bluuebunny/crossref_metadata_2025_split huggingface dataset:
The germicidal effect of the open air in different parts of The Netherlands
Authors: de Mik G. , de Groot Ida 
Published: May 2009

SUMMARYUsing the microthread technique the survival ofEscherichia coliMRE 162 in open air was measured in different parts of The Netherlands.The presence of bactericidal compounds (open air factor = OAF) could be demonstrated on several days and quantitated in relative units of OAF concentration.In the absence of ozone the OAF concentration was always low. In the presence of ozone the OAF concentration was dependent on wind direction. At the selected microthread exposure sites air from areas with high traffic intensity contributed more to OAF production than air from industrial areas. OAF production is probably related to the nature of hydrocarbons in the air.
Mechanisms of inactivation of bacteriophage φX174 and its DNA in aerosols by ozone and ozonized cyclohexene
Authors: de Mik G. , de Groot Ida 
Published: May 2009

SUMMARYThe mechanisms of inactivation of aerosolized bacteriophage øX174 in atmospheres containing ozone, cyclohexene, or ozonized cyclohexene were studied by using32P-labelled phage. The inactivation of the aerosolized phage in clean air or in air containing cyclohexene is due to damage of the protein coat since the deoxyribonucleic acid (DNA) extracted from the inactivated phage retains its biological activity. Inactivation of the phage in air containing ozone is mainly due to protein damage whereas inactivation in air containing ozonized cyclohexene is due both to protein and DNA damage. Sucrose gradient analysis shows that aerosolized inactivated øX174 releases unbroken DNA. In contrast, the DNA from phage øX174 inactivated by ozonized cyclohexene is broken.The inactivation of aerosolized phage øX174-DNA was studied in the same atmospheres using32P-labelled DNA. øX174-DNA aerosolized in clean air or air containing cyclohexene at 75% r.h. is inactivated by a factor of 2 in 30 min. The inactivated DNA is broken. Ozone as well as ozonized cyclohexene inactivates DNA very fast causing breaks in the molecule. This is in contrast with the intact bacteriophage in which ozone does not produce breaks in the DNA.
Influenza surveillance 1972–75
Authors:   The Public Health Laboratory Service Standing Advisory Committee on Influenza
Published: May 2009

SUMMARYThe surveillance programme described in an earlier report was used to monitor outbreaks of influenza in three successive winters. Influenza virus A was active in all of them, but the only major outbreak of influenza B was in 1973–4. The highest incidence of influenza A was in the 0–4 age group in all three winters, but schoolchildren bore the brunt of infections by influenza virus B.
Experimental transplacental transmission of porcine cytomegalovirus
Authors: Edington N. , Watt R. G. , Plowrights W. , Wrathall A. E. , Done J. T. 
Published: May 2009

SUMMARYSix serologically negative sows were infected by intranasal instillation of porcine cytomegalovirus (PCMV) between 31 and 85 days of pregnancy. Four sows showed an afebrile anorexia and lethargy 14–25 days after infection and all 6 developed significant increases in indirect immunofluorescent (IIF) antibody titres within 35 days. Virus was recovered from nasal and/or cervical swabs from 2 sows during life and from lung macrophage cultures after death.At term the sows were killed and their fetuses harvested by caesarean section. The number of mummified and stillborn fetuses increased from 4/63 in 6 previous litters to 18/60 in the 6 present litters. Nine of 43 fetuses born alive were reared in isolators for up to 6 weeks but the majority were killed for examination on the day of birth. Virus was isolated from 16 piglets from 4 of the 6 litters examined; it was isolated most frequently from lungs and liver but also from spleen, kidney, brain and nasal mucosa. Unsuckled day-old pigs had insignificant IIF titres, irrespective of whether they were excreting virus or not. The 5 congenital excretors which were reared all died within 7 days but no deaths occurred among their 4 litter-mates. Post-natal infection of 2 of these piglets reared in contact with congenitally infected pigs was suggested by the recovery of virus from nasal swabs 17 and 27 days after birth and the subsequent rise in IIF titre to 1/256 by day 42.
Salmonella in pig carcasses for human consumption in Hong Kong: a study on the mode of contamination
Authors: Chau P. Y. , Shortridge K. F. , Huang C. T. 
Published: May 2009

SUMMARYA very high proportion (75%) of the pigs slaughtered in Hong Kong were found to be infected with salmonellas. Seven serotypes including Salmonella choleraesuis were isolated but the majority (91%) were S. anatum and S. derby. These serotypes, especially S. anatum and S. derby, had been isolated frequently from clinical cases, symptomless carriers and in this study from abattoir workers, suggesting that the pig was a significant source of human salmonella infection.The majority of pigs slaughtered are imported and the high level of apparent infection was thought to be due to cross-infection during transport of the pigs under stress. S. anatum and S. derby were also isolated from pigs on local farms but the incidence was threefold lower. Scalding the pigs at 60 °C for 5 min caused no great reduction in the degree of superficial contamination. The two predominant serotypes were isolated from the tank and from drain swabs, and also from the latter held under scalding tank conditions. Thus, in spite of the introduction of hygienic slaughter under modernized conditions employing an automatic conveyance system, 55% of the carcasses were superficially contaminated after dressing before despatch to customers. Control of infection before slaughtering would appear crucial and a more thorough rinsing or washing of the dressed carcasses desirable.
The reliability of the examination of foods, processed for safety, for enteric pathogens and Enterobacteriaceae: a mathematical and ecological study
Authors: Drion E. F. , Mossel D. A. A. 
Published: May 2009

SUMMARYBecause of the paucity of quantitative data on numbers of other enteric pathogens in food, the reliability of the examination of processed foods for Enterobacteriaceae was estimated takingSalmonellaas a model. For this purpose an assessment was carried out of the risk of acceptingSalmonellacontaminated consignments of foods, despite a negative outcome of (i) examination of 1·5 kg samples forSalmonella;(ii) examination of one or two 1 g samples for Enterobacteriaceae; (iii) simultaneous application of both tests. The computations were based on the results of the examination of 6830 samples of dried foods, processed for safety, out of a total of 18170 samples.Only 69 samples permitted the exact calculation of the factor, defined as c.f.u./g of Enterobacteriaceae/c.f.u./g ofSalmonella;4642 were positive for the former group but ‘free’ fromSalmonella, and the rest were negative in both tests. Numbers of c.f.u./g for both groups, and hence the factors, varied widely between commodities and also between different consignments of the same food product. The average for amounted to 5·8 × 103, far from the base-line value of 0·75 × 103assessed earlier. In only 0·1% of samples did the Enterobacteriaceae test fail to achieve the required consumer protection.This investigation therefore substantiates that testing foods processed for safety by examining accurately chosen quantities for ecologically well selected and taxonomically thoroughly defined index organisms is a most effective procedure in terms both of consumer protection and simplicity of examination without compelling the food industry to achieve hardly attainable microbiological quality standards.
Multiple skin testing of tuberculosis patients with a range of new tuberculins, and a comparison with leprosy andMycobacterium ulceransinfection
Authors: Shield M. J. , Stanford J. L. , Paul R. C. , Carswell J. W. 
Published: May 2009

SUMMARYFour hundred and seventy tuberculosis patients were each skin tested with four of a range of 17 mycobacterial reagents in four countries in all of which tuberculosis and leprosy were endemic. Sixteen of the reagents were new tuberculins prepared from extracts of living mycobacteria disrupted by ultrasonic disintegration and the last was PPD, RT23.The effect that tuberculosis exerted on the delayed-type skin test response to these antigens was assessed by comparing results for tuberculosis patients with those for Tuberculin positive and Tuberculin negative control populations. Tuberculosis patients on Rifampicin therapy showed no difference in their skin test responses to any of the antigens from those patients on other forms of anti-tuberculosis treatment.Amongst the normal population it was found that possession of Tuberculin positivity was associated with an enhanced response to all the other mycobacterial antigens with the exception of A*-in which demonstrated a reciprocal relationship with Tuberculin in Burma. It was also noted, in Burma particularly, that sensitization to mycobacterial species other thanMycobacterium tuberculosis, especially to the slow growers, plays a role in determining responses to different mycobacterial species.In tuberculosis patients enhanced skin test responses were also seen but only in those countries, e.g. Libya, where the prevalence of mycobacterial species was low. Where mycobacteria were common, as in Burma, the converse was true and tuberculosis was associated with a diminished skin test response to each antigen. The high prevalence of A*-in positivity in Burma, its reciprocal relationship with Tuberculin there and the results for all the antigens in the tuberculosis patients indicate that the cell mediated skin test response may have a threshold. If this is exceeded the skin test becomes negative so that non-reactors then include those who have been excessively sensitized as well as those who have not been sensitized. Despite this, a greater percentage of tuberculosis patients in each country responded to the specific reagent Tuberculin than did the control populations and their mean positive induration sizes were consistently larger. Nevertheless, amongst the tuberculosis patients in Burma 13% were complete non-reactors to Tuberculim and this apparent anergy also applied to the other reagents with which these individuals were tested.This differs from lepromatous leprosy where the anergic state pertain exclusively toM. lepraeand a few seemingly closely related species. The breadth of anergy inM. ulceransinfection has not been measured but it is known to effect both Burulin and the PPD, RT23.Just as in leprosy andM. ulceransinfection, tuberculosis can be shown to have a disease spectrum here detected by multiple skin testing. The significance of this spectrum and its similarities with and differences from that of the other mycobacterioses is discussed.
Inhibition of β-haemolysis by opacity factor in group A streptococci
Authors: Pinney Alison M. , Widdowson Jean P. , Maxted W. R. 
Published: May 2009

SUMMARYGroup-A streptococci belonging to opacity-factor (OF)-positive M types were poorly haemolytic on horse-blood agar, but members of OF-negative M types, and M-negative variants of OF-positive strains gave good haemolysis. Horse-serum extracts of strains of OF-negative serotypes 6 and 12, and M-negative variant cultures of OF-positive serotypes 4 and 49, had higher titres of streptolysin S than did similar extracts of OF-positive, M-positive cultures of types 4 and 49. However, much larger amounts of streptolysin S could be extracted with ribonuclease (RNAase)-digested yeast ribonucleic acid (RNA) and M-positive OF-positive cultures treated in this way gave extracts at least as strong as did their M-negative variants or the OF-negative strains. Extraction of streptolysin S from OF-negative strains by serum could be inhibited by previous incubation of the serum with extracellular OF, suggesting that the production of diffusable OF by M-positive variants of OF-positive serotypes interferes with the extraction of streptolysin S by serum and leads to poor haemolysis on blood agar.The haemolysis of all strains on blood agar was greatly improved by the incorporation of 0·1% (w/v) RNAase-digested yeast RNA into the medium, but the improvement was most marked in OF-positive serotypes.
The response to inactivated influenza A (H3N2) vaccines: the development and effect of antibodies to the surface antigens
Authors: Smith A. J. , Davies Joan R. 
Published: May 2009

SUMMARYA controlled trial of influenza vaccines in a boys' public school from November 1970 to October 1975 provided an opportunity to study the response to vaccine and the effect on subsequent natural challenge in boys with differing natural experience of influenza A strains. The response to influenza A (H3N2) vaccines was assessed by estimating homotypic and heterotypic antibodies to the surface antigens. Previous natural experience of influenza A was found to influence vaccine response and the effect of natural challenge. The antibody response to revaccination with the same strain showed a progressively poorer response to second and third doses. The protective effect of naturally acquired and vaccine-induced antibodies was assessed during two outbreaks of influenza A which occurred in the trial period.
Resurgence of cholera in Hong Kong
Authors: Lee S. H. , Lai S. T. , Lai J. Y. , Leung N. K. 
Published: May 2009

SummaryCholera is one of the three diseases subject to the International Health Regulations. After a period of over 30 years, the seventh pandemic of cholera, which started in South East Asia in 1961, still shows no sign of a decline. On the contrary, it has increased its severity and invaded many other countries in Africa and Latin America. In the last two years, there has been a recrudescence of the disease in South East Asia and Western Pacific Regions. The discovery of a new strain of Vibrio cholerae 0139 in these regions is causing concern in view of its potential to cause major epidemics and higher mortality. Hong Kong had two intensive outbreaks of cholera in the last two years. The cause of these outbreaks was not clear, but adverse environmental conditions and increasing pollution of coastal waters have been implicated. The spread of cholera knows no geographical boundaries. There is a need for intensified efforts among health authorities in the affected areas to prevent the international spread of the disease.
Hepatitis B virus infection in general population in Madagascar: evidence for different epidemiological patterns in urban and in rural areas
Authors: Boisier P. , Rabarijaona L. , Piollet M. , Roux J. F. , Zeller H. G. 
Published: May 2009

SummaryTo describe the features of hepatitis B virus (HBV) infection in Madagascar, a randomized sero-epidemiological survey was undertaken in the general population ≥ 1 year old of two provinces which represents 45% of the total population. In the 921 sera tested, the prevalence of HBV markers was 20·5% for HBsAg, 38·2% for anti-HBc and 6·9% for HBeAg. HBsAg and anti-HBc prevalence rates were significantly higher in males. A large difference in HBsAg prevalence was observed between urban (5·3%) and rural areas (26·0%). The same contrast in prevalence was noticed for the other HBV markers. In rural areas, HBV infection was more frequently acquired early in infancy, which suggests predominantly perinatal or postnatal transmission. The presence of HBV markers was not significantly associated with a history of blood transfusion, surgery or parenteral injection. High infectivity carriers represented 5·3% and the overall frequency of chronic carriers was 10·4%. These results place Madagascar among areas of high endemicity.
Seroprevalence of astrovirus types 1 and 6 in London, determined using recombinant virus antigen
Authors: Kriston S. , Willcocks M. M. , Carter M. J. , Cubitt W. D. 
Published: May 2009

SummaryWe have developed a microimmunofluorescence test (IF) which uses cells infected with a recombinant baculovirus which expresses the capsid proteins of astrovirus types 1 or 6. The IF test was sensitive and specific and the results for human astrovirus type 1 (HAst-1) were comparable to those obtained by immune electronmicroscopy and radioimmunoassay. Application of the test to a panel of 273 sera collected from patients and staff at two childrens hospitals in London showed that over 50% of the population were infected by Hast-1 between the age of 5 and 12 months rising to 90% by 5 years, whereas human astrovirus type 6 (HAst6) was relatively uncommon (10–30%) in all age groups.
The application of genotyping techniques to the epidemiological analysis ofCampylobacter jejuni
Authors: Jackson C. J. , Fox A. J. , Wareing D. R. A. , Hutchinson D. N. , Jones D. M. 
Published: May 2009

SummaryCampylobacter jejuniserogroup reference strains and collections of sporadic and outbreak- associated isolates were examined for restriction fragment length polymorphisms (RFLPs), usingC. jejunirandom chromosomal and 16S rRNA gene probes. A collection of 48 Penner (HS) and 14 Lior (HL) serogroup reference strains, plus 10 clinical isolates, generated 35 RFLP and 26 ribotype patterns. In combination the two loci generated 48 distinct genotypes. Both probes were able to differentiate between certain random isolates of the same HS/HL serogroups but greater discrimination was obtained with RFLP than with ribotyping. Genotyping distinguished accurately between related and unrelated strains when applied to several outbreaks. Genotypic analysis ofC. jejuniby restriction fragment length polymorphisms is a valuable technique for epidemiological typing. Chromosomal variation detected by the two unlinked probe loci provides some information about the genetic relationship between isolates.
Cryptosporidiosis in Wisconsin: A case-control study of post-outbreak transmission
Authors: Osewe P. , Addiss D. G. , Blair K. A. , Hightower A. , Kamb M. L. , Davis J. P. 
Published: May 2009

SummaryDuring March–April 1993, an estimated 403000 residents of the 5-county greater Milwaukee, Wisconsin area developed cryptosporidiosis after drinking contaminated municipal water. Although the number of cases dropped precipitously after the implicated water plant closed on 9 April, cases continued to occur. To investigate risk factors for post-outbreak cryptosporidiosis, 33 Milwaukee-area residents who had laboratory-confirmed Cryptosporidium infection with onset of diarrhoea between 1 May and 27 June 1993 were interviewed by telephone. Of these, 28(85%) had onset of diarrhoea during May, 12(36%) had watery diarrhoea during the outbreak, and 5 (15%) were HIV-infected. In a neighbourhood-matched case-control study, immunosuppression (matched odds ratio (MOR) not calculable, 95 % confidence interval (CI) 3·0, infinity) and having a child less than 5 years old in the household (MOR = 17·0, CI 2·0, 395·0) were independently associated with infection. When persons who had diarrhoea during the outbreak were excluded, immunosuppression remained significantly associated with illness (MOR not calculable, CI 1·6, infinity). Cryptosporidium transmission continued after this massive waterborne outbreak but decreased rapidly within 2 months.
Epidemiological patterns of hepatitis B virus (HBV) in highly endemic areasr
Authors: Edmunds W. J. , Medley G. F. , Nokes D. J. , O'Callaghan C. J. , Whittle H. C. , Hall A. J. 
Published: May 2009

SummaryThis paper uses meta-analysis of published data and a deterministic mathematical model of hepatitis B virus (HBV) transmission to describe the patterns of HBV infection in high endemicity areas. We describe the association between the prevalence of carriers and a simple measure of the rate of infection, the age at which half the population have been infected (A50), and assess the contribution of horizontal and perinatal transmission to this association. We found that the two main hyper-endemic areas of sub-Saharan Africa and east Asia have similar prevalences of carriers and values of A50, and that there is a negative nonlinear relationship between A50and the prevalence of carriers in high endemicity areas (Spearman's Rank,P= 0·0086). We quantified the risk of perinatal transmission and the age-dependent rate of infection to allow a comparison between the main hyper-endemic areas. East Asia was found to have higher prevalences of HBeAg positive mothers and a greater risk of perinatal transmission from HBeAg positive mothers than sub-Saharan Africa, though the differences were not statistically significant. However, the two areas have similar magnitudes and age-dependent rates of horizontal transmission. Results of a simple compartmental model suggest that similar rates of horizontal transmission are sufficient to generate the similar patterns between A50and the prevalences of carriers. Interrupting horizontal transmission by mass immunization is expected to have a significant, nonlinear impact on the rate of acquisition of new carriers.
Seroepidemiology of HTLV-I in relation to that of HIV-1 in the Gauteng region, South Africa, using dried blood spots on filter papers
Authors: Taylor M. B. , Parker S. P. , Crewe-Brown H. H. , McIntyre J. , Cubitt W. D. 
Published: May 2009

SummaryThe seroprevalence of human T-lymphotropic virus type I (HTLV-I), in relation to that of human immunodeficiency virus type 1 (HIV-1), was determined in a comparative unlinked anonymous antenatal and neonatal (for indirect measurement of maternal antibodies) serosurvey in the Gauteng region of South Africa, using dried blood spots (DBS) and modified particle agglutination assays. Samples were confirmed to be antibody positive by western blot. A total of 2582 DBS collected during 1993 and 1994 from subjects of African, European and coloured origin were tested. Ten were confirmed as positive for HTLV-I and 128 for HIV-1. No antibodies to HTLV-I or HIV-l were demonstrated in the 221 women of European and coloured origin who were screened. The HTLV-I seroprevalence rate in subjects of African origin appeared to increase from 0% in 1993 to 0·49% in 1994, while HIV-1 seroprevalence rates of 5·2% and 5·4% were recorded for 1993 and 1994 respectively. No significant differences in HTLV-I and HIV-1 seroprevalence rates were noted for the two areas investigated. These results indicate that HTLV-I should be included in infection control programs, and provide baseline data for monitoring the possible spread of HTLV-I in the heterosexual population in this region.
Serratia marcescensinfection associated with early abortion in cows and buffaloes
Authors: Das A. M. , Paranjape V. L. , Pitt T. L. 
Published: May 2009

SUMMARYSerratia marcescenswas isolated in pure culture from cases of septic abortion in 4 cows on one farm and 10 buffaloes on two other farms. A reddish vaginal discharge was observed after abortion in all animals and in the internal organs of the aborted fetuses. All but two of the isolates produced prodigiosin, and two of the isolates from buffaloes were atypical in that they fermented raffinose. O-serological, bacteriophage and bacteriocin typing revealed four different strains. All cows were infected by the same strain, and this strain was also isolated from the semen of a breeding bull on the same farm. In another farm a strain of serotype O 14 was isolated from 6 of 10 buffaloes, and two other distinct strains were isolated from the remainder. The strain from the cattle was sensitive to gentamicin and so were two of the buffalo isolates. The infected cows were treated with intra-uterine gentamicin and the organism disappeared from cervical mucus after 3 days. Each animal after abortion showed a raised titre of agglutinating antibody to their respective isolate. A survey of 1172 healthy buffaloes and cattle gave an incidence of 1·8% with raised titres towardsS. marcescens.