests, thereby reducing the number of animals required forin vivovirulence testing.
Patient and strain characteristics in relation to the outcome of meningococcal disease: a multivariate analysis
Authors: Scholten R. J. P. M. , Bijlmer H. A. , Valkenburg H. A. , Dankert J.
Published: May 2009

To investigate the joint association of patient and strain characteristics with the outcome of meningococcal disease (MD), data were collected on 563 consecutive cases of MD reported between 1989 and 1990 in The Netherlands. The meningococcal isolates were characterized with regard to their surface characteristics. Sequelae occurred in 8.5% of the patients, and were only associated with the presence of bacteraemia. The case-fatality rate was 7.7%. Infants aged ≤ 5 months and patients in the age-groups of 10–19 years and ≥ 50 years had an increased risk for a fatal outcome compared with children from 6 months to 9 years old (Odds Ratios [ORs]: 5.1, 3.4 and 9.8, respectively). The OR for females versus males was 2.3. The ORs for patients with bacteraemia, or a combination of bacteraemia and meningitis, compared with meningitic patients, were 2.3 and 3.1. Meningococcal strain characteristics did not influence the case-fatality rate substantially. In conclusion, host factors were found to be determinants for a fatal outcome of MD in The Netherlands from 1989 to 1990.
Some properties of coagulase–negative staphylococci isolated from cases of ovine mastitis
Authors: Fthenakis G. C. , Marples R. R. , Richardson J. F. , Jones J. E. T.
Published: May 2009

Of 41 coagulase-negative staphylococcal isolates from cases of ovine mastitis, 80% were speciated by the ‘API-Staph SYSTEM’ and 90% by a combination of biochemical tests.Staphylococcus simulansandStaph. xylosuswere the two most prevalent species.
Genomic fingerprints ofStaphylococcus aureusof bovine origin by polymerase chain reaction-based DNA fingerprinting
Authors: Matthews K. R. , Kumar S. J. , O'Conner S. A. , Harmon R. J. , Pankey J. W. , Fox L. K. , Oliver S. P.
Published: May 2009

Staphylococcus aureus(n = 75) isolated from mammary secretions of cows with subclinical and clinical mastitis from several geographic locations in the USA were examined using polymerase chain reaction-based DNA fingerprinting. DNA fingerprints were produced using a synthetic oligonucleotide primer (5‘GTAACGCC3’) to produce a distinct spectrum of amplified DNA fragments facilitating a high degree of resolution for differentiatingS. aureusstrains. PCR-based DNA fingerprinting grouped the 75S. aureusisolates into 19 distinct profiles. The technique differentiated closely related strains within and between geographic locations. Findings suggest that certain types are found across geographic regions suggesting a common clonal type. Within herd data suggest heterogeneity among subclinical and clinical isolates ofS. aureusstrains. Compared to existing typing methods, PCR-based DNA fingerprinting is easy to perform and interpret. Use of PCR-based DNA fingerprinting may allow for a more detailed investigation of the epidemiology ofS. aureusmastitis in dairy cows.
Prevalence of human astrovirus serotypes in the Oxford region 1976–92, with evidence for two new serotypes
Authors: Lee T. W. , Kurtz J. B.
Published: May 2009

Results of serotyping on 291 astrovirus-positive stools collected between 1976 and 1992 showed that about two-thirds (64.9%) were serotype 1. Infections were more frequent in the fourth quarter of the year and there was a suggestion that during the past 5 years serotype 1 has occurred with greater frequency in alternate years. Evidence is provided for the existence of two new serotypes, 6 and 7.
Insertion sequence IS200 fingerprinting ofSalmonella typhi: an assessment of epidemiological applicability
Authors: Threlfall E. J. , Torre E. , Ward L. R. , Dávalos-Pérez A. , Rowe B. , Gibert I.
Published: May 2009

WhenPstI–generated digests of genomic DNA from each of the type strains of 49 of the Vi phage types ofSalmonella typhiwere probed with a PCR–amplified IS200 gene probe, all strains were found to possess at least 11 IS200 elements carried on fragments in the range 24.2–1.2 kb. Fourteen fingerprints were identified but two patterns designated IS200Sty1 and IS200Sty2 predominated. In one strain, a plasmid–mediated IS200 element was identified. When IS200 fingerprinting was applied to epidemiologically–unrelated strains ofS. typhiisolated in Ecuador, 3 patterns were identified in 10 strains belonging to 9 different phage types. It is concluded that Vi phage typing remains the method of choice for the primary differentiation ofS. typhibut that IS200 fingerprinting may be of limited use in laboratories which do not have access to phage typing.
Ribotyping as an epidemiologic tool forEscherichia coli
Authors: Tarkka E. , Åhman H. , Siitonen A.
Published: May 2009

Restriction fragment length polymorphism of ribosomal RNA genes was analysed among 133Escherichia colistrains predominantly from blood and urine, including 21 isolates from faeces of healthy persons. The strains had also been characterized for their O:K:H serotypes, for the presence of P, S and type 1C fimbriae, non–P, non-S mannose–resistant haemagglutinins and haemolysin production.HindIII–digested genomic DNA was subjected to Southern blot analysis with either plasmid pKK3535 containingE. colirRNA operon or purified rRNA as a probe. Among the 133 strains 20 ribotypes were obtained. The distribution of strains into different ribotypes generally correlated with their O:K:H serotype. Ribotype variation within serotypes was mainly seen among strains with the K5 capsule. The origin of the strains or the presence of virulence-associated factors did not correlate with the ribotype. In conclusion, ribotyping appears to be a valuable method in epidemiologic studies especially when the serotyping methods are not available.
False positive legionella serology in campylobacter infection: campylobacter serotypes, duration of antibody response and elimination of cross-reactions in the indirect fluorescent antibody test
Authors: Marshall L. E. , Boswell T. C. J. , Kudesia G.
Published: May 2009

Sera from 83 patients with campylobacter gastroenteritis were examined for the presence of legionella antibodies by indirect immunofluorescence. Twenty–one patients (25%) had positive titres (≥ 16) including 11 patients with titres of ≥ 128. Legionella seropositivity persisted in 5 of 9 patients (55%) studied for 6–9 months. Campylobacter isolates were serotyped by the Penner scheme. Isolates associated with legionella seropositivity included Penner types 1, 2 and 4, the common endemic serotypes in England. Campylobacter blocking fluids were prepared from a range of Penner reference strains. The blocking fluid prepared from Penner type 11 was the most efficient at inhibiting the false-positive legionella titres. Using this absorption step legionella titres were inhibited from 24 of 26 patients (92%) with campylobacter but not from 8 patients with cultureproven legionnaires' disease. We recommend that this method is incorporated into routine diagnostic legionella serology in order to eliminate false-positive reactions due to campylobacter.
A study of a hospital cluster of systemic candidosis using DNA typing methods
Authors: Romano F. , Ribera G. , Giuliano M.
Published: May 2009

A cluster of disseminatedCandida albicansinfections, which occurred at the Intensive Care Unit of the Department of Heart Surgery, was investigated. Ten patients became infected and seven died. A wide microbiological surveillance was carried out. A total of 14 isolates ofCandida albicans, four environmental and ten human, were examined using the Restriction Endonuclease Analysis (REA) of DNA. The isolates were classified into five different main groups. Five of the clinical isolates had the predominant pattern Ab and two more clinical strains were very closely related. Two more isolates from the emergency kit desk and the hands of a nurse gave the same REA profile. Such a relationship proved the epidemic nature of the cluster, with most of the patients cross-infected, and strongly suggested transmission on the hands of the staff as a determinant of the epidemic. Thus, REA has the potential to address many important questions in the study of nosocomial epidemiology ofCandida albicans.
The diagnosis of toxoplasmosis using IgG avidity
Authors: Holliman R. E. , Raymond R. , Renton N. , Johnson J. D.
Published: May 2009

Current methods to establish the duration of toxoplasma infection in pregnant women and for the diagnosis of toxoplasmosis in the neonate or HIV infected patient have significant limitations. We assessed the precision of a commercial ELISA for the detection of toxoplasma specific IgG and adapted the assay to measure avidity using an elution agent washing step. The sensitivity and specificity of the ELISA were 100 and 75 % respectively and optimal measurement of avidity was achieved using 6 M urea as the elution agent.

Toxoplasma lymphadenopathy of less than 3 months duration was associated with low avidity specific IgG but some discordant findings were recorded. Serial measurement of IgG avidity assisted the distinction between actively produced antibody in infants with congenital toxoplasmosis and passively acquired antibody of maternal origin in uninfected babies. There was no significant difference between avidity levels in HIV infected patients with or without cerebral toxoplasmosis.
Illness in a community associated with an episode of water contamination with sewage
Authors: Fogarty J. , Thornton L. , Hayes C. , Laffoy M. , O'Flanagan D. , Devlin J. , Corcoran R.
Published: May 2009

Following an episode of water contamination with sewage in a rural Irish town, a community-wide survey of gastrointestinal-associated illness and health service utilization was conducted. Random sampling of households yielded residents who were surveyed using a self-administered questionnaire. Of 560 respondents from 167 (84%) households, equal proportions lived in areas known to have been exposed and unexposed to the contaminated water, although 65% of subjects reported using contaminated water. Sixty-one percent of subjects met the case definition. The most common symptoms among cases were abdominal cramps (80%), diarhoea (75%), appetite loss (69%), nausea (68%) and tiredness (66%). Mean duration of illness was 7·4 days. Only 22 % of cases attended their general practitioner. Drinking unboiled water from the exposed area was strongly associated with being a case. A substantial degree of community illness associated with exposure to contaminated water was observed. The episode ranks as one of the largest reported water-borne outbreaks causing gastrointestinal illness in recent times.
Epidemiology of measles in Taiwan: dynamics of transmission and timeliness of reporting during an epidemic in 1988–9
Authors: Lee M. S. , King C. C. , Chen C. J. , Yang S. Y. , Ho M. S.
Published: May 2009

We analysed nation-wide reported measles cases during the 1988–9 epidemic and found that longer duration and wider spread were two major characteristics of the outbreak. All the 22 county/city index cases were reported with a delay of > 4 days and 64% were aged 5–14 years. This epidemic occurred mainly among 5–14-year-old school-children (59%), infants under 1 year (19%), and pre-school children (18%). The overall attack rate was 0·63 cases per 10000 population, with the highest attack rate (7·4 cases per 10000 population) occurring in infants. Among 280 confirmed cases <15 months of age, 9-month-old infants (42 cases) had a higher risk of measles and peaked at 10 months (49 cases). This epidemic started in March 1988 among 5–9-year-old children in the northern suburban area, then spread to Taipei City and neighbouring counties or cities. It continued to spread from the northern to southern and western areas during the summer vacation and New Year holidays. Multiple logistic regression analysis showed that the delay of measles reporting was strongly associated with the cases infected early in the epidemic (OR= 6·9,P< 0·001) and reported from teaching hospitals (OR = 2·6,P< 0·001). The reappearance of high attack rates among 5–9-year-old children in the 1985 and 1988–9 measles epidemics in Taiwan indicated the persistence of pockets of susceptible individuals even after mass immunization.
A pseudo-outbreak of salmonellosis
Authors: Joce R. E. , Murphy F. , Robertson M. H.
Published: May 2009

During July 1991, a single laboratory reported an increased number of an unusual salmonella isolate. An outbreak control team was convened. A case was defined as an individual with diarrhoea from whose faecal sample Salmonella hadar was isolated after 1 July 1991. By 30 July, 90 isolates had been identified and 57 persons interviewed including 39 primary cases. Interviews failed to identify any common features among the cases. A review of the laboratory procedures revealed that the selenite enrichment medium was inoculated using the spoon from the stool collection kit after it was used to emulsify the faecal sample with saline for microscopy. Salmonella hadar was isolated from this saline. Once this practice was stopped, no further isolates of S. hadar were made. This pseudo-outbreak is a powerful reminder to verify the existence of an outbreak, especially when epidemiological data are inconsistent.
Epidemiology of invasiveHaemophilus influenzaeinfections in England and Wales in the pre-vaccination era (1990–2)
Authors: Anderson E. C. , Begg N. T. , Crawshaw S. C. , Hargreaves R. M. , Howard A. J. , Slack M. P. E.
Published: May 2009

This survey defined the pattern of invasiveHaemophilus influenzaeinfections during 1990–2 in six regions in England and Wales during the pre-vaccination era providing a baseline against which any changes in patterns of disease due to the introduction of theHaemophilus influenzaetype b vaccination programme can be monitored. A total of 946 cases of invasiveHaemophilus influenzaewere recorded during the survey period of which almost 90 % were due to type b and most of the remainder were non-typeable. Type b infections occurred predominantly in children less than 5 years of age (88%) with the highest attack rate in male infants in the 6–11 month age group. Diagnostic category varied with both age and serotype; meningitis was the commonest presentation overall but pneumonia and bacteraemia were more common in adults and non-typeable isolates. Mortality was highest in neonates and the elderly (over 65 years of age) who were more likely to have an underlying predisposing condition than older children and adults. Children under 5 years of age had a higher case fatality rate for non-typeable than for type b infections. Ampicillin resistance was 15% and there were no cefotaxime resistant type b isolates.
Tuberculosis in Inner London: evidence for an increase in young adults and immigrants
Authors: Barkham T. M. S. , Drury A. , Pearson A. D. , Dybowski R. , Atkinson H.
Published: May 2009

We report a marked increase in the rate of notifications of tuberculosis in young adults in the London Borough of Lambeth. Analysis of notifications made to the Proper Officer over a 10-year period showed that the age specific notification rate in the cohort aged 20–44 years increased from 30/100000 in 1983 to 51/100000 in 1992. Analysis of St. Thomas' Hospital laboratory records of patients seen between 1984 and 1991 from whom Mycobacterium tuberculosis was isolated showed an increase in the number of patients of African origin from five in the first half of the study period (1984–7) to 25 in the second half (1988–91): 21 of these 25 had immigrated into England within 4 years of their illness. This finding is being further investigated in a prospective study of ethnicity, travel history and date of immigration of Lambeth residents notified with tuberculosis.
An outbreak of viral gastroenteritis associated with adequately prepared oysters
Authors: Chalmers J. W. T. , McMillan J. H.
Published: May 2009

Over Christmas 1993, an outbreak of food poisoning occurred among guests in a hotel in South West Scotland. Evidence from a cohort study strongly suggested that raw oysters were the vehicle for infection, probably due to a Small Round Structured Virus (SRSV). Detailed enquiry about the source and preparation of the oysters revealed no evidence of any unsafe handling at any stage in the food chain, nor any evidence of bacterial contamination. It is suggested that the present standards of preparation and monitoring are inadequate to protect the consumer, and that bacteriophage monitoring may be a useful method of screening for viral contamination in future.
Hand-genital transmission of genital warts? An analysis of prevalence data
Authors: Fairley C. K. , Gay N. J. , Forbes A. , Abramson M. , Garland S. M.
Published: May 2009

The role of hand-genital transmission in the aetiology of genital warts is unclear. However this route is suggested by a number of observations including the relatively high proportion of genital warts in children which contain HPV types 1–4 (15% for children and 2% for adults). We compared two transmission models; one which assumes that hand-genital transmission occurs and one that it does not, and determined the conditions in which each model can reflect the available prevalence data. Hand-genital transmission provides a simple explanation of the observed differences in the proportions of genital warts containing HPV types 1–4 and 6/11 in children and adults. If hand-genital transmission does not occur, the observed difference could only be explained by an eightfold greater probability of transmission to children of types 1–4 than types 6/11, or by an eightfold greater duration of infection with types 1–4. Our findings provide support for the view that genital warts may be transmitted by hand-genital contact.
Evidence for a high prevalence of spotted fever group rickettsial infections in diverse ecologic zones of Inner Mongolia
Authors: Liu Qing-Huai , Chen Guo-Ying , Jin Yan , Te Meng , Niu Li-Chun , Dong Shi-Ping , Walker D. H.
Published: May 2009

A 3-year study of spotted fever group rickettsial ecology in Inner Mongolia revealed that nearly half of the human population tested had antibodies toRickettsia sibiricadetected by complement fixation test. Infected persons, ticks and a high proportion of seropositive livestock and wild rodents were found in all five vegetation zones (desert, steppe, forest, forest-grassland and grassland).
Salmonella outbreak from microwave cooked food
Authors: Evans M. R. , Parry S. M. , Ribeiro C. D.
Published: May 2009

Following a buffet meal served to six guests at a private domestic function, five of the guests and the host developed symptoms of food poisoning.Salmonella enteritidisphage type 4 (PT4) was isolated from all four individuals who submitted faecal samples for investigation. Leftover samples of a savoury rice dish consumed by all six ill persons contained 6×103/gmSalmonella enteritidisPT4. The rice salad comprised boiled rice, raw carrots, eggs, cheese and curry powder. The curry powder and remainder of the pack of six eggs were negative on microbiological analysis. The rice dish had been prepared by heating in a 500 W microwave oven with a rotating turntable on full power for 5 min. Although the hazards of inadequate microwave cooking are well recognized, this is only the second outbreak of food poisoning from microwave cooking to be reported.
A serosurvey of water-borne pathogens amongst canoeists in South Africa
Authors: Taylor M. B. , Becker P. J. , Van Rensburg E. Janse , Harris B. N. , Bailey I. W. , Grabow W. O. K.
Published: May 2009

Certain health risks have been associated with recreational exposure to faecally polluted water. Canoeing in certain South African waters is considered to be a high risk activity with regard to schistosomiasis. gastroenteritis and possibly hepatitis. In a cross-sectional study, a serosurvey was conducted amongst canoeists to ascertain whether or not they had a higher seroprevalence to hepatitis A virus. Norwalk virus andSchistosomaspp. than non-canoeists. In comparisons between the two groups, a significant association could not be demonstrated between canoeing and antibody response to hepatitis A and Norwalk viruses (P-values for age-adjustedχ2were 0·083 and 0·219 respectively), but a significant association could be demonstrated between canoeing and the antibody response to Schistosoma spp. (P> 0·001: age-adjusted).
Biotype traits and antibiotic susceptibility ofVibrio choleraeserogroup O1 before, during and after the emergence of the O139 serogroup
Authors: Mukhopadhyay A. K. , Garg S. , Nair G. Balakrish , Kar S. , Ghosh R. K. , Pajni S. , Ghosh A. , Shimada T. , Takeda T. , Takeda Y.
Published: May 2009

Sixty-nine strains ofVibrio cholerae01 isolated at different times were analysed to investigate if there were any differences among the 01 strains isolated before, during and after the advent of the O139 serogroup. Of the 69 01 strains examined, 68 belonged to the Ogawa serotype while one belonged to the Inaba serotype. With the exception of one strain all other strains ofV. cholerae01 belonged to the eltor biotype. A single O1 strain isolated before the emergence of the O139 serogroup could not be classified as either eltor or classical biotype because it was resistant to both classical and eltor specific bacteriophages. Marked variations in the susceptibility to antibiotics ofV. choleraeO1 isolated during the different periods were observed. In addition, strains ofV. choleraeisolated after the epidemic of serogroup O139 in Calcutta showed an expanding R-type with resistance to a variety of drugs as compared to the 01 strains isolated before the advent of the O139 serogroup. From this study, it is clear that there is a substantial mobility in genetic elements ofV. choleraeOl which necessitates a continuous monitoring to keep abreast of the changing traits of the etiologic agent of cholera.
Chaos under canvas: a Salmonella enteritidis PT 6B outbreak
Authors: Brugha R. F. , Howard A. J. , Thomas G. R. , Parry R. , Ward L. R. , Palmer S. R.
Published: May 2009

An outbreak of Salmonella enteritidis PT 6B food poisoning, the first reported of this recently described phage type, resulted in illness among 46 of 49 members of a camping group in North Wales. 33 of whom were hospitalized. Epidemiological evidence (P < 0·0001) indicated that a lemon meringue pie was the vehicle of infection. Fresh shell eggs, stored after purchase at ambient temperature, appear to be the most likely source of infection, with multiplication during preparation and subsequent storage of the pie a significant contributory factor. Campers may be at greater risk than others and should consider the use of cold boxes for the transport and storage of eggs, and avoid the preparation of lightly cooked egg products under these basic conditions.
Occurrence ofListeriaspecies in ready to eat foods
Authors: Wilson I. G.
Published: May 2009

Over 8000 ready to eat foods were examined for the presence ofListeriaspecies. Overall. 5% of foods were found to contain these organisms. Higher occurrence was found in some foods such as chicken (11%) and fish (14%). Most of theListeriaspecies isolated wereL. monocytogenes(49%) andL. innocua(36%) with lower numbers of other species. No seasonal pattern in the recovery ofL. monocytogeneswas found. Unsatisfactory or potentially hazardous levels ofL. monocytogeneswere found in 14 products (< 0·2%). mostly cooked meats. Undercooked chicken products appeared to present the greatest risk for the duration of this survey. The small number of samples which were potentially hazardous suggests that the risk to consumers is not high, and this is confirmed by the absence of clinical cases in the region during the period of study.
Prevalence of antibodies againstEntamoeba histolyticain Mexico measured by ELISA
Authors: González C. R. , Isibasi A. , Ortiz-Navarrete V. , Paniagua J. , García J. A. , Ramirez A. , Salvatierra B. , Tapia R. , Sepúlveda J. , Gutiérrez G. , Kumate J.
Published: May 2009

The prevalence of antibodies againstEntamoeba histolyticawas studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture ofEntamoeba histolyticaHM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60538 samples suppliedbythe National Seroepidemiology Survey, antibodies were found in 4·49 % (4·32–;4·65% at 95 % confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1·25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country.

Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.
Inactivation of HIV-1 by chemical disinfectants: sodium hypochlorite
Authors: Van Bueren J. , Simpson R. A. , Salmax H. , Farrelly H. D. , Cookson B. D.
Published: May 2009

The efficacy of sodium hypochlorite was assessed against human immunodeficiency virus type 1 suspended in low (8% v/v) or high (80% v/v) concentrations of serum or in a high (80%) concentration of blood. In the presence of 8% serum. 100 p.p.m. available chlorine in the disinfectant test mixture inactivated 3·75 log TCID50HIV/ml within 30 s. When the test mixture contained 80% serum. 500 p.p.m. available chlorine inactivated more than 4 log TCID50HIV/ml in 1–2 min. Lower concentrations of available chlorine were unable to inactivate the virus completely. In the presence of 80% blood. 1000 p.p.m. available chlorine in the disinfectant test mixture was unable to inactivate 3·75 log TCID50HIV/ml. although 2500 p.p.m. available chlorine was able to inactivate at least 1·5 log TCID50HIV/ml. In all test mixtures, the chlorine rapidly became combined and thus less active. Our results emphasise the importance of cleaning prior to disinfection with sodium hypochlorite since it may prove to be ineffective in the presence of high levels of organic matter. In cases where prior cleaning is impossible, care must be taken to use the higher recommended concentration (a minimum of 10000 p.p.m. available chlorine).
Micromorphometrical analysis of rodent related (SPF) and unrelated (human) gut microbial flora in germfree mice by digital image processing
Authors: Veenendaal D. , de Boer J. , Meijer B. C. , van der Waaij D. , Wilkinson M. H. F.
Published: May 2009

Digital image processing (DIP) of bacterial smears is a new method of analysing the composition of the gut microbial flora. This method provides the opportunity to compare and evaluate differences in the complex highly concentrated anaerobic fraction of gut microbial flora, based on micromorphological differences. There is ample evidence that this fraction can be characterized as related or unrelated to the host organism by its immunogenicity. In this study germfree ND2 mice were associated with either related (rodent) SPF microflora (SPF-MF) or unrelated human MF (HUM-MF). DIP analysis was performed on original SPF-MF and HUM-MF and on the faeces of ex-germfree mice 4 weeks after association. The micromorphological pattern of highly concentrated anaerobic bacteria in faeces of HUM-MF associated ex-germfree mice was significantly different from SPF-MF associated counterparts with regard to the scores for elongation (P< 0·01) and morphological variety (P< 0·05). Moreover, gross morphological variability was present between individual HUM-MF associated mice but not between individual SPF-MF associated animals. No differences were found between original SPF and HUM-MF. The data are discussed with regard to differences in the presence of (non-)immunogenic bacteria and the ability for related and unrelated flora to colonize the murine gut. This study provides evidence that murine host specificity of microbial flora may not only be reflected in the number of non-immunogenic bacteria but also in the micromorphological pattern of highly concentrated anaerobic bacteria in faeces measured by DIP analysis.
Measles immunity and response to revaccination among secondary school children in Cumbria
Authors: Calvert N. , Cutts F. , Irving R. , Brown D. , Marsh J. , Miller E.
Published: May 2009

The prevalence of antibody to measles virus in 759 children aged 11–18 years attending a secondary school in Cumbria was measured using a salivary IgG antibody capture assay. Serum IgG antibody levels were measured using a plaque reduction neutralization assay in subjects whose saliva was antibody negative. Vaccination histories were obtained from the child health computer and general practice records. A total of 662 pupils (87 % of those tested) had detectable measles-specific IgG in saliva. Of the remaining 97, 82 provided blood samples and 29 had serum neutralizing antibody levels above 200 mlU/ml. After adjusting for non-participation rates, the proportion considered non-immune (no IgG in saliva and ≤ 200 mlU/ml in serum) was 9 % overall, ranging from 6 % in vaccinated children to 20 % in unvaccinated children. Measles-mumps-rubella vaccine was given to 50 children of whom 38 provided post-vaccination serum and 32 saliva samples. Thirty (79 %) had a fourfold or greater rise in serum neutralizing antibody and 28 (88 %) developed IgG antibody in saliva. Half of the children considered non-immune by antibody testing would have been overlooked in a selective vaccination programme targeted at those without a history of prior vaccination. A programme targeted at all school children should substantially reduce the proportion non-immune since a primary or booster response was achieved in three quarters of previously vaccinated children with low antibody levels and in all unvaccinated children. While it is feasible to screen a school-sized population for immunity to measles relatively quickly using a salivary IgG assay, a simple inexpensive field assay would need to be developed before salivary screening and selective vaccination could substitute for universal vaccination of populations at risk of measles outbreaks. The salivary IgG assay provided a sensitive measure of a booster response to vaccination.
Preventing epidemics in a community of households
Authors: Hall R. , Becker N. G.
Published: May 2009

The occurrence of epidemics of vaccine-preventable diseases, and the immunization coverage required to prevent them, is affected by the presence of households and heterogeneity in the community. We consider a community where individuals live in households and are of different types, according to infectivity and/or susceptibility to infection. We describe a method for computing the critical immunization coverage to prevent epidemics in such communities and discuss the effectiveness of immunization strategies. In a heterogeneous community where individuals live in households several immunization strategies are possible and we examine strategies targeting households, randomly selected individuals, or groups with highly intense transmission, such as school children. We compare estimates of the critical immunization coverage if we assume that disease is spread solely by random mixing with estimates which result if we assume the effects of the household structure. Estimates made under these two sets of assumptions differ. The results provide insights into the community effects of vaccination, and the household structure of the community should be taken into account when designing immunization policies.
Problems in the diagnosis of foodborne infection in general practice
Authors: Palmer S. , Houston H. , Lervy B. , Ribeiro D. , Thomas P.
Published: May 2009

The incidence of acute gastroenteritis and self suspected food poisoning in general practice populations was compared with consultation rates in four group practices during a 3-month winter period and a 2-month autumn period. The average monthly consultation rate for acute gastroenteritis and self suspected food poisoning was 0·3 % and 0·06 % respectively. However, over the same period, on average, an estimated 7% of the practice population per month reported an acute gastroenteritis illness, and 0·7% suspected a food poisoning illness. Only about one in 26 people who suffer an acute episode of gastroenteritis consult their general practitioner (GP). In two practices, faecal samples were sought from all patient cases; the isolation rate for salmonellas was 2% (3/191) and for campylobacters it was 12% (23/191). In the other two practices following routine management, the isolation rate for salmonellas was 9% (6/64) and for campylobacters it was 2% (1/64). Isolation of faecal pathogens was not associated with patients' suspicion of food poisoning. A history of eating out in the week before onset was associated with a significantly increased yield of salmonellas and campylobacters.
The dynamics of scarlet fever epidemics in England and Wales in the 19th century
Authors: Duncan C. J. , Duncan S. R. , Scott S.
Published: May 2009

There was a marked rise in scarlet fever mortality in England and Wales in the mid-nineteenth century and spectral analysis of the registration details, 1847–80, shows that the interepidemic interval was 5–6 years, but after 1880 the endemic level fell and the fatal epidemics disappeared. The dynamics of the scarlet fever epidemics can be represented by a linearized mathematical model and because the system is lightly damped, it could be driven by an oscillation in susceptibility. Epidemics were significantly correlated with dry conditions in spring/summer (P< 0·001), suggesting that these produced a low amplitude oscillation in susceptibility which drove the system. Epidemics also correlated (P< 0·001) with an oscillation in wheat prices but at a lag of 3 years, suggesting that malnutrition during pregnancy caused increased susceptibility in the subsequent children which interacted synergistically with seasonal dry conditions. Scarlet fever mortality was sharply reduced after 1880 in parallel with falling wheat prices suggesting that the remarkable period of high scarlet fever mortality (1840–80) was dependent on poor nutritive levels during that time.
Distribution ofmip-related sequences in 39 species (48 serogroups) ofLegionellaceae
Authors: Riffard S. , Vandenesch F. , Reyrolle M. , Etienne J.
Published: May 2009

The macrophage infectivity potentiator gene (mip) fromLegionella pneumophilais a major virulence factor of the species. Thus,mip-detection by amplification has been proposed to assess the presence ofL. pneumophilain clinical and environmental samples. The distribution ofmip-related sequences within theLegionellaceaewas studied by DNA amplification usingmip-specific primers followed by Southern blot hybridization with an internal probe. Thirty nine species (48 serogroups) ofLegionellaceaewere screened in this attempt. Using this approach, sequences related tomipwere observed in 89% of the tested species including the most recently describedL. fairfieldensis, L. lansingensisandL. shakespearei. In several cases, cloning and sequencing of the amplified products confirmed the high levels of similarity between the sequence found in non-pneumophilaspecies with that of theL. pneumophila mipgene. This confirms previous reports thatmiprelated genes are widespread amongLegionellaceaeand therefore specific detection of the speciesL. pneumophilacannot be based onmip-targeted amplification.
The consequences of uncertainty for the prediction of the effects of schistosomiasis control programmes
Authors: Chan M. S.
Published: May 2009

Progress in the development of schistosomiasis models for use in control programmes is limited by the considerable uncertainty in many of the biological parameters. In this paper, this problem is addressed by a comprehensive sensitivity analysis of a schistosomiasis model using the Latin Hypercube method. Fifty simulations with different parameter contributions are run for 50 years with treatment during the first 20 years and reinfection thereafter. The analysis shows only a relatively small divergence between simulations during the chemotherapy treatment programme but considerable divergence in reinfection levels after treatment is stopped. A skewed distribution of outcomes was seen with most simulations showing effective control and a few where control had less impact. The most important uncertainty source was due to the unknown levels of acquired immunity and also uncertainty in the true worm burden. In particular, the strength of the immune response was most important in determining whether control was effective with higher immunity leading to less effective control. Among those simulations in which control was not very effective, those in which the mean worm burden was high showed the least effective control. Since both these are areas of genuine uncertainty, it is proposed that uncertainty analysis should be an integral part of any projection of control programmes.
A comparative study of the heat resistance of salmonellas in homogenized whole egg, egg yolk or albumen
Authors: Humphrey T. J. , Chapman P. A. , Rowe B. , Gilbert R. J.
Published: May 2009

Salmonella enteritidis PT4 was found to be more resistant to heat in egg than some other common egg-associated salmonellas. This organism was significantly more heat sensitive than S. senftenberg 775W, however, and should not survive in pasteurized liquid egg.
Intestinal spirochaetes in a Gulf Arab population
Authors: Barrett S. P.
Published: May 2009

Spirochaetal bacteria were isolated from the faeces of 11·4% of 1000 hospital patients and 26·7% of 292 healthy local nationals in the Muscat area of the Sultanate of Oman. A case-control study of patient records showed the isolation of the spirochaete to be associated with Omani nationality, age in excess of 2 years and attendance at self-referral health-care facilities. No association was found with symptomatic intestinal disease or microscopic abnormalities of the stool.
Rejoinder to Mearsheimer and Walt
Authors: Lieberman Robert C.
Published: May 2009

In their reply, Professors Mearsheimer and Walt focus quite reasonably on my two main claims: that their research methods are flawed and that their evidence is weak. But they begin, tellingly, by citing a range of indirect evidence that appears to depict a powerful “Israel lobby.” Lots of knowledgeable Washington insiders, they say—policymakers, journalists, candidates for office, and the like—say and do things that seem to acknowledge the “lobby's” power. I draw attention to this opening for several reasons. First, it is not clear how much weight some of this evidence will bear. Take, for example, theNational Journalsurvey of members of Congress that Mearsheimer and Walt cite twice in their reply (and once in their book). In this survey, conducted once, in 2005, seventy-three members of Congress (out of 535—less than 15 percent) responded to the question, “Which two interest groups do you believe are most effective on Capitol Hill?” Of these respondents, thirteen (less than 20 percent of the sample) mentioned American Israel Public Affairs Committee (AIPAC) as one of their two choices. It seems something of a leap from the observation that a dozen or so members of Congress said once that AIPAC is “effective” (which might mean any number of things) to the inference that AIPAC—or the lobby more generally—is powerful. Or take the observation that important politicians regularly address AIPAC's annual conference and make friendly speeches when they do. Surely these same politicians visit other such organizations regularly. And when they appear before, say, the AFL-CIO or the NAACP, surely they say nice things about the issues that these organizations and their conference attendees care about. Successful politicians rarely voice open disagreement with the people they are talking to. But are we to conclude from this behavior that the AFL-CIO and the NAACP, or any other groups that regularly receive such visits, are powerful? Again, this inference requires something of a logical leap.
Theorizing Politics, Politicizing Theory, and the Responsibility That Runs Between
Authors: Ish-Shalom Piki
Published: May 2009

What are social science theorists' responsibilities for the effects of their theories in the real world? I maintain that politicians and ideologues place theories in their political agendas without necessarily heeding their actual content. Hence, the ramifications of theories in the real world are mostly the result of political uses and, at times, political abuses. Consequently, theorists cannot be held morally responsible for these. They do, however, bear the obligation to examine if there are some intrinsic features of theorization and theory that render these susceptible to public misinterpretation and vulnerable to political abuse. Pointing to the rhetorical capital inherent in theories, and supported by examples involving democratic-peace theory and its political destinies, I conclude that, to discharge this task, social science theorists should substitute the prevailing objective ethic with a normative one.