bluuebunny/crossref_metadata_2025 huggingface dataset:
Specific IgE response in patients with brucellosis
Authors: Araj G. F. , Lulu A. R. , Khateeb M. I. , Haj M.
Published: May 2009

In the search to find discriminative serological markers to differentiate between patients with acute brucellosis and those with chronic brucellosis, an enzyme-linked immunosorbent assay (ELISA) was used to determine and compare the brucella-specific IgE response in 80 sera from patients with acute brucellosis, 37 sera from patients with chronic brucellosis, 26 sera from patients with positive blood cultures for bacteria other than brucella and 51 sera from healthy controls. The IgE findings were compared to brucella-specific IgG, IgM, IgA and IgG1–4demonstrated by ELISA, and to microagglutination test (MAT) results. Elevated (positive) antibrucella IgE titres were detected in 89 and 81 % of sera from patients with acute and chronic brucellosis respectively. The predominant antibodies found in patients with acute brucellosis were of the IgG, IgM, IgA, IgE, IgG1and IgG3types while in chronic brucellosis IgG, IgA, IgE and IgG4were found. Although IgE can be detected in patients with brucellosis, it does not discriminate between the acute and chronic stages of the disease.
Acute upper respiratory tract viral illness and influenza immunization in homes for the elderly
Authors: Nicholson K. G. , Baker D. J. , Farquhar A. , Hurd D. , Kent J. , Smith S. H.
Published: May 2009

Occupants of 482 long-stay and 33 short-stay beds in 11 Leicester City Council homes for the elderly were studied during a 30-week period from September 1988 to March 1989 to determine the incidence, aetiology, morbidity, and mortality of acute upper respiratory tract viral infections and the use of influenza vaccine.

Influenza immunization rates by home ranged from 15·4 to 90% (mean 45%). There were no differences in the distribution of medical conditions by home. The highest immunization rates were seen in people with chest disease (77%), heart disease (60%), diabetes (56%), and those with three medical conditions (75%). There was an average of 0·7 upper respiratory episodes per bed per annum with a mortality of 3·4% (6/179). Half of all episodes were seen by a general medical practitioner and 81 of 90 (90%) referrals were prescribed antibiotics costing approximately £7.50 per patient. Lower respiratory tract complications developed during 45 (25%) of 179 episodes including 3 of 12 coronavirus infections, 3 of 9 respiratory syncytial virus infections, 2 of 4 adenovirus infections, 1 of 11 rhinovirus infections, but none of 5 influenza infections. Respiratory infections were caused mostly by pathogens other than influenza virus during the influenza period documented nationally. This highlights the role of coronaviruses, respiratory syncytial virus, and unidentified agents in the elderly, and questions the assumptions made in American estimates on the impact of influenza and the value of influenza vaccines.
The prevalence of Salmonella enteritidis and other Salmonella spp. among Canadian registered commercial layer flocks
Authors: Poppe C. , Irwin R. J. , Forsberg C. M. , Clarke R. C. , Oggel J.
Published: May 2009

A survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial egg producing flocks. Environmental (faecal and eggbelt) samples from 152 of 295 (52·9%) randomly selected flocks were contaminated with salmonellas. Thirty-five different salmonella serovars were isolated. Eggbelt samples were more often contaminated with salmonellas than faecal samples (25·7 v. 10·1 %). The most prevalent serovars were S. heidelberg, S. infantis, S. hadar, and S. schwarzengrund; they were isolated from samples of 59/295 (20%), 18/295 (6·1%), 17/295 (5·8%), and 15/295 (5·1%) flocks, respectively. Feed samples of 21/295 (7·2%) flocks were contaminated with salmonellas. Salmonella enteritidis was isolated from the environmental samples of 8/295 (2·7%) flocks. Salmonella enteritidis phage type (PT) 8 was isolated from 5 flocks, PT 13a from 2 flocks, and PT 13 from 1 flock.
Endotoxin liberation by strains ofN. meningitidisisolated from patients and healthy carriers
Authors: Mellado M. C. , Rodríguez-Contreras R. , Fernandez-Crehuet M. , Lopez-Gigosos R. , Rodriguez M. Delgado , Galvez-Vargas R.
Published: May 2009

The main objective of this study was to assess whether the capacity ofNeisseria meningitidisto release endotoxin depends upon the type of strain or upon bacterial mass. Endotoxin release was studied in 32 strains isolated from patients with meningococcal infections and in 49 from asymptomatic carriers, using a quantitative test (limulus test with a chromogenic substrate). The results show that the strains from patients release significantly higher amounts of endotoxin than strains from carriers regardless of serogroup and isolation site. No correlation was found between stage of bacterial growth and the amount of endotoxin liberated. These findings suggest that endotoxin liberation is a characteristic of certain strains ofN. meningitidisand is not determined simply by bacterial mass.
Chronic atrophic oral candidiasis among patients with diabetes mellitus – role of secretor status
Authors: Aly F. Z. , Blackwell C. C. , MacKenzie D. A. C. , Weir D. M. , Elton R. A. , Cumming C. G. , Sofaer J. A. , Clarke B. F.
Published: May 2009

Non-diabetic individuals who are non-secretors of blood group antigens are prone to superficial infections by Candida albicans. In this study, 216 patients with diabetes mellitus who were denture wearers were examined for the presence or absence of denture stomatitis. There was an overall trend for non-secretors to be prone to denture stomatitis compared with secretors. Stepwise linear discriminant analysis was used to dissect the contribution of secretor status and other variables to the development of the disease. Secretor status was found to be a contributory factor among patients with non-insulin dependent diabetes but not among those with insulin-dependent diabetes. The possible reasons for this are discussed.
Isolation and identification of arboviruses from the Sultanate of Oman
Authors: Al-Busaidy S. M. , Mellor P. S.
Published: May 2009

Sentinel herds and a vector surveillance system were used to identify the presence of arboviruses in Oman. Two strains of bluetongue virus (BTV) serotype 4 and two strains of Akabane virus, were isolated and identified. Both BTV isolates and one Akabane virus isolate came from goats while the second Akabane isolate came from Culicoides imicola. This is the first isolation of an Akabane virus from Culicoides in Arabia. Vector competence studies with the Oman viruses in laboratory reared C. variipennis showed that after oral infection both viruses replicated in Culicoides and were maintained at high titre for at least 10 days post infection.
Rubella in the United Kingdom
Authors: Miller E.
Published: May 2009

The first description of rubella in the UK was by an English physician, Dr William Maton, who reported an outbreak of an illness resembling a mild form of scarlatina in a boys' public school in 1815 [1]. Some years later, when observing the spread of a rash-associated illness in a large family, Maton described the characteristic clinical features of rubella, namely a mild prodromal illness followed by a generalized and often tingling rash lasting for a few days and associated with enlarged and tender glands in the occipital and postauricular regions. He also correctly identified the relatively long incubation period of rubella and noted the absence of fever and other signs of constitutional upset. Maton did not suggest an English name for this disease which had been previously described and called Rothëln by German physicians in the late 18th century. The term ‘rubella’ (Latin for ‘little red’) was first used in 1866 by another English physician, Dr Henry Veale, when describing an outbreak of Rothëln in a boys' school in India [2].
Bluetongue in the Sultanate of Oman, a preliminary epidemiological study
Authors: Taylor W. P. , Al Busaidy S. M. , Mellor P. S.
Published: May 2009

A group specific agar-gel immunodiffusion test was used to demonstrate that there is a frequent and widespread distribution of bluetongue virus throughout the Sultanate of Oman. The Culicoides midges C. imicola and C. schultzei, both capable of transmitting bluetongue group viruses, were recorded throughout the year. Although these studies did not establish that bluetongue is enzootic in Oman, type-specific neutralizing antibody results supported previous evidence for the existence of a Saudi Arabian bluetongue ecosystem. Variations in antibody evidence of virus activity within a restricted locality suggested a hot-spot theory concerning the perpetuation of the virus.
Cockroaches (Blattella germanica) as carriers of microorganisms of medical importance in hospitals
Authors: Fotedar R. , Shriniwas U. Banerjee , Verma A.
Published: May 2009

A study was conducted to isolate and identify microorganisms of medical importance from cockroaches (Blattella germanica) and to ascertain their vector potential in the epidemiology of nosocomial infections. Bacteria, fungi and parasites of medical importance were isolated and identified. Important bacterial pathogens responsible for wound infections, were further studies by antibiograms. One hundred and fifty-eight out of 159 (99·4%) cockroaches collected from hospital (test) and 113 out of 120 (94·2%) cockroaches collected from residential areas (control) were carrying medically important microorganisms (P < 0·05). A significantly higher (P < 0·001) number of test cockroaches were carrying a higher bacterial load (1 × 104 and 1 × 105) as compared to control cockroaches. Multiple drug-resistant bacteria were isolated from test cockroaches. The diversity of drug-resistant bacterial species isolated from test cockroaches suggests their involvement in the transmission of drug-resistant bacteria. Various fungi and parasitic cysts of medical importance were also isolated from the test and control cockroaches, but the carriage rates were low. The findings suggest that cockroaches, in hospitals, can act as potential vectors of medically important bacteria/parasites/fungi.
Gentamicin-resistantSalmonella typhimuriumphage type 204c: molecular studies and strain diversity in a putative bovine outbreak
Authors: Platt D. J. , Smith I.
Published: May 2009

As part of the investigation of a putative bovine outbreak, 13 isolates of Salmonellatyphimuriumphage type 204c were subjected to plasmid analysis.Plasmid profiles suggested that several distinct strains were involved and these observations were supported by minor variations in antibiotic resistance pattern. Restriction enzyme fingerprinting and conjugational segregation of the plasmids confirmed these findings. Although 12 of the 13 isolates were resistant to gentamicin, resistance was conferred by 4 distinct plasmids; 3 of these belonged to Inc I and were distantly related on the basis of restriction fingerprints and the fourth was a resistant derivative of the 60 MDaS. typhimuriumserotype-specific plasmid. The molecular evidence refuted the hypothesis that geographical and temporal clustering of these gentamicin-resistant isolates could be explained on the basis of a single epidmiological episode.
Epidemiology and infection in famine and disasters
Authors: Shears P.
Published: May 2009

Despite advances in health care in the tropics, and the inputs of international and voluntary organisations, famine and disaster continue to cause major devastation in many developing countries. In the aftermath of acute disasters such as earthquakes or cyclones and in chronic post-famine relief camps, mortality rates may be 20–30 times greater than those in ‘normal’ years [1]. The interaction of malnutrition, crowding, poor environmental sanitation, and changes in host parasite relationships due to migration or environmental change, result in communicable diseases playing a major role in excess morbidity and mortality.
Characterization ofNeisseria meningitidisisolates by ribosomal RNA gene restriction patterns and restriction endonuclease digestion of chromosomal DNA
Authors: Jordens J. Z. , Pennington T. H.
Published: May 2009

The use of ribosomal RNA (rRNA) gene restriction patterns to study the molecular epidemiology ofNeisseria meningitidiswas investigated. Ninety-four isolates ofNeisseria meningitidiswere characterized by their rRNA gene restriction patterns with 16 + 23 S rRNA fromEscherichia colias a probe. Thirteen rRNA gene restriction patterns were recognized; each of these patterns represented between 1 and 30 isolates. Isolates with the outbreak-associated phenotype B15P1.16 (sulphonamide resistant) all gave a single rRNA gene restriction pattern but this pattern also contained isolates with other phenotypes. Further discrimination between isolates was achieved by comparison of banding patterns resulting from restriction endonuclease digestion of chromosomal DNA withBglII. This gave a banding pattern consisting of about ten bands which was simple to interpret. Using this technique 94 isolates were classified in 54 patterns containing between 1 and 14 isolates. Restriction endonuclease analysis withBglII characterized outbreak-associated isolates with the phenotype B15P1.16 and enabled strains not typable by conventional methods to be identified as probable outbreak-associated isolates. The techniques should prove useful for epidemiological studies.
The social and economic impact of salmonellosis: A report of a national survey in England and Wales of laboratory-confirmed salmonella infections
Authors: Sockett P. N. , Roberts J. A.
Published: May 2009

This study presents the findings of a national survey of 1482 cases of salmonellosis reported to Environmental Health Departments in England and Wales between August 1988 and March 1989. A questionnaire survey of ill individuals and the environmental health officers who investigated them sought information about costs which were imposed upon public health authorities, the health sector, individuals and their families and the costs to the wider economy in terms of lost production.

Costs of £996339 were identified. Over half (£507555) resulted from lost production due to sickness absence and more than a third (£392822) were costs to the public sector which resulted from health care and local authority investigation of cases. The remaining costs (£95962), although the smallest proportion of the total, indicated that salmonellosis can have a significant impact on affected individuals and their families.
An outbreak of pneumonia and meningitis caused by a previously undescribed Gram-negative bacterium in a hot spring spa
Authors: Hubert B. , De Mahenge A. , Grimont F. , Richard C. , Peloux Y. , De Mahenge C. , Fleurette J. , Grimont P. A. D.
Published: May 2009

An outbreak of infection caused by a previously undescribed Gram-negative bacterium affected people attending a hot (37 °C) spring spa in France in 1987. Thirty-five case of pneumonia and two cases of meningitis occurred. None of these patients died. Attack rates were significantly higher for patients above 70 years old and for male patients. An epidemiological comparison of the 26 hospitalized eases with 52 matched controls suggests that spa treatment early on the first day (OR = 4·8) and attendance at the vapour baths (OR = 10·7) were significant risk factors for acquiring the infection. Person-to-person spread was not thought to have occurred. The same bacterium was isolated from the hot spring water. All strains studied shows a single rRNA gene restriction pattern. Epidemiological data indicated that the thermal water was the source of infection. This outbreak stresses the need for increased surveillance of infections in people attending hot spring spas.
The dynamics of microfilaraemia and its relation with development of disease in periodic Brugia malayi infection in South India
Authors: Sabesan S. , Krishnamoorthy K. , Panicker K. N. , Vanamail P.
Published: May 2009

Rates of acquisition and loss of Brugia malayi microfilaraemia were estimated using the parasitological data of a cohort of population in Shertallai, South India. The rate of acquisition of microfilaraemia was found to be dependent on age but not gender. The decline in the rate of acquisition of microfilaraemia in adults above 35 years could be due to the development of acquired immunity. The mean reproductive lifespan for the periodic Brugia malayi adult female worm was estimated to be 34 years and it was independent of host age and gender. The age-specific estimated proportion of population at risk (microfilaria carriers who lost their microfilaria in course of time) of developing lymphoedema approximately mirrored the observed age specific prevalence of lymphoedema in the study-population. On an average, 99% of population at risk developed manifestations of disease. The estimated population at risk of developing disease in different endemic areas is compared and its epidemiological significance is discussed.
Bacteriological quality of potable water sources supplying Morogoro municipality and its outskirts: a case study in Tanzania.
Authors: Jiwa S. F. H. , Mugula J. K. , Msangi M. J.
Published: May 2009

Bacteriological quality of potable water supplying Morogoro municipality and its outskirts (population 135000 people) was assessed by the determination of the most probable number (MPN) of faecal coliforms, Escherichia coli, faecal streptococci andClostridium perfringensfor a period of 6 months. River water and chlorinated pipeborne water were found contaminated with microorganisms in the order of 3·8 x 101to 4·95 x 103; 3·2 x 101to 4·5 x 103; 101to 6·4 x 101and 1·2 x 101to 2·5 x 102/100 ml of water respectively. Injured coliforms in treated water averaged 87 %. Pollution of river water by organic matter was much above acceptable standard. These findings indicate that there is a need for further treatment of water before consumption in order to avoid potential health hazards.
Evaluating the sensitivity and predictive value of tests of recent infection: toxoplasmosis in pregnancy
Authors: Ades A. E.
Published: May 2009

The diagnosis of maternal infection in early pregnancy depends on tests which are sensitive to recent infection, such as specific IgM. Two types of test are considered: those where the response persists for a period following infection and then declines, such as IgM. and those whose response increases with time since infection, such as IgG-avidity. However, individuals vary in their response to infection, and it may not always be possible to determine whether an infection occurred during pregnancy or before it. Mathematical methods are developed to evaluate the performance of these tests, and are applied to the diagnosis of toxoplasmosis in pregnancy. It is shown that, based on existing information, tests of recent infection are unlikely to be both sensitive and predictive. More data on these tests are required, before they can be reliably used to determine whether infection has occurred during pregnancy or before it.
The population structure and transmission ofEscherichia coliin an isolated human community; studies on an antarctic base
Authors: Tzabar Y. , Pennington T. H.
Published: May 2009

The population structure and transmission ofEscherichia coliin a small group of individuals isolated for 26 weeks on an Antarctic base were studied by multilocus electrophoresis of eight enzymes and plasmid analysis. Two hundred and sixty-nine strains were isolated. They were grouped into 60 allozyme types (ETs). Half of these ETs were only isolated once; others were repeatedly isolated from single subjects. Eleven were found in more than one subject and the pattern of the occurrence of some of them was considered to provide evidence of their spread from subject to subject.
Study of colonization resistance for Enterobacteriaceae in man by experimental contamination and biotyping as well as the possible role of antibodies in the clearance of these bacteria from the intestines
Authors: Apperloo-Renkema H. Z. , Van Der Waaij D.
Published: May 2009

The colonization resistance (CR) of the digestive tract was determined in 10 healthy volunteers by oral contamination with a neomycin resistantEscherichia coli(NR-E. coli) strain and measurement of the faecal concentration of this strain during 14 days after the contamination. This ‘gold standard’ was compared with another parameter of CR; the determination of the mean number of different biotypes of Enterobacteriaceae isolated from four faecal samples per volunteer. Both measures are significantly correlated (P < 0.01). The NR-E. colistrain could be cultured from faecal samples of 4/10 volunteers as long as 300 days after contamination. Serum antibody titres against endogenousE. colistrains and the NR-E. colistrain used for experimental oral contamination were measured by an indirect immunofluorescence (IIF) assay. The assay was read by a video camera connected to an image processing system. The 95% confidence limits of antibody titres (log2) against endogenousE. colistrains ranged between < 3 and 7.1 for IgA, between < 3 and 8.7 for IgG and between < 3 and 7.4 for IgM. Antibody titres against the NR-E. coli4 strain were within this (normal) range. The serum antibody titres against the NR-E. colistrain increased slowly after oral contamination, especially IgG and IgM. Little increase in IgA titres could be observed. An increase of serum antibody titres did not correlate with the elimination of the oral contaminant from the intestines. Therefore, we conclude that the CR is not IgG nor IgM antibody mediated.
High prevalence rates of antibody to three sandfly fever viruses (Sicilian, Naples and Toscana) among Cypriots
Authors: Eitrem R. , Stylianou M. , Niklasson B.
Published: May 2009

Neutralizing antibodies to sandfly fever Naples, sandfly fever Sicilian and Toscana viruses were investigated among 479 sera collected from a normal human population in Cyprus. Antibody prevalence rates of 57%, 32% and 20% were found to Naples, Sicilian and Toscana viruses, respectively. The observed frequency of dual and triple infections was higher than would be expected with a random chance of infection. Antibody prevalence rates were similar for men and women for all three viruses tested, but one of two study sites had significantly higher antibody prevalence to Naples and Sicilian viruses than the other. Individuals with antibodies to both Naples and Toscana viruses had higher antibody levels to Naples virus than those with antibodies to Naples virus only. If the antibody prevalence rates found in this study reflect a history of clinical disease as described in the literature, sandfly fever poses a significant public health problem in Cyprus.
Ribosomal RNA gene patterns ofHelicobacter pylorifrom surgical patients with healed and recurrent peptic ulcers
Authors: Owen R. J. , Bickley J. , Lastovica A. , Dunn J. P. , Borman P. , Hunton C.
Published: May 2009

Fifty–two strains ofHelicobacter pyloriwere examined by DNA restriction endonuclease digestion, ribosomal (r)RNA gene probe hybridization and bio–typing. Most (49) strains originated from gastric (antral) biopsies of patients before or after elective surgery for duodenal ulcers. Chromosomal DNAHindIII ribopatterns showed 9 strain clusters of which the largest contained 12 strains each with 3 common bands (1·50, 3·45, and 4·26 kb) but which were heterogeneous with respect to biotype and total digest pattern. Isolates from post–operative patients with either healed or recurrent ulcers showed ribopattern heterogeneity and exhibited a similar distribution ofH. pyloriribopattern types; no single type predominated in any patient group or was more highly associated with recurrent ulcers than with healed ulcers. Multiple isolates from two surgical patients had only minor genomic variations in each set whereas isolates from two brothers had different ribopatterns. We conclude thatHindIII ribopatterns in conjunction with total digest patterns might provide the basis for future epidemiological typing studies.
Antibody-capture enzyme-linked immunosorbent assays that use enzyme-labelled antigen for detection of virus-specific immunoglobulin M, A and G in patients with varicella or herpes zoster
Authors: Van Loon A. M. , van der Logt J. T. M. , Heessen F. W. A. , Heeren M. C. A. , Zoll J.
Published: May 2009

Antibody-capture enzyme-linked immunosorbent assays (AC-ELISA) which use enzyme-labelled antigen were developed for detection of varicella-zoster virus-(VZV) specific IgM, IgA and IgG antibody in patients with varicella or herpes zoster and in sera from healthy individuals. All 18 patients with varicella developed a VZV-IgM and a VZV-IgG response, 17 also a VZV-IgA response. In contrast, all 19 patients with herpes zoster were shown to be positive for VZV-IgA whereas only 13 of these reacted positively for VZV-IgM. A VZV-IgM response was detected in only two sera from 100 healthy individuals and an IgA response in only one. The presence of virus-specific IgA and IgG in the cerebrospinal fluid as determined by AC-ELISA was a useful indicator of VZV infection of the central nervous system.

By AC-ELISA, VZV-IgG was detected predominantly in sera from patients with acute or recent VZV infection. Only 14 sera from 100 healthy individuals were positive for VZV-IgG by AC-ELISA, whereas all were positive by an indirect ELISA. These results indicate that AC-ELISA's may be useful assays for determination for acute or recurrent VZV infection, but are not suitable for determination of past infection with this virus.
A prolonged outbreak of ornithosis in duck processors
Authors: Newman C. P. ST. J. , Palmer S. R. , Kirby F. D. , Caul E. O.
Published: May 2009

In 1985 an outbreak of ornithosis affected 13 of 80 (16%) workers in a duck-processing plant. New employees were three times more likely to become cases than established employees. The highest attack rate was in those on the production line. Following the outbreak, an occupational health scheme was set up to monitor the health of new recruits to the company. Serological evidence of recent infection was demonstrated in 18 of 37 (49%) new employees tested in the first 3 months of employment. Five (14%) also had clinical evidence of ornithosis. Veterinary investigation of the ducks demonstrated a high proportion with asymptomatic chlamydial infection. It is suggested that ornithosis may be more common in duck processors than ins processors than is currently supposed. Strategies to reduce occupational risks are discussed.
Genetic relationships among strains ofSalmonella enteritidisin a national epidemic in Switzerland
Authors: Stanley J. , Burnens A. P. , Threlfall E. J. , Chowdry N. , Goldsworthy M.
Published: May 2009

A collection ofSalmonella enteritidisstrains isolated in Switzerland (1965–90) was characterized. The phage type and plasmid profile of isolates were compared with the copy number and insertion loci of the DNA insertion element IS200. Three clonal lines ofS. enteritidiswere identified by IS200profile; the various phage types were subtypes reproducibly associated with one of these lines. All human and poultry isolates contained a 38 Mda plasmid which hybridized with a mouse virulence-associated gene probe. InS. enteritidis, the IS200profile is a race-specific molecular marker of the chromosome, and may be particularly applicable for studying the epidemiology of less common serovars.
Reactivity of human serum antibody with lipopolysaccharide O 78 antigen from enterotoxigenicEscherichia coli
Authors: Brüssow H. , Sidoti J.
Published: May 2009

Fifteen and five of 20 volunteers challenged with the enterotoxigenicEscherichia colistrain O 78·H11 showed a fourfold titre increase of serum ELISA antibody to the homologous O 78 and the heterologous O 8 lipopolysaccharide antigen, respectively. Sixty-three of 191 sera from 1- to 48-month-old German children showed serum antibody reactive with O 78 antigen, all but two of these O 78-positive sera also showed reactivity with at least one further O antigen. Only 14 of the O 78 reactive sera also showed antibody to heat-labile enterotoxin. In addition, soluble O 8 antigen could inhibit the binding of serum antibody to absorbed O 78 in 68% of the German children. Antibody reactive with O 78 antigen is thus not a reliable serological marker for enterotoxigenicE. coliinfection in German children.
A longitudinal study of trachoma in a Gambian village: implications concerning the pathogenesis of chlamydial infection
Authors: Mabey D. C. W. , Bailey R. L. , Ward M. E. , Whittle H. C.
Published: May 2009

In order to investigate risk factors for the acquisition of trachoma, and to study the effect of continued exposure to ocular chlamydial infection on the severity of inflammatory trachoma and its cicatricial sequelae, a longitudinal study was conducted in a Gambian village. Over a 20-month period, the incidence of active (inflammatory) trachoma was significantly higher among those sharing a bedroom with an active case (64/561, 11·4%) than among those who were not exposed in this way (37/658, 5·6%) (relative risk 1·97, 95% confidence interval 1·33–2.90). There was a positive trend in the odds ratio for severe to moderate inflammatory disease versus mild disease as the number of active cases in the bedroom increased, but this failed to achieve statistical significance (P= 0·0506). Individuals with inflammatory trachoma of moderate or severe intensity at one survey were significantly more likely than others to have moderate or severe inflammatory changes at a previous or subsequent survey (odds ratio 14·9, 95% confidence interval 3·9–68·0), implying that host factors may be more important determinants of severity than the frequency of exposure to reinfection.
Extended phage-typing scheme forCampylobacter jejuniandCampylobacter coli
Authors: Khakhria R. , Lior H.
Published: May 2009

The extended phage-typing scheme described forCampylobacter jejuniandCampylobacter colihas established 46 different phage types using 19 typing phages. Altogether 754 campylobacter isolates, 672C. jejuniand 82C. coli, isolated from human and non-human sources received from 17 different countries were phage-typed. Overall, 80·6% of the total isolates were typable. Among typable strains, 9 phage types (3, 5, 10, 11, 18, 19, 23, 26 and 44) represented 57·0% of the strains, 21·3% of the strains belonged to another 37 phage types and the remaining 2·3% of isolates were designated atypical. The most common phage type 11 (140/754) was frequently observed amongC. jejuniisolates from human (113/561) and non-human sources (18/111). whereas type 44 was frequent amongC. coliisolates from human (22/59) and from non-human sources (8/23). A study of the animal host-associations of common phage types showed that contaminated cattle and poultry appear to be the most common sources of human infection. The greatest variety of phage types was observed in Canada (24 phage types), followed by Portugal (17 types) and the UK (14 types), reflecting the larger sample sizes from these countries. Phage type 11 was encountered in 12 different countries and prevalence of other phage types varied from one country to another. The number of isolates typable with the scheme varied from 93·2% (261/280) in Canada to 61% (47/77) in Thailand. However, the number and diversity of phage types makes phage typing the method of choice in epidemiological studies of campylobacter infections.
The epidemiology of varicella–zoster virus infections: a mathematical model
Authors: Garnett G. P. , Grenfell B. T.
Published: May 2009

Herpes-zoster is caused by the reactivation of varicella–zoster virus (VZV). In this paper different hypotheses of how this re-emergence of virus comes about are reviewed and discussed. From these hypotheses, and epidemiological data describing the initial transmission of the virus, a mathematical model of primary disease (varicella) and reactivated disease (zoster) in developed countries is derived. The steady-state age distributions of zoster cases predicted by this model are compared with the observed distribution, derived from a review and analysis of published epidemiological data. The model allows differentiation between published hypotheses in which age of host may or may not influence the probability of viral reactivation. The results indicate that the probability of reactivation must increase with age to allow the observed pattern of zoster cases. The basic mathematical model presented provides a conceptual framework, which may be extended to assess possible control programmes.
Enteroviruses in recreational waters of Northern Ireland
Authors: Hughes M. S. , Coyle P. V. , Connolly J. H.
Published: May 2009

Virus surveillance of Northern Ireland recreational waters, between April 1986 and May 1989 demonstrated widespread enteroviral contamination of coastal and inland waters. In 1986, enteroviruses were detected in 4 of 46 (8·7%) water samples, collected from 6 coastal bathing waters. In 1987, 49 of 107 (45·8%) samples, from 16 coastal bathing waters, yielded enteroviruses; 33 of the enterovirus positive samples passed one or both of the coliform standards outlined by the European Economic Community (EEC) bathing water directive (76/160/EEC). Enteroviruses were also detected in 33 of 39 (84·6%) samples tested from 3 inland recreational waters.
Streptococcal pharyngitis in general practice. 1. Some unusual features of the epidemiology
Authors: Higgins P. M.
Published: May 2009

This report is based on a study of acute infections of the upper respiratory tract in 1965 and detailed records of such infections in 1963 and 1964. A change from illnesses mainly yielding viruses to illnesses mainly yielding group A streptococci was noted around the age of 5 years. A positive culture for group A streptococci in patients over 4 years of age was highly correlated with a complaint of sore throat and with serological evidence of streptococcal infection. A bimodal age distribution curve for pharyngitis associated with a positive culture for group A streptococci was consistently noted. The incidence was highest in children aged 5–9 but a second smaller peak occurred among adults in the 30–39 age group. The evidence suggests that being female increases the risk of acquiring group A streptococci and of experiencing sore throat.
Concordance of auxotype/serovar classes ofNeisseria gonorrhoeaebetween sexual contacts
Authors: Ison C. A. , Whitaker L. , Renton A.
Published: May 2009

One hundred and three known sexual-contact pairs of patients with culture-proven gonorrhoea who attended St Mary's Hospital, London between May 1989 and February 1991 were identified. All isolates from these patients were serotyped and auxotyped and compared for type concordance within sexual-contact pairs. Serotype was concordant in 80 (78%) of 103 sexual-contact pairs, auxotype in 88 (85%) and auxotype/serovar (A/S) class in 66 (64%) on the first screening. All pairs of isolates showed concordance in both serotype and auxotype when typing was repeated using a single set of serotyping reagents and of auxotyping media. Seventeen serovars. 9 auxotypes and 36 A/S classes were found in this population. Our results suggest that both serotyping and auxotyping may be used as markers to allow tracing of sexual-contact pairs, but that a single set of reagents should be used to ensure maximum reliability.
Virulence factors of entericEscherichia coliin young Aboriginal children in north-west Australia
Authors: Gunzburg S. T. , Chang B. J. , Burke V. , Gracey M.
Published: May 2009

EnterotoxigenicEscherichia coli(ETEC) were the most frequently identified enteric pathogens associated with diarrhoea in 0–5 year old Aboriginal children in tropical north-west Australia with an incidence similar to those from other tropical regions. Heat-stable toxin-producing (ST + ) strains were associated with diarrhoea throughout the year but heat-labile toxin-producing (LT + ) strains were more important in the monsoonal summer season. ST + strains were commonest in children with diarrhoea between 6 and 18 months of age while LT + strains were associated with diarrhoea in children aged 18–24 months. VerotoxigenicE. coli(VTEC) which produced VT1, but not VT2, and enteroadherent (EAF + )E. coliwere significant causes of diarrhoea, mainly in children below 18 months but without a seasonal pattern.
Identification of human and bovine rotavirus serotypes by polymerase chain reaction
Authors: Taniguchi K. , Wakasugi F. , Pongsuwanna Y. , Urasawa T. , Ukae S. , Chiba S. , Urasawa S.
Published: May 2009

The use of the polymerase chain reaction (PCR) for identifying serotypes of human and bovine rotaviruses was examined. In the identification of 115 human rotavirus samples in stools, results with PCR showed excellent agreement with results of serotyping by an enzyme-linked immunosorbent assay (ELISA) using serotype-specific monoclonal antibodies. Furthermore, the PCR showed a much higher sensitivity (93%) than the ELISA test (82·6%). The PCR method could also be applied for identifying the serotype of bovine rotaviruses.
Selective Gastrointestinal Decontamination History of recognition and measurement of colonization resistance of the digestive tract as an introduction to selective gastrointestinal decontamination
Authors: Waaij D. van der
Published: May 2009

Selective decontamination of the digestive tract was developed following the observation that the digestive tract normally has considerable resistance to colonization by newly ingested bacteria. The research that eventually led to selective decontamination was performed because in the late 1960s and early 1970s, the need for prophylaxis against Gram-negative infections in immuno-compromized patients became evident. At that time, the relatively small number of antibiotics available for therapy of serious infections often lead to treatment failure. To introduce the subject of selective decontamination, this paper, therefore, starts with a short historical overview of the kind of infectious agents as well as the antibiotics available in the 1960s; particularly regarding the type and treatment of infections in severely compromised patients. The fact that the possibilities in infectious diseases were limited was the reason for our experimental search for ways of successful prophylactic treatment with minimal risk of development of resistance.
Selective decontamination of the digestive tract in intensive care
Authors: Boom S. J. , Ramsay G.
Published: May 2009

Nosocomial infection in intensive care unit (ICU) practice is a common problem and is associated with abnormal carriage of Gram-negative aerobic bacilli in the gastrointestinal tract, resulting in endogenous infections. Selective decontamination of the digestive tract (SDD) is a regimen aimed at preventing or eradicating this abnormal carriage.

A large number of trials examining SDD in ICU practice have been published, the vast majority showing a significant reduction in the incidence of nosocomial, Gram-negative infection. However, the impact on morbidity and mortality is much less certain. A recent meta-analysis has suggested a 10–20% reduction in mortality (3–6% absolute difference) with SDD. A discussion of these results is presented together with potential criticisms of SDD.
The relationship between infecting dose and severity of disease in reported outbreaks of salmonella infections
Authors: Glynn J. R. , Bradley D. J.
Published: May 2009

The relationship between size of the infecting dose and severity of the resulting disease has been investigated for salmonella infections by reanalysis of data within epidemics for 32 outbreaks, and comparing data between outbreaks for 68 typhoid epidemics and 49 food-poisoning outbreaks due to salmonellas. Attack rate, incubation period, amount of infected food consumed and type of vehicle are used as proxy measures of infecting dose, while case fatality rates for typhoid and case hospitalization rates for food poisoning salmonellas were used to assess severity. Limitations of the data are discussed. Both unweighted and logit analysis models are used.

There is no evidence for a dose-severity relationship forSalmonella typhi, but evidence of a correlation between dose and severity is available from within-epidemic or between-epidemic analysis, or both, forSalmonella typhimurium, S. enteritidis, S. infantis, S. newport, andS. thompson. The presence of such a relationship affects the way in which control interventions should be assessed.
High level resistance to trimethoprim, cotrimoxazole and other antimicrobial agents among clinical isolates of Shigella species in Ontario, Canada – an update
Authors: Harnett N.
Published: May 2009

A total of 598 isolates of Shigella species (24 S. dysenteriae, 254 S. flexneri, 30 S. boydii, 290 S. sonnei) submitted to the Ontario Public Health Laboratories in 1990 were tested for their susceptibility to 14 antimicrobial agents by the agar dilution method. Overall 79·6% of isolates were resistant to one or more antimicrobial agents and 52·0% were resistant to four or more. Trimethoprim resistance ranged from 26·7% among isolates of S. boydii to 39·4% among S. flexneri strains. The majority of the 224 TMP resistant isolates (88·8%) demonstrated high level resistance (MIC > 1000 mg/1) to trimethoprim. Resistance to cotrimoxazole increased from 3% in 1978 to between 26·7 and 37·6% in 1990. MICs for 90% of isolates (MIC90S) for ampicillin, ticarcillin and piperacillin were 128 to > 256 mg/1, > 256 for tetracycline and chloramphenicol, and > 2·0/38·0 for cotrimoxazole. These results from the Canadian Province of Ontario emphasize the need for prudent use of antimicrobial agents in the treatment of shigellosis.
Cockroaches as carriers of bacteria in multi-family dwellings
Authors: Cloarec A. , Rivault C. , Fontaine F. , Guyader A. Le
Published: May 2009

The potential risk of bacterial dissemination due to the presence of cockroaches (Blattella germanica, Blattellidae) in low-income flats was investigated. Cockroaches can carry a great variety of bacterial species; we identified 30 different species from 52 different flats. Klebsiella oxycytoca, K. pneumoniae and Enterobacter cloacae were the most frequently found. Pathogenic and potentially pathogenic bacteria represented 54% of all the bacterial identifications. Bacteria were carried either on the cuticle or in the gut. Contamination through external contact is sufficient to insure bacterial diffusion. There was a very low level of overlap estimated by Pianka's index (a) between the bacterial flora of neighbouring blocks of flats, and (b) between bacterial flora of different flats in the same block.
Salmonella enteritidis outbreak in a restaurant chain: the continuing challenges of prevention
Authors: Vugia D. J. , Mishu B. , Smith M. , Tavris D. R. , Hickman-Brenner F. W. , Tauxe R. V.
Published: May 2009

In 1990, a Salmonella enteritidis (SE) outbreak occurred in a restaurant chain in Pennsylvania. To determine its cause(s), we conducted a case-control study and a cohort study at one restaurant, and a survey of restaurants. Egg dishes were associated with illness (P = 0.03). Guests from one hotel eating at the restaurant had a diarrhocal attack rate of 14%, 4.7-fold higher than among those not eating there (P = 0.04). There were no differences in egg handling between affected and unaffected restaurants. Eggs supplied to affected restaurants were medium grade AA eggs from a single farm, and were reportedly refrigerated during distribution. Human and hen SE isolates were phage type 8 and had similar plasmid profiles and antibiograms. We estimate the prevalence of infected eggs during the outbreak to be as high as 1 in 12. Typical restaurant egg-handling practices and refrigeration during distribution appear to be insufficient by themselves to prevent similar outbreaks.
Molecular epidemiology of the plasmid-encoded TEM-1 β-lactamase in Scotland
Authors: Thomson C. J. , Amyes S. G. B.
Published: May 2009

A survey of the β-lactamases responsible for ampicillin resistance in urinaryEscherichia coliisolated in central Scotland has been performed. The TEM-1 β-lactamase was found to be most prevalent occurring in 88.2% of ampicillin-resistant isolates tested. Forty-six percent of the TEM-1 producing strains were able to transfer this resistance toE. coliJ62–2 at 37 ° C. Analysis of the resulting transconjugants revealed that the degree of resistance to amoxycillin and amoxycillin in combination with clavulanic acid was related to the specific activity of the TEM-1 β-lactamase. The variation in specific activity was shown to be related to plasmid type as determined by restriction analysis. No obvious relationship between β-lactamase specific activity and resistance to amoxycillin and amoxycillin plus clavulanic acid could be demonstrated in the original plasmid donor strains.
Acute respiratory illness in the community. Frequency of illness and the agents involved
Authors: Monto A. S. , Sullivan K. M.
Published: May 2009

Investigations of respiratory illnesses and infections in Tecumseh. Michigan. USA, were carried out in two phases, together covering 11 years. During the second phase, there were 5363 person-years of observation. Respiratory illness rates in both males and females peaked in the 1–2 year age group and fell thereafter. Adult females had more frequent illnesses than adult males; illnesses were less common in working women than in women not working outside the home. Isolation of viruses fell with increasing age; rhinoviruses were the most common isolate. Influenza infection rates, determined serologically, suggested relative sparing of young children from infection with type A (H1N1) and type B. Infection rates were highest in adult age groups for type A (H3N2). The isolation and serological infection rates were used to estimate the extent to which laboratory procedures underestimated the proportion of respiratory illnesses caused by each infectious agent; data from other studies were also used in this estimation. Severity of respiratory illnesses was assessed by the proportion of such illnesses that resulted in consultation of a physician. Rhinoviruses produced the greatest number of consultations. Overall, physician consultations were associated with 25.4% of respiratory illnesses.
Molecular studies of plasmids of multiply-resistantShigellaspp. in Hong Kong
Authors: Ling J. M. , Shaw P. C. , Kam K. M. , Cheng A. F. , French G. L.
Published: May 2009

One hundred and twoShigellaspp. isolated in two hospitals in Hong Kong were analysed for antibiotic resistances, resistance plasmids and plasmid profiles. Three quarters of the isolates wereS.flexneri. All isolates harboured plasmids, up to a maximum of ten within one strain. Plasmids of 220 kb encoding resistances to tetracycline, chloramphenicol and sulphonamide and probably also associated with invasivenes in the Sereny test were found in 80 strains and were transferable in 18% of cases. Resistance plasmids of 92 and 99 kb were found in 27 and 15 strains respectively and encoded resistances to ampicillin, tetracycline, chloramphenicol, kanamycin, sulphonamide, trimethoprim, cotrimoxazole and gentamicin; these plasmids were usually transferable. Four plasmids of 3·9, 2·8, 2·2 and 1·8 kb were commonly found inS. flexneristrains, but were rare in other species. In contrast, there was no predominant plasmid profile inS. sonnei. S. flexneriis endemic in Hong Kong and these plasmid studies suggest that the strains in circulation are derived from only a few clones.
Occurrence of FImeplasmids in multiply antimicrobial-resistantEscherichia coliisolated from urinary tract infection
Authors: Riley P. A. , Threlfall E. J. , Cheasty T. , Wooldridge K. G. , Williams P. H. , Phillips I.
Published: May 2009

Plasmids belonging to the FImeincompatibility group were found in seven different serogroups of multiply antimicrobial-resistantEscherichia coliisolated from patients with urinary tract infection (UTI) and living in south-east London. Although widespread inSalmonellaspp., FImeplasmids have only previously been described inE. coliin a strain of serogroup O15 K52 H1 responsible for an extensive and protracted outbreak of invasive community-acquired infection in south-east London in 1986. Our findings suggest either a wider background occurrence of FImeplasmids inE. coliassociated with UTI than previously reported or alternatively, the dissemination and subsequent molecular diversification of the FImeplasmid associated with the epidemic strain of serogroup O15 K52 H1.